/* 学径 LearnPath · 官网首页样板 V2.0
   科技教育风：深蓝底 + 蓝紫渐变 + 明亮蓝点缀
   独立样板，所有资源走相对路径 assets/，不影响主站 */

:root {
  --bg: #070d1f;
  --bg2: #0a1226;
  --panel: rgba(255, 255, 255, .045);
  --panel-line: rgba(139, 156, 255, .16);
  --ink: #e8eefb;
  --ink-2: #9db0d4;
  --ink-3: #6c7fa3;
  --blue: #38bdf8;
  --blue-deep: #2563eb;
  --violet: #8b5cf6;
  --grad: linear-gradient(120deg, #38bdf8 0%, #6366f1 48%, #a855f7 100%);
  --radius: 16px;
  --max: 1180px;
  --shadow: 0 18px 48px rgba(2, 8, 26, .55);
}

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

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

body {
  font-family: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.7;
  overflow-x: hidden;
}

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

::selection { background: rgba(99, 102, 241, .45); }

/* ---------- 通用 ---------- */
.wrap { max-width: var(--max); margin: 0 auto; padding: 0 24px; }

section { position: relative; padding: 96px 0; }

.sec-tag {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 13px; letter-spacing: .18em; color: var(--blue);
  margin-bottom: 14px; font-weight: 600;
}
.sec-tag::before {
  content: ""; width: 26px; height: 1px;
  background: linear-gradient(90deg, transparent, var(--blue));
}

.sec-title {
  font-size: clamp(26px, 4vw, 38px); font-weight: 700;
  line-height: 1.35; margin-bottom: 14px;
}
.sec-title .hl {
  background: var(--grad);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
}
.sec-sub { color: var(--ink-2); font-size: 15.5px; max-width: 640px; }

.grad-text {
  background: var(--grad);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
}

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 13px 26px; border-radius: 999px; font-size: 15px; font-weight: 600;
  border: 1px solid transparent; cursor: pointer;
  transition: transform .25s ease, box-shadow .25s ease, background .25s ease;
}
.btn:hover { transform: translateY(-2px); }
.btn-primary {
  background: var(--grad); color: #fff;
  box-shadow: 0 8px 26px rgba(79, 70, 229, .42);
}
.btn-primary:hover { box-shadow: 0 12px 34px rgba(99, 102, 241, .55); }
.btn-ghost {
  border-color: var(--panel-line); color: var(--ink);
  background: rgba(255, 255, 255, .03);
}
.btn-ghost:hover { border-color: rgba(139, 156, 255, .45); background: rgba(255, 255, 255, .07); }

/* 滚动浮现动画（JS 加 .in 触发） */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity .7s ease, transform .7s ease; }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  * { animation-duration: .01ms !important; animation-iteration-count: 1 !important; }
}

/* ---------- 顶部导航 ---------- */
.site-header {
  position: fixed; inset: 0 0 auto 0; z-index: 90;
  background: rgba(7, 13, 31, .78);
  backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(139, 156, 255, .1);
}
.nav { display: flex; align-items: center; gap: 16px; height: 66px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; }
.brand-mark {
  width: 34px; height: 34px; border-radius: 10px; flex: none;
  background: var(--grad);
  display: grid; place-items: center;
  box-shadow: 0 4px 14px rgba(79, 70, 229, .5);
}
.brand-mark svg { width: 20px; height: 20px; }
.brand small { font-size: 11px; color: var(--ink-3); font-weight: 500; display: block; line-height: 1.2; }

.nav-links { display: flex; gap: 18px; margin-left: auto; font-size: 14px; }
.nav-links a { color: var(--ink-2); transition: color .2s; position: relative; padding: 6px 0; white-space: nowrap; }
.nav-links a:hover, .nav-links a:focus-visible { color: var(--ink); }
.nav-links a::after {
  content: ""; position: absolute; left: 0; bottom: 0; height: 2px; width: 0;
  background: var(--grad); border-radius: 2px; transition: width .25s ease;
}
.nav-links a:hover::after { width: 100%; }
.nav .btn { padding: 9px 14px; font-size: 13.5px; white-space: nowrap; }
.nav .nav-dl { padding: 9px 12px; margin-right: 6px; color: var(--ink-2); font-weight: 500; white-space: nowrap; }
.nav .nav-dl svg { width: 15px; height: 15px; color: var(--blue); flex: none; }
.nav .nav-dl:hover { color: var(--ink); }
/* 会员中心：金色胶囊，全顶栏唯一暖色，第一眼就能看到 */
.nav .nav-member {
  padding: 9px 14px; margin-right: 6px;
  background: linear-gradient(135deg, #ffd66b, #f0940f);
  color: #33210a; font-weight: 700; white-space: nowrap;
  box-shadow: 0 6px 20px rgba(240, 148, 15, .45);
}
.nav .nav-member svg { width: 15px; height: 15px; flex: none; }
.nav .nav-member:hover { box-shadow: 0 10px 28px rgba(240, 148, 15, .62); color: #33210a; }
/* 登录：全站登录总入口，放在会员中心左侧 */
.nav .nav-login {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 9px 10px; margin-right: 2px; border-radius: 999px;
  color: var(--ink-2); font-size: 13.5px; font-weight: 600; white-space: nowrap;
  text-decoration: none; transition: color .2s, background .2s;
}
.nav .nav-login svg { width: 15px; height: 15px; flex: none; }
.nav .nav-login:hover { color: var(--ink); background: rgba(47, 111, 237, .08); }

.nav-toggle {
  display: none; margin-left: auto; width: 42px; height: 42px;
  background: none; border: 1px solid var(--panel-line); border-radius: 10px;
  cursor: pointer; position: relative;
}
.nav-toggle span, .nav-toggle span::before, .nav-toggle span::after {
  content: ""; position: absolute; left: 11px; width: 18px; height: 2px;
  background: var(--ink); border-radius: 2px; transition: transform .25s ease, opacity .2s;
}
.nav-toggle span { top: 20px; }
.nav-toggle span::before { left: 0; top: -6px; }
.nav-toggle span::after { left: 0; top: 6px; }
.nav-toggle[aria-expanded="true"] span { background: transparent; }
.nav-toggle[aria-expanded="true"] span::before { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span::after { transform: translateY(-6px) rotate(-45deg); }

.mobile-menu {
  display: none; flex-direction: column; gap: 4px;
  padding: 10px 24px 20px;
  border-top: 1px solid rgba(139, 156, 255, .1);
  background: rgba(7, 13, 31, .97);
}
.mobile-menu a {
  padding: 12px 6px; color: var(--ink-2); font-size: 15px;
  border-bottom: 1px solid rgba(139, 156, 255, .07);
}
.mobile-menu a:last-child { border-bottom: 0; }
.mobile-menu.open { display: flex; }

/* ---------- 首屏 ---------- */
.hero {
  min-height: 100vh; display: flex; flex-direction: column; justify-content: center;
  padding: 130px 0 80px; overflow: hidden;
}
#graphCanvas {
  position: absolute; inset: 0; width: 100%; height: 100%;
  z-index: -2; opacity: .9;
}
.hero-glow {
  position: absolute; inset: 0; z-index: -1; pointer-events: none;
  background:
    radial-gradient(680px 420px at 18% 26%, rgba(56, 189, 248, .16), transparent 65%),
    radial-gradient(760px 520px at 82% 68%, rgba(139, 92, 246, .17), transparent 65%);
}
.hero-inner { max-width: 860px; }
.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 7px 16px; border-radius: 999px; font-size: 13px; color: var(--blue);
  border: 1px solid rgba(56, 189, 248, .35); background: rgba(56, 189, 248, .08);
  margin-bottom: 26px;
}
.hero-badge i {
  width: 7px; height: 7px; border-radius: 50%; background: var(--blue);
  box-shadow: 0 0 10px var(--blue); animation: pulse 2.2s infinite;
}
@keyframes pulse { 50% { opacity: .35; } }

.hero h1 {
  font-size: clamp(34px, 6.4vw, 62px); font-weight: 800;
  line-height: 1.22; letter-spacing: .01em;
}
.hero p.lead {
  margin-top: 22px; font-size: clamp(16px, 2.2vw, 19px);
  color: var(--ink-2); max-width: 560px;
}
.hero-cta { display: flex; flex-wrap: wrap; gap: 16px; margin-top: 38px; }
/* 学习第一步：全面摸底测试（首屏最醒目） */
.hero-cta .btn-first { padding: 15px 32px; font-size: 16.5px; font-weight: 750; box-shadow: 0 12px 30px rgba(47, 111, 237, .45); }
.hero-dl svg { width: 16px; height: 16px; color: var(--blue); flex: none; }
.hero-note { margin-top: 16px; font-size: 12.5px; color: var(--ink-3); }

.hero-stats {
  display: flex; flex-wrap: wrap; gap: 0; margin-top: 64px;
  border: 1px solid var(--panel-line); border-radius: var(--radius);
  background: var(--panel); backdrop-filter: blur(8px);
  max-width: 640px; overflow: hidden;
}
.hero-stats div { flex: 1 1 33%; text-align: center; padding: 22px 10px; position: relative; }
.hero-stats div + div::before {
  content: ""; position: absolute; left: 0; top: 22%; height: 56%; width: 1px;
  background: var(--panel-line);
}
.hero-stats b {
  display: block; font-size: clamp(24px, 3.4vw, 34px); font-weight: 800;
  background: var(--grad);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
}
.hero-stats span { font-size: 13px; color: var(--ink-2); }

.scroll-hint {
  position: absolute; left: 50%; bottom: 26px; transform: translateX(-50%);
  color: var(--ink-3); font-size: 12px; display: flex; flex-direction: column;
  align-items: center; gap: 8px;
}
.scroll-hint i {
  width: 1px; height: 38px; background: linear-gradient(var(--blue), transparent);
  animation: drop 1.8s infinite;
}
@keyframes drop { 0% { transform: scaleY(0); transform-origin: top; } 55% { transform: scaleY(1); } 100% { transform: scaleY(0); transform-origin: bottom; } }

/* ---------- 知识图谱主视觉 ---------- */
.split { display: grid; grid-template-columns: 1fr 1.1fr; gap: 56px; align-items: center; }
.split .pic {
  border-radius: var(--radius); overflow: hidden;
  border: 1px solid var(--panel-line); box-shadow: var(--shadow);
  background: var(--bg2);
}
.split .pic img { width: 100%; aspect-ratio: 16/10; object-fit: cover; }

.check-list { margin-top: 22px; display: grid; gap: 14px; }
.check-list li { display: flex; gap: 12px; color: var(--ink-2); font-size: 15px; }
.check-list li b { color: var(--ink); font-weight: 600; }
.check-list .tick {
  flex: none; width: 22px; height: 22px; border-radius: 50%; margin-top: 3px;
  background: rgba(56, 189, 248, .14); border: 1px solid rgba(56, 189, 248, .4);
  display: grid; place-items: center; font-size: 11px; color: var(--blue);
}
.split .actions { margin-top: 30px; display: flex; flex-wrap: wrap; gap: 14px; }

/* ---------- 核心功能 ---------- */
#features { background: linear-gradient(180deg, transparent, rgba(37, 50, 105, .14) 30%, transparent); }
.card-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; margin-top: 48px; }
.f-card {
  padding: 30px 26px; border-radius: var(--radius);
  border: 1px solid var(--panel-line); background: var(--panel);
  transition: transform .3s ease, border-color .3s ease, box-shadow .3s ease;
}
.f-card:hover {
  transform: translateY(-6px);
  border-color: rgba(99, 102, 241, .5);
  box-shadow: 0 16px 40px rgba(30, 27, 92, .45);
}
.f-ico {
  width: 48px; height: 48px; border-radius: 13px; margin-bottom: 18px;
  display: grid; place-items: center; font-size: 22px;
  background: linear-gradient(135deg, rgba(56, 189, 248, .18), rgba(139, 92, 246, .18));
  border: 1px solid rgba(139, 156, 255, .25);
}
.f-card h3 { font-size: 17px; margin-bottom: 10px; font-weight: 700; }
.f-card p { font-size: 14px; color: var(--ink-2); }

/* ---------- 会员定价 ---------- */
.price-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; margin-top: 46px; align-items: stretch; }
.p-card {
  position: relative; display: flex; flex-direction: column;
  padding: 26px 22px; border-radius: var(--radius);
  border: 1px solid var(--panel-line); background: var(--panel);
}
.p-card h3 { font-size: 17px; margin: 0 0 12px; }
.p-price { display: flex; align-items: baseline; gap: 6px; margin: 0 0 4px; }
.p-price b {
  font-size: 34px; font-weight: 800; letter-spacing: -1px;
  background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent;
}
.p-price span { font-size: 13px; color: var(--ink-3); }
.p-sub { font-size: 13px; color: var(--ink-3); margin: 0 0 18px; }
.p-list { list-style: none; display: grid; gap: 10px; padding: 0; margin: 0 0 24px; font-size: 13.5px; color: var(--ink-2); }
.p-list li { position: relative; padding-left: 18px; }
.p-list li::before {
  content: ""; position: absolute; left: 0; top: 8px;
  width: 6px; height: 6px; border-radius: 50%; background: var(--blue);
}
.p-cta { margin-top: auto; width: 100%; text-align: center; }
.p-card.featured {
  border-color: rgba(56, 189, 248, .45);
  background: linear-gradient(180deg, rgba(56, 189, 248, .10), rgba(168, 85, 247, .06));
  box-shadow: 0 20px 50px -28px rgba(56, 189, 248, .6);
}
.p-badge {
  position: absolute; top: -11px; right: 18px; padding: 3px 10px;
  border-radius: 999px; font-size: 11.5px; font-weight: 700; color: #04101f;
  background: linear-gradient(135deg, var(--blue), #a855f7);
}
.p-note { margin: 22px 0 0; font-size: 12.5px; color: var(--ink-3); line-height: 1.8; }
@media (max-width: 900px) { .price-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 600px) { .price-grid { grid-template-columns: 1fr; } }

/* ---------- 前置诊断 ---------- */
.steps { margin-top: 34px; display: grid; gap: 18px; }
.step { display: flex; gap: 18px; align-items: flex-start; }
.step-num {
  flex: none; width: 40px; height: 40px; border-radius: 12px;
  display: grid; place-items: center; font-weight: 800; font-size: 16px; color: #fff;
  background: var(--grad); box-shadow: 0 6px 18px rgba(79, 70, 229, .4);
}
.step h4 { font-size: 16px; margin-bottom: 4px; }
.step p { font-size: 14px; color: var(--ink-2); }

/* ---------- AI 辅助 ---------- */
.badge-dev {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 6px 14px; border-radius: 999px; font-size: 12.5px; font-weight: 600;
  color: #fbbf24; border: 1px solid rgba(251, 191, 36, .4);
  background: rgba(251, 191, 36, .08); margin-bottom: 18px;
}
.badge-dev i {
  width: 7px; height: 7px; border-radius: 50%; background: #fbbf24;
  box-shadow: 0 0 8px rgba(251, 191, 36, .8); animation: pulse 2s infinite;
}
.ai-modes { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; margin-top: 30px; }
.ai-mode {
  padding: 22px 20px; border-radius: 14px;
  border: 1px dashed rgba(139, 156, 255, .3); background: rgba(255, 255, 255, .025);
}
.ai-mode b { display: block; font-size: 15px; margin-bottom: 6px; }
.ai-mode span { font-size: 13px; color: var(--ink-2); }

/* ---------- 学习闭环 ---------- */
.loop { display: grid; grid-template-columns: repeat(5, 1fr); gap: 16px; margin-top: 52px; }
.loop-step { text-align: center; position: relative; }
.loop-step .ph {
  border-radius: 14px; overflow: hidden; border: 1px solid var(--panel-line);
  aspect-ratio: 16/11; background: var(--bg2); margin-bottom: 14px;
  transition: transform .3s ease, border-color .3s ease;
}
.loop-step:hover .ph { transform: translateY(-5px); border-color: rgba(56, 189, 248, .55); }
.loop-step .ph img { width: 100%; height: 100%; object-fit: cover; object-position: top; }
.loop-step b {
  display: inline-grid; place-items: center;
  width: 26px; height: 26px; border-radius: 50%; font-size: 12.5px; color: #fff;
  background: var(--grad); margin-bottom: 8px;
}
.loop-step h4 { font-size: 15.5px; margin-bottom: 4px; }
.loop-step p { font-size: 12.5px; color: var(--ink-3); }
.loop-step:not(:last-child)::after {
  content: ""; position: absolute; top: 26%; right: -12px; width: 22px; height: 1px;
  background: linear-gradient(90deg, rgba(99, 102, 241, .6), transparent);
}

/* ---------- 截图画廊 ---------- */
.shots { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-top: 48px; }
.shot {
  border-radius: 14px; overflow: hidden; cursor: zoom-in;
  border: 1px solid var(--panel-line); background: var(--bg2);
  transition: transform .3s ease, border-color .3s ease, box-shadow .3s ease;
}
.shot:hover { transform: translateY(-5px); border-color: rgba(139, 92, 246, .55); box-shadow: var(--shadow); }
.shot img { width: 100%; aspect-ratio: 16/10; object-fit: cover; object-position: top; }
.shot figcaption {
  padding: 12px 16px; font-size: 13px; color: var(--ink-2);
  border-top: 1px solid var(--panel-line);
}

/* lightbox */
.lightbox {
  position: fixed; inset: 0; z-index: 120; display: none;
  background: rgba(4, 8, 22, .88); backdrop-filter: blur(6px);
  align-items: center; justify-content: center; padding: 4vh 4vw; cursor: zoom-out;
}
.lightbox.open { display: flex; }
.lightbox img {
  max-width: 100%; max-height: 88vh; border-radius: 12px;
  border: 1px solid var(--panel-line); box-shadow: var(--shadow);
}
.lightbox .lb-close {
  position: absolute; top: 20px; right: 26px; font-size: 30px; color: var(--ink-2);
  background: none; border: 0; cursor: pointer; line-height: 1;
}
.lightbox .lb-cap { position: absolute; bottom: 24px; font-size: 14px; color: var(--ink-2); }

/* ---------- 价值说明 ---------- */
.value-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; margin-top: 48px; }
.value-card {
  padding: 36px 32px; border-radius: 20px; position: relative; overflow: hidden;
  border: 1px solid var(--panel-line); background: var(--panel);
}
.value-card::before {
  content: ""; position: absolute; inset: 0 0 auto 0; height: 3px;
  background: var(--grad);
}
.value-card .who {
  display: inline-flex; align-items: center; gap: 10px;
  font-size: 17px; font-weight: 700; margin-bottom: 20px;
}
.value-card .who span {
  width: 38px; height: 38px; border-radius: 11px; display: grid; place-items: center;
  font-size: 19px; background: linear-gradient(135deg, rgba(56, 189, 248, .18), rgba(139, 92, 246, .2));
  border: 1px solid rgba(139, 156, 255, .28);
}
.value-card ul { display: grid; gap: 13px; }
.value-card li { display: flex; gap: 10px; font-size: 14.5px; color: var(--ink-2); }
.value-card li::before { content: "✦"; color: var(--blue); flex: none; }

/* ---------- 底部 ---------- */
.final-cta {
  text-align: center; padding: 84px 24px; border-radius: 24px;
  background:
    radial-gradient(520px 300px at 30% 20%, rgba(56, 189, 248, .14), transparent 70%),
    radial-gradient(520px 320px at 74% 84%, rgba(139, 92, 246, .16), transparent 70%),
    var(--bg2);
  border: 1px solid var(--panel-line);
}
.final-cta h2 { font-size: clamp(24px, 3.6vw, 34px); margin-bottom: 12px; }
.final-cta p { color: var(--ink-2); margin-bottom: 30px; }
.final-cta .btns { display: flex; justify-content: center; flex-wrap: wrap; gap: 16px; }

/* APK 下载 */
.dl-row { margin-top: 28px; display: flex; flex-direction: column; align-items: center; gap: 12px; }
.dl-btn {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 12px 22px; border-radius: 999px; font-size: 14.5px; font-weight: 600;
  color: var(--ink); background: rgba(255, 255, 255, .05);
  border: 1px solid rgba(139, 156, 255, .28);
  transition: transform .2s, border-color .2s, background .2s, box-shadow .2s;
}
.dl-btn:hover {
  transform: translateY(-2px); border-color: rgba(56, 189, 248, .5);
  background: rgba(56, 189, 248, .1); box-shadow: 0 10px 30px rgba(56, 189, 248, .18);
}
.dl-btn svg { width: 18px; height: 18px; color: var(--blue); flex: none; }
.dl-tag {
  font-size: 11.5px; font-weight: 600; letter-spacing: .02em; color: var(--blue);
  padding: 2px 8px; border-radius: 999px; background: rgba(56, 189, 248, .12);
  border: 1px solid rgba(56, 189, 248, .25);
}
.final-cta .dl-note { margin: 0; font-size: 12.5px; color: var(--ink-3); }

.site-footer {
  border-top: 1px solid rgba(139, 156, 255, .1);
  padding: 56px 0 34px; background: #060b1a;
}
.foot-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 40px; }
.foot-brand p { margin-top: 14px; font-size: 13.5px; color: var(--ink-3); max-width: 320px; }
.foot-col h5 {
  font-size: 13px; letter-spacing: .14em; color: var(--ink-3);
  margin-bottom: 16px; font-weight: 600;
}
.foot-col a { display: block; padding: 5px 0; font-size: 14px; color: var(--ink-2); transition: color .2s; }
.foot-col a:hover { color: var(--blue); }
.foot-base {
  margin-top: 44px; padding-top: 22px; border-top: 1px solid rgba(139, 156, 255, .08);
  display: flex; flex-wrap: wrap; gap: 10px; justify-content: space-between;
  font-size: 12.5px; color: var(--ink-3);
}

/* ---------- 响应式 ---------- */
@media (max-width: 1100px) {
  .nav .nav-dl, .nav .nav-member, .nav .nav-login { display: none; }   /* 顶栏空间不够时收起，移动菜单仍有登录/下载与会员入口 */
}

@media (max-width: 1020px) {
  .card-grid { grid-template-columns: repeat(2, 1fr); }
  .loop { grid-template-columns: repeat(5, minmax(150px, 1fr)); overflow-x: auto; padding-bottom: 10px; }
  .loop-step:not(:last-child)::after { display: none; }
  .foot-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 820px) {
  section { padding: 72px 0; }
  .nav-links, .nav > .btn { display: none; }
  .nav-toggle { display: block; }
  .split, .value-grid { grid-template-columns: 1fr; gap: 34px; }
  .split.rev .pic { order: -1; }
  .shots { grid-template-columns: repeat(2, 1fr); }
  .ai-modes { grid-template-columns: 1fr; }
  .hero { padding-top: 110px; }
  .hero-stats div { flex: 1 1 100%; }
  .hero-stats div + div::before { left: 22%; top: 0; height: 1px; width: 56%; }
  .scroll-hint { display: none; }
}

@media (max-width: 540px) {
  .card-grid { grid-template-columns: 1fr; }
  .shots { grid-template-columns: 1fr; }
  .foot-grid { grid-template-columns: 1fr; gap: 28px; }
  .hero-cta .btn { width: 100%; }
  .final-cta .btns .btn { width: 100%; }
  .dl-btn { padding: 11px 18px; font-size: 14px; }
  .final-cta .dl-note { max-width: 260px; line-height: 1.6; }
}

/* ===== 介绍视频 ===== */
#video { padding-top: 40px; }
.video-head { text-align: center; max-width: 640px; margin: 0 auto 34px; }
.video-head .sec-sub { margin-top: 12px; }
.video-shell {
  max-width: 880px; margin: 0 auto; border-radius: 18px; overflow: hidden;
  border: 1px solid rgba(148, 163, 255, .22);
  background: #0b1228;
  box-shadow: 0 24px 70px -30px rgba(56, 130, 246, .45);
}
.video-shell video { display: block; width: 100%; aspect-ratio: 16 / 9; object-fit: contain; background: #060b1c; }

/* 单列文字版块（无配图） */
.split.solo { grid-template-columns: 1fr; max-width: 780px; margin: 0 auto; }
.split.solo .sec-title br { display: none; }