/* ============================================================
   好奇实验室 Curious Lab · 官网样式
   风格：儿童友好的「科学笔记本 / 实验台」
   ============================================================ */

:root {
  --paper: #f6f3ea;
  --paper-2: #efeadd;
  --paper-3: #e9e3d1;
  --ink: #1c2a3a;
  --ink-soft: #4a5a6d;
  --line: #d8d1bc;
  --line-strong: #b9b09a;
  --acid: #b9d94b;
  --acid-deep: #93b52f;
  --tangerine: #f28c28;
  --red: #e0523f;
  --blue: #2e6f95;
  --night: #14222f;
  --night-2: #1d3142;
  --radius: 14px;
  --font-title: 'Noto Serif SC', 'Songti SC', 'SimSun', serif;
  --font-hand: 'LXGW WenKai', 'Kaiti SC', 'STKaiti', 'KaiTi', cursive;
  --font-body: -apple-system, BlinkMacSystemFont, 'PingFang SC', 'HarmonyOS Sans SC',
    'Microsoft YaHei', 'Noto Sans SC', sans-serif;
  --shadow-1: 0 2px 6px rgba(28, 42, 58, .08), 0 12px 28px rgba(28, 42, 58, .1);
  --shadow-2: 0 4px 12px rgba(28, 42, 58, .1), 0 24px 48px rgba(28, 42, 58, .14);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 84px; }

body {
  font-family: var(--font-body);
  background: var(--paper);
  color: var(--ink);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* ---- 纸张质感：圆点网格 + 噪点 ---- */
body::before {
  content: '';
  position: fixed; inset: 0;
  background-image: radial-gradient(circle, rgba(28, 42, 58, .07) 1px, transparent 1.4px);
  background-size: 24px 24px;
  pointer-events: none;
  z-index: 0;
}

.grain {
  position: fixed; inset: -50%; width: 200%; height: 200%;
  pointer-events: none; z-index: 9999; opacity: .05;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='240' height='240'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

::selection { background: var(--acid); color: var(--ink); }

a { color: inherit; text-decoration: none; }
img, svg { display: block; max-width: 100%; }

.visually-hidden {
  position: absolute; width: 1px; height: 1px; overflow: hidden;
  clip: rect(0 0 0 0); white-space: nowrap;
}

/* ---------- 通用组件 ---------- */

.btn {
  display: inline-flex; align-items: center; gap: .5rem;
  font-family: var(--font-body); font-weight: 700; font-size: 1rem;
  padding: .9rem 1.8rem; border-radius: 999px;
  border: 2.4px solid var(--ink); cursor: pointer;
  transition: transform .18s ease, box-shadow .18s ease, background .18s ease, color .18s ease;
}
.btn:hover { transform: translateY(-2px) rotate(-.6deg); }
.btn:active { transform: translateY(0); }
.btn .arrow { transition: transform .18s ease; }
.btn:hover .arrow { transform: translateX(4px); }

.btn-primary {
  background: var(--acid); color: var(--ink);
  box-shadow: 4px 4px 0 var(--ink);
}
.btn-primary:hover { box-shadow: 6px 6px 0 var(--ink); background: var(--acid-deep); }

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

.btn-small { padding: .6rem 1.2rem; font-size: .9rem; }

/* 手写贴纸 */
.sticker {
  display: inline-block;
  font-family: var(--font-hand); font-weight: 700; font-size: .98rem;
  color: var(--ink);
  background: var(--acid);
  border: 2px solid var(--ink);
  border-radius: 8px;
  padding: .35rem 1rem;
  transform: rotate(-1.6deg);
  box-shadow: 3px 3px 0 rgba(28, 42, 58, .85);
}

.kicker {
  font-family: var(--font-hand); color: var(--blue); font-size: 1.05rem;
  letter-spacing: .12em; text-transform: uppercase; font-weight: 700;
}

.section-head {
  text-align: center; max-width: 760px; margin: 0 auto 3.2rem;
}
.section-head.left { text-align: left; margin-left: 0; }
.section-head h2 {
  font-family: var(--font-title); font-weight: 900; font-size: clamp(1.9rem, 3.4vw, 2.7rem);
  line-height: 1.35; margin: .7rem 0 .9rem;
}
.section-head h2 em { font-style: normal; color: var(--blue); }
.section-sub { color: var(--ink-soft); font-size: 1.06rem; }

/* 入场动画（JS 注入 .js 后才隐藏，保证无 JS 时可见） */
.js .reveal { opacity: 0; transform: translateY(26px); transition: opacity .7s ease, transform .7s cubic-bezier(.2, .7, .3, 1); }
.js .reveal.in { opacity: 1; transform: none; }

/* ============================================================
   顶部导航
   ============================================================ */

.site-header {
  position: sticky; top: 0; z-index: 100;
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  padding: .7rem clamp(1rem, 4vw, 3rem);
  background: rgba(246, 243, 234, .88);
  backdrop-filter: blur(10px);
  border-bottom: 2px solid var(--line);
}

.brand { display: inline-flex; align-items: center; gap: .6rem; }
.brand-mark { width: 38px; height: 38px; flex: none; filter: drop-shadow(2px 2px 0 rgba(28,42,58,.25)); }
.brand-text { font-family: var(--font-title); font-weight: 900; font-size: 1.18rem; line-height: 1.1; }
.brand-text em { display: block; font-style: normal; font-family: var(--font-hand); font-size: .72rem; color: var(--blue); letter-spacing: .08em; }

.site-nav { display: flex; gap: 1.6rem; }
.site-nav a {
  position: relative; font-weight: 600; font-size: .95rem; color: var(--ink-soft);
  padding: .3rem 0; transition: color .15s ease;
}
.site-nav a::after {
  content: ''; position: absolute; left: 0; bottom: -2px; height: 2.4px; width: 100%;
  background: var(--acid); transform: scaleX(0); transform-origin: left;
  transition: transform .22s ease;
}
.site-nav a:hover { color: var(--ink); }
.site-nav a:hover::after { transform: scaleX(1); }

.header-actions { display: flex; align-items: center; gap: .8rem; }

.nav-toggle {
  display: none; background: none; border: 2px solid var(--ink); border-radius: 8px;
  width: 42px; height: 42px; cursor: pointer; flex-direction: column;
  align-items: center; justify-content: center; gap: 5px;
}
.nav-toggle span { display: block; width: 20px; height: 2.6px; background: var(--ink); border-radius: 2px; transition: transform .25s ease, opacity .2s ease; }
.nav-toggle.open span:nth-child(1) { transform: translateY(7.6px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7.6px) rotate(-45deg); }

/* ============================================================
   Hero
   ============================================================ */

.hero { position: relative; padding: clamp(3rem, 7vw, 6rem) clamp(1rem, 5vw, 4rem) 5rem; }
.hero-grid {
  max-width: 1180px; margin: 0 auto;
  display: grid; grid-template-columns: 1.05fr .95fr; gap: clamp(2rem, 5vw, 4rem);
  align-items: center;
}

.hero h1 {
  font-family: var(--font-title); font-weight: 900;
  font-size: clamp(2.5rem, 5.4vw, 4.2rem);
  line-height: 1.22; margin: 1.4rem 0 1.3rem;
  letter-spacing: .01em;
}
.accent-ink {
  position: relative; display: inline-block; color: var(--blue); white-space: nowrap;
}
.accent-ink::after {
  content: ''; position: absolute; left: -2%; bottom: .06em; width: 104%; height: .34em;
  background: var(--acid); z-index: -1; transform: rotate(-1.2deg);
  border-radius: 3px;
}

.hero-sub { color: var(--ink-soft); font-size: clamp(1.02rem, 1.6vw, 1.16rem); max-width: 34rem; }
.hero-sub span { font-weight: 700; color: var(--ink); border-bottom: 3px solid var(--acid); }

.hero-cta { display: flex; flex-wrap: wrap; gap: 1rem; margin: 2rem 0 2.4rem; }

.hero-metrics {
  list-style: none; display: flex; gap: clamp(1.2rem, 3vw, 2.6rem);
  border-top: 2px dashed var(--line-strong); padding-top: 1.4rem;
}
.hero-metrics li { display: flex; flex-direction: column; }
.hero-metrics b {
  font-family: var(--font-title); font-weight: 900; font-size: 2.1rem; line-height: 1;
  color: var(--ink);
}
.hero-metrics b::after { content: ''; display: block; width: 26px; height: 4px; background: var(--tangerine); margin: .45rem 0 .55rem; }
.hero-metrics span { font-size: .86rem; color: var(--ink-soft); }

/* ---- 实验台插图（纯 CSS/SVG） ---- */

.hero-lab { position: relative; }

.lab-desk {
  position: relative;
  background: var(--paper-2);
  border: 2.4px solid var(--ink);
  border-radius: 22px;
  box-shadow: 8px 8px 0 rgba(28, 42, 58, .9);
  min-height: 430px;
  overflow: hidden;
}
.lab-desk::before { /* 桌面木纹感 */
  content: ''; position: absolute; inset: 0;
  background: repeating-linear-gradient(90deg, transparent 0 38px, rgba(28,42,58,.04) 38px 39px);
  pointer-events: none;
}

.flask { position: absolute; bottom: 26px; }
.flask svg { width: 92px; }
.flask-a { left: 6%; }
.flask-b { left: 42%; bottom: 18px; transform: rotate(7deg); }
.flask-b svg { width: 74px; }

.bubble {
  position: absolute; background: var(--blue); border-radius: 50%;
  opacity: .5; animation: rise 2.8s ease-in infinite;
}
.b1 { width: 8px; height: 8px; left: 40px; bottom: 108px; animation-delay: 0s; }
.b2 { width: 5px; height: 5px; left: 58px; bottom: 96px; animation-delay: 1.2s; background: var(--tangerine); }
.b3 { width: 6px; height: 6px; left: 34px; bottom: 88px; animation-delay: .6s; }
@keyframes rise {
  0% { transform: translateY(0) scale(.8); opacity: 0; }
  15% { opacity: .6; }
  100% { transform: translateY(-46px) scale(1.1); opacity: 0; }
}

.lab-screen {
  position: absolute; right: 7%; bottom: 30px; width: 46%;
  background: var(--night); border: 2.4px solid var(--ink); border-radius: 12px;
  padding: 10px 12px 12px;
  box-shadow: 5px 5px 0 rgba(28, 42, 58, .85);
  transform: rotate(1.4deg);
}
.screen-top { display: flex; gap: 5px; margin-bottom: 8px; }
.screen-top i { width: 9px; height: 9px; border-radius: 50%; background: var(--red); }
.screen-top i:nth-child(2) { background: var(--tangerine); }
.screen-top i:nth-child(3) { background: var(--acid); }
.chart-live { width: 100%; height: 62px; }
.chart-line {
  fill: none; stroke: var(--acid); stroke-width: 2.6; stroke-linecap: round;
  filter: drop-shadow(0 0 4px rgba(185, 217, 75, .8));
  stroke-dasharray: 600; stroke-dashoffset: 600;
  animation: draw 2.6s ease forwards 1s;
}
@keyframes draw { to { stroke-dashoffset: 0; } }
.screen-readout { display: flex; justify-content: space-between; margin-top: 8px; font-size: .66rem; color: #9fb2c2; }
.screen-readout b { color: var(--acid); font-size: .74rem; }

.sensor-chip {
  position: absolute; top: 34px; left: 12%;
  width: 74px; transform: rotate(-7deg);
  filter: drop-shadow(4px 4px 0 rgba(28,42,58,.3));
}
.sensor-chip svg { width: 100%; animation: floaty 4.5s ease-in-out infinite; }
@keyframes floaty { 0%, 100% { transform: translateY(0) rotate(0); } 50% { transform: translateY(-7px) rotate(2deg); } }
.chip-label {
  position: absolute; right: -64px; top: 22px;
  font-family: var(--font-hand); font-weight: 700; font-size: .78rem;
  background: var(--paper); border: 2px dashed var(--line-strong); border-radius: 6px; padding: .1rem .5rem;
  white-space: nowrap;
}

.tape {
  position: absolute; width: 110px; height: 26px;
  background: rgba(242, 140, 40, .75);
  opacity: .85;
}
.tape-1 { top: -12px; left: 18%; transform: rotate(-4deg); }
.tape-2 { top: -12px; right: 14%; transform: rotate(5deg); background: rgba(185, 217, 75, .85); }
.tape-3 { top: -12px; left: 12%; transform: rotate(-5deg); background: rgba(46, 111, 149, .65); }

.lab-note {
  position: absolute; font-family: var(--font-hand); font-size: .92rem; line-height: 1.55;
  background: var(--paper); border: 2px dashed var(--line-strong); border-radius: 8px;
  padding: .5rem .8rem; transform: rotate(2.4deg);
}
.note-1 { top: 74px; right: 9%; }
.note-2 { bottom: 20px; left: 46%; transform: rotate(-2deg); background: var(--acid); border-style: solid; border-color: var(--ink); }

.scroll-hint {
  position: absolute; left: 50%; transform: translateX(-50%); bottom: 1.4rem;
  display: flex; flex-direction: column; align-items: center; gap: .4rem;
  font-family: var(--font-hand); font-size: .85rem; color: var(--ink-soft);
}
.scroll-line { width: 2px; height: 42px; background: var(--line-strong); position: relative; overflow: hidden; }
.scroll-line::after {
  content: ''; position: absolute; left: 0; top: -50%; width: 100%; height: 50%;
  background: var(--blue); animation: scroll 2s ease-in-out infinite;
}
@keyframes scroll { 0% { top: -50%; } 60%, 100% { top: 110%; } }

/* ============================================================
   政策公告
   ============================================================ */

.policy { padding: clamp(2.5rem, 6vw, 5rem) clamp(1rem, 5vw, 4rem); }

.policy-card {
  max-width: 980px; margin: 0 auto;
  background: var(--night); color: var(--paper);
  border-radius: 22px; padding: clamp(1.6rem, 4vw, 2.8rem);
  position: relative;
  box-shadow: 8px 8px 0 rgba(28, 42, 58, .9);
  overflow: hidden;
}
.policy-card::before {
  content: ''; position: absolute; inset: 10px;
  border: 1.6px dashed rgba(246, 243, 234, .25); border-radius: 14px;
  pointer-events: none;
}
.policy-head { display: flex; align-items: center; gap: 1rem; flex-wrap: wrap; }
.policy-head h2 { font-family: var(--font-title); font-size: clamp(1.3rem, 2.6vw, 1.8rem); font-weight: 700; }
.policy-stamp {
  font-family: var(--font-hand); font-weight: 700; font-size: .85rem;
  color: var(--night); background: var(--acid); border-radius: 6px;
  padding: .2rem .7rem; transform: rotate(-3deg);
  border: 1.6px solid var(--acid-deep);
}
.policy-lead { margin: 1.2rem 0 1.5rem; color: #c6d2de; font-size: 1.02rem; }
.policy-lead strong { color: var(--acid); font-weight: 700; }
.policy-points { list-style: none; display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; }
.policy-points li {
  background: var(--night-2); border: 1.6px solid rgba(246,243,234,.14);
  border-radius: 12px; padding: 1rem 1.1rem;
  display: flex; flex-direction: column; gap: .15rem;
  transition: transform .2s ease, border-color .2s ease;
}
.policy-points li:hover { transform: translateY(-3px); border-color: var(--acid); }
.pp-num { font-family: var(--font-hand); color: var(--tangerine); font-size: .85rem; }
.policy-points b { font-size: 1.02rem; }
.policy-points i { font-style: normal; font-size: .84rem; color: #93a5b6; }
.policy-foot { margin-top: 1.4rem; font-family: var(--font-hand); color: var(--acid); font-size: .98rem; }

/* ============================================================
   怎么玩 · 五环节
   ============================================================ */

.how { padding: clamp(3rem, 6vw, 5.5rem) clamp(1rem, 5vw, 4rem); background: var(--paper-2); border-top: 2px solid var(--line); border-bottom: 2px solid var(--line); }

.steps { list-style: none; display: grid; grid-template-columns: repeat(5, 1fr); gap: 1.1rem; max-width: 1180px; margin: 0 auto; counter-reset: step; }

.step {
  position: relative; background: var(--paper);
  border: 2.4px solid var(--ink); border-radius: var(--radius);
  padding: 1.4rem 1.2rem 1.5rem;
  display: flex; flex-direction: column; gap: .5rem;
  box-shadow: 5px 5px 0 rgba(28, 42, 58, .9);
  transition: transform .2s ease, box-shadow .2s ease;
}
.step:hover { transform: translateY(-6px) rotate(-.5deg); box-shadow: 7px 9px 0 rgba(28, 42, 58, .9); }

.step-num {
  position: absolute; top: -16px; left: 14px;
  font-family: var(--font-title); font-weight: 900; font-size: 1.5rem;
  background: var(--acid); border: 2.4px solid var(--ink); border-radius: 50%;
  width: 46px; height: 46px; display: grid; place-items: center;
  transform: rotate(-6deg);
}
.step:nth-child(even) .step-num { transform: rotate(5deg); background: var(--tangerine); }

.step-icon { width: 58px; height: 58px; margin-top: .9rem; }
.step-icon svg { width: 100%; height: 100%; }

.step h3 { font-family: var(--font-title); font-weight: 900; font-size: 1.18rem; }
.step p { font-size: .9rem; color: var(--ink-soft); }

/* 连接线（桌面端） */
@media (min-width: 900px) {
  .steps { position: relative; }
  .step:not(:last-child)::after {
    content: ''; position: absolute; top: 46%; right: -1.1rem; width: 1.1rem; height: 3px;
    background: var(--line-strong); z-index: 1;
  }
  .step:not(:last-child)::before {
    content: '→'; position: absolute; top: 41%; right: -1.35rem; z-index: 2;
    font-family: var(--font-hand); font-size: 1.15rem; color: var(--tangerine); font-weight: 700;
  }
}

/* ============================================================
   六大主题
   ============================================================ */

.themes { padding: clamp(3rem, 6vw, 5.5rem) clamp(1rem, 5vw, 4rem); }

.theme-grid {
  max-width: 1180px; margin: 0 auto;
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.6rem;
}

.theme-card {
  position: relative;
  background: var(--paper);
  border: 2.4px solid var(--ink); border-radius: var(--radius);
  padding: 1.4rem 1.4rem 1.2rem;
  box-shadow: 5px 5px 0 rgba(28, 42, 58, .9);
  overflow: hidden;
  transition: transform .22s ease, box-shadow .22s ease;
}
.theme-card:hover { transform: translateY(-6px) rotate(-.5deg); box-shadow: 7px 9px 0 rgba(28, 42, 58, .9); }
.theme-card::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 7px;
  background: var(--tc, var(--blue));
  transition: height .2s ease;
}
.theme-card:hover::before { height: 12px; }

.theme-top { display: flex; justify-content: space-between; align-items: center; margin-bottom: .6rem; }
.theme-tag {
  font-family: var(--font-hand); font-size: .8rem; font-weight: 700;
  color: var(--paper); background: var(--ink); border-radius: 999px;
  padding: .15rem .75rem;
}
.theme-ico {
  width: 42px; height: 42px; display: grid; place-items: center;
  font-size: 1.15rem; font-weight: 900;
  background: var(--tc, var(--blue)); border: 2.2px solid var(--ink); border-radius: 50%;
  transform: rotate(6deg);
}

.theme-card h3 { font-family: var(--font-title); font-weight: 900; font-size: 1.32rem; margin-bottom: .7rem; }

.theme-projects { list-style: none; display: flex; flex-direction: column; gap: .42rem; margin-bottom: 1.1rem; }
.theme-projects li {
  position: relative; padding-left: 1.35rem; font-size: .94rem; color: var(--ink-soft);
}
.theme-projects li::before {
  content: '✎'; position: absolute; left: 0; top: 0;
  font-family: var(--font-hand); color: var(--tc, var(--blue)); font-weight: 700;
}

.theme-note {
  font-family: var(--font-hand); font-size: .82rem; color: var(--ink-soft);
  border-top: 1.6px dashed var(--line-strong); padding-top: .7rem;
}

.t-health { --tc: var(--red); }
.t-eco { --tc: var(--acid-deep); }
.t-earth { --tc: var(--blue); }
.t-space { --tc: var(--tangerine); }
.t-industry { --tc: #d4a017; }
.t-ai { --tc: #7c5cbf; }

/* ============================================================
   实验盒
   ============================================================ */

.box { padding: clamp(3rem, 6vw, 5.5rem) clamp(1rem, 5vw, 4rem); background: var(--paper-2); border-top: 2px solid var(--line); border-bottom: 2px solid var(--line); }

.box-grid { max-width: 1180px; margin: 0 auto; display: grid; grid-template-columns: .9fr 1.1fr; gap: clamp(2rem, 5vw, 4rem); align-items: center; }

.box-visual { display: flex; justify-content: center; }

.kit { position: relative; width: min(340px, 88%); }
.kit-lid {
  background: var(--blue); color: var(--paper);
  border: 2.4px solid var(--ink); border-radius: 12px 12px 4px 4px;
  padding: 1rem 1.2rem; position: relative; z-index: 2;
  display: flex; flex-direction: column; gap: .2rem;
  box-shadow: 6px 6px 0 rgba(28, 42, 58, .9);
  transform: translateY(0);
}
.kit-lid span { font-family: var(--font-title); font-weight: 900; font-size: 1rem; letter-spacing: .04em; }
.kit-lid i { font-style: normal; font-family: var(--font-hand); font-size: .86rem; color: #cfe6f0; }
.kit-logo { width: 30px; height: 30px; margin-bottom: .3rem; }

.kit-body {
  position: relative; min-height: 190px;
  background: var(--paper-3); border: 2.4px solid var(--ink);
  border-radius: 4px 4px 16px 16px; padding: 1.4rem 1.2rem;
  box-shadow: 6px 8px 0 rgba(28, 42, 58, .9);
}
.kit-sticker {
  display: inline-block; font-family: var(--font-hand); font-size: .92rem; font-weight: 700;
  background: var(--paper); border: 2px solid var(--ink); border-radius: 8px;
  padding: .3rem .8rem; margin: .35rem; transform: rotate(-2deg);
  box-shadow: 2px 3px 0 rgba(28, 42, 58, .5);
}
.kit-sticker.k2 { transform: rotate(1.6deg); background: var(--acid); }
.kit-sticker.k3 { transform: rotate(-1.4deg); background: #f7c98a; }
.kit-sticker.k4 { transform: rotate(2deg); }

.box-features { list-style: none; display: flex; flex-direction: column; gap: 1.5rem; margin-top: 1.8rem; }
.box-features li { display: flex; gap: 1.1rem; }
.bf-num {
  font-family: var(--font-title); font-weight: 900; font-size: 1.5rem;
  color: var(--blue); line-height: 1; flex: none;
}
.box-features h3 { font-family: var(--font-title); font-size: 1.14rem; margin-bottom: .25rem; }
.box-features p { color: var(--ink-soft); font-size: .95rem; }

/* 传感器演示面板 */
.sensor-demo {
  margin-top: 2rem; background: var(--night); color: var(--paper);
  border: 2.4px solid var(--ink); border-radius: var(--radius);
  padding: 1.1rem 1.2rem 1.2rem; box-shadow: 5px 5px 0 rgba(28, 42, 58, .9);
}
.sd-head { font-size: .88rem; color: #9fb2c2; display: flex; justify-content: space-between; align-items: center; }
.sd-live { color: var(--acid); font-size: .78rem; animation: blink 1.6s ease infinite; }
@keyframes blink { 0%, 100% { opacity: 1; } 50% { opacity: .35; } }
.sd-reading { display: flex; gap: 1.4rem; margin: .9rem 0 .6rem; }
.sd-cell { display: flex; flex-direction: column; }
.sd-cell b { font-family: var(--font-title); font-size: 1.7rem; color: var(--acid); line-height: 1.15; }
.sd-cell span { font-size: .72rem; color: #9fb2c2; }
.sd-chart { width: 100%; height: 60px; }
.sd-chart polyline { fill: none; stroke: var(--tangerine); stroke-width: 2.2; stroke-linecap: round; }

/* ============================================================
   AI 助手
   ============================================================ */

.ai { padding: clamp(3rem, 6vw, 5.5rem) clamp(1rem, 5vw, 4rem); }
.ai-grid { max-width: 1180px; margin: 0 auto; display: grid; grid-template-columns: 1fr 1fr; gap: clamp(2rem, 5vw, 4rem); align-items: center; }

.ai-lead { color: var(--ink-soft); margin: 1.2rem 0 1.4rem; font-size: 1.05rem; }
.ai-points { list-style: none; display: flex; flex-direction: column; gap: .85rem; }
.ai-points li { position: relative; padding-left: 2rem; font-size: .98rem; }
.ai-points li::before {
  content: ''; position: absolute; left: 0; top: .45rem;
  width: 14px; height: 14px; border-radius: 3px;
  background: var(--acid); border: 2px solid var(--ink); transform: rotate(7deg);
}
.ai-points b { display: block; font-size: 1.02rem; }

.ai-demo {
  background: var(--night); color: var(--paper);
  border: 2.4px solid var(--ink); border-radius: 16px; overflow: hidden;
  box-shadow: 7px 7px 0 rgba(28, 42, 58, .9);
}
.chat-head {
  display: flex; align-items: center; gap: .6rem;
  padding: .9rem 1.1rem; background: var(--night-2);
  border-bottom: 1.6px solid rgba(246,243,234,.14);
  font-weight: 700; font-size: .95rem;
}
.chat-head em { font-style: normal; font-family: var(--font-hand); font-weight: 400; font-size: .82rem; color: #93a5b6; }
.chat-ava {
  width: 32px; height: 32px; border-radius: 50%;
  background: var(--acid); color: var(--ink); font-weight: 900; font-size: .8rem;
  display: grid; place-items: center; border: 2px solid var(--acid-deep);
}
.chat-body { padding: 1.2rem 1.1rem; display: flex; flex-direction: column; gap: .8rem; min-height: 240px; }
.msg {
  max-width: 86%; padding: .65rem 1rem; border-radius: 14px;
  font-size: .94rem; line-height: 1.6;
  animation: pop .35s ease both;
}
@keyframes pop { from { opacity: 0; transform: translateY(10px) scale(.97); } }
.msg.kid { align-self: flex-end; background: var(--blue); color: var(--paper); border-radius: 14px 14px 4px 14px; }
.msg.bot { align-self: flex-start; background: var(--night-2); border: 1.6px solid rgba(246,243,234,.18); border-radius: 14px 14px 14px 4px; }
.msg.bot::before { content: '🧭 '; }

.chat-next {
  margin: 0 1.1rem 1rem; width: calc(100% - 2.2rem);
  background: var(--acid); color: var(--ink);
  border: 2.2px solid var(--ink); border-radius: 999px;
  font-weight: 800; font-size: .95rem; padding: .75rem; cursor: pointer;
  transition: transform .15s ease, background .15s ease;
}
.chat-next:hover { transform: translateY(-2px); background: var(--acid-deep); }
.chat-notes { text-align: center; font-family: var(--font-hand); font-size: .8rem; color: #93a5b6; padding-bottom: .9rem; }

/* ============================================================
   成长档案
   ============================================================ */

.portfolio { padding: clamp(3rem, 6vw, 5.5rem) clamp(1rem, 5vw, 4rem); background: var(--paper-2); border-top: 2px solid var(--line); border-bottom: 2px solid var(--line); }
.pf-grid { max-width: 1180px; margin: 0 auto; display: grid; grid-template-columns: 1.05fr .95fr; gap: clamp(2rem, 5vw, 4rem); align-items: center; }

.pf-card {
  background: #fbfaf4; border: 2.4px solid var(--ink); border-radius: 8px;
  padding: 1.5rem 1.6rem 1.2rem;
  box-shadow: 7px 7px 0 rgba(28, 42, 58, .9);
  transform: rotate(-1.2deg);
}
.pf-head { display: flex; justify-content: space-between; align-items: baseline; border-bottom: 2.4px solid var(--ink); padding-bottom: .6rem; margin-bottom: .9rem; }
.pf-head b { font-family: var(--font-title); font-size: 1.15rem; }
.pf-head span { font-family: var(--font-hand); font-size: .84rem; color: var(--ink-soft); }
.pf-topic { font-family: var(--font-hand); font-size: .92rem; background: var(--acid); border: 1.8px solid var(--ink); border-radius: 6px; padding: .35rem .8rem; display: inline-block; transform: rotate(-.6deg); margin-bottom: 1rem; }
.pf-row { display: flex; gap: .8rem; margin-bottom: .85rem; }
.pf-label { flex: none; font-family: var(--font-hand); font-weight: 700; font-size: .82rem; color: var(--blue); width: 4.6rem; padding-top: .15rem; }
.pf-row p { font-size: .9rem; color: var(--ink-soft); }
.pf-mini { background: var(--night); border-radius: 8px; padding: .35rem .5rem; }
.pf-mini svg { width: 100%; height: 44px; }
.pf-foot { font-family: var(--font-hand); font-size: .82rem; color: var(--ink-soft); border-top: 1.6px dashed var(--line-strong); padding-top: .7rem; }

.pf-lead { color: var(--ink-soft); margin: 1.2rem 0 1.5rem; font-size: 1.05rem; }
.pf-points { list-style: none; display: flex; flex-direction: column; gap: 1.1rem; margin-bottom: 1.8rem; }
.pf-points li { display: flex; gap: .9rem; align-items: flex-start; font-size: .97rem; }
.pf-points li::before {
  content: '✓'; flex: none; width: 26px; height: 26px; border-radius: 50%;
  background: var(--acid); border: 2.2px solid var(--ink);
  display: grid; place-items: center; font-weight: 900; font-size: .85rem;
  transform: rotate(-4deg);
}
.pf-points b { display: block; }

/* ============================================================
   学段选择
   ============================================================ */

.grades { padding: clamp(3rem, 6vw, 5.5rem) clamp(1rem, 5vw, 4rem); }
.grade-grid { max-width: 1100px; margin: 0 auto; display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.6rem; align-items: stretch; }

.grade-card {
  position: relative; background: var(--paper);
  border: 2.4px solid var(--ink); border-radius: var(--radius);
  padding: 1.7rem 1.5rem;
  box-shadow: 5px 5px 0 rgba(28, 42, 58, .9);
  display: flex; flex-direction: column; gap: .6rem;
  transition: transform .2s ease;
}
.grade-card:hover { transform: translateY(-5px); }
.grade-range {
  font-family: var(--font-hand); font-weight: 700; font-size: .92rem;
  color: var(--blue);
}
.grade-card h3 { font-family: var(--font-title); font-size: 1.35rem; font-weight: 900; }
.grade-card p { color: var(--ink-soft); font-size: .95rem; }
.grade-card ul { list-style: none; margin: .4rem 0 .8rem; display: flex; flex-direction: column; gap: .35rem; }
.grade-card li { font-size: .88rem; color: var(--ink-soft); padding-left: 1.3rem; position: relative; }
.grade-card li::before { content: '▸'; position: absolute; left: 0; color: var(--tangerine); font-weight: 900; }
.grade-price { font-family: var(--font-title); font-weight: 900; font-size: 1.5rem; margin-top: auto; }

.grade-card.popular { background: var(--night); color: var(--paper); }
.grade-card.popular p, .grade-card.popular li { color: #c6d2de; }
.grade-card.popular .grade-range { color: var(--acid); }
.grade-card.popular .grade-price { color: var(--acid); }
.grade-flag {
  position: absolute; top: -14px; right: 18px;
  background: var(--tangerine); color: var(--ink); font-weight: 900; font-size: .8rem;
  border: 2.2px solid var(--ink); border-radius: 999px; padding: .2rem .9rem;
  transform: rotate(4deg);
}

/* ============================================================
   定价
   ============================================================ */

.pricing { padding: clamp(3rem, 6vw, 5.5rem) clamp(1rem, 5vw, 4rem); background: var(--paper-2); border-top: 2px solid var(--line); border-bottom: 2px solid var(--line); }
.price-grid { max-width: 1100px; margin: 0 auto; display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.6rem; align-items: stretch; }

.price-card {
  position: relative; background: var(--paper);
  border: 2.4px solid var(--ink); border-radius: var(--radius);
  padding: 1.8rem 1.5rem;
  box-shadow: 5px 5px 0 rgba(28, 42, 58, .9);
  display: flex; flex-direction: column; gap: .5rem;
}
.price-card h3 { font-family: var(--font-title); font-size: 1.2rem; }
.price { display: flex; align-items: baseline; gap: .4rem; margin: .4rem 0 .6rem; }
.price b { font-family: var(--font-title); font-size: 2.3rem; font-weight: 900; }
.price span { color: var(--ink-soft); font-size: .9rem; }
.price-card ul { list-style: none; display: flex; flex-direction: column; gap: .5rem; margin-bottom: 1.4rem; }
.price-card li { font-size: .92rem; color: var(--ink-soft); padding-left: 1.5rem; position: relative; }
.price-card li::before { content: '✓'; position: absolute; left: 0; color: var(--acid-deep); font-weight: 900; }
.price-card .btn { justify-content: center; margin-top: auto; }

.price-card.featured {
  background: var(--night); color: var(--paper);
  transform: translateY(-8px);
  box-shadow: 7px 9px 0 rgba(28, 42, 58, .9), 0 0 0 3px var(--acid);
}
.price-card.featured li { color: #c6d2de; }
.price-card.featured .price span { color: #93a5b6; }
.price-flag {
  position: absolute; top: -15px; left: 50%; transform: translateX(-50%) rotate(-2deg);
  background: var(--acid); color: var(--ink); font-weight: 900; font-size: .82rem;
  border: 2.2px solid var(--ink); border-radius: 999px; padding: .25rem 1rem;
  white-space: nowrap;
}
.pricing-note { text-align: center; font-family: var(--font-hand); font-size: .86rem; color: var(--ink-soft); margin-top: 1.6rem; }

/* ============================================================
   家长说
   ============================================================ */

.love { padding: clamp(3rem, 6vw, 5.5rem) clamp(1rem, 5vw, 4rem); }
.love-grid { max-width: 1100px; margin: 0 auto; display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.6rem; }

.love-card {
  background: var(--paper); border: 2.4px solid var(--ink); border-radius: var(--radius);
  padding: 1.6rem 1.4rem 1.2rem; margin: 0;
  box-shadow: 5px 5px 0 rgba(28, 42, 58, .9);
  display: flex; flex-direction: column; gap: 1rem;
  transition: transform .2s ease;
}
.love-card:hover { transform: rotate(-.7deg) translateY(-4px); }
.love-card:nth-child(2) { transform: rotate(1deg); }
.love-card blockquote { font-size: .97rem; color: var(--ink-soft); position: relative; }
.love-card blockquote::before { content: '“'; font-family: var(--font-title); font-size: 3rem; color: var(--acid); line-height: .6; display: block; height: 1.4rem; }
.love-card figcaption { display: flex; align-items: center; gap: .7rem; border-top: 1.6px dashed var(--line-strong); padding-top: .9rem; }
.love-ava {
  width: 38px; height: 38px; border-radius: 50%;
  display: grid; place-items: center; font-weight: 900; color: var(--paper);
  border: 2.2px solid var(--ink);
}
.av1 { background: var(--blue); }
.av2 { background: var(--tangerine); }
.av3 { background: #7c5cbf; }
.love-card figcaption b { font-size: .94rem; }
.love-card figcaption i { font-style: normal; font-size: .78rem; color: var(--ink-soft); }

/* ============================================================
   FAQ
   ============================================================ */

.faq { padding: clamp(3rem, 6vw, 5.5rem) clamp(1rem, 5vw, 4rem); background: var(--paper-2); border-top: 2px solid var(--line); border-bottom: 2px solid var(--line); }
.faq-list { max-width: 820px; margin: 0 auto; display: flex; flex-direction: column; gap: .9rem; }

.faq-list details {
  background: var(--paper); border: 2.4px solid var(--ink); border-radius: 12px;
  overflow: hidden; box-shadow: 4px 4px 0 rgba(28, 42, 58, .85);
  transition: box-shadow .2s ease;
}
.faq-list details[open] { box-shadow: 6px 6px 0 rgba(28, 42, 58, .85); }
.faq-list summary {
  cursor: pointer; list-style: none;
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  font-weight: 700; font-size: 1rem; padding: 1.05rem 1.3rem;
}
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after {
  content: '+'; font-family: var(--font-title); font-size: 1.5rem; font-weight: 700;
  color: var(--blue); transition: transform .25s ease; flex: none;
}
.faq-list details[open] summary::after { transform: rotate(45deg); }
.faq-list details p { padding: 0 1.3rem 1.2rem; color: var(--ink-soft); font-size: .95rem; }

/* ============================================================
   CTA
   ============================================================ */

.cta { padding: clamp(3rem, 7vw, 5.5rem) clamp(1rem, 5vw, 4rem); }
.cta-inner {
  max-width: 860px; margin: 0 auto; text-align: center;
  background: var(--night); color: var(--paper);
  border-radius: 24px; padding: clamp(2rem, 5vw, 3.4rem);
  position: relative; box-shadow: 8px 8px 0 rgba(28, 42, 58, .9);
  overflow: hidden;
}
.cta-inner::before { content: ''; position: absolute; inset: 10px; border: 1.6px dashed rgba(246,243,234,.25); border-radius: 16px; pointer-events: none; }
.cta-kicker { font-family: var(--font-hand); color: var(--acid); font-size: .98rem; font-weight: 700; }
.cta-inner h2 { font-family: var(--font-title); font-weight: 900; font-size: clamp(1.7rem, 3.4vw, 2.5rem); margin: .8rem 0 .8rem; }
.cta-inner > p:not(.cta-fine) { color: #c6d2de; font-size: 1.04rem; max-width: 34rem; margin: 0 auto 1.8rem; }

.cta-form { display: flex; flex-wrap: wrap; gap: .8rem; justify-content: center; position: relative; z-index: 1; }
.cta-form input, .cta-form select {
  font-family: var(--font-body); font-size: .98rem;
  padding: .85rem 1.1rem; border-radius: 999px;
  border: 2.4px solid var(--ink); background: var(--paper); color: var(--ink);
  min-width: 0;
}
.cta-form input { flex: 1 1 210px; }
.cta-form select { flex: 1 1 130px; }
.cta-form .btn { flex: 1 1 200px; justify-content: center; }
.cta-fine { font-size: .78rem; color: #93a5b6; margin-top: 1.2rem; }
.cta-form.done .btn { pointer-events: none; }
.cta-success { margin-top: 1rem; font-family: var(--font-hand); color: var(--acid); font-weight: 700; font-size: 1.05rem; }

/* ============================================================
   Footer
   ============================================================ */

.site-footer { background: var(--night); color: var(--paper); padding: 3rem clamp(1rem, 5vw, 4rem) 1.6rem; }
.footer-grid {
  max-width: 1180px; margin: 0 auto;
  display: grid; grid-template-columns: 1.4fr 1fr 1fr 1.6fr; gap: 2rem;
  padding-bottom: 2.2rem; border-bottom: 1.6px solid rgba(246,243,234,.14);
}
.footer-brand .brand-text em { color: var(--acid); }
.footer-brand p { color: #93a5b6; font-size: .9rem; margin-top: .9rem; max-width: 22rem; }
.footer-col h4 { font-size: .88rem; letter-spacing: .1em; color: var(--acid); margin-bottom: .9rem; }
.footer-col a { display: block; color: #c6d2de; font-size: .92rem; padding: .25rem 0; transition: color .15s ease, padding-left .15s ease; }
.footer-col a:hover { color: var(--paper); padding-left: .3rem; }
.footer-legal { color: #93a5b6; font-size: .82rem; line-height: 1.8; }
.footer-bottom {
  max-width: 1180px; margin: 0 auto; padding-top: 1.2rem;
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: .5rem;
  font-family: var(--font-hand); font-size: .84rem; color: #93a5b6;
}

/* ============================================================
   响应式
   ============================================================ */

@media (max-width: 1020px) {
  .hero-grid, .box-grid, .pf-grid, .ai-grid { grid-template-columns: 1fr; }
  .hero-lab { max-width: 560px; margin: 0 auto; width: 100%; }
  .steps { grid-template-columns: repeat(3, 1fr); }
  .step:nth-child(4) { grid-column: 1 / 3; }
  .theme-grid, .grade-grid, .price-grid, .love-grid { grid-template-columns: repeat(2, 1fr); }
  .policy-points { grid-template-columns: 1fr; }
  .site-nav {
    position: fixed; top: 64px; right: 1rem; left: 1rem;
    flex-direction: column; gap: .2rem;
    background: var(--paper); border: 2.4px solid var(--ink); border-radius: 14px;
    padding: 1rem; box-shadow: 6px 6px 0 rgba(28,42,58,.85);
    display: none;
  }
  .site-nav.open { display: flex; }
  .nav-toggle { display: flex; }
  .site-nav a { padding: .7rem .6rem; border-bottom: 1.6px dashed var(--line); }
  .site-nav a:last-child { border-bottom: none; }
}

@media (max-width: 640px) {
  html { scroll-padding-top: 70px; }
  .steps, .theme-grid, .grade-grid, .price-grid, .love-grid { grid-template-columns: 1fr; }
  .step:nth-child(4) { grid-column: auto; }
  .price-card.featured { transform: none; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .hero-metrics { flex-wrap: wrap; }
  .lab-desk { min-height: 380px; }
  .lab-screen { width: 56%; }
  .flask-a { left: 3%; }
  .flask-b { left: 38%; }
  .chat-body { min-height: 200px; }
}

/* ============================================================
   无障碍：减弱动效
   ============================================================ */

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }
  html { scroll-behavior: auto; }
  .js .reveal { opacity: 1; transform: none; }
}