/* ============================================================
   荷聚云 AI 实训平台官网 — 设计系统（浅色现代简约风）
   ============================================================ */

/* ---------- 设计令牌 ---------- */
:root {
  /* 色彩 */
  --bg: #ffffff;
  --bg-tint: #f6f8f7;
  --bg-mint: #ecfdf5;
  --text: #0f1f16;
  --text-2: #51635a;
  --text-3: #7d8f85;
  --border: #e3ece7;
  --border-strong: #cfe0d6;
  --brand: #10b981;
  --brand-deep: #059669;
  --brand-dark: #047857;
  --brand-ring: rgba(16, 185, 129, 0.16);
  --footer-bg: #0c1a13;
  --footer-text: #9fb3a8;

  /* 字阶 */
  --fs-hero: clamp(1.4rem, 2.8vw, 2.2rem);
  --fs-h1: clamp(2rem, 3.6vw, 2.75rem);
  --fs-h2: clamp(1.65rem, 3vw, 2.2rem);
  --fs-h3: 1.2rem;
  --fs-body: 1rem;
  --fs-lead: 1.1rem;
  --fs-small: 0.9rem;
  --fs-caption: 0.82rem;

  /* 间距 */
  --space-section: clamp(4.5rem, 9vw, 7rem);
  --radius-card: 16px;
  --radius-lg: 22px;
  --radius-pill: 999px;

  /* 阴影 */
  --shadow-sm: 0 1px 2px rgba(15, 31, 22, 0.05), 0 2px 8px rgba(15, 31, 22, 0.04);
  --shadow-md: 0 4px 12px rgba(15, 31, 22, 0.06), 0 12px 32px rgba(15, 31, 22, 0.08);
  --shadow-lg: 0 8px 24px rgba(15, 31, 22, 0.08), 0 24px 64px rgba(15, 31, 22, 0.12);

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

/* ---------- 基础 ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: var(--fs-body);
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

::selection { background: var(--brand); color: #fff; }

:focus-visible {
  outline: 2px solid var(--brand);
  outline-offset: 2px;
  border-radius: 4px;
}

.container {
  width: 100%;
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- 通用文字 ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  background: var(--bg-mint);
  border: 1px solid #c9eedd;
  color: var(--brand-dark);
  font-size: var(--fs-caption);
  font-weight: 600;
  letter-spacing: 0.06em;
}

.text-gradient {
  background: linear-gradient(115deg, var(--brand) 10%, var(--brand-dark) 90%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.section { padding: var(--space-section) 0; }
.section--tint { background: var(--bg-tint); }

.section-head {
  max-width: 640px;
  margin: 0 auto clamp(2.5rem, 5vw, 4rem);
  text-align: center;
}
.section-head .eyebrow { margin-bottom: 18px; }
.section-head h2 {
  font-size: var(--fs-h2);
  font-weight: 800;
  letter-spacing: -0.01em;
  line-height: 1.25;
  margin-bottom: 14px;
}
.section-head p {
  color: var(--text-2);
  font-size: var(--fs-lead);
  line-height: 1.7;
}
.section-note {
  font-size: var(--fs-caption);
  color: var(--text-3);
  text-align: right;
  margin-top: 18px;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 22px;
  border-radius: var(--radius-pill);
  font-size: 0.95rem;
  font-weight: 600;
  line-height: 1.2;
  border: 1px solid transparent;
  transition: transform 0.25s var(--ease), box-shadow 0.25s var(--ease),
    background 0.25s var(--ease), border-color 0.25s var(--ease), color 0.25s var(--ease);
  white-space: nowrap;
}
.btn svg { width: 15px; height: 15px; flex: none; }

.btn--primary {
  background: linear-gradient(120deg, var(--brand) 0%, var(--brand-deep) 100%);
  color: #fff;
  box-shadow: 0 6px 16px rgba(16, 185, 129, 0.32);
}
.btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 24px rgba(16, 185, 129, 0.42);
}

.btn--ghost {
  background: #fff;
  border-color: var(--border-strong);
  color: var(--text);
}
.btn--ghost:hover {
  border-color: var(--brand);
  color: var(--brand-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.btn--white {
  background: #fff;
  color: var(--brand-dark);
  box-shadow: 0 8px 20px rgba(6, 40, 26, 0.22);
}
.btn--white:hover { transform: translateY(-2px); box-shadow: 0 12px 28px rgba(6, 40, 26, 0.3); }

.btn--lg { padding: 13px 30px; font-size: 1rem; }

.btn--outline {
  background: transparent;
  border-color: var(--brand);
  color: var(--brand-dark);
}
.btn--outline:hover {
  background: var(--bg-mint);
  transform: translateY(-2px);
}
.btn--sm { padding: 9px 18px; font-size: 0.9rem; }

/* ============================================================
   Header / 导航（js/nav.js 渲染）
   ============================================================ */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.82);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s, box-shadow 0.3s, background 0.3s;
}
.site-header.is-scrolled {
  border-bottom-color: var(--border);
  box-shadow: 0 2px 16px rgba(15, 31, 22, 0.05);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  height: 72px;
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 1.12rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  flex: none;
}
.logo-icon { width: 34px; height: 34px; flex: none; }

.nav {
  display: flex;
  align-items: center;
  gap: 2px;
}

.nav-link,
.nav-dropdown-trigger {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 9px 14px;
  border-radius: 10px;
  font-size: 0.95rem;
  color: var(--text-2);
  transition: color 0.2s, background 0.2s;
}
.nav-link:hover,
.nav-dropdown-trigger:hover { color: var(--text); background: var(--bg-tint); }
.nav-link.is-active,
.nav-item--dropdown.is-active > .nav-dropdown-trigger {
  color: var(--brand-dark);
  font-weight: 600;
}

.nav-chevron {
  width: 10px; height: 10px;
  transition: transform 0.25s var(--ease);
}
.nav-item--dropdown.is-open .nav-chevron { transform: rotate(180deg); }

.nav-item--dropdown {
  position: relative;
  display: inline-flex;
  align-items: center;
  border-radius: 10px;
}

/* 父级同时是链接时：文字链接 + 箭头按钮 */
.nav-item--dropdown.has-main-link .nav-dropdown-main {
  padding-right: 5px;
  border-top-right-radius: 0;
  border-bottom-right-radius: 0;
}
.nav-item--dropdown.has-main-link .nav-dropdown-trigger {
  padding-left: 5px;
  border-top-left-radius: 0;
  border-bottom-left-radius: 0;
}
.nav-item--dropdown.has-main-link:hover .nav-dropdown-main,
.nav-item--dropdown.has-main-link:hover .nav-dropdown-trigger,
.nav-item--dropdown.has-main-link.is-active .nav-dropdown-main,
.nav-item--dropdown.has-main-link.is-active .nav-dropdown-trigger {
  color: var(--brand-dark);
  font-weight: 600;
  background: var(--bg-tint);
}

.nav-dropdown {
  position: absolute;
  top: calc(100% + 10px);
  left: 50%;
  transform: translateX(-50%) translateY(6px);
  min-width: 264px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 14px;
  box-shadow: var(--shadow-lg);
  padding: 8px;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.22s var(--ease), transform 0.22s var(--ease), visibility 0.22s;
  z-index: 120;
}
.nav-item--dropdown.is-open .nav-dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

.nav-dropdown a {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 10px 12px;
  border-radius: 10px;
  transition: background 0.18s;
}
.nav-dropdown a:hover { background: var(--bg-tint); }
.nav-dropdown a.is-active { background: var(--bg-mint); }
.nav-dropdown-label { font-size: 0.95rem; font-weight: 600; color: var(--text); }

/* 桌面端鼠标悬停展开下拉 */
@media (hover: hover) and (min-width: 641px) {
  .nav-item--dropdown::before {
    content: '';
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    height: 12px;
  }
  .nav-item--dropdown:hover .nav-dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
  }
  .nav-item--dropdown:hover .nav-chevron { transform: rotate(180deg); }
}

.header-cta { flex: none; margin-left: 8px; }
.header-cta--secondary { margin-left: 0; }
/* 容器 1180px，视口收窄到 1200px 以下时空间不足，仅保留「预约演示」 */
@media (max-width: 1200px) { .header-cta--secondary { display: none; } }

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 42px;
  height: 42px;
  padding: 10px;
  border-radius: 10px;
}
.nav-toggle:hover { background: var(--bg-tint); }
.nav-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  border-radius: 2px;
  background: var(--text);
  transition: transform 0.3s var(--ease), opacity 0.2s;
}
.nav-toggle.is-open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.is-open span:nth-child(2) { opacity: 0; }
.nav-toggle.is-open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ============================================================
   Hero（首页）
   ============================================================ */
.hero {
  position: relative;
  padding: calc(72px + clamp(2.5rem, 6vw, 4.5rem)) 0 clamp(3.5rem, 7vw, 5.5rem);
  background:
    radial-gradient(720px 420px at 88% -8%, rgba(16, 185, 129, 0.09), transparent 65%),
    radial-gradient(560px 380px at -6% 12%, rgba(5, 150, 105, 0.06), transparent 60%),
    var(--bg);
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: clamp(2rem, 4.5vw, 4rem);
  align-items: center;
}

.hero-eyebrow { margin-bottom: 16px; }

.hero-title {
  font-size: var(--fs-hero);
  font-weight: 800;
  line-height: 1.25;
  letter-spacing: -0.02em;
  margin-bottom: 18px;
}

.hero-desc {
  font-size: var(--fs-lead);
  color: var(--text-2);
  line-height: 1.7;
  max-width: 480px;
  margin-bottom: 28px;
}

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

.hero-stats {
  display: flex;
  gap: clamp(1.5rem, 3.5vw, 2.8rem);
  margin-top: clamp(1.8rem, 3.5vw, 2.6rem);
  padding-top: 22px;
  border-top: 1px solid var(--border);
}
.stat-num {
  display: block;
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  line-height: 1.2;
}
.stat-label { font-size: var(--fs-small); color: var(--text-3); }

.hero-media { position: relative; }
.hero-media::before {
  content: "";
  position: absolute;
  inset: 8% -4% -4% 10%;
  border-radius: 28px;
  background: linear-gradient(135deg, rgba(16, 185, 129, 0.14), rgba(5, 150, 105, 0.05));
  transform: rotate(2.5deg);
  z-index: 0;
}
.hero-media img {
  position: relative;
  z-index: 1;
  width: 100%;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  border: 1px solid rgba(227, 236, 231, 0.9);
}

/* Hero 轮播（高级卡片堆叠 - 苹果/Tesla风格） */
.hero-carousel {
  position: relative;
  z-index: 1;
  aspect-ratio: 4 / 3;
  perspective: 1800px;
}

.hero-slides {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
}

.hero-slide {
  position: absolute;
  inset: 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  cursor: pointer;
  transition:
    transform 850ms cubic-bezier(0.22, 1, 0.36, 1),
    opacity 500ms ease,
    filter 700ms ease,
    box-shadow 850ms cubic-bezier(0.22, 1, 0.36, 1);
  will-change: transform, opacity;
}

/* 卡片层级与偏移 - 创建深度感 */
.hero-slide {
  z-index: 1;
  opacity: 0.85;
  transform: translateZ(-60px) translateY(16px) scale(0.92);
  box-shadow: 0 8px 32px rgba(15, 31, 22, 0.12), 0 2px 8px rgba(15, 31, 22, 0.06);
}

.hero-slide.pos-3 {
  z-index: 2;
  opacity: 0.9;
  transform: translateZ(-40px) translateY(10px) scale(0.95);
  box-shadow: 0 12px 40px rgba(15, 31, 22, 0.14), 0 4px 12px rgba(15, 31, 22, 0.08);
}

.hero-slide.pos-2 {
  z-index: 3;
  opacity: 0.95;
  transform: translateZ(-20px) translateY(5px) scale(0.975);
  box-shadow: 0 16px 48px rgba(15, 31, 22, 0.16), 0 6px 16px rgba(15, 31, 22, 0.1);
}

/* 顶层卡片 */
.hero-slide.pos-1 {
  z-index: 4;
  opacity: 1;
  transform: translateZ(0) translateY(0) scale(1);
  box-shadow: 0 24px 64px rgba(15, 31, 22, 0.2), 0 8px 24px rgba(15, 31, 22, 0.12);
}

/* 顶层卡片 hover - 微微上浮增强交互感 */
.hero-slide.pos-1:hover {
  transform: translateZ(30px) translateY(-8px) scale(1.02);
  box-shadow: 0 32px 80px rgba(15, 31, 22, 0.25), 0 12px 32px rgba(15, 31, 22, 0.15);
}

.hero-slide img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transform: scale(1.06);
  transition: transform 1400ms cubic-bezier(0.22, 1, 0.36, 1);
}

/* 顶层卡片图片缓慢回缩（Ken Burns 视差） */
.hero-slide.pos-1 img {
  transform: scale(1);
}

/* 堆叠中沉底、不可见的卡片 */
.hero-slide.is-docked {
  opacity: 0.7;
}

/* 切换时后方卡片从后到前错峰前移（级联波浪） */
.hero-slides.is-cascading .hero-slide.pos-2 {
  transition-delay: 70ms;
}

.hero-slides.is-cascading .hero-slide.pos-1 {
  transition-delay: 140ms;
}

/* 离场动画 - 顶层卡片向前浮起、放大并模糊渐隐 */
.hero-slide.is-leaving {
  z-index: 10;
  opacity: 0;
  filter: blur(14px) saturate(1.15);
  transform: translateZ(140px) translateY(-24px) scale(1.05);
  box-shadow: 0 48px 120px rgba(15, 31, 22, 0.28);
  pointer-events: none;
  transition:
    transform 750ms cubic-bezier(0.4, 0, 0.2, 1),
    opacity 600ms ease,
    filter 700ms ease,
    box-shadow 750ms ease;
  transition-delay: 0ms;
}

/* 底部导航点 */
.hero-dots {
  position: absolute;
  left: 50%;
  bottom: 14px;
  transform: translateX(-50%);
  z-index: 20;
  display: flex;
  gap: 8px;
  padding: 6px 10px;
  border-radius: 999px;
  background: rgba(15, 23, 20, 0.32);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.hero-dot {
  position: relative;
  overflow: hidden;
  width: 8px;
  height: 8px;
  padding: 0;
  border: none;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.4);
  cursor: pointer;
  transition:
    width 400ms cubic-bezier(0.22, 1, 0.36, 1),
    background-color 350ms ease,
    transform 350ms ease;
}

.hero-dot:hover {
  background: rgba(255, 255, 255, 0.7);
  transform: scale(1.1);
}

/* 当前点展开为进度胶囊，内部填充随轮播周期推进 */
.hero-dot.is-active {
  width: 28px;
  background: rgba(255, 255, 255, 0.3);
  box-shadow: 0 0 12px rgba(255, 255, 255, 0.35);
}

.hero-dot.is-active::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: #fff;
  transform: scaleX(0);
  transform-origin: left center;
  animation: dotProgress var(--dot-interval, 5000ms) linear forwards;
}

.hero-dots.is-paused .hero-dot.is-active::after {
  animation-play-state: paused;
}

@keyframes dotProgress {
  from { transform: scaleX(0); }
  to { transform: scaleX(1); }
}

/* 减弱动态偏好：降级为纯淡入淡出 */
@media (prefers-reduced-motion: reduce) {
  .hero-slide,
  .hero-slide img {
    transition: opacity 300ms ease;
  }

  .hero-slide.is-leaving {
    transform: none;
    filter: none;
  }

  .hero-dot.is-active::after {
    animation: none;
    transform: scaleX(1);
  }
}

/* 响应式适配 */
@media (max-width: 768px) {
  .hero-slide {
    transform: translateZ(-40px) translateY(10px) scale(0.9);
  }

  .hero-slide.pos-3 {
    transform: translateZ(-25px) translateY(6px) scale(0.93);
  }

  .hero-slide.pos-2 {
    transform: translateZ(-10px) translateY(3px) scale(0.97);
  }

  .hero-slide.pos-1 {
    transform: translateZ(0) translateY(0) scale(1);
  }

  .hero-slide.pos-1:hover {
    transform: translateZ(20px) translateY(-4px) scale(1.01);
  }

  .hero-dot.is-active {
    width: 20px;
  }
}

/* ============================================================
   教学闭环带
   ============================================================ */
.loop {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 16px;
  counter-reset: loop;
}
.loop-step {
  position: relative;
  text-align: center;
  padding: 26px 12px 22px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), border-color 0.3s;
}
.loop-step:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: #bfe8d4;
}
.loop-num {
  display: inline-grid;
  place-items: center;
  width: 44px;
  height: 44px;
  margin-bottom: 12px;
  border-radius: 50%;
  background: var(--bg-mint);
  border: 1px solid #c9eedd;
  color: var(--brand-dark);
  font-weight: 800;
  font-size: 1.02rem;
}
.loop-step h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: 6px; }
.loop-step p { font-size: var(--fs-small); color: var(--text-2); line-height: 1.6; }

/* ============================================================
   定制流程（横向时间线样式）
   ============================================================ */
.process-flow {
  display: flex;
  justify-content: center;
  gap: 0;
  padding: 20px 0;
}
.process-step {
  flex: 1;
  max-width: 220px;
  text-align: center;
  position: relative;
  padding: 0 20px;
}
.process-step:not(:last-child)::after {
  content: '';
  position: absolute;
  top: 28px;
  right: -10px;
  width: 20px;
  height: 2px;
  background: linear-gradient(90deg, var(--brand), var(--brand-light));
}
.process-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  margin-bottom: 16px;
  border-radius: 50%;
  background: #fff;
  color: var(--brand);
  font-weight: 800;
  font-size: 1.25rem;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.1);
  position: relative;
  z-index: 1;
  border: 2px solid var(--brand-light);
}
.process-step h4 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-1);
  margin-bottom: 8px;
}
.process-step p {
  font-size: var(--fs-small);
  color: var(--text-2);
  line-height: 1.6;
}

@media (max-width: 768px) {
  .process-flow {
    flex-direction: column;
    align-items: center;
    gap: 24px;
  }
  .process-step {
    max-width: 320px;
    padding: 0;
  }
  .process-step:not(:last-child)::after {
    display: none;
  }
  .process-step::before {
    content: '';
    position: absolute;
    left: 50%;
    bottom: -20px;
    transform: translateX(-50%);
    width: 2px;
    height: 24px;
    background: linear-gradient(180deg, var(--brand), var(--brand-light));
  }
  .process-step:last-child::before {
    display: none;
  }
}

/* ============================================================
   通用卡片
   ============================================================ */
.cards { display: grid; gap: 22px; }
.cards--2 { grid-template-columns: repeat(2, 1fr); }
.cards--3 { grid-template-columns: repeat(3, 1fr); }
.cards--4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  padding: 30px 28px;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), border-color 0.3s;
}
.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: #bfe8d4;
}
.card h3 { font-size: var(--fs-h3); font-weight: 700; margin: 20px 0 10px; }
.card p { color: var(--text-2); font-size: 0.96rem; line-height: 1.72; }

.icon-chip {
  display: grid;
  place-items: center;
  width: 50px;
  height: 50px;
  border-radius: 13px;
  background: var(--bg-mint);
  border: 1px solid #d3f0e2;
  color: var(--brand-deep);
}
.icon-chip svg { width: 26px; height: 26px; }
.icon-chip span { font-weight: 800; font-size: 1rem; color: var(--brand-dark); }

/* ---------- 角色价值卡 ---------- */
.role-card {
  background: var(--bg-tint);
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  padding: 32px 30px;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), background 0.3s;
}
.role-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); background: #fff; }
.role-card h3 {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: var(--fs-h3);
  font-weight: 700;
  margin-bottom: 12px;
}
.role-card h3::before {
  content: "";
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--brand);
  flex: none;
}
.role-card p { color: var(--text-2); font-size: 0.96rem; line-height: 1.72; }

/* ============================================================
   双引擎大卡（首页）
   ============================================================ */
.engine-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}
.engine-card {
  display: flex;
  flex-direction: column;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: transform 0.35s var(--ease), box-shadow 0.35s var(--ease), border-color 0.35s;
}
.engine-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: #bfe8d4;
}
.engine-card img {
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  background: var(--bg-tint);
}
.engine-card-body { padding: 26px 30px 30px; }
.engine-tag {
  display: inline-block;
  padding: 4px 12px;
  margin-bottom: 14px;
  border-radius: var(--radius-pill);
  background: var(--bg-mint);
  color: var(--brand-dark);
  font-size: var(--fs-caption);
  font-weight: 700;
  letter-spacing: 0.05em;
}
.engine-card-body h3 { font-size: 1.4rem; font-weight: 800; margin-bottom: 10px; letter-spacing: -0.01em; }
.engine-card-body p { color: var(--text-2); font-size: 0.97rem; line-height: 1.7; margin-bottom: 18px; }

.card-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--brand-dark);
  font-weight: 600;
  font-size: 0.96rem;
}
.card-link svg { width: 16px; height: 16px; transition: transform 0.25s var(--ease); }
.card-link:hover svg { transform: translateX(4px); }

/* 可点击卡片（solutions 交付模式等）：整体作为链接 */
a.card { display: block; height: 100%; color: inherit; text-decoration: none; }
a.card .card-link { margin-top: 14px; }

/* ============================================================
   合作伙伴卡片
   ============================================================ */
.partner-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 20px;
}
.partner-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  padding: 28px 20px 24px;
  text-align: center;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), border-color 0.3s;
}
.partner-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: #bfe8d4;
}
.partner-logo {
  width: 56px;
  height: 56px;
  border-radius: 14px;
  margin-bottom: 16px;
  background: var(--bg-tint);
  display: flex;
  align-items: center;
  justify-content: center;
}
.partner-logo img {
  width: 40px;
  height: 40px;
  object-fit: contain;
}

/* 特别鸣谢页 - 合作伙伴项 */
.partner-item {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  padding: 32px 24px;
  text-align: center;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), border-color 0.3s;
}
.partner-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: #bfe8d4;
}
.partner-item h4 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--text-1);
}
.partner-item .partner-logo {
  width: auto;
  height: auto;
  background: transparent;
  margin-bottom: 0;
}
.partner-item .partner-logo img {
  width: 160px;
  height: auto;
  max-height: 60px;
}
.partner-item .partner-logo--large img {
  width: auto;
  height: 70px;
}
.partner-grid--2col {
  grid-template-columns: repeat(2, 1fr);
  max-width: 700px;
  margin: 0 auto;
}

@media (max-width: 640px) {
  .partner-grid--2col {
    grid-template-columns: 1fr;
  }
}

/* ============================================================
   特别鸣谢页 - AI 服务提供商
   ============================================================ */
.ai-provider-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.ai-provider-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  padding: 32px 20px;
  text-align: center;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), border-color 0.3s;
}
.ai-provider-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: #bfe8d4;
}
.ai-provider-logo {
  width: 48px;
  height: 48px;
  margin-bottom: 12px;
}

/* 特别鸣谢页 - 技术卡片中的 logo */
.tech-logo {
  width: 48px;
  height: 48px;
  margin-bottom: 16px;
}
.ai-provider-name {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--text-1);
  margin-bottom: 4px;
}
.ai-provider-desc {
  font-size: var(--fs-caption);
  color: var(--text-3);
}

@media (max-width: 1024px) {
  .ai-provider-grid { grid-template-columns: repeat(3, 1fr); }
}
@media (max-width: 768px) {
  .ai-provider-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 480px) {
  .ai-provider-grid { grid-template-columns: 1fr; }
}

/* ============================================================
   特别鸣谢页 - 核心贡献者
   ============================================================ */
.contributor-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.contributor-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  padding: 32px 28px;
  text-align: center;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), border-color 0.3s;
}
.contributor-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: #bfe8d4;
}
.contributor-avatar {
  width: 100%;
  max-width: 160px;
  height: 200px;
  margin: 0 auto 20px;
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid var(--border);
  background: var(--bg-tint);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}
.contributor-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.contributor-name {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-1);
  margin-bottom: 8px;
}
.contributor-title {
  font-size: var(--fs-caption);
  color: var(--brand);
  font-weight: 600;
  margin-bottom: 12px;
}
.contributor-desc {
  font-size: var(--fs-small);
  color: var(--text-2);
  line-height: 1.7;
  text-align: left;
}

@media (max-width: 1024px) {
  .contributor-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 640px) {
  .contributor-grid { grid-template-columns: 1fr; }
}
.partner-info h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 6px;
}
.partner-info p {
  font-size: var(--fs-caption);
  color: var(--text-3);
}

@media (max-width: 1024px) {
  .partner-grid { grid-template-columns: repeat(3, 1fr); }
}
@media (max-width: 640px) {
  .partner-grid { grid-template-columns: repeat(2, 1fr); }
  .partner-card { padding: 20px 16px; }
}

/* ============================================================
   子页面 Hero（产品/方案/研究）
   ============================================================ */
.page-hero {
  padding: calc(72px + clamp(2.6rem, 6vw, 4.5rem)) 0 clamp(3.4rem, 7vw, 5.5rem);
  background:
    radial-gradient(640px 360px at 92% 0%, rgba(16, 185, 129, 0.08), transparent 62%),
    var(--bg);
}
.page-hero-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: clamp(2.4rem, 5vw, 4.2rem);
  align-items: center;
}
.kicker {
  display: block;
  font-size: var(--fs-caption);
  font-weight: 700;
  letter-spacing: 0.16em;
  color: var(--brand-dark);
  margin-bottom: 18px;
}
.page-hero h1 {
  font-size: var(--fs-h1);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -0.015em;
  margin-bottom: 20px;
}
.page-hero .lead {
  color: var(--text-2);
  font-size: var(--fs-lead);
  line-height: 1.75;
  max-width: 520px;
  margin-bottom: 32px;
}
.page-hero-media img {
  width: 100%;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-lg);
}

/* Hero 区 Lottie 动画（渐进增强：动画层覆盖在静态截图上） */
.hero-lottie {
  position: relative;
}
.hero-lottie-stage {
  position: absolute;
  inset: 0;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  background: #fbfffd;
  opacity: 0;
  transition: opacity 0.5s ease;
}
.hero-lottie--on .hero-lottie-stage {
  opacity: 1;
}
.hero-lottie-stage svg {
  display: block;
  width: 100%;
  height: 100%;
}

/* ============================================================
   步骤流（方案落地 / 工作流）
   ============================================================ */
.steps {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 18px;
  counter-reset: step;
}
.step {
  position: relative;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  padding: 26px 22px;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), border-color 0.3s;
}
.step:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: #bfe8d4; }
.step-num {
  display: block;
  font-size: 1.9rem;
  font-weight: 800;
  line-height: 1;
  margin-bottom: 14px;
  background: linear-gradient(120deg, var(--brand), var(--brand-dark));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.step h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: 8px; }
.step p { font-size: var(--fs-small); color: var(--text-2); line-height: 1.65; }

/* ============================================================
   对比表
   ============================================================ */
.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  background: #fff;
  box-shadow: var(--shadow-sm);
}
.compare-table {
  width: 100%;
  min-width: 620px;
  border-collapse: collapse;
}
.compare-table th {
  background: var(--bg-tint);
  text-align: left;
  font-size: var(--fs-small);
  font-weight: 700;
  color: var(--text-2);
  padding: 15px 22px;
  border-bottom: 1px solid var(--border);
}
.compare-table td {
  padding: 17px 22px;
  font-size: 0.96rem;
  color: var(--text);
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}
.compare-table tr:last-child td { border-bottom: none; }
.compare-table td:first-child { font-weight: 700; white-space: nowrap; }

/* ============================================================
   研究成果卡片（并排紧凑布局）
   ============================================================ */
.outcome-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  margin-bottom: var(--space-section);
}

.outcome-card {
  position: relative;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  padding: 28px 26px 24px;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), border-color 0.3s;
}
.outcome-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: #bfe8d4;
}

.outcome-icon {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--bg-mint);
  border: 1px solid #c9eedd;
  color: var(--brand-dark);
  font-weight: 800;
  font-size: 1.1rem;
  margin-bottom: 16px;
}

.outcome-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 12px;
  color: var(--text);
}

.outcome-card p {
  color: var(--text-2);
  font-size: 0.9rem;
  line-height: 1.7;
  margin-bottom: 18px;
}

.outcome-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--brand-dark);
  font-weight: 600;
  font-size: 0.88rem;
}
.outcome-link svg { transition: transform 0.2s; }
.outcome-card:hover .outcome-link svg { transform: translateX(3px); }

/* ============================================================
   研究方向（横向紧凑）
   ============================================================ */
.direction-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.direction-item {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 18px 20px;
  background: var(--bg-tint);
  border: 1px solid var(--border);
  border-radius: 12px;
  transition: background 0.25s, border-color 0.25s;
}
.direction-item:hover {
  background: var(--bg-mint);
  border-color: #c9eedd;
}

.direction-num {
  font-size: 1.4rem;
  font-weight: 800;
  background: linear-gradient(120deg, var(--brand), var(--brand-dark));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  flex: none;
}

.direction-item h4 {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text);
  line-height: 1.4;
}

/* ============================================================
   研究成果（学术报告风格）
   ============================================================ */
.research-paper {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin-bottom: 32px;
  transition: box-shadow 0.3s var(--ease), border-color 0.3s;
}
.research-paper:hover {
  box-shadow: var(--shadow-md);
  border-color: #bfe8d4;
}

.paper-header {
  padding: 28px 32px 24px;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(180deg, var(--bg-tint) 0%, var(--bg) 100%);
}

.paper-title {
  font-size: 1.35rem;
  font-weight: 800;
  line-height: 1.35;
  letter-spacing: -0.01em;
  margin-bottom: 14px;
  color: var(--text);
}

.paper-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.paper-tag {
  display: inline-flex;
  align-items: center;
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  background: var(--bg-mint);
  border: 1px solid #c9eedd;
  color: var(--brand-dark);
  font-size: var(--fs-caption);
  font-weight: 600;
}

.paper-body {
  padding: 28px 32px;
}

.paper-section {
  margin-bottom: 24px;
}
.paper-section:last-child { margin-bottom: 0; }

.paper-section h4 {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--brand-dark);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 10px;
  padding-bottom: 8px;
  border-bottom: 1px dashed var(--border);
}

.paper-section p {
  color: var(--text-2);
  font-size: 0.97rem;
  line-height: 1.8;
}

.paper-highlights {
  list-style: none;
  padding: 0;
  margin: 0;
}
.paper-highlights li {
  position: relative;
  padding-left: 28px;
  margin-bottom: 10px;
  color: var(--text-2);
  font-size: 0.97rem;
  line-height: 1.7;
}
.paper-highlights li:last-child { margin-bottom: 0; }
.paper-highlights li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--brand);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='none'%3E%3Cpath d='M4.5 8.5l2.3 2.3L11.5 6' stroke='white' stroke-width='1.8' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-size: 10px;
  background-position: center;
  background-repeat: no-repeat;
}

.paper-footer {
  padding: 20px 32px;
  border-top: 1px solid var(--border);
  background: var(--bg-tint);
  display: flex;
  justify-content: flex-end;
}

/* ============================================================
   合作案例（首页）
   ============================================================ */
.case-fact {
  max-width: 720px;
  margin: 0 auto;
  padding: clamp(26px, 3.5vw, 40px);
  text-align: center;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  transition: box-shadow 0.3s var(--ease), border-color 0.3s;
}
.case-fact:hover { box-shadow: var(--shadow-lg); border-color: #bfe8d4; }
.case-fact h3 {
  font-size: 1.3rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  margin-bottom: 10px;
}
.case-fact p {
  color: var(--text-2);
  font-size: 1rem;
  line-height: 1.7;
}
.case-more {
  margin-top: 26px;
  text-align: center;
  font-size: var(--fs-small);
  color: var(--text-3);
}

/* ============================================================
   CTA
   ============================================================ */
.cta-section { padding-bottom: var(--space-section); }
.cta-panel {
  position: relative;
  overflow: hidden;
  border-radius: 26px;
  padding: clamp(3rem, 7vw, 4.6rem) clamp(1.6rem, 5vw, 4rem);
  text-align: center;
  color: #fff;
  background: linear-gradient(130deg, #0aa06f 0%, #047857 55%, #065f46 100%);
  box-shadow: 0 24px 60px rgba(6, 78, 59, 0.32);
}
.cta-panel::before,
.cta-panel::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.09);
}
.cta-panel::before { width: 340px; height: 340px; top: -160px; right: -90px; }
.cta-panel::after { width: 260px; height: 260px; bottom: -140px; left: -70px; }
.cta-panel h2 {
  position: relative;
  font-size: var(--fs-h2);
  font-weight: 800;
  line-height: 1.3;
  letter-spacing: -0.01em;
  margin-bottom: 16px;
}
.cta-panel p {
  position: relative;
  color: rgba(255, 255, 255, 0.86);
  font-size: var(--fs-lead);
  max-width: 520px;
  margin: 0 auto 32px;
  line-height: 1.7;
}
.cta-panel .btn { position: relative; }

/* ============================================================
   下载页
   ============================================================ */
.download-hero {
  padding: calc(72px + clamp(2.6rem, 6vw, 4.5rem)) 0 var(--space-section);
  background:
    radial-gradient(680px 380px at 50% -10%, rgba(16, 185, 129, 0.08), transparent 62%),
    var(--bg);
}
.download-hero-head { max-width: 620px; margin: 0 auto clamp(2.6rem, 5vw, 4rem); text-align: center; }
.download-hero-head .eyebrow { margin-bottom: 18px; }
.download-hero-head h1 { font-size: var(--fs-h1); font-weight: 800; letter-spacing: -0.015em; margin-bottom: 14px; }
.download-hero-head p { color: var(--text-2); font-size: var(--fs-lead); }

.dl-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  align-items: stretch;
}
.dl-grid--2 { grid-template-columns: repeat(2, 1fr); max-width: 860px; margin: 0 auto; }
.dl-subhead { max-width: 640px; margin: clamp(3rem, 6vw, 4.5rem) auto clamp(2rem, 4vw, 3rem); text-align: center; }
.dl-subhead h2 { font-size: var(--fs-h2); font-weight: 800; letter-spacing: -0.01em; margin-bottom: 10px; }
.dl-subhead p { color: var(--text-2); font-size: var(--fs-lead); line-height: 1.7; }
.dl-card {
  display: flex;
  flex-direction: column;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 30px 28px;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), border-color 0.3s;
}
.dl-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: #bfe8d4; }

.dl-card-head { display: flex; align-items: center; gap: 16px; margin-bottom: 22px; }
.dl-card-title h2 { font-size: 1.25rem; font-weight: 800; }
.dl-card-title p { font-size: var(--fs-small); color: var(--text-3); margin-top: 2px; }

.qr-box {
  text-align: center;
  background: var(--bg-tint);
  border: 1px dashed var(--border-strong);
  border-radius: var(--radius-card);
  padding: 24px 18px;
  margin-bottom: 22px;
}
.qr-box img {
  width: 168px;
  height: 168px;
  margin: 0 auto 12px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: #fff;
  padding: 8px;
}
.qr-box strong { display: block; font-size: 0.98rem; margin-bottom: 4px; }
.qr-box span { font-size: var(--fs-caption); color: var(--text-3); }

.dl-actions { display: flex; flex-direction: column; gap: 12px; margin-bottom: 22px; }
.dl-btn {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 16px;
  border: 1px solid var(--border);
  border-radius: 13px;
  transition: border-color 0.25s, background 0.25s, transform 0.25s var(--ease), box-shadow 0.25s var(--ease);
}
a.dl-btn:hover {
  border-color: var(--brand);
  background: var(--bg-mint);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}
.dl-btn-icon { width: 30px; height: 30px; flex: none; color: var(--text-2); }
a.dl-btn:hover .dl-btn-icon { color: var(--brand-dark); }
.dl-btn-text { flex: 1; display: flex; flex-direction: column; }
.dl-btn-text strong { font-size: 0.98rem; }
.dl-btn-text small { font-size: var(--fs-caption); color: var(--text-3); }
.dl-btn-arrow { width: 18px; height: 18px; color: var(--text-3); flex: none; }
a.dl-btn:hover .dl-btn-arrow { color: var(--brand-dark); }
.dl-btn--disabled { opacity: 0.55; cursor: default; }

.dl-points { margin-top: auto; display: flex; flex-direction: column; gap: 9px; }
.dl-points li {
  position: relative;
  padding-left: 24px;
  font-size: var(--fs-small);
  color: var(--text-2);
  line-height: 1.55;
}
.dl-points li::before {
  content: "";
  position: absolute;
  left: 0; top: 3px;
  width: 15px; height: 15px;
  border-radius: 50%;
  background: var(--bg-mint) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='none'%3E%3Cpath d='M4.5 8.5l2.3 2.3L11.5 6' stroke='%23059669' stroke-width='1.8' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") center / 10px no-repeat;
  border: 1px solid #c9eedd;
}

.download-note {
  margin-top: 40px;
  text-align: center;
  font-size: var(--fs-small);
  color: var(--text-3);
}
.download-note a { color: var(--brand-dark); font-weight: 600; }
.download-note a:hover { text-decoration: underline; }

/* ============================================================
   Footer（js/nav.js 渲染）
   ============================================================ */
.site-footer {
  background: var(--footer-bg);
  color: var(--footer-text);
}
.footer-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 40px;
  padding: clamp(3rem, 6vw, 4.5rem) 0 2.6rem;
}
.footer-brand-col {
  grid-column: 1 / -1;
}
.footer-brand { display: flex; align-items: center; gap: 10px; color: #fff; font-weight: 800; font-size: 1.1rem; margin-bottom: 16px; }
.footer-desc { font-size: var(--fs-small); line-height: 1.75; max-width: 480px; }
.footer-col h4 {
  color: #fff;
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 18px;
}
.footer-col a {
  display: block;
  font-size: var(--fs-small);
  padding: 5px 0;
  transition: color 0.2s;
}
.footer-col a:hover { color: #fff; }
.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 22px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  font-size: var(--fs-caption);
  text-align: center;
}
.footer-bottom a {
  color: inherit;
  text-decoration: none;
  transition: color 0.2s;
}
.footer-bottom a:hover { color: #fff; }

/* ============================================================
   动效
   ============================================================ */
.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 0.75s var(--ease), transform 0.75s var(--ease);
}
.reveal.is-visible { opacity: 1; transform: none; }
.delay-1 { transition-delay: 0.1s; }
.delay-2 { transition-delay: 0.2s; }
.delay-3 { transition-delay: 0.3s; }
.delay-4 { transition-delay: 0.4s; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  .reveal { opacity: 1; transform: none; }
}

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 1024px) {
  .hero-grid,
  .page-hero-grid { grid-template-columns: 1fr; }
  .hero-media,
  .page-hero-media { max-width: 620px; }
  .cards--4 { grid-template-columns: repeat(2, 1fr); }
  .cards--3 { grid-template-columns: repeat(2, 1fr); }
  .loop { grid-template-columns: repeat(3, 1fr); }
  .steps { grid-template-columns: repeat(3, 1fr); }
  .engine-grid { grid-template-columns: 1fr; max-width: 640px; margin: 0 auto; }
  .dl-grid { grid-template-columns: 1fr; max-width: 560px; margin: 0 auto; }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
  .outcome-grid { grid-template-columns: 1fr; }
  .direction-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 640px) {
  .nav {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    z-index: 110;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    padding: 14px 20px 20px;
    background: #fff;
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-lg);
    display: none;
  }
  .nav.is-open { display: flex; }
  .nav-link, .nav-dropdown-trigger { padding: 12px 14px; font-size: 1rem; justify-content: space-between; }
  .nav-dropdown {
    position: static;
    transform: none;
    min-width: 0;
    box-shadow: none;
    border: none;
    border-left: 2px solid var(--border);
    border-radius: 0;
    margin: 2px 0 6px 14px;
    padding: 2px 0 2px 10px;
    display: none;
    opacity: 1;
    visibility: visible;
  }
  .nav-item--dropdown.is-open .nav-dropdown { display: block; transform: none; }
  .nav-toggle { display: flex; }
  .header-cta { display: none; }

  .cards--4, .cards--3, .cards--2 { grid-template-columns: 1fr; }
  .loop { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: 1fr; }
  .hero-stats { flex-wrap: wrap; gap: 20px 32px; }
  .footer-grid { grid-template-columns: 1fr; gap: 28px; }
  .footer-brand-col { grid-column: auto; }
  .footer-bottom { flex-direction: column; align-items: center; }
  .card, .role-card { padding: 24px 22px; }

  /* 研究成果响应式 */
  .outcome-grid { grid-template-columns: 1fr; gap: 16px; }
  .outcome-card { padding: 22px 20px; }
  .outcome-card h3 { font-size: 1rem; }
  .outcome-card p { font-size: 0.88rem; }
  .direction-grid { grid-template-columns: 1fr; }

  /* 学术报告样式响应式 */
  .paper-header { padding: 20px 20px 18px; }
  .paper-title { font-size: 1.15rem; }
  .paper-body { padding: 20px 20px; }
  .paper-footer { padding: 16px 20px; }
  .paper-footer .btn { width: 100%; justify-content: center; }
}

/* ============================================================
   开发者合作（首页）
   ============================================================ */
.dev-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 14px;
  margin-top: 36px;
}
.dev-note {
  margin-top: 18px;
  text-align: center;
  color: var(--text-2);
  font-size: 0.92rem;
  line-height: 1.7;
}
@media (max-width: 640px) {
  .dev-actions .btn { width: 100%; }
}