/* ============================================================
   妙奇豆AI编程 — Clean Edition
   依靠字号层级、留白、色彩节制完成设计
   ============================================================ */

:root {
  /* 基础色 */
  --ink: #111217;
  --ink-2: #2E3139;
  --text: #1A1C22;
  --text-soft: #55586B;
  --text-muted: #8A8D9C;

  /* 纸面 */
  --paper: #FDFBF5;
  --paper-2: #F6F2E9;
  --paper-3: #EFEADF;
  --surface: #FFFFFF;
  --line: #E8E2D3;
  --line-soft: #F0EBDD;

  /* 品牌主色 — 使用更克制 */
  --brand: #E84B1C;           /* 主橙 — 按钮、重点 */
  --brand-soft: #FBE4DA;      /* 淡橙底 */
  --accent: #2547E6;          /* 辅助蓝 */
  --accent-soft: #E3E8FF;
  --highlight: #FFD93F;       /* 高亮黄 — 只用于 mark 与小徽章 */
  --mint: #3FC18D;
  --mint-soft: #DFF3E8;
  --pink: #FF4F8B;
  --pink-soft: #FFE0EC;
  --lavender: #ECE5FF;

  /* 阴影 — 全部柔和 */
  --shadow-1: 0 1px 2px rgba(17, 18, 23, 0.04), 0 1px 1px rgba(17, 18, 23, 0.03);
  --shadow-2: 0 4px 12px rgba(17, 18, 23, 0.06), 0 1px 2px rgba(17, 18, 23, 0.04);
  --shadow-3: 0 12px 32px rgba(17, 18, 23, 0.08), 0 2px 6px rgba(17, 18, 23, 0.04);
  --shadow-focus: 0 0 0 3px rgba(232, 75, 28, 0.18);

  /* 圆角 */
  --r-xs: 6px;
  --r-sm: 10px;
  --r-md: 14px;
  --r-lg: 20px;
  --r-xl: 28px;
  --r-pill: 999px;

  /* 字体 */
  --font-body: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Segoe UI', system-ui, sans-serif;
  --font-serif: 'Fraunces', 'Noto Serif SC', Georgia, serif;
  --font-mono: 'JetBrains Mono', ui-monospace, 'SF Mono', 'Menlo', monospace;

  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
  --t: 0.22s;
}

/* ============================================================
   Reset & base
   ============================================================ */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  font-family: var(--font-body);
  color: var(--text);
  background: var(--paper);
  line-height: 1.65;
  overflow-x: hidden;
  font-weight: 400;
  font-feature-settings: "palt" 1;
}

a { text-decoration: none; color: inherit; }
img { max-width: 100%; display: block; }
button { font-family: inherit; }
ul { list-style: none; }

.container { max-width: 1200px; margin: 0 auto; padding: 0 32px; }

/* ============================================================
   Typography — 依靠字重与字号建立清晰等级
   ============================================================ */
h1, h2, h3, h4 {
  font-family: var(--font-body);
  color: var(--ink);
  letter-spacing: -0.02em;
  font-weight: 700;
  line-height: 1.25;
}
h1 { font-size: clamp(34px, 4.6vw, 52px); line-height: 1.15; letter-spacing: -0.025em; }
h2 { font-size: clamp(26px, 3.2vw, 38px); line-height: 1.2; }
h3 { font-size: clamp(18px, 1.6vw, 20px); font-weight: 600; }
h4 { font-size: 17px; font-weight: 600; }

p { color: var(--text-soft); }

.serif { font-family: var(--font-serif); font-weight: 500; font-style: italic; letter-spacing: -0.01em; }
.mono { font-family: var(--font-mono); font-size: 0.9em; letter-spacing: -0.02em; }

/* 品牌文字高亮 — 细腻的下划线，不再是粗记号笔 */
.mark {
  position: relative;
  white-space: nowrap;
  color: var(--ink);
  font-weight: 700;
  background-image: linear-gradient(180deg, transparent 60%, rgba(255, 217, 63, 0.55) 60%);
  background-repeat: no-repeat;
  padding: 0 2px;
}
.mark-pink { background-image: linear-gradient(180deg, transparent 60%, rgba(255, 79, 139, 0.25) 60%); }
.mark-mint { background-image: linear-gradient(180deg, transparent 60%, rgba(63, 193, 141, 0.28) 60%); }
.mark-blue { background-image: linear-gradient(180deg, transparent 60%, rgba(37, 71, 230, 0.18) 60%); }

/* scribble 不再画圆圈，改为优雅斜体橙色 */
.scribble {
  font-family: var(--font-serif);
  font-style: italic;
  font-weight: 600;
  color: var(--brand);
  letter-spacing: -0.01em;
}

.ink-orange { color: var(--brand); }
.ink-blue { color: var(--accent); }
.ink-pink { color: var(--pink); }
.ink-mint { color: var(--mint); }

/* ============================================================
   Buttons — 简洁扁平，主按钮有身份感
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font-body);
  font-weight: 500;
  font-size: 14.5px;
  padding: 11px 22px;
  border: 1px solid transparent;
  border-radius: var(--r-pill);
  background: var(--surface);
  color: var(--ink);
  cursor: pointer;
  transition: background var(--t) var(--ease), color var(--t) var(--ease), border-color var(--t), transform var(--t), box-shadow var(--t);
  white-space: nowrap;
  line-height: 1;
}
.btn:hover { transform: translateY(-1px); }
.btn:active { transform: translateY(0); }

.btn-sm { padding: 9px 16px; font-size: 13.5px; }
.btn-lg { padding: 14px 28px; font-size: 15.5px; }
.btn-block { width: 100%; }

.btn-primary {
  background: var(--brand);
  color: #fff;
  box-shadow: var(--shadow-1);
}
.btn-primary:hover { background: #D43E14; box-shadow: var(--shadow-2); }

.btn-secondary { background: var(--accent); color: #fff; }
.btn-secondary:hover { background: #1D3ACC; }

.btn-yellow { background: var(--highlight); color: var(--ink); }
.btn-yellow:hover { background: #FFC62B; }

.btn-mint { background: var(--mint); color: #fff; }
.btn-white { background: var(--surface); color: var(--ink); border-color: var(--line); }
.btn-white:hover { border-color: var(--ink); }

.btn-outline {
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--line);
}
.btn-outline:hover { border-color: var(--ink); background: var(--surface); }

.btn-ghost {
  background: transparent;
  color: var(--ink);
}
.btn-ghost:hover { background: var(--paper-2); }

.btn-icon { font-size: 1.05em; line-height: 1; }

/* ============================================================
   Header
   ============================================================ */
.header {
  position: fixed; top: 0; left: 0; right: 0;
  z-index: 1000;
  background: rgba(253, 251, 245, 0.85);
  backdrop-filter: saturate(180%) blur(16px);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--t), background var(--t);
}
.header.scrolled { border-bottom-color: var(--line); }

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
  gap: 32px;
}
.logo {
  display: flex; align-items: center; gap: 10px;
  font-family: var(--font-body);
  font-size: 18px;
  font-weight: 700;
  color: var(--ink);
  letter-spacing: -0.01em;
}
.logo-svg { width: 34px; height: 34px; }
.logo-text {}
.logo-domain {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  color: var(--text-muted);
  background: var(--paper-2);
  padding: 3px 8px;
  border-radius: var(--r-xs);
  letter-spacing: 0;
}

.nav { display: flex; gap: 2px; }
.nav-link {
  font-size: 14.5px;
  font-weight: 500;
  color: var(--text-soft);
  padding: 8px 14px;
  border-radius: var(--r-pill);
  transition: color var(--t), background var(--t);
}
.nav-link:hover { color: var(--ink); background: var(--paper-2); }

.header-actions { display: flex; align-items: center; gap: 10px; }

.mobile-menu-btn {
  display: none;
  width: 40px; height: 40px;
  background: transparent;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  cursor: pointer;
  padding: 11px 9px;
  flex-direction: column;
  justify-content: space-between;
}
.mobile-menu-btn span {
  display: block; height: 1.5px; background: var(--ink); border-radius: 1px;
}

.mobile-nav-overlay {
  position: fixed; inset: 0;
  background: rgba(17, 18, 23, 0.35);
  z-index: 999;
  opacity: 0; visibility: hidden;
  transition: all var(--t) ease;
}
.mobile-nav-overlay.active { opacity: 1; visibility: visible; }
.mobile-nav {
  position: fixed; top: 0; right: 0; bottom: 0;
  width: min(320px, 85vw);
  background: var(--paper);
  border-left: 1px solid var(--line);
  z-index: 1001;
  padding: 88px 24px 24px;
  transform: translateX(100%);
  transition: transform 0.3s var(--ease);
  overflow-y: auto;
}
.mobile-nav.active { transform: translateX(0); }
.mobile-nav-link {
  display: block;
  font-size: 16px;
  font-weight: 500;
  padding: 14px 4px;
  border-bottom: 1px solid var(--line-soft);
  color: var(--ink);
}
.mobile-nav-actions { margin-top: 24px; }

/* ============================================================
   Hero
   ============================================================ */
.hero {
  min-height: 100vh;
  padding: 132px 0 80px;
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
}
.hero-bg-shapes { position: absolute; inset: 0; pointer-events: none; z-index: 0; }
.shape {
  position: absolute;
  border-radius: 50%;
  filter: blur(40px);
  opacity: 0.35;
}
.shape-1 { top: 8%; left: -80px; width: 280px; height: 280px; background: var(--pink-soft); }
.shape-2 { top: 60%; left: 30%; width: 220px; height: 220px; background: var(--mint-soft); }
.shape-3 { top: 14%; right: 8%; width: 260px; height: 260px; background: #FFF0C9; }
.shape-4 { bottom: 5%; right: -60px; width: 300px; height: 300px; background: var(--lavender); opacity: 0.5; }

.hero-inner {
  position: relative; z-index: 1;
  width: 100%;
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 72px;
  align-items: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: 0.02em;
  padding: 6px 12px;
  background: var(--surface);
  color: var(--text-soft);
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  margin-bottom: 28px;
}
.hero-badge::before {
  content: "";
  width: 6px; height: 6px;
  background: var(--mint);
  border-radius: 50%;
  animation: pulse 1.8s infinite ease-in-out;
}
@keyframes pulse { 0%, 100% { opacity: 1; transform: scale(1); } 50% { opacity: 0.4; transform: scale(0.85); } }

.hero-title {
  font-family: 'ZCOOL KuaiLe', 'Ma Shan Zheng', var(--font-body);
  font-size: clamp(44px, 6vw, 78px);
  line-height: 1.08;
  letter-spacing: 0.005em;
  margin-bottom: 28px;
  color: var(--ink);
  font-weight: 400;
  text-shadow:
    1px 0 0 currentColor,
    0 1px 0 currentColor,
    -0.5px -0.5px 0 currentColor;
}
.hero-title .line-2 { display: block; margin-top: 4px; }
.hero-title .mark {
  font-family: inherit;
  background-image: linear-gradient(180deg, transparent 78%, var(--highlight) 78%, var(--highlight) 96%, transparent 96%);
  padding: 0 6px;
}
.hero-title .serif-accent {
  font-family: var(--font-serif);
  font-weight: 500;
  font-style: italic;
  color: var(--brand);
}

.hero-desc {
  font-size: 17px;
  line-height: 1.75;
  color: var(--text-soft);
  margin-bottom: 36px;
  max-width: 560px;
}

.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 48px;
}

.hero-stats {
  display: flex;
  align-items: stretch;
  gap: 0;
  padding: 18px 24px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-1);
  width: fit-content;
  max-width: 100%;
}
.stat-item {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  padding: 0 22px;
}
.stat-item:first-child { padding-left: 0; }
.stat-item:last-child { padding-right: 0; }
.stat-number {
  font-size: 28px;
  font-weight: 700;
  line-height: 1;
  color: var(--ink);
  letter-spacing: -0.02em;
}
.stat-suffix {
  font-size: 18px;
  font-weight: 700;
  color: var(--brand);
  margin-left: 2px;
}
.stat-label {
  font-size: 12.5px;
  font-weight: 500;
  color: var(--text-muted);
  margin-top: 6px;
}
.stat-divider {
  width: 1px;
  background: var(--line);
  margin: 4px 0;
}

/* Hero visual */
.hero-visual { position: relative; }

/* ============================================================
   Hero Build Stage — animated 4-step sequence
   ============================================================ */
.build-stage {
  position: relative;
  background:
    radial-gradient(circle at 18% 22%, rgba(255, 209, 63, 0.18), transparent 55%),
    radial-gradient(circle at 82% 78%, rgba(124, 92, 255, 0.12), transparent 55%),
    var(--surface);
  border: 1.5px solid var(--ink);
  border-radius: var(--r-xl);
  box-shadow: 8px 8px 0 var(--ink);
  aspect-ratio: 4 / 5;
  max-width: 460px;
  margin-left: auto;
  overflow: hidden;
  padding: 18px;
  display: flex;
  flex-direction: column;
}

/* Step pill bar */
.build-steps-bar {
  position: relative;
  z-index: 5;
  display: flex;
  justify-content: space-between;
  gap: 6px;
  padding: 6px;
  background: var(--paper-2);
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  flex-shrink: 0;
}
.build-pill {
  flex: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 5px;
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--text-soft);
  padding: 6px 4px;
  border-radius: var(--r-pill);
  background: transparent;
  white-space: nowrap;
  animation: pill-active 16s ease-in-out infinite;
  transition: none;
}
.build-pill b {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--paper-3);
  color: var(--text-soft);
  font-size: 10px;
  font-weight: 700;
  border: 1px solid var(--line);
  transition: none;
}
.is-step-1 { animation-delay: 0s; }
.is-step-2 { animation-delay: 4s; }
.is-step-3 { animation-delay: 8s; }
.is-step-4 { animation-delay: 12s; }
@keyframes pill-active {
  0%, 1% { background: transparent; color: var(--text-soft); }
  3%, 23% { background: var(--ink); color: #FFF6E8; }
  25%, 100% { background: transparent; color: var(--text-soft); }
}
.build-pill {
  position: relative;
}

/* Build cards (each step) absolutely positioned in stage body */
.build-card {
  position: absolute;
  top: 70px;
  left: 18px;
  right: 18px;
  bottom: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  animation: stage-show 16s ease-in-out infinite;
  pointer-events: none;
}
.build-card--user { animation-delay: 0s; }
.build-card--ai { animation-delay: 4s; }
.build-card--code { animation-delay: 8s; }
.build-card--phone { animation-delay: 12s; }
@keyframes stage-show {
  0% { opacity: 0; transform: translateY(18px) scale(0.97); }
  3% { opacity: 1; transform: translateY(0) scale(1); }
  23% { opacity: 1; transform: translateY(0) scale(1); }
  26%, 100% { opacity: 0; transform: translateY(-14px) scale(0.97); }
}

/* Chat bubbles */
.bubble {
  display: inline-flex;
  align-items: flex-start;
  gap: 10px;
  padding: 14px 18px;
  border-radius: 18px;
  font-size: 14.5px;
  line-height: 1.5;
  max-width: 88%;
  box-shadow: 4px 4px 0 var(--ink);
  border: 1.5px solid var(--ink);
}
.bubble-avatar {
  font-size: 22px;
  width: 32px;
  height: 32px;
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--paper-2);
  border: 1.5px solid var(--ink);
  border-radius: 50%;
}
.bubble-avatar--ai {
  background: var(--highlight);
}
.bubble--user {
  background: var(--brand);
  color: #FFF6E8;
}
.bubble--ai {
  background: var(--surface);
  color: var(--ink);
}
.bubble-text {
  font-weight: 500;
}
.bubble-tags {
  display: inline-flex;
  gap: 6px;
  margin-top: 8px;
  flex-wrap: wrap;
}
.bubble-tag {
  font-size: 11.5px;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 999px;
  background: var(--paper-2);
  border: 1px solid var(--line);
  color: var(--ink);
}
.build-card--ai .bubble-tag:nth-child(1) {
  animation: tag-pop 16s ease-in-out infinite;
  animation-delay: 4.6s;
}
.build-card--ai .bubble-tag:nth-child(2) {
  animation: tag-pop 16s ease-in-out infinite;
  animation-delay: 4.85s;
}
.build-card--ai .bubble-tag:nth-child(3) {
  animation: tag-pop 16s ease-in-out infinite;
  animation-delay: 5.1s;
}
@keyframes tag-pop {
  0% { transform: scale(0.6); opacity: 0; }
  3% { transform: scale(1.08); opacity: 1; }
  5%, 23% { transform: scale(1); opacity: 1; }
  26%, 100% { opacity: 1; transform: scale(1); }
}
.bubble-typing {
  position: absolute;
  bottom: 28%;
  left: 12%;
  display: inline-flex;
  gap: 4px;
  padding: 8px 12px;
  border-radius: 14px;
  background: var(--surface);
  border: 1.5px solid var(--ink);
  box-shadow: 3px 3px 0 var(--ink);
  opacity: 0;
  animation: typing-show 16s ease-in-out infinite;
  animation-delay: 4s;
}
.bubble-typing i {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--ink);
  display: block;
  animation: typing-dot 1.1s ease-in-out infinite;
}
.bubble-typing i:nth-child(2) { animation-delay: 0.18s; }
.bubble-typing i:nth-child(3) { animation-delay: 0.36s; }
@keyframes typing-show {
  0%, 0.5% { opacity: 0; }
  3%, 14% { opacity: 1; }
  17%, 100% { opacity: 0; }
}
@keyframes typing-dot {
  0%, 100% { transform: translateY(0); opacity: 0.35; }
  50% { transform: translateY(-4px); opacity: 1; }
}

/* Code window */
.code-window {
  width: 100%;
  max-width: 360px;
  background: var(--ink);
  border-radius: 12px;
  border: 1.5px solid var(--ink);
  box-shadow: 5px 5px 0 var(--brand);
  overflow: hidden;
  font-family: var(--font-mono);
}
.code-window-bar {
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 8px 12px;
  background: #20222C;
  border-bottom: 1px solid #2C2E3A;
}
.code-window-bar .dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: #4A4D5C;
}
.code-window-bar .dot:nth-child(1) { background: #FF5F57; }
.code-window-bar .dot:nth-child(2) { background: #FFBD2E; }
.code-window-bar .dot:nth-child(3) { background: #28C940; }
.code-window-name {
  margin-left: auto;
  font-size: 11px;
  color: rgba(253, 251, 245, 0.6);
  letter-spacing: 0.05em;
}
.code-body {
  padding: 14px 14px 16px;
  font-size: 13px;
  line-height: 1.7;
  color: rgba(253, 251, 245, 0.92);
}
.code-line {
  display: block;
  opacity: 0;
  animation: code-line-in 16s ease-in-out infinite;
  white-space: nowrap;
}
.code-line:nth-child(1) { animation-delay: 8.3s; }
.code-line:nth-child(2) { animation-delay: 8.7s; }
.code-line:nth-child(3) { animation-delay: 9.1s; }
.code-line:nth-child(4) { animation-delay: 9.5s; }
.code-line:nth-child(5) { animation-delay: 9.9s; }
@keyframes code-line-in {
  0%, 0.5% { opacity: 0; transform: translateX(-6px); }
  3%, 23% { opacity: 1; transform: translateX(0); }
  26%, 100% { opacity: 1; transform: translateX(0); }
}
.code-line .ln {
  display: inline-block;
  width: 18px;
  color: rgba(253, 251, 245, 0.35);
  user-select: none;
}
.code-line .kw { color: #FF7AB6; font-weight: 600; }
.code-line .cn { color: #FFD93F; }
.code-line .st { color: #6BD49B; }
.code-line .fn { color: #7FB8FF; }
.code-line .caret {
  display: inline-block;
  width: 7px;
  height: 14px;
  background: var(--brand);
  vertical-align: middle;
  margin-left: 2px;
  animation: caret-blink 0.8s steps(2) infinite;
}
@keyframes caret-blink { to { opacity: 0; } }

.code-progress {
  position: absolute;
  bottom: 6%;
  left: 14%;
  right: 14%;
  height: 6px;
  background: var(--paper-3);
  border: 1px solid var(--ink);
  border-radius: 999px;
  overflow: hidden;
}
.code-progress span {
  display: block;
  height: 100%;
  width: 0;
  background: var(--brand);
  animation: code-fill 16s ease-in-out infinite;
  animation-delay: 8s;
}
@keyframes code-fill {
  0%, 0.5% { width: 0; }
  23% { width: 100%; }
  26%, 100% { width: 100%; }
}

/* Phone mock */
.phone-mock {
  width: 130px;
  background: #1B1C24;
  border: 1.5px solid var(--ink);
  border-radius: 24px;
  padding: 5px;
  position: relative;
  box-shadow: 6px 6px 0 var(--brand);
  animation: phone-bob 3s ease-in-out infinite;
  animation-delay: 12.4s;
}
@keyframes phone-bob {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-6px); }
}
.phone-mock-notch {
  position: absolute;
  top: 5px;
  left: 50%;
  transform: translateX(-50%);
  width: 36px;
  height: 9px;
  background: #1B1C24;
  border-radius: 0 0 8px 8px;
  z-index: 2;
}
.phone-mock-screen {
  background: linear-gradient(170deg, #FFE4D0 0%, #FFC79A 45%, #FF9466 100%);
  border-radius: 20px;
  padding: 22px 12px 16px;
  min-height: 200px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 9px;
}
.phone-app-title {
  font-family: 'ZCOOL KuaiLe', var(--font-body);
  font-size: 15px;
  color: var(--ink);
  margin-top: 6px;
}
.phone-app-mood {
  display: flex;
  gap: 6px;
  font-size: 18px;
}
.phone-app-mood span {
  width: 24px;
  height: 24px;
  background: rgba(255, 255, 255, 0.7);
  border-radius: 8px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(0, 0, 0, 0.08);
}
.phone-app-note {
  font-size: 10.5px;
  color: var(--ink);
  text-align: center;
  background: rgba(255, 255, 255, 0.55);
  border-radius: 8px;
  padding: 6px 8px;
  line-height: 1.5;
  width: 92%;
}
.phone-app-btn {
  font-size: 10.5px;
  font-weight: 600;
  background: var(--ink);
  color: #FFF6E8;
  padding: 6px 14px;
  border-radius: 999px;
  margin-top: auto;
}
.phone-mock-bar {
  position: absolute;
  bottom: 8px;
  left: 50%;
  transform: translateX(-50%);
  width: 38%;
  height: 3px;
  border-radius: 2px;
  background: rgba(255, 255, 255, 0.85);
  z-index: 2;
}

.phone-spark {
  position: absolute;
  font-size: 16px;
  color: var(--brand);
  animation: phone-spark 1.6s ease-in-out infinite;
}
.phone-spark.s1 { top: 18%; left: 22%; animation-delay: 12.4s; }
.phone-spark.s2 { top: 28%; right: 18%; font-size: 12px; animation-delay: 12.8s; color: #7C5CFF; }
.phone-spark.s3 { bottom: 22%; right: 24%; font-size: 14px; animation-delay: 13.2s; color: #FFD93F; }
@keyframes phone-spark {
  0%, 100% { opacity: 0; transform: scale(0.4) rotate(0deg); }
  40%, 60% { opacity: 1; transform: scale(1.1) rotate(20deg); }
}

.phone-tag {
  position: absolute;
  bottom: 8%;
  left: 50%;
  transform: translateX(-50%);
  font-size: 12px;
  font-weight: 600;
  background: var(--surface);
  color: var(--ink);
  padding: 7px 14px;
  border-radius: 999px;
  border: 1.5px solid var(--ink);
  box-shadow: 3px 3px 0 var(--ink);
  white-space: nowrap;
  opacity: 0;
  animation: tag-rise 16s ease-in-out infinite;
  animation-delay: 12s;
}
@keyframes tag-rise {
  0%, 4% { opacity: 0; transform: translate(-50%, 12px); }
  7%, 23% { opacity: 1; transform: translate(-50%, 0); }
  26%, 100% { opacity: 0; transform: translate(-50%, -8px); }
}

/* ============================================================
   Trust bar — 简洁分隔条
   ============================================================ */
.trust-bar {
  background: var(--surface);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 20px 0;
}
.trust-items {
  display: flex;
  justify-content: space-around;
  flex-wrap: wrap;
  gap: 28px;
  align-items: center;
}
.trust-item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 500;
  font-size: 14px;
  color: var(--text-soft);
}
.trust-icon {
  font-size: 16px;
  display: inline-flex;
  width: 28px; height: 28px;
  align-items: center;
  justify-content: center;
  background: var(--paper-2);
  color: var(--ink);
  border-radius: 50%;
}

/* ============================================================
   Section primitives
   ============================================================ */
.section { padding: 96px 0; position: relative; }
.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 56px;
}
.section-eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  margin-bottom: 14px;
}
.section-title { margin-bottom: 14px; }
.section-desc {
  font-size: 16px;
  color: var(--text-soft);
  line-height: 1.7;
}

/* ============================================================
   Features — 白底卡片 + 细边框，彩色仅用于图标
   ============================================================ */
.features {
  background: var(--paper-2);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.feature-card {
  padding: 32px 28px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  transition: border-color var(--t), box-shadow var(--t), transform var(--t);
  position: relative;
}
.feature-card:hover {
  border-color: var(--ink);
  box-shadow: var(--shadow-2);
  transform: translateY(-2px);
}
.feature-num {
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 500;
  color: var(--text-muted);
  letter-spacing: 0.04em;
  display: block;
  margin-bottom: 20px;
}
.feature-doodle {
  width: 96px;
  height: 96px;
  margin: 6px auto 22px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.feature-doodle svg {
  width: 100%;
  height: 100%;
  display: block;
  overflow: visible;
}
.feature-card { text-align: center; }
.feature-card h3 {
  margin-bottom: 10px;
  color: var(--ink);
  max-width: 18ch;
  margin-left: auto;
  margin-right: auto;
}
.feature-card p {
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--text-soft);
  max-width: 30ch;
  margin-left: auto;
  margin-right: auto;
}
.feature-num {
  display: block;
  text-align: left;
}

/* ============================================================
   Modes
   ============================================================ */
.modes {
  background: var(--paper-2);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.modes-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  align-items: stretch;
}
.mode-card {
  padding: 28px 26px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  position: relative;
  transition: border-color var(--t), box-shadow var(--t);
  display: flex;
  flex-direction: column;
}
.mode-card:hover { border-color: var(--ink); box-shadow: var(--shadow-2); }
.mode-card.featured {
  background: var(--ink);
  color: #fff;
  border-color: var(--ink);
  box-shadow: var(--shadow-3);
}
.mode-card.featured h3 { color: #fff; }
.mode-card.featured .mode-features li { color: rgba(255, 255, 255, 0.88); border-bottom-color: rgba(255, 255, 255, 0.1); }
.mode-card.featured .mode-quote {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.15);
  color: rgba(255, 255, 255, 0.85);
}
.mode-card.featured .mode-badge { background: rgba(255, 255, 255, 0.12); color: #fff; }

.mode-popular {
  position: absolute;
  top: 18px; right: 18px;
  font-size: 11px;
  font-weight: 600;
  background: var(--brand);
  color: #fff;
  padding: 4px 10px;
  border-radius: var(--r-pill);
  letter-spacing: 0.02em;
}
.mode-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 500;
  padding: 3px 10px;
  background: var(--paper-2);
  color: var(--ink);
  border-radius: var(--r-pill);
  margin-bottom: 14px;
  align-self: flex-start;
}

.mode-photo-wrap {
  aspect-ratio: 16 / 10;
  border-radius: var(--r-md);
  overflow: hidden;
  margin-bottom: 18px;
  background: var(--paper-3);
}
.mode-photo { width: 100%; height: 100%; object-fit: cover; }

.mode-card h3 { margin-bottom: 16px; }

.mode-features { margin-bottom: 20px; }
.mode-features li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 8px 0;
  font-size: 14px;
  color: var(--text-soft);
  border-bottom: 1px solid var(--line-soft);
}
.mode-features li:last-child { border-bottom: none; }
.check, .muted {
  flex-shrink: 0;
  width: 18px; height: 18px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  font-weight: 700;
  font-size: 11px;
  margin-top: 1px;
}
.check { background: var(--mint-soft); color: var(--mint); }
.mode-card.featured .check { background: rgba(63, 193, 141, 0.25); color: #5ED8A5; }
.muted { background: var(--paper-2); color: var(--text-muted); }
.mode-features li .muted ~ span { opacity: 0.6; }

.mode-quote {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 14.5px;
  padding: 14px 16px;
  background: var(--paper-2);
  border-radius: var(--r-md);
  color: var(--text-soft);
  line-height: 1.55;
  margin-top: auto;
}

/* ============================================================
   How it works — 横向简洁步骤
   ============================================================ */
.how-it-works { background: var(--paper); }
.steps {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr auto 1fr;
  align-items: stretch;
  gap: 12px;
}
.step {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 26px 22px;
  transition: border-color var(--t), box-shadow var(--t);
  text-align: center;
}
.step:hover { border-color: var(--ink); box-shadow: var(--shadow-2); }

.step-number {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  color: var(--brand);
  margin-bottom: 12px;
  letter-spacing: 0.04em;
  display: block;
}
.step-doodle {
  width: 82px;
  height: 82px;
  margin: 4px auto 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--paper-2);
  border-radius: var(--r-md);
  border: 1px dashed var(--line);
}
.step-doodle svg {
  width: 100%;
  height: 100%;
  display: block;
  overflow: visible;
}
.step h3 { margin-bottom: 8px; }
.step p {
  font-size: 14px;
  line-height: 1.65;
  color: var(--text-soft);
}

.step-connector {
  align-self: center;
  width: 28px;
  height: 1px;
  background: var(--line);
  position: relative;
}
.step-connector::after {
  content: "";
  position: absolute;
  right: -1px; top: 50%;
  width: 5px; height: 5px;
  border-right: 1px solid var(--text-muted);
  border-top: 1px solid var(--text-muted);
  transform: translateY(-50%) rotate(45deg);
}

/* ============================================================
   Demo chat section
   ============================================================ */
.demo-section {
  background: var(--paper-2);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.demo-wrapper {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}
.demo-content .section-eyebrow { margin-bottom: 12px; }
.demo-content .section-title { text-align: left; margin-bottom: 16px; }
.demo-desc { font-size: 16px; color: var(--text-soft); margin-bottom: 28px; line-height: 1.75; }

.demo-highlights { display: grid; gap: 12px; }
.highlight-item {
  display: flex;
  gap: 14px;
  padding: 16px 18px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  transition: border-color var(--t);
}
.highlight-item:hover { border-color: var(--ink); }
.highlight-icon {
  flex-shrink: 0;
  font-size: 18px;
  width: 40px; height: 40px;
  background: var(--paper-2);
  border-radius: var(--r-sm);
  display: flex;
  align-items: center;
  justify-content: center;
}
.highlight-item strong { font-size: 15px; font-weight: 600; color: var(--ink); display: block; margin-bottom: 2px; }
.highlight-item p { font-size: 13.5px; color: var(--text-soft); line-height: 1.55; }

/* Phone 简化 */
.demo-chat { display: flex; justify-content: center; }
.demo-phone {
  width: 330px;
  background: var(--ink);
  border-radius: 36px;
  padding: 14px 8px;
  box-shadow: var(--shadow-3);
}
.demo-phone-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 14px;
  color: var(--paper);
  font-weight: 500;
  font-size: 14px;
}
.demo-messages {
  background: var(--surface);
  border-radius: 22px;
  padding: 16px;
  min-height: 430px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.demo-msg { display: flex; gap: 8px; align-items: flex-end; }
.demo-avatar {
  width: 28px; height: 28px;
  background: var(--paper-2);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 15px;
  flex-shrink: 0;
}
.demo-bubble {
  padding: 9px 13px;
  border-radius: 14px;
  font-size: 13.5px;
  line-height: 1.55;
  max-width: 78%;
}
.demo-ai .demo-bubble { background: var(--paper-2); color: var(--ink); border-bottom-left-radius: 4px; }
.demo-user { justify-content: flex-end; }
.demo-user .demo-bubble { background: var(--brand); color: #fff; border-bottom-right-radius: 4px; }

.demo-option, .demo-style-card {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  margin: 4px 4px 0 0;
  padding: 4px 9px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  font-size: 11.5px;
  font-weight: 500;
  color: var(--ink);
}
.demo-style-card.active { background: var(--ink); color: #fff; border-color: var(--ink); }

.demo-input {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 10px;
  padding: 10px 14px;
  background: var(--paper-2);
  border-radius: var(--r-pill);
  font-size: 12.5px;
  color: var(--text-muted);
}
.demo-send {
  width: 24px; height: 24px;
  background: var(--brand);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 11px;
}

/* ============================================================
   Showcase — 纯净卡片，无胶带
   ============================================================ */
.showcase { background: var(--paper); }
.section-photo-banner {
  position: relative;
  width: 100%;
  max-width: 860px;
  margin: 0 auto 36px;
  aspect-ratio: 21 / 6;
  overflow: hidden;
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-2);
}
.section-banner-img { width: 100%; height: 100%; object-fit: cover; }
.section-banner-overlay {
  position: absolute; inset: 0;
  background: linear-gradient(180deg, transparent 60%, rgba(17, 18, 23, 0.25) 100%);
}
.showcase-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.showcase-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  overflow: hidden;
  transition: border-color var(--t), box-shadow var(--t), transform var(--t);
}
.showcase-card:hover { border-color: var(--ink); box-shadow: var(--shadow-2); transform: translateY(-2px); }

.showcase-preview {
  aspect-ratio: 16 / 11;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.showcase-app-svg { width: 60%; height: 60%; object-fit: contain; }

.showcase-info { padding: 18px 20px 20px; }
.showcase-info h4 { font-size: 17px; margin-bottom: 4px; color: var(--ink); }
.showcase-info p { font-size: 13.5px; color: var(--text-soft); margin-bottom: 12px; line-height: 1.55; }
.showcase-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12.5px;
  padding-top: 12px;
  border-top: 1px solid var(--line-soft);
}
.showcase-author { color: var(--text-muted); font-weight: 500; }
.showcase-likes { color: var(--pink); font-weight: 600; }

/* ============================================================
   Pricing
   ============================================================ */
.pricing {
  background: var(--paper-2);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 32px;
  align-items: stretch;
}
.pricing-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 32px 28px;
  transition: border-color var(--t), box-shadow var(--t);
  display: flex;
  flex-direction: column;
  position: relative;
}
.pricing-card:hover { border-color: var(--ink); box-shadow: var(--shadow-2); }
.pricing-featured {
  background: var(--ink);
  color: #fff;
  border-color: var(--ink);
  box-shadow: var(--shadow-3);
}
.pricing-featured h3 { color: #fff; }
.pricing-featured .pricing-period { color: rgba(255, 255, 255, 0.6); }
.pricing-featured .pricing-features li { color: rgba(255, 255, 255, 0.88); border-bottom-color: rgba(255, 255, 255, 0.1); }
.pricing-featured .pricing-header { border-bottom-color: rgba(255, 255, 255, 0.15); }

.pricing-popular {
  position: absolute;
  top: 18px; right: 18px;
  font-size: 11px;
  font-weight: 600;
  background: var(--brand);
  color: #fff;
  padding: 4px 10px;
  border-radius: var(--r-pill);
  letter-spacing: 0.02em;
}
.pricing-header { margin-bottom: 24px; padding-bottom: 20px; border-bottom: 1px solid var(--line-soft); }
.pricing-header h3 { margin-bottom: 14px; font-weight: 600; }
.pricing-amount { display: flex; align-items: baseline; gap: 4px; }
.price {
  font-size: 44px;
  font-weight: 700;
  line-height: 1;
  color: var(--ink);
  letter-spacing: -0.03em;
}
.pricing-featured .price { color: #fff; }
.currency { font-size: 14px; color: var(--text-muted); font-weight: 500; }
.pricing-featured .currency { color: rgba(255, 255, 255, 0.6); }
.pricing-period { font-size: 12.5px; color: var(--text-muted); margin-top: 8px; }

.pricing-features { margin-bottom: 24px; flex-grow: 1; }
.pricing-features li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 9px 0;
  font-size: 14px;
  color: var(--text-soft);
  border-bottom: 1px solid var(--line-soft);
}
.pricing-features li:last-child { border-bottom: none; }
.pricing-features li.disabled { opacity: 0.5; text-decoration: line-through; }
.pf-check, .pf-x {
  flex-shrink: 0;
  width: 18px; height: 18px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 11px;
  border-radius: 50%;
  margin-top: 1px;
}
.pf-check { background: var(--mint-soft); color: var(--mint); }
.pf-x { background: var(--paper-2); color: var(--text-muted); }
.pricing-featured .pf-check { background: rgba(63, 193, 141, 0.25); color: #5ED8A5; }
.pricing-featured .pf-x { background: rgba(255, 255, 255, 0.08); color: rgba(255, 255, 255, 0.5); }

.pricing-school {
  max-width: 960px;
  margin: 0 auto;
}
.school-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 32px 36px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
}
.school-info h3 { color: var(--ink); margin-bottom: 6px; }
.school-info p { max-width: 540px; font-size: 14.5px; color: var(--text-soft); line-height: 1.65; }

/* ============================================================
   Parent section (家长放心 · floating cards)
   ============================================================ */
.parent-section {
  background:
    radial-gradient(circle at 12% 18%, rgba(124, 92, 255, 0.06), transparent 42%),
    radial-gradient(circle at 88% 82%, rgba(255, 217, 63, 0.08), transparent 45%),
    var(--paper);
  position: relative;
  overflow: hidden;
}
.parent-section::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--line-soft) 1px, transparent 1px),
    linear-gradient(90deg, var(--line-soft) 1px, transparent 1px);
  background-size: 56px 56px;
  opacity: 0.35;
  mask-image: radial-gradient(circle at 50% 50%, #000 30%, transparent 75%);
  pointer-events: none;
}
.parent-wrapper {
  display: grid;
  grid-template-columns: 1fr 1.05fr;
  gap: 72px;
  align-items: center;
  position: relative;
  z-index: 1;
}

/* —— Stage —— */
.parent-stage {
  position: relative;
  min-height: 540px;
}
.float-card {
  position: absolute;
  width: 290px;
  padding: 22px 22px 20px;
  border-radius: 18px;
  border: 1.5px solid var(--ink);
  box-shadow: 6px 6px 0 var(--ink);
  background: var(--surface);
  transition: transform 0.35s var(--ease), box-shadow 0.35s var(--ease);
  z-index: 1;
}
.float-card:hover {
  transform: translateY(-4px) rotate(0deg) !important;
  box-shadow: 8px 10px 0 var(--ink);
  z-index: 5;
}
.float-card--white { background: var(--surface); color: var(--ink); }
.float-card--purple {
  background: #7C5CFF;
  color: #fff;
  border-color: var(--ink);
}
.float-card--purple p { color: rgba(255, 255, 255, 0.88); }
.float-card--purple h4 { color: #fff; }

.float-card--tilt-l { transform: rotate(-5deg); }
.float-card--tilt-r { transform: rotate(4.5deg); }

.float-card--pos-1 { top: 0; left: 8px; }
.float-card--pos-2 { top: 168px; right: 0; z-index: 2; }
.float-card--pos-3 { top: 360px; left: 28px; }

.float-card-head {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 10px;
}
.float-card-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 10px;
  font-size: 18px;
  flex-shrink: 0;
  border: 1.5px solid var(--ink);
}
.float-card-icon--red { background: var(--brand-soft); }
.float-card-icon--white {
  background: #fff;
  color: var(--ink);
}
.float-card h4 { font-size: 15.5px; line-height: 1.3; }
.float-card p {
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--text-soft);
  margin: 0;
}

/* —— Floating chip —— */
.float-chip {
  position: absolute;
  bottom: 10px;
  right: 22px;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 9px 14px 9px 12px;
  background: var(--ink);
  color: #fff;
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.02em;
  box-shadow: 4px 4px 0 var(--brand);
  transform: rotate(-3deg);
  z-index: 3;
}
.float-chip-label {
  color: rgba(255, 255, 255, 0.6);
  font-size: 11px;
}
.float-chip-value {
  color: var(--highlight);
  font-weight: 600;
}

/* —— Right: text & promises —— */
.parent-text .section-eyebrow { margin-bottom: 14px; }
.parent-title {
  font-size: clamp(28px, 3.4vw, 40px);
  line-height: 1.18;
  letter-spacing: -0.025em;
  color: var(--ink);
  margin-bottom: 22px;
}
.parent-highlight {
  position: relative;
  display: inline-block;
  padding: 0 4px;
  z-index: 1;
}
.parent-highlight::after {
  content: '';
  position: absolute;
  left: -2px;
  right: -2px;
  bottom: 4px;
  height: 14px;
  background: var(--highlight);
  z-index: -1;
  transform: skew(-6deg);
}
.parent-italic {
  font-family: var(--font-serif);
  font-style: italic;
  font-weight: 500;
  color: var(--brand);
  letter-spacing: -0.01em;
}
.parent-period { color: var(--brand); }

.parent-lead {
  font-size: 15.5px;
  line-height: 1.75;
  color: var(--text-soft);
  margin-bottom: 32px;
  max-width: 540px;
}

.parent-promises {
  display: grid;
  gap: 0;
  border-top: 1px solid var(--line);
}
.promise-item {
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: 18px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
  align-items: start;
  transition: padding-left var(--t) var(--ease);
}
.promise-item:hover { padding-left: 8px; }
.promise-num {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 500;
  color: var(--ink);
  background: var(--paper-2);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 4px 0;
  text-align: center;
  letter-spacing: 0.02em;
}
.promise-body h5 {
  font-size: 14.5px;
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 4px;
  letter-spacing: -0.005em;
}
.promise-body p {
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--text-soft);
  margin: 0;
}

/* ============================================================
   About
   ============================================================ */
.about {
  background: var(--paper-2);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.about-wrapper {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}
.about-content .section-eyebrow { margin-bottom: 12px; }
.about-content .section-title { text-align: left; margin-bottom: 20px; }
.about-content > p {
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--text-soft);
  margin-bottom: 18px;
}
.about-content > p strong { color: var(--ink); font-weight: 600; }

.about-values { margin-top: 28px; display: grid; gap: 12px; }
.value-item {
  display: flex;
  gap: 14px;
  padding: 16px 18px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
}
.value-icon {
  flex-shrink: 0;
  font-size: 18px;
  width: 36px; height: 36px;
  background: var(--paper-2);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}
.value-item strong { font-size: 15px; font-weight: 600; color: var(--ink); display: block; margin-bottom: 2px; }
.value-item p { font-size: 13.5px; color: var(--text-soft); line-height: 1.55; }

.about-visual { position: relative; }
.about-photo-wrap {
  border-radius: var(--r-xl);
  overflow: hidden;
  box-shadow: var(--shadow-3);
  margin-bottom: 20px;
  aspect-ratio: 16 / 11;
}
.about-photo { width: 100%; height: 100%; object-fit: cover; }

.about-stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}
.about-stat {
  padding: 20px 18px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  text-align: left;
}
.about-stat-number {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 4px;
  line-height: 1;
  color: var(--ink);
  letter-spacing: -0.02em;
}
.about-stat-label { font-size: 13px; font-weight: 500; color: var(--text-muted); }

/* ============================================================
   CTA
   ============================================================ */
.cta-section { background: var(--paper); padding: 72px 0 96px; }
.cta-wrapper {
  background: var(--ink);
  color: #fff;
  border-radius: var(--r-xl);
  padding: 64px 48px;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.cta-wrapper h2 { color: #fff; margin-bottom: 12px; font-size: clamp(24px, 3vw, 34px); }
.cta-wrapper > p { font-size: 16px; color: rgba(255, 255, 255, 0.72); margin-bottom: 32px; position: relative; z-index: 1; max-width: 600px; margin-left: auto; margin-right: auto; }
.cta-bg-shapes { position: absolute; inset: 0; pointer-events: none; z-index: 0; }
.cta-shape { position: absolute; border-radius: 50%; filter: blur(60px); opacity: 0.25; }
.cta-shape-1 { width: 320px; height: 320px; top: -140px; left: -80px; background: var(--brand); }
.cta-shape-2 { width: 280px; height: 280px; bottom: -100px; right: -60px; background: var(--accent); }
.cta-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
  position: relative;
  z-index: 1;
}

/* ============================================================
   Footer
   ============================================================ */
.footer {
  background: var(--paper-2);
  color: var(--text);
  padding: 72px 0 28px;
  border-top: 1px solid var(--line);
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr repeat(4, 1fr);
  gap: 40px;
  margin-bottom: 40px;
}
.footer-logo { display: flex; align-items: center; gap: 10px; margin-bottom: 14px; }
.footer-logo .logo-text { color: var(--ink); }
.footer-tagline { color: var(--text-soft); margin-bottom: 20px; font-size: 14px; line-height: 1.6; }
.footer-contact p { font-size: 13px; color: var(--text-muted); margin-bottom: 6px; }

.footer-links h4 { color: var(--ink); margin-bottom: 16px; font-size: 14px; font-weight: 600; }
.footer-links a {
  display: block;
  padding: 5px 0;
  font-size: 13.5px;
  color: var(--text-muted);
  transition: color var(--t);
}
.footer-links a:hover { color: var(--ink); }

.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid var(--line);
  text-align: center;
  font-size: 12.5px;
  color: var(--text-muted);
}

/* ============================================================
   Floating CS button
   ============================================================ */
.floating-cs { position: fixed; bottom: 24px; right: 24px; z-index: 900; cursor: pointer; }
.cs-btn {
  width: 52px; height: 52px;
  background: var(--ink);
  color: #fff;
  border-radius: 50%;
  box-shadow: var(--shadow-3);
  font-size: 22px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform var(--t);
}
.floating-cs:hover .cs-btn { transform: scale(1.06); }
.cs-tooltip {
  position: absolute;
  right: 64px; top: 50%;
  transform: translateY(-50%);
  background: var(--ink);
  color: #fff;
  padding: 7px 12px;
  border-radius: var(--r-sm);
  font-size: 12.5px;
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--t);
}
.floating-cs:hover .cs-tooltip { opacity: 1; }

/* ============================================================
   Differentiator (和别的少儿编程不一样)
   ============================================================ */
.differentiator {
  background: var(--paper-2);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.differentiator-head {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 60px;
  align-items: end;
  margin-bottom: 48px;
}
.differentiator-intro { display: flex; flex-direction: column; gap: 18px; }
.differentiator-title {
  font-size: clamp(38px, 5.4vw, 64px);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.01em;
  color: var(--ink);
  margin: 0;
}
.differentiator-highlight { color: var(--brand); }
.differentiator-period { color: var(--brand); }
.differentiator-desc {
  color: var(--text-soft);
  font-size: 15px;
  line-height: 1.75;
  max-width: 38ch;
  align-self: end;
  margin: 0;
}
.differentiator-desc strong {
  color: var(--ink);
  font-weight: 600;
  background-image: linear-gradient(180deg, transparent 62%, rgba(255, 217, 63, 0.55) 62%);
  padding: 0 2px;
}

.differentiator-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr;
  grid-template-rows: 1fr 1fr;
  gap: 20px;
  margin-bottom: 28px;
}
.diff-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 26px 26px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  transition: border-color var(--t), transform var(--t), box-shadow var(--t);
}
.diff-card:hover {
  border-color: var(--ink);
  transform: translateY(-2px);
  box-shadow: var(--shadow-2);
}
.diff-card-icon {
  font-size: 22px;
  width: 44px;
  height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--paper-2);
  border-radius: var(--r-sm);
  margin-bottom: 4px;
}
.diff-card-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--ink);
  line-height: 1.3;
  margin: 0;
}
.diff-card-desc {
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-soft);
  margin: 0;
}

.diff-card--feature {
  grid-row: span 2;
  background: var(--brand);
  border-color: var(--brand);
  color: #FFF6E8;
  padding: 32px 32px 28px;
  position: relative;
  overflow: hidden;
}
.diff-card--feature::after {
  content: "";
  position: absolute;
  inset: -30% -30% auto auto;
  width: 240px;
  height: 240px;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.16), transparent 65%);
  pointer-events: none;
}
.diff-card--feature .diff-card-title { color: #FFF6E8; font-size: 28px; }
.diff-card--feature .diff-card-desc { color: rgba(255, 246, 232, 0.85); font-size: 14.5px; }
.diff-card--feature .diff-card-icon {
  background: rgba(255, 255, 255, 0.18);
  border: 1px solid rgba(255, 255, 255, 0.25);
}
.diff-card--feature:hover {
  border-color: rgba(0, 0, 0, 0.18);
  transform: translateY(-2px);
}

.diff-card-chat {
  margin-top: auto;
  background: rgba(0, 0, 0, 0.16);
  border-radius: var(--r-md);
  padding: 16px 18px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  line-height: 1.75;
  position: relative;
  z-index: 1;
}
.diff-chat-line {
  display: flex;
  gap: 12px;
  align-items: flex-start;
}
.diff-chat-tag {
  color: rgba(255, 246, 232, 0.55);
  min-width: 28px;
  flex-shrink: 0;
}
.diff-chat-text {
  color: #FFF6E8;
  flex: 1;
}
.diff-chat-indent {
  display: inline-block;
  padding-left: 0;
}

/* Timeline (dark band) */
.differentiator-timeline {
  background: var(--ink);
  color: #FDFBF5;
  border-radius: var(--r-lg);
  padding: 36px 40px 38px;
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 40px;
  align-items: center;
  position: relative;
  overflow: hidden;
}
.differentiator-timeline::before {
  content: "";
  position: absolute;
  inset: -50% auto auto -10%;
  width: 380px;
  height: 380px;
  background: radial-gradient(circle, rgba(232, 75, 28, 0.18), transparent 65%);
  filter: blur(30px);
  pointer-events: none;
}
.timeline-head { position: relative; z-index: 1; }
.timeline-title {
  font-size: 26px;
  font-weight: 800;
  line-height: 1.25;
  color: #FDFBF5;
  margin: 0 0 12px;
}
.timeline-quote {
  color: var(--brand);
  font-style: italic;
  font-family: var(--font-serif);
  font-weight: 600;
}
.timeline-quote--yellow { color: var(--highlight); }
.timeline-sub {
  font-size: 13px;
  color: rgba(253, 251, 245, 0.6);
  margin: 0;
  line-height: 1.6;
}

.timeline-track {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 0;
  position: relative;
  margin: 0;
  padding: 0;
  z-index: 1;
}
.timeline-track::before {
  content: "";
  position: absolute;
  top: 11px;
  left: 8.33%;
  right: 8.33%;
  border-top: 1.5px dashed rgba(253, 251, 245, 0.25);
  z-index: 0;
}
.timeline-node {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  position: relative;
  z-index: 1;
}
.timeline-dot {
  width: 14px;
  height: 14px;
  border-radius: 999px;
  border: 1.5px solid rgba(253, 251, 245, 0.4);
  background: var(--ink);
  display: block;
}
.timeline-node--done .timeline-dot {
  background: var(--brand);
  border-color: var(--brand);
  box-shadow: 0 0 0 4px rgba(232, 75, 28, 0.18);
}
.timeline-label {
  font-size: 13px;
  font-weight: 600;
  color: #FDFBF5;
  text-align: center;
}
.timeline-meta {
  font-family: var(--font-mono);
  font-size: 11px;
  color: rgba(253, 251, 245, 0.5);
  letter-spacing: 0.04em;
}

/* ============================================================
   Playbook (dark spotlight: 三步)
   ============================================================ */
.playbook {
  background: var(--paper-3);
  color: var(--ink);
  position: relative;
  overflow: hidden;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.playbook::before {
  content: "";
  position: absolute;
  inset: -10% -20% auto auto;
  width: 520px;
  height: 520px;
  background: radial-gradient(circle, rgba(232, 75, 28, 0.18), transparent 65%);
  filter: blur(50px);
  pointer-events: none;
}

.playbook-head {
  display: grid;
  grid-template-columns: 1.45fr 1fr;
  gap: 60px;
  align-items: end;
  margin-bottom: 56px;
  position: relative;
}
.playbook-intro { display: flex; flex-direction: column; gap: 22px; }
.playbook-eyebrow {
  color: var(--text-muted);
}
.playbook-eyebrow::before {
  background: var(--brand);
}
.playbook-title {
  font-size: clamp(40px, 5.6vw, 68px);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.01em;
  color: var(--ink);
  margin: 0;
}
.playbook-accent {
  font-family: var(--font-serif);
  font-style: italic;
  font-weight: 600;
  color: var(--brand);
}
.playbook-period { color: var(--brand); }

.playbook-desc {
  color: var(--text-soft);
  font-size: 15px;
  line-height: 1.75;
  max-width: 38ch;
  align-self: end;
  margin: 0;
}
.playbook-desc strong {
  color: var(--ink);
  font-weight: 600;
  background-image: linear-gradient(180deg, transparent 62%, rgba(255, 217, 63, 0.55) 62%);
  padding: 0 2px;
}

.playbook-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
  position: relative;
}
.playbook-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 28px 26px 28px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  transition: border-color var(--t), transform var(--t), box-shadow var(--t);
}
.playbook-card:hover {
  border-color: var(--ink);
  transform: translateY(-2px);
  box-shadow: var(--shadow-2);
}
.playbook-step {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--brand);
  text-transform: uppercase;
}
.playbook-card-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--ink);
  margin: 0;
  letter-spacing: -0.005em;
}
.playbook-card-desc {
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-soft);
  margin: 0 0 8px;
}
.playbook-demo {
  margin-top: auto;
  background: var(--paper-2);
  border: 1px solid var(--line-soft);
  border-radius: var(--r-md);
  padding: 18px 16px;
  min-height: 220px;
  display: flex;
  flex-direction: column;
}

/* Chat bubbles */
.playbook-demo--chat {
  gap: 10px;
  justify-content: center;
}
.chat-row {
  display: flex;
  align-items: flex-end;
  gap: 6px;
}
.chat-row--user { justify-content: flex-end; }
.chat-row--ai { justify-content: flex-start; }
.chat-avatar {
  font-size: 14px;
  width: 22px;
  height: 22px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--paper-3);
  border: 1px solid var(--line-soft);
  border-radius: 999px;
  flex-shrink: 0;
}
.chat-bubble {
  max-width: 78%;
  padding: 7px 12px;
  border-radius: 12px;
  font-size: 13px;
  line-height: 1.45;
}
.chat-bubble--user {
  background: var(--brand);
  color: #FFF6E8;
  border-bottom-right-radius: 4px;
}
.chat-bubble--ai {
  background: var(--paper-3);
  color: var(--ink);
  border: 1px solid var(--line-soft);
  border-bottom-left-radius: 4px;
}

/* Code pills */
.playbook-demo--code {
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  justify-content: center;
}
.code-pill {
  align-self: flex-start;
  padding: 7px 14px;
  border-radius: 999px;
  background: var(--paper-3);
  color: var(--ink);
  border: 1px solid var(--line-soft);
  display: inline-flex;
  gap: 6px;
  align-items: center;
  white-space: nowrap;
}
.code-kw {
  background: var(--ink);
  color: #FFF6E8;
  padding: 1px 6px;
  border-radius: 4px;
  font-weight: 600;
  letter-spacing: 0.04em;
}
.code-pill--when { background: var(--brand); color: #FFF6E8; border-color: var(--brand); }
.code-pill--when .code-kw { background: rgba(0, 0, 0, 0.22); }
.code-pill--if { background: #7C5CFF; color: #FFF6E8; border-color: #7C5CFF; }
.code-pill--if .code-kw { background: rgba(0, 0, 0, 0.22); }
.code-pill--action {
  background: #E8F7EF;
  color: #1F8657;
  border-color: #BFE6CF;
}
.code-pill--action-purple {
  background: #F0EBFF;
  color: #4F37B8;
  border-color: #D6CCFF;
}
.code-pill--action-orange {
  background: #FFE8DE;
  color: #B83814;
  border-color: #FFCBB5;
}

/* Phone mockup */
.playbook-demo--phone {
  align-items: center;
  justify-content: center;
  gap: 18px;
  padding-top: 22px;
  padding-bottom: 22px;
}
.phone-frame {
  width: 116px;
  padding: 4px;
  background: #2A2C36;
  border-radius: 22px;
  border: 1.5px solid rgba(253, 251, 245, 0.18);
  position: relative;
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.35);
}
.phone-notch {
  position: absolute;
  top: 4px;
  left: 50%;
  transform: translateX(-50%);
  width: 32px;
  height: 8px;
  background: #15161C;
  border-radius: 0 0 6px 6px;
  z-index: 2;
}
.phone-screen {
  background: linear-gradient(165deg, #FFCBA8 0%, #FF8E55 50%, #E84B1C 100%);
  border-radius: 18px;
  padding: 26px 14px 18px;
  min-height: 150px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  gap: 10px;
  position: relative;
}
.phone-app-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
  margin-top: 8px;
}
.phone-app {
  font-size: 22px;
  width: 36px;
  height: 36px;
  background: rgba(255, 255, 255, 0.22);
  border: 1px solid rgba(255, 255, 255, 0.35);
  border-radius: 9px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(4px);
}
.phone-home-bar {
  position: absolute;
  bottom: 7px;
  left: 50%;
  transform: translateX(-50%);
  width: 38%;
  height: 3px;
  border-radius: 2px;
  background: rgba(255, 255, 255, 0.7);
}
.share-chips {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  justify-content: center;
}
.chip {
  font-family: var(--font-mono);
  font-size: 11px;
  background: var(--surface);
  color: var(--ink);
  border: 1px solid var(--line-soft);
  padding: 4px 10px;
  border-radius: 999px;
  letter-spacing: 0.02em;
}
.chip--more {
  background: var(--brand);
  color: #FFF6E8;
  border-color: var(--brand);
}

/* ============================================================
   Utilities
   ============================================================ */
.hide-mobile { display: inline; }
.show-mobile { display: none; }

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 1024px) {
  .features-grid, .showcase-grid, .pricing-grid { grid-template-columns: repeat(2, 1fr); }
  .modes-grid { grid-template-columns: 1fr; gap: 20px; }
  .steps {
    grid-template-columns: 1fr 1fr;
    gap: 20px;
  }
  .step-connector { display: none; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
  .demo-wrapper, .about-wrapper, .hero-inner { grid-template-columns: 1fr; gap: 48px; }
  .hero-visual { max-width: 460px; margin: 0 auto; }

  .playbook-head { grid-template-columns: 1fr; gap: 28px; align-items: start; }
  .playbook-desc { align-self: start; }
  .playbook-grid { grid-template-columns: 1fr; gap: 18px; }
  .playbook-card { padding: 26px 22px; }

  .parent-wrapper { grid-template-columns: 1fr; gap: 56px; }
  .parent-stage {
    min-height: auto;
    display: flex;
    flex-wrap: wrap;
    gap: 18px;
    justify-content: center;
    padding: 12px 0 56px;
  }
  .float-card {
    position: static;
    width: min(100%, 320px);
  }
  .float-card--tilt-l { transform: rotate(-3deg); }
  .float-card--tilt-r { transform: rotate(3deg); }
  .float-chip {
    position: static;
    align-self: center;
    transform: rotate(-2deg);
  }
}

@media (max-width: 720px) {
  .nav, .header-actions .btn { display: none; }
  .mobile-menu-btn { display: flex; }
  .hide-mobile { display: none; }

  .container { padding: 0 20px; }
  .hero { min-height: 0; padding: 104px 0 56px; }
  .hero-title { font-size: 42px; line-height: 1.1; }
  .hero-stats { flex-wrap: wrap; gap: 14px; justify-content: flex-start; padding: 16px 20px; }
  .stat-divider { display: none; }
  .stat-item { padding: 0 16px 0 0; }

  .section { padding: 64px 0; }
  .section-header { margin-bottom: 40px; }
  .features-grid, .showcase-grid, .pricing-grid { grid-template-columns: 1fr; }
  .parent-title { font-size: 28px; }
  .promise-item { grid-template-columns: 48px 1fr; gap: 14px; }
  .steps { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 24px; }

  .trust-items { gap: 16px; flex-direction: column; align-items: flex-start; }
  .school-card { flex-direction: column; align-items: flex-start; text-align: left; }
  .cta-wrapper { padding: 48px 24px; }
}