/* ============================================================
   创而不代 — AI儿童美术创造力启发平台
   视觉基调：绘本颜料笔触 × 现代教育科技官网
   ============================================================ */

:root {
  /* 色板：取自 logo 笔触 */
  --paper: #FFF7EC;
  --paper-deep: #FDEEDC;
  --surface: #FFFFFF;
  --ink: #22376B;
  --ink-soft: #5C6B94;
  --line: #EADDC8;
  --sun: #FFC531;
  --sun-soft: #FFE9A8;
  --coral: #FF7E9D;
  --coral-soft: #FFD6E2;
  --sky: #4EA8DE;
  --sky-soft: #CFE9F8;
  --leaf: #4CB782;
  --leaf-soft: #D8F0E2;

  --shadow: 0 12px 28px -14px rgba(34, 55, 107, 0.16);
  --shadow-sm: 0 6px 16px -10px rgba(34, 55, 107, 0.2);

  --radius-sm: 10px;
  --radius-md: 18px;
  --radius-lg: 26px;

  --container: 1120px;
  --font-display: "ZCOOL KuaiLe", "PingFang SC", "Hiragino Sans GB", sans-serif;
  --font-body: "Noto Sans SC", -apple-system, BlinkMacSystemFont, "PingFang SC",
    "Microsoft YaHei", sans-serif;
}

/* ---------- Base ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img { max-width: 100%; height: auto; display: block; }
ul, ol { margin: 0; padding: 0; list-style: none; }
h1, h2, h3, p { margin: 0; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; cursor: pointer; border: none; background: none; }

:focus-visible {
  outline: 3px solid var(--sky);
  outline-offset: 3px;
  border-radius: 4px;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--ink);
  color: var(--surface);
  padding: 10px 18px;
  z-index: 100;
}
.skip-link:focus { left: 12px; top: 12px; }

.container {
  width: min(var(--container), 100% - 48px);
  margin-inline: auto;
}

section[id] { scroll-margin-top: 88px; }

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 247, 236, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.25s ease, box-shadow 0.25s ease;
}
.site-header.is-scrolled {
  border-bottom-color: var(--line);
  box-shadow: 0 8px 20px -18px rgba(34, 55, 107, 0.35);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 68px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
}
.brand-logo {
  height: 48px;
  width: auto;
  border-radius: 10px;
}
.brand-mark { display: inline-flex; }
.brand-text {
  font-family: var(--font-display);
  font-size: 24px;
  letter-spacing: 0.04em;
  color: var(--ink);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 4px;
}
.site-nav a {
  padding: 8px 14px;
  font-size: 15px;
  font-weight: 500;
  color: var(--ink-soft);
  border-radius: 999px;
  transition: color 0.2s ease, background 0.2s ease;
}
.site-nav a:hover { color: var(--ink); background: rgba(255, 197, 49, 0.28); }

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  place-items: center;
  flex-direction: column;
  gap: 5px;
  border-radius: var(--radius-sm);
}
.nav-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--ink);
  border-radius: 2px;
  transition: transform 0.25s ease, opacity 0.2s ease;
}
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 26px;
  font-size: 16px;
  font-weight: 700;
  border-radius: 999px;
  transition: transform 0.18s ease, box-shadow 0.18s ease, background 0.18s ease;
}
.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0); }

.btn-primary {
  background: var(--ink);
  color: var(--surface);
  box-shadow: var(--shadow-sm);
}
.btn-primary:hover { box-shadow: 0 14px 26px -12px rgba(34, 55, 107, 0.45); }

.btn-ghost {
  background: transparent;
  color: var(--ink);
  border: 2px solid var(--ink);
}
.btn-ghost:hover { background: var(--sun-soft); }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  padding: 72px 0 40px;
  overflow: hidden;
}

.hero-blobs { position: absolute; inset: 0; pointer-events: none; }
.blob { position: absolute; opacity: 0.9; }
.blob-a { width: 320px; top: 4%; right: -40px; }
.blob-b { width: 240px; bottom: 12%; left: -60px; }
.blob-c { width: 200px; top: 40%; left: 34%; opacity: 0.55; }

.star-float { position: absolute; width: 36px; }
.star-1 { top: 3%; right: 4%; animation: bob 5s ease-in-out infinite; }

@keyframes bob {
  0%, 100% { transform: translateY(0) rotate(-6deg); }
  50% { transform: translateY(-12px) rotate(6deg); }
}

.hero-inner {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
  gap: 56px;
  align-items: center;
}

.hero-eyebrow { margin-bottom: 18px; }
.tape {
  display: inline-block;
  padding: 6px 16px;
  background: var(--sun);
  color: var(--ink);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.08em;
  transform: rotate(-1.5deg);
  box-shadow: 2px 3px 0 rgba(34, 55, 107, 0.18);
}

.hero-title { line-height: 1.15; }
.hero-name {
  display: block;
  font-family: var(--font-display);
  font-size: clamp(56px, 8vw, 92px);
  letter-spacing: 0.06em;
  color: var(--ink);
  text-shadow: 4px 5px 0 var(--sun-soft);
}
.hero-claim {
  display: block;
  margin-top: 12px;
  font-family: var(--font-display);
  font-size: clamp(26px, 3.4vw, 40px);
  color: var(--ink);
  letter-spacing: 0.03em;
}
.claim-mark {
  background: linear-gradient(transparent 62%, var(--sun-soft) 62%);
  padding: 0 2px;
}

.hero-desc {
  margin-top: 22px;
  max-width: 34em;
  font-size: 17px;
  color: var(--ink-soft);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 30px;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 28px;
}
.hero-tags li {
  padding: 6px 14px;
  font-size: 13px;
  font-weight: 500;
  color: var(--ink);
  background: var(--surface);
  border: 1.5px dashed var(--line);
  border-radius: 999px;
}

.hero-art { position: relative; }
.art-star { position: absolute; animation: bob 5.6s ease-in-out infinite; }
.art-star-1 { width: 34px; top: -26px; right: 14%; }
.art-star-2 { width: 24px; bottom: -16px; left: 10%; animation-delay: 0.8s; }
.art-star-3 { width: 20px; top: 38%; right: -18px; animation-delay: 1.4s; }
.hero-frame {
  background: var(--surface);
  border: 3px solid var(--ink);
  border-radius: var(--radius-lg);
  padding: 14px;
  box-shadow: 10px 12px 0 var(--sun-soft);
  transform: rotate(1.2deg);
}
.hero-frame img { border-radius: var(--radius-md); width: 100%; }

.hero-sticker {
  position: absolute;
  padding: 12px 14px;
  font-family: var(--font-display);
  font-size: 15px;
  line-height: 1.35;
  text-align: center;
  color: var(--ink);
  border: 2.5px solid var(--ink);
  border-radius: 50%;
  background: var(--coral-soft);
}
.sticker-1 {
  top: -18px;
  left: -22px;
  width: 88px;
  height: 88px;
  display: grid;
  place-items: center;
  transform: rotate(-10deg);
  background: var(--sky-soft);
}
.sticker-2 {
  bottom: -10px;
  right: -18px;
  width: 96px;
  height: 96px;
  display: grid;
  place-items: center;
  transform: rotate(8deg);
  background: var(--sun-soft);
}

.hero-wave {
  margin-top: 56px;
  line-height: 0;
}
.hero-wave svg { width: 100%; height: 64px; display: block; }

/* ---------- Sections 公共 ---------- */
.section { padding: 96px 0; }

.section-head {
  max-width: 720px;
  margin-bottom: 56px;
}
.section-kicker {
  display: inline-block;
  margin-bottom: 14px;
  padding: 4px 12px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--ink);
  background: var(--sun-soft);
  border-radius: 4px;
}
.section-title {
  font-family: var(--font-display);
  font-size: clamp(30px, 4vw, 44px);
  line-height: 1.35;
  letter-spacing: 0.02em;
}
.section-lead {
  margin-top: 18px;
  font-size: 17px;
  color: var(--ink-soft);
}

/* ---------- Why 背景挑战 ---------- */
.why { background: var(--paper); }

.why-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
}

.why-card {
  background: var(--surface);
  border: 2px solid var(--ink);
  border-radius: var(--radius-md);
  padding: 30px 26px;
  box-shadow: 6px 7px 0 var(--line);
}
.why-icon {
  width: 56px;
  height: 56px;
  margin-bottom: 18px;
}
.why-icon svg { width: 100%; height: 100%; }
.why-card h3 {
  font-family: var(--font-display);
  font-size: 22px;
  letter-spacing: 0.02em;
  margin-bottom: 10px;
}
.why-card p {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.85;
}

/* ---------- Idea 核心理念 + 对比小剧场 ---------- */
.idea { background: var(--surface); }

.demo {
  border: 3px solid var(--ink);
  border-radius: var(--radius-lg);
  background: var(--paper);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.demo-tabs {
  display: flex;
  gap: 8px;
  padding: 14px;
  background: var(--ink);
}
.demo-tab {
  flex: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 16px;
  font-size: 15px;
  font-weight: 700;
  color: rgba(255, 255, 255, 0.72);
  border-radius: var(--radius-sm);
  transition: background 0.2s ease, color 0.2s ease;
}
.demo-tab:hover { color: var(--surface); background: rgba(255, 255, 255, 0.1); }
.demo-tab.is-active {
  background: var(--sun);
  color: var(--ink);
}
.tab-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}
.tab-dot-bad { background: var(--coral); }
.tab-dot-good { background: var(--leaf); }
.demo-tab.is-active .tab-dot-bad { background: var(--coral); }
.demo-tab.is-active .tab-dot-good { background: var(--leaf); }

.demo-panel { padding: 32px 28px 28px; }
.demo-panel[hidden] { display: none; }

.chat-scene {
  margin-bottom: 22px;
  padding: 12px 16px;
  font-size: 14px;
  color: var(--ink-soft);
  background: var(--sun-soft);
  border-left: 4px solid var(--sun);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.bubble {
  position: relative;
  max-width: 78%;
  margin-bottom: 14px;
  padding: 14px 18px;
  font-size: 15px;
  line-height: 1.8;
  border: 2px solid var(--ink);
  border-radius: 16px;
  background: var(--surface);
}
.bubble-kid {
  margin-left: auto;
  background: var(--sky-soft);
  border-bottom-right-radius: 4px;
}
.bubble-ai {
  background: var(--surface);
  border-bottom-left-radius: 4px;
}
.bubble-name {
  display: inline-block;
  margin-right: 8px;
  padding: 1px 8px;
  font-size: 12px;
  font-weight: 700;
  color: var(--ink);
  background: var(--sun-soft);
  border-radius: 4px;
  vertical-align: 1px;
}
.bubble-result {
  max-width: 100%;
  margin-top: 20px;
  border-style: dashed;
  background: var(--leaf-soft);
  border-bottom-left-radius: 16px;
}
#panel-replace .bubble-result { background: var(--coral-soft); }

.demo-verdict {
  margin-top: 22px;
  padding: 12px 18px;
  font-size: 15px;
  font-weight: 700;
  text-align: center;
  border-radius: 999px;
}
.verdict-bad {
  color: #A13A56;
  background: var(--coral-soft);
}
.verdict-good {
  color: #1F6B48;
  background: var(--leaf-soft);
}

/* 对比小剧场入场动画 */
.demo-panel.is-active .bubble {
  opacity: 0;
  transform: translateY(10px);
  animation: bubbleIn 0.45s ease forwards;
}
.demo-panel.is-active .bubble[data-step="1"] { animation-delay: 0.05s; }
.demo-panel.is-active .bubble[data-step="2"] { animation-delay: 0.45s; }
.demo-panel.is-active .bubble[data-step="3"] { animation-delay: 0.95s; }
.demo-panel.is-active .bubble[data-step="4"] { animation-delay: 1.45s; }
.demo-panel.is-active .bubble[data-step="5"] { animation-delay: 1.95s; }
.demo-panel.is-active .bubble[data-step="6"] { animation-delay: 2.45s; }
.demo-panel.is-active .bubble[data-step="7"] { animation-delay: 2.95s; }

@keyframes bubbleIn {
  to { opacity: 1; transform: translateY(0); }
}

@media (prefers-reduced-motion: reduce) {
  .demo-panel.is-active .bubble { animation: none; opacity: 1; transform: none; }
  .star-float { animation: none; }
  html { scroll-behavior: auto; }
}

.idea-principles {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 28px;
  margin-top: 56px;
}
.principle {
  padding-top: 22px;
  border-top: 3px solid var(--ink);
}
.principle-num {
  display: block;
  font-family: var(--font-display);
  font-size: 28px;
  color: var(--coral);
  letter-spacing: 0.05em;
}
.principle h3 {
  margin: 8px 0 10px;
  font-family: var(--font-display);
  font-size: 22px;
}
.principle p {
  font-size: 15px;
  color: var(--ink-soft);
}

/* ---------- Platform 平台模块 ---------- */
.platform { background: var(--paper-deep); }

.platform-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
}

.platform-card {
  background: var(--surface);
  border: 2px solid var(--ink);
  border-radius: var(--radius-md);
  padding: 26px 24px 28px;
  box-shadow: 7px 8px 0 rgba(34, 55, 107, 0.1);
}
.card-student { box-shadow: 7px 8px 0 var(--sky-soft); }
.card-teacher { box-shadow: 7px 8px 0 var(--coral-soft); }
.card-research { box-shadow: 7px 8px 0 var(--sun-soft); }

.platform-badge {
  display: inline-block;
  margin-bottom: 18px;
  padding: 6px 14px;
  font-family: var(--font-display);
  font-size: 18px;
  letter-spacing: 0.04em;
  border: 2px solid var(--ink);
  border-radius: 999px;
}
.card-student .platform-badge { background: var(--sky-soft); }
.card-teacher .platform-badge { background: var(--coral-soft); }
.card-research .platform-badge { background: var(--sun-soft); }

.platform-mock {
  border: 2px solid var(--ink);
  border-radius: var(--radius-sm);
  overflow: hidden;
  background: var(--paper);
  margin-bottom: 20px;
}
.mock-bar {
  display: flex;
  gap: 6px;
  padding: 8px 10px;
  background: var(--ink);
}
.mock-bar i {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.45);
}
.mock-body { padding: 16px 14px 18px; }

.mock-bubble-line {
  height: 12px;
  margin-bottom: 10px;
  border-radius: 6px;
  background: var(--sky-soft);
  border: 1.5px solid var(--ink);
}
.mock-bubble-line.w70 { width: 70%; }
.mock-bubble-line.w50 { width: 50%; }
.mock-bubble-line.w80 { width: 80%; }
.mock-bubble-line.me { margin-left: auto; background: var(--coral-soft); }

.mock-sketch {
  margin-top: 12px;
  padding: 8px;
  background: var(--surface);
  border: 1.5px dashed var(--ink);
  border-radius: var(--radius-sm);
}
.mock-sketch svg { width: 100%; height: 54px; }

.mock-row { display: flex; gap: 8px; margin-bottom: 12px; }
.mock-chip {
  padding: 4px 10px;
  font-size: 11px;
  font-weight: 700;
  color: var(--ink);
  background: var(--sun-soft);
  border: 1.5px solid var(--ink);
  border-radius: 999px;
}
.mock-list-line {
  height: 10px;
  margin-bottom: 8px;
  border-radius: 5px;
  background: var(--line);
}
.mock-list-line.short { width: 62%; }

.mock-chart {
  display: flex;
  align-items: flex-end;
  gap: 10px;
  height: 62px;
  margin-bottom: 12px;
}
.mock-chart span {
  flex: 1;
  background: var(--leaf);
  border: 1.5px solid var(--ink);
  border-radius: 5px 5px 0 0;
}
.mock-chart span:nth-child(2) { background: var(--sun); }
.mock-chart span:nth-child(3) { background: var(--sky); }
.mock-chart span:nth-child(4) { background: var(--coral); }

.feature-list li {
  position: relative;
  padding: 7px 0 7px 26px;
  font-size: 15px;
  color: var(--ink);
  border-bottom: 1px dashed var(--line);
}
.feature-list li:last-child { border-bottom: none; }
.feature-list li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 15px;
  width: 10px;
  height: 10px;
  border: 2px solid var(--ink);
  background: var(--sun);
  transform: rotate(45deg);
}

.platform-note {
  margin-top: 36px;
  padding: 22px 26px;
  font-size: 15.5px;
  color: var(--ink);
  background: var(--surface);
  border-left: 5px solid var(--sun);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

/* ---------- Flow 教学流程 ---------- */
.flow { background: var(--surface); }

.flow-track {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 20px;
  counter-reset: step;
  position: relative;
}
.flow-track::before {
  content: "";
  position: absolute;
  top: 46px;
  left: 8%;
  right: 8%;
  height: 3px;
  background: repeating-linear-gradient(
    90deg,
    var(--ink) 0 10px,
    transparent 10px 18px
  );
  opacity: 0.35;
}

.flow-step {
  position: relative;
  background: var(--paper);
  border: 2px solid var(--ink);
  border-radius: var(--radius-md);
  padding: 26px 22px 24px;
  text-align: center;
}
.flow-node {
  width: 64px;
  height: 64px;
  margin: -52px auto 16px;
  background: var(--surface);
  border-radius: 50%;
}
.flow-node svg { width: 100%; height: 100%; }

.flow-step h3 {
  font-family: var(--font-display);
  font-size: 22px;
  letter-spacing: 0.03em;
  margin-bottom: 10px;
}
.flow-step p {
  font-size: 14.5px;
  color: var(--ink-soft);
  line-height: 1.8;
  text-align: left;
}
.flow-role {
  display: inline-block;
  margin-top: 16px;
  padding: 5px 12px;
  font-size: 12.5px;
  font-weight: 700;
  color: var(--ink);
  background: var(--sun-soft);
  border-radius: 999px;
}

/* ---------- Research 研究方案 ---------- */
.research { background: var(--paper); }

.conditions {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 22px;
  margin-bottom: 48px;
}
.condition {
  padding: 28px 24px;
  background: var(--surface);
  border: 2px solid var(--ink);
  border-radius: var(--radius-md);
}
.condition.is-focus {
  background: var(--sun-soft);
  box-shadow: 7px 8px 0 var(--sun);
}
.condition-tag {
  display: inline-block;
  margin-bottom: 14px;
  padding: 4px 12px;
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.06em;
  border-radius: 4px;
  border: 2px solid var(--ink);
}
.tag-a { background: var(--sky-soft); }
.tag-b { background: var(--coral-soft); }
.tag-c { background: var(--leaf); }
.condition h3 {
  font-family: var(--font-display);
  font-size: 21px;
  margin-bottom: 10px;
}
.condition p {
  font-size: 15px;
  color: var(--ink-soft);
}

.research-lower {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.1fr);
  gap: 28px;
}

.eval-block,
.method-block {
  padding: 30px 28px;
  background: var(--surface);
  border: 2px solid var(--ink);
  border-radius: var(--radius-md);
}
.block-title {
  font-family: var(--font-display);
  font-size: 22px;
  margin-bottom: 18px;
  padding-bottom: 12px;
  border-bottom: 2px dashed var(--line);
}

.eval-list li {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 11px 0;
  border-bottom: 1px dashed var(--line);
}
.eval-list li:last-child { border-bottom: none; }
.eval-list strong {
  flex-shrink: 0;
  min-width: 5.5em;
  color: var(--ink);
}
.eval-list span {
  font-size: 14.5px;
  color: var(--ink-soft);
}

.method-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 18px;
}
.method-tags span {
  padding: 7px 15px;
  font-size: 14px;
  font-weight: 500;
  background: var(--paper-deep);
  border: 1.5px solid var(--ink);
  border-radius: 999px;
}
.method-note {
  font-size: 15px;
  color: var(--ink-soft);
}

/* ---------- Innovation 创新点 ---------- */
.innovation { background: var(--paper-deep); }

.innov-list {
  display: grid;
  gap: 18px;
  max-width: 860px;
}
.innov-item {
  display: flex;
  gap: 22px;
  align-items: flex-start;
  padding: 26px 28px;
  background: var(--surface);
  border: 2px solid var(--ink);
  border-radius: var(--radius-md);
}
.innov-index {
  flex-shrink: 0;
  width: 52px;
  height: 52px;
  display: grid;
  place-items: center;
  font-family: var(--font-display);
  font-size: 26px;
  color: var(--ink);
  background: var(--sun);
  border: 2.5px solid var(--ink);
  border-radius: 50%;
}
.innov-item:nth-child(2) .innov-index { background: var(--coral-soft); }
.innov-item:nth-child(3) .innov-index { background: var(--sky-soft); }
.innov-item h3 {
  font-family: var(--font-display);
  font-size: 22px;
  margin-bottom: 8px;
}
.innov-item p {
  font-size: 15.5px;
  color: var(--ink-soft);
}

/* ---------- Outcomes 预期成果 ---------- */
.outcomes { background: var(--surface); }

.outcome-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 22px;
}
.outcome-card {
  padding: 26px 24px;
  background: var(--paper);
  border: 2px solid var(--ink);
  border-radius: var(--radius-md);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.outcome-card:hover {
  transform: translateY(-4px);
  box-shadow: 6px 8px 0 var(--sun-soft);
}
.outcome-icon {
  display: inline-flex;
  width: 44px;
  height: 44px;
  margin-bottom: 14px;
}
.outcome-icon svg { width: 100%; height: 100%; }
.outcome-card h3 {
  font-family: var(--font-display);
  font-size: 19px;
  margin-bottom: 10px;
}
.outcome-card p {
  font-size: 14.5px;
  color: var(--ink-soft);
}

/* ---------- Closing ---------- */
.closing {
  background: var(--ink);
  color: var(--surface);
  padding: 88px 0;
}
.closing-inner { text-align: center; }
.closing-brush {
  width: min(420px, 70%);
  margin: 0 auto 28px;
}
.closing-claim {
  font-family: var(--font-display);
  font-size: clamp(26px, 3.6vw, 42px);
  line-height: 1.55;
  letter-spacing: 0.03em;
}
.closing-sub {
  margin-top: 20px;
  font-size: 16px;
  color: rgba(255, 255, 255, 0.72);
}
.closing-cta { margin-top: 30px; }
.btn-sun {
  background: var(--sun);
  color: var(--ink);
}
.btn-sun:hover { background: var(--sun-soft); }

/* ---------- Footer ---------- */
.site-footer {
  background: var(--ink);
  color: rgba(255, 255, 255, 0.72);
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  padding: 26px 0 34px;
}
.footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.footer-brand { display: flex; align-items: baseline; gap: 12px; }
.footer-brand .brand-text { color: var(--surface); font-size: 20px; }
.footer-tag { font-size: 13px; }
.footer-note { font-size: 13px; }

/* ---------- 滚动入场 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .hero-inner { grid-template-columns: 1fr; gap: 40px; }
  .hero-art { max-width: 560px; margin-inline: auto; }
  .flow-track { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 48px 20px; }
  .flow-track::before { display: none; }
  .outcome-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 860px) {
  .nav-toggle { display: inline-grid; }
  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    padding: 12px 24px 20px;
    background: var(--paper);
    border-bottom: 2px solid var(--ink);
    box-shadow: var(--shadow);
  }
  .site-nav.is-open { display: flex; }
  .site-nav a { padding: 12px 14px; border-radius: var(--radius-sm); }

  .why-grid,
  .idea-principles,
  .platform-grid,
  .conditions,
  .research-lower { grid-template-columns: 1fr; }

  .bubble { max-width: 92%; }
  .demo-panel { padding: 24px 18px 22px; }
  .demo-tabs { flex-direction: column; }
}

@media (max-width: 620px) {
  .container { width: min(var(--container), 100% - 32px); }
  .section { padding: 68px 0; }
  .hero { padding: 48px 0 24px; }
  .hero-name { text-shadow: 3px 3px 0 var(--sun-soft); }
  .hero-actions .btn { width: 100%; }
  .sticker-1 { width: 72px; height: 72px; font-size: 12px; top: -12px; left: -8px; }
  .sticker-2 { width: 78px; height: 78px; font-size: 12px; right: -6px; }
  .flow-track { grid-template-columns: 1fr; gap: 44px; }
  .outcome-grid { grid-template-columns: 1fr; }
  .innov-item { flex-direction: column; gap: 14px; }
  .footer-inner { flex-direction: column; align-items: flex-start; }
}

/* ============================================================
   美化层 · 纸纹 / 笔触 / 动效
   ============================================================ */

/* 纸纹肌理（feTurbulence 内联，无外部资源） */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 200;
  pointer-events: none;
  opacity: 0.045;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='260' height='260'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='260' height='260' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* 标题笔刷下划线 · 自绘 */
.hero-name { position: relative; display: inline-block; }
.brush-underline {
  position: absolute;
  left: 2%;
  bottom: -10px;
  width: 96%;
  height: 22px;
  overflow: visible;
}
.brush-path {
  stroke-dasharray: 320;
  stroke-dashoffset: 320;
  animation: brushDraw 1.1s cubic-bezier(0.5, 0, 0.2, 1) 0.5s forwards;
}
.closing-brush .brush-path {
  stroke-dasharray: 620;
  stroke-dashoffset: 620;
  animation: none;
}
.closing-brush.is-drawn .brush-path {
  animation: brushDraw 1.2s cubic-bezier(0.5, 0, 0.2, 1) 0.15s forwards;
}
@keyframes brushDraw {
  to { stroke-dashoffset: 0; }
}

/* 跑马灯字带 */
.marquee {
  overflow: hidden;
  background: var(--ink);
  color: var(--sun);
  padding: 18px 0;
  border-top: 3px solid var(--ink);
  border-bottom: 3px solid var(--ink);
}
.marquee-track {
  display: flex;
  width: max-content;
  animation: marqueeScroll 26s linear infinite;
}
.marquee-track span {
  display: inline-flex;
  align-items: center;
  gap: 26px;
  padding-right: 26px;
  font-family: var(--font-display);
  font-size: 22px;
  letter-spacing: 0.12em;
  white-space: nowrap;
}
.marquee-track i {
  font-style: normal;
  color: var(--coral);
  font-size: 16px;
}
@keyframes marqueeScroll {
  to { transform: translateX(-50%); }
}

/* 颜料笔触分节带 */
.brush-divider {
  line-height: 0;
  background: var(--surface);
  margin-bottom: -1px;
}
.brush-divider svg {
  display: block;
  width: 100%;
  height: 72px;
}

/* 光标颜料拖尾 */
.trail-dot {
  position: fixed;
  z-index: 150;
  width: 12px;
  height: 12px;
  border-radius: 50% 46% 52% 48%;
  pointer-events: none;
  opacity: 0.75;
  animation: trailFade 0.7s ease-out forwards;
}
@keyframes trailFade {
  0% { transform: scale(1) rotate(0deg); opacity: 0.75; }
  100% { transform: scale(0.2) rotate(40deg); opacity: 0; }
}

/* 贴纸微摆动 */
.hero-sticker { transition: transform 0.35s cubic-bezier(0.34, 1.56, 0.64, 1); }
.sticker-1:hover { transform: rotate(-2deg) scale(1.08); }
.sticker-2:hover { transform: rotate(14deg) scale(1.08); }

/* 按钮颜料感 hover */
.btn { position: relative; overflow: hidden; }
.btn-primary::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at var(--mx, 50%) var(--my, 50%), rgba(255, 197, 49, 0.45), transparent 55%);
  opacity: 0;
  transition: opacity 0.25s ease;
}
.btn-primary:hover::after { opacity: 1; }

/* 卡片 hover 微倾（平台/成果卡） */
.platform-card, .outcome-card {
  transition: transform 0.28s cubic-bezier(0.34, 1.4, 0.64, 1), box-shadow 0.28s ease;
}
.platform-card:hover { transform: translateY(-6px) rotate(-0.6deg); }
.outcome-card:hover { transform: translateY(-5px) rotate(0.6deg); }

/* 入场错落 */
.why-grid .reveal:nth-child(2),
.platform-grid .reveal:nth-child(2),
.outcome-grid .reveal:nth-child(2),
.conditions .reveal:nth-child(2),
.flow-track .reveal:nth-child(2) { transition-delay: 0.12s; }
.why-grid .reveal:nth-child(3),
.platform-grid .reveal:nth-child(3),
.outcome-grid .reveal:nth-child(3),
.conditions .reveal:nth-child(3),
.flow-track .reveal:nth-child(3) { transition-delay: 0.24s; }
.outcome-grid .reveal:nth-child(4) { transition-delay: 0.1s; }
.outcome-grid .reveal:nth-child(5) { transition-delay: 0.2s; }
.outcome-grid .reveal:nth-child(6) { transition-delay: 0.3s; }

/* AI 气泡思考点 */
.bubble-ai .typing {
  display: inline-flex;
  gap: 4px;
  margin-left: 8px;
  vertical-align: middle;
}
.bubble-ai .typing i {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--ink-soft);
  animation: typingBounce 1s ease-in-out infinite;
}
.bubble-ai .typing i:nth-child(2) { animation-delay: 0.15s; }
.bubble-ai .typing i:nth-child(3) { animation-delay: 0.3s; }
@keyframes typingBounce {
  0%, 60%, 100% { transform: translateY(0); opacity: 0.45; }
  30% { transform: translateY(-4px); opacity: 1; }
}

/* verdict 弹性入场 */
.demo-panel.is-active .demo-verdict {
  animation: verdictPop 0.55s cubic-bezier(0.34, 1.56, 0.64, 1) 3.2s backwards;
}
@keyframes verdictPop {
  from { transform: scale(0.86); opacity: 0; }
  to { transform: scale(1); opacity: 1; }
}

@media (prefers-reduced-motion: reduce) {
  .brush-path { animation: none; stroke-dashoffset: 0; }
  .marquee-track { animation: none; }
  .trail-dot { display: none; }
  .demo-panel.is-active .demo-verdict { animation: none; }
  .bubble-ai .typing i { animation: none; }
  body::before { display: none; }
}

/* ============================================================
   特效层 · 颜料流体 / 溅射 / 动态排印
   ============================================================ */

/* 滚动颜料进度条 */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  z-index: 300;
  pointer-events: none;
  background: transparent;
}
.scroll-progress i {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--sun), var(--coral), var(--sky), var(--leaf));
  border-radius: 0 3px 3px 0;
  transition: width 0.08s linear;
}

/* Hero 颜料流体背景 */
.hero-paint {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
}
.hero-blobs { z-index: 0; }
.hero-inner { z-index: 1; }
.hero-wave { position: relative; z-index: 2; }

/* 标题逐字浮现 */
.hero-name .k-char {
  display: inline-block;
  opacity: 0;
  transform: translateY(0.5em) rotate(4deg);
  animation: charPop 0.62s cubic-bezier(0.34, 1.56, 0.64, 1) forwards;
}
@keyframes charPop {
  to { opacity: 1; transform: none; }
}

/* 卡片光泽扫过 */
.shine {
  position: relative;
  overflow: hidden;
}
.shine::after {
  content: "";
  position: absolute;
  top: -60%;
  left: -80%;
  width: 45%;
  height: 220%;
  background: linear-gradient(
    100deg,
    transparent,
    rgba(255, 255, 255, 0.55),
    transparent
  );
  transform: skewX(-18deg);
  transition: left 0.55s ease;
  pointer-events: none;
}
.shine:hover::after { left: 130%; }

/* 点击颜料溅射 */
.splash-dot {
  position: fixed;
  z-index: 250;
  width: 10px;
  height: 10px;
  border-radius: 52% 48% 55% 45%;
  pointer-events: none;
  animation: splashFly 0.62s cubic-bezier(0.2, 0.7, 0.3, 1) forwards;
}
@keyframes splashFly {
  0% { transform: translate(0, 0) scale(1); opacity: 0.95; }
  100% { transform: translate(var(--dx), var(--dy)) scale(0.15) rotate(60deg); opacity: 0; }
}

/* 磁吸按钮 */
.btn { transition: transform 0.22s cubic-bezier(0.34, 1.4, 0.64, 1), box-shadow 0.22s ease, background 0.22s ease; }

@media (prefers-reduced-motion: reduce) {
  .scroll-progress i { transition: none; }
  .hero-name .k-char { animation: none; opacity: 1; transform: none; }
  .shine::after { display: none; }
  .splash-dot { display: none; }
}