/* ============================================================
   白城出品官网 · 光影剧场设计系统
   深色电影感基底 + 珊瑚琥珀暖渐变 + 电紫青科技色点缀
   ============================================================ */

/* ---------- 设计令牌 ---------- */
:root {
  /* 背景层 */
  --bg-0: #0E0B16;
  --bg-1: #14101F;
  --bg-2: #1B1530;
  --card: rgba(255, 255, 255, 0.045);
  --card-2: rgba(255, 255, 255, 0.06);
  --card-hover: rgba(255, 255, 255, 0.085);
  --border: rgba(255, 255, 255, 0.09);
  --border-strong: rgba(255, 255, 255, 0.16);

  /* 文字 */
  --text-1: #FFFFFF;
  --text-2: rgba(255, 255, 255, 0.72);
  --text-3: rgba(255, 255, 255, 0.48);
  --text-dim: rgba(255, 255, 255, 0.32);

  /* 品牌色（暖：珊瑚→琥珀，可爱大气） */
  --brand-1: #FF6B9D;
  --brand-2: #FFB347;
  --brand-3: #FF8E72;
  --brand-grad: linear-gradient(135deg, #FF6B9D 0%, #FFB347 100%);
  --brand-grad-soft: linear-gradient(135deg, rgba(255,107,157,0.18), rgba(255,179,71,0.18));

  /* 科技色（电紫→青蓝，AI/现代） */
  --tech-1: #7C5CFC;
  --tech-2: #00D4FF;
  --tech-grad: linear-gradient(135deg, #7C5CFC 0%, #00D4FF 100%);
  --tech-grad-soft: linear-gradient(135deg, rgba(124,92,252,0.18), rgba(0,212,255,0.18));

  /* 圆角 */
  --r-sm: 12px;
  --r: 18px;
  --r-lg: 26px;
  --r-xl: 36px;
  --r-full: 999px;

  /* 阴影 */
  --shadow-1: 0 4px 24px rgba(0, 0, 0, 0.3);
  --shadow-2: 0 12px 40px rgba(0, 0, 0, 0.45);
  --shadow-brand: 0 12px 40px rgba(255, 107, 157, 0.28);
  --shadow-tech: 0 12px 40px rgba(124, 92, 252, 0.3);

  /* 字体 */
  --font-serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "STSong", serif;
  --font-sans: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;

  /* 布局 */
  --nav-h: 72px;
  --maxw: 1240px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

/* ---------- 重置 ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font-sans);
  background: var(--bg-0);
  color: var(--text-1);
  line-height: 1.7;
  font-size: 16px;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; border: none; background: none; color: inherit; }
ul, ol { list-style: none; }
input, textarea { font-family: inherit; }

/* ---------- 背景氛围层 ---------- */
.bg-aurora {
  position: fixed; inset: 0; z-index: -2; pointer-events: none;
  background:
    radial-gradient(60vw 50vw at 85% -5%, rgba(255,107,157,0.16), transparent 60%),
    radial-gradient(50vw 45vw at 8% 8%, rgba(124,92,252,0.14), transparent 60%),
    radial-gradient(55vw 50vw at 50% 110%, rgba(255,179,71,0.1), transparent 60%),
    var(--bg-0);
}
.bg-blob {
  position: fixed; border-radius: 50%; filter: blur(80px); z-index: -1;
  pointer-events: none; opacity: 0.5; will-change: transform;
}
.bg-blob.b1 { width: 480px; height: 480px; top: -120px; right: -80px; background: rgba(255,107,157,0.35); animation: drift1 22s var(--ease) infinite alternate; }
.bg-blob.b2 { width: 420px; height: 420px; top: 35%; left: -120px; background: rgba(124,92,252,0.3); animation: drift2 28s var(--ease) infinite alternate; }
.bg-blob.b3 { width: 460px; height: 460px; bottom: -140px; right: 15%; background: rgba(255,179,71,0.28); animation: drift3 30s var(--ease) infinite alternate; }
@keyframes drift1 { from { transform: translate(0,0) scale(1); } to { transform: translate(-60px,80px) scale(1.15); } }
@keyframes drift2 { from { transform: translate(0,0) scale(1); } to { transform: translate(80px,-50px) scale(1.1); } }
@keyframes drift3 { from { transform: translate(0,0) scale(1); } to { transform: translate(-70px,-60px) scale(1.2); } }

/* 噪点纹理 */
.bg-grain {
  position: fixed; inset: 0; z-index: -1; pointer-events: none; opacity: 0.035;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='3'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* ---------- 容器 ---------- */
.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
.container-sm { max-width: 860px; }

/* ---------- 导航 ---------- */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  height: var(--nav-h); display: flex; align-items: center;
  transition: background 0.4s var(--ease), border-color 0.4s var(--ease), backdrop-filter 0.4s;
  border-bottom: 1px solid transparent;
}
.nav.scrolled {
  background: rgba(14, 11, 22, 0.72);
  backdrop-filter: blur(20px) saturate(140%);
  -webkit-backdrop-filter: blur(20px) saturate(140%);
  border-bottom-color: var(--border);
}
.nav-inner { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: flex; align-items: center; gap: 12px; font-family: var(--font-serif); font-weight: 700; font-size: 22px; letter-spacing: 0.5px; }
.brand-logo {
  width: 42px; height: 42px; border-radius: 13px; display: grid; place-items: center;
  background: var(--brand-grad); box-shadow: var(--shadow-brand); position: relative; overflow: hidden;
}
.brand-logo::after { content: ""; position: absolute; inset: 0; background: linear-gradient(135deg, transparent 30%, rgba(255,255,255,0.4) 50%, transparent 70%); }
.brand-logo svg { width: 24px; height: 24px; position: relative; z-index: 1; }
.brand b { background: var(--brand-grad); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }

.nav-links { display: flex; align-items: center; gap: 6px; }
.nav-links a {
  padding: 9px 16px; border-radius: var(--r-full); font-size: 15px; color: var(--text-2);
  font-weight: 500; transition: color 0.25s, background 0.25s;
}
.nav-links a:hover { color: var(--text-1); background: var(--card); }
.nav-links a.active { color: var(--text-1); background: var(--card-2); }

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

/* 移动端菜单按钮 */
.nav-toggle { display: none; width: 42px; height: 42px; border-radius: 12px; place-items: center; background: var(--card); border: 1px solid var(--border); }
.nav-toggle span { position: relative; width: 20px; height: 2px; background: var(--text-1); border-radius: 2px; transition: 0.3s var(--ease); }
.nav-toggle span::before, .nav-toggle span::after { content: ""; position: absolute; left: 0; width: 20px; height: 2px; background: var(--text-1); border-radius: 2px; transition: 0.3s var(--ease); }
.nav-toggle span::before { top: -6px; } .nav-toggle span::after { top: 6px; }
.nav-toggle.open span { background: transparent; }
.nav-toggle.open span::before { top: 0; transform: rotate(45deg); }
.nav-toggle.open span::after { top: 0; transform: rotate(-45deg); }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 13px 24px; border-radius: var(--r-full); font-weight: 600; font-size: 15px;
  transition: transform 0.25s var(--ease), box-shadow 0.25s, background 0.25s; white-space: nowrap;
  border: 1px solid transparent;
}
.btn svg { width: 18px; height: 18px; }
.btn:active { transform: scale(0.96); }
.btn-primary { background: var(--brand-grad); color: #2a0a14; box-shadow: var(--shadow-brand); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 16px 48px rgba(255,107,157,0.42); }
.btn-tech { background: var(--tech-grad); color: #06122a; box-shadow: var(--shadow-tech); }
.btn-tech:hover { transform: translateY(-2px); box-shadow: 0 16px 48px rgba(124,92,252,0.45); }
.btn-ghost { background: var(--card); color: var(--text-1); border-color: var(--border); }
.btn-ghost:hover { background: var(--card-hover); border-color: var(--border-strong); transform: translateY(-2px); }
.btn-lg { padding: 16px 32px; font-size: 16px; }
.btn-sm { padding: 9px 18px; font-size: 14px; }

/* ---------- 通用区块 ---------- */
.section { padding: 96px 0; position: relative; }
.section-sm { padding: 64px 0; }
.section-head { max-width: 680px; margin-bottom: 48px; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px; font-size: 13px; font-weight: 600;
  letter-spacing: 1px; text-transform: uppercase; color: var(--brand-2); margin-bottom: 16px;
}
.eyebrow::before { content: ""; width: 28px; height: 2px; background: var(--brand-grad); border-radius: 2px; }
.eyebrow.tech { color: var(--tech-2); }
.eyebrow.tech::before { background: var(--tech-grad); }
.section-title { font-family: var(--font-serif); font-size: clamp(28px, 4vw, 44px); font-weight: 700; line-height: 1.25; letter-spacing: -0.5px; }
.section-title .grad { background: var(--brand-grad); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.section-title .grad-tech { background: var(--tech-grad); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.section-sub { margin-top: 16px; color: var(--text-2); font-size: 17px; line-height: 1.75; }

/* ---------- 玻璃卡片 ---------- */
.glass {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--r-lg);
  backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
}
.card-hover { transition: transform 0.4s var(--ease), border-color 0.4s, background 0.4s, box-shadow 0.4s; }
.card-hover:hover { transform: translateY(-6px); border-color: var(--border-strong); background: var(--card-hover); box-shadow: var(--shadow-2); }

/* ---------- Hero ---------- */
.hero { position: relative; padding: calc(var(--nav-h) + 72px) 0 80px; overflow: hidden; }
.hero-grid { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 56px; align-items: center; }
.hero h1 { font-family: var(--font-serif); font-size: clamp(38px, 6vw, 72px); line-height: 1.1; font-weight: 700; letter-spacing: -1px; }
.hero h1 .grad { background: var(--brand-grad); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.hero h1 .grad-tech { background: var(--tech-grad); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.hero-lead { margin-top: 24px; font-size: 19px; color: var(--text-2); line-height: 1.8; max-width: 540px; }
.hero-cta { margin-top: 36px; display: flex; gap: 14px; flex-wrap: wrap; }
.hero-stats { margin-top: 48px; display: flex; gap: 36px; flex-wrap: wrap; }
.stat-num { font-family: var(--font-serif); font-size: 36px; font-weight: 700; background: var(--brand-grad); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.stat-label { font-size: 13px; color: var(--text-3); margin-top: 4px; }

/* Hero 视觉装置 */
.hero-visual { position: relative; aspect-ratio: 1 / 1.05; max-width: 460px; margin-left: auto; }
.phone-mock {
  position: relative; width: 100%; height: 100%; border-radius: 42px; padding: 12px;
  background: linear-gradient(160deg, #241a36, #15101f); box-shadow: var(--shadow-2), 0 0 0 1px var(--border-strong);
}
.phone-screen { width: 100%; height: 100%; border-radius: 32px; overflow: hidden; position: relative; background: linear-gradient(180deg, #1a1428, #0f0a18); }
.phone-bar { position: absolute; top: 14px; left: 16px; right: 16px; display: flex; justify-content: space-between; align-items: center; z-index: 3; }
.phone-bar .dots { display: flex; gap: 6px; }
.phone-bar .dots i { width: 9px; height: 9px; border-radius: 50%; background: rgba(255,255,255,0.3); }
.phone-content { position: absolute; inset: 50px 14px 14px; display: flex; flex-direction: column; gap: 12px; }
.feed-item { border-radius: 16px; overflow: hidden; position: relative; background: var(--card-2); border: 1px solid var(--border); }
.feed-item .thumb { height: 70px; position: relative; }
.feed-item .thumb.g1 { background: linear-gradient(135deg, #FF6B9D, #7C5CFC); }
.feed-item .thumb.g2 { background: linear-gradient(135deg, #FFB347, #FF6B9D); }
.feed-item .thumb.g3 { background: linear-gradient(135deg, #00D4FF, #7C5CFC); }
.feed-item .thumb::after { content: "▶"; position: absolute; inset: 0; display: grid; place-items: center; font-size: 20px; color: rgba(255,255,255,0.9); }
.feed-item .meta { padding: 8px 12px; display: flex; justify-content: space-between; align-items: center; font-size: 11px; color: var(--text-2); }
.feed-item .meta b { color: var(--text-1); font-weight: 600; }

.float-chip {
  position: absolute; background: rgba(20,16,31,0.85); backdrop-filter: blur(12px); border: 1px solid var(--border-strong);
  border-radius: var(--r); padding: 12px 16px; display: flex; align-items: center; gap: 10px; box-shadow: var(--shadow-2);
  font-size: 13px; font-weight: 600; animation: floaty 4s var(--ease) infinite alternate;
}
.float-chip .ico { width: 34px; height: 34px; border-radius: 10px; display: grid; place-items: center; }
.float-chip.c1 { top: -22px; left: -28px; animation-delay: 0s; }
.float-chip.c1 .ico { background: var(--brand-grad-soft); }
.float-chip.c2 { bottom: 30px; left: -40px; animation-delay: 1.2s; }
.float-chip.c2 .ico { background: var(--tech-grad-soft); }
.float-chip.c3 { top: 40%; right: -36px; animation-delay: 2s; }
.float-chip.c3 .ico { background: var(--brand-grad-soft); }
@keyframes floaty { from { transform: translateY(0); } to { transform: translateY(-12px); } }

/* ---------- 视频卡片 ---------- */
.video-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.video-card { cursor: pointer; }
.video-thumb {
  position: relative; aspect-ratio: 3 / 4; border-radius: var(--r); overflow: hidden;
  border: 1px solid var(--border); transition: transform 0.4s var(--ease);
}
.video-card:hover .video-thumb { transform: translateY(-4px); }
.video-thumb .art { position: absolute; inset: 0; transition: transform 0.6s var(--ease); }
.video-card:hover .video-thumb .art { transform: scale(1.08); }
.video-thumb .badge { position: absolute; top: 12px; left: 12px; z-index: 2; }
.video-thumb .dur { position: absolute; bottom: 12px; right: 12px; z-index: 2; background: rgba(0,0,0,0.7); color: #fff; font-size: 12px; padding: 3px 8px; border-radius: 6px; font-weight: 600; }
.video-thumb .play { position: absolute; inset: 0; display: grid; place-items: center; z-index: 2; opacity: 0; transition: opacity 0.3s; }
.video-thumb .play span { width: 56px; height: 56px; border-radius: 50%; background: rgba(255,255,255,0.95); display: grid; place-items: center; color: #1a0a14; font-size: 20px; }
.video-card:hover .video-thumb .play { opacity: 1; }
.video-info { padding: 14px 4px; }
.video-info h3 { font-size: 15px; font-weight: 600; line-height: 1.45; margin-bottom: 6px; }
.video-info .vmeta { font-size: 13px; color: var(--text-3); display: flex; gap: 10px; }

/* 视频封面渐变艺术 */
.art-a { background: linear-gradient(135deg, #FF6B9D 0%, #7C5CFC 100%); }
.art-b { background: linear-gradient(135deg, #FFB347 0%, #FF6B9D 100%); }
.art-c { background: linear-gradient(135deg, #00D4FF 0%, #7C5CFC 100%); }
.art-d { background: linear-gradient(135deg, #7C5CFC 0%, #FF6B9D 100%); }
.art-e { background: linear-gradient(135deg, #FF8E72 0%, #FFB347 100%); }
.art-f { background: linear-gradient(135deg, #00D4FF 0%, #FF6B9D 100%); }
.art-g { background: linear-gradient(135deg, #2a1a4a 0%, #7C5CFC 60%, #FF6B9D 100%); }
.art-h { background: linear-gradient(135deg, #1a2a4a 0%, #00D4FF 100%); }
.art::after { content: ""; position: absolute; inset: 0; background: radial-gradient(circle at 30% 20%, rgba(255,255,255,0.25), transparent 50%); }

.badge { font-size: 11px; font-weight: 700; padding: 4px 10px; border-radius: var(--r-full); letter-spacing: 0.5px; }
.badge-hot { background: var(--brand-grad); color: #2a0a14; }
.badge-new { background: var(--tech-grad); color: #06122a; }
.badge-ai { background: linear-gradient(135deg, rgba(124,92,252,0.9), rgba(0,212,255,0.9)); color: #06122a; }
.badge-cat { background: rgba(0,0,0,0.6); color: #fff; border: 1px solid var(--border-strong); }

/* ---------- 横向卡片（特性/步骤） ---------- */
.feature-card { padding: 32px; height: 100%; }
.feature-ico { width: 54px; height: 54px; border-radius: 15px; display: grid; place-items: center; margin-bottom: 20px; }
.feature-ico svg { width: 26px; height: 26px; }
.feature-ico.brand { background: var(--brand-grad-soft); color: var(--brand-2); }
.feature-ico.tech { background: var(--tech-grad-soft); color: var(--tech-2); }
.feature-card h3 { font-family: var(--font-serif); font-size: 21px; font-weight: 700; margin-bottom: 10px; }
.feature-card p { color: var(--text-2); font-size: 15px; line-height: 1.75; }

/* ---------- 筛选 Chips ---------- */
.filter-bar { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 36px; }
.chip {
  padding: 9px 18px; border-radius: var(--r-full); font-size: 14px; font-weight: 500;
  background: var(--card); border: 1px solid var(--border); color: var(--text-2);
  transition: all 0.25s var(--ease);
}
.chip:hover { color: var(--text-1); border-color: var(--border-strong); }
.chip.active { background: var(--brand-grad); color: #2a0a14; border-color: transparent; font-weight: 600; }

/* ---------- 数字滚动统计带 ---------- */
.stats-band { padding: 56px 0; border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); background: rgba(255,255,255,0.015); }
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.stat-cell { text-align: center; }
.stat-cell .num { font-family: var(--font-serif); font-size: clamp(32px, 4vw, 48px); font-weight: 700; background: var(--brand-grad); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; line-height: 1; }
.stat-cell .num.tech { background: var(--tech-grad); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.stat-cell .lab { font-size: 14px; color: var(--text-3); margin-top: 10px; }

/* ---------- 步骤 ---------- */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; counter-reset: step; }
.step-card { position: relative; padding: 36px 28px; height: 100%; }
.step-card::before { counter-increment: step; content: "0" counter(step); font-family: var(--font-serif); font-size: 48px; font-weight: 700; background: var(--brand-grad); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; opacity: 0.5; position: absolute; top: 20px; right: 24px; }
.step-card h3 { font-family: var(--font-serif); font-size: 20px; margin-bottom: 10px; margin-top: 8px; }
.step-card p { color: var(--text-2); font-size: 14.5px; line-height: 1.7; }

/* ---------- 下载区 ---------- */
.download-hero { padding: calc(var(--nav-h) + 80px) 0 80px; }
.dl-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 64px; align-items: center; }
.dl-visual { position: relative; aspect-ratio: 1; max-width: 440px; }
.qr-box { width: 220px; height: 220px; margin: 0 auto; border-radius: 28px; padding: 16px; background: #fff; position: relative; box-shadow: var(--shadow-2); }
.qr-box .qr { width: 100%; height: 100%; background:
  repeating-conic-gradient(#0a0a14 0% 25%, #fff 0% 50%) 0 0 / 14px 14px;
  border-radius: 8px; position: relative; }
.qr-box .qr::after { content: ""; position: absolute; inset: 30%; background: #fff; display: grid; place-items: center; }
.qr-box .qr::before { content: "白城出品"; position: absolute; inset: 0; display: grid; place-items: center; z-index: 2; font-size: 13px; font-weight: 700; color: #0a0a14; background: #fff; width: 40px; height: 40px; margin: auto; border-radius: 8px; text-align: center; line-height: 1.1; }
.dl-features { list-style: none; margin-top: 28px; }
.dl-features li { display: flex; align-items: flex-start; gap: 12px; padding: 14px 0; border-bottom: 1px solid var(--border); font-size: 15px; color: var(--text-2); }
.dl-features li:last-child { border-bottom: none; }
.dl-features .tick { width: 24px; height: 24px; border-radius: 7px; background: var(--brand-grad-soft); color: var(--brand-2); display: grid; place-items: center; flex-shrink: 0; font-size: 14px; }
.store-btn { display: inline-flex; align-items: center; gap: 10px; padding: 14px 22px; border-radius: var(--r-full); background: rgba(0,0,0,0.4); border: 1px solid var(--border-strong); transition: all 0.25s; }
.store-btn:hover { background: rgba(0,0,0,0.6); transform: translateY(-2px); }
.store-btn svg { width: 26px; height: 26px; }
.store-btn .t { display: flex; flex-direction: column; line-height: 1.1; }
.store-btn .t small { font-size: 11px; color: var(--text-3); }
.store-btn .t b { font-size: 16px; font-weight: 600; }

/* ---------- 评论 ---------- */
.testimonial-card { padding: 30px; height: 100%; display: flex; flex-direction: column; }
.testimonial-card .stars { color: var(--brand-2); margin-bottom: 14px; letter-spacing: 2px; }
.testimonial-card p { color: var(--text-2); font-size: 15px; line-height: 1.75; flex: 1; }
.testimonial-card .who { display: flex; align-items: center; gap: 12px; margin-top: 20px; }
.testimonial-card .av { width: 42px; height: 42px; border-radius: 50%; display: grid; place-items: center; font-family: var(--font-serif); font-weight: 700; color: #2a0a14; }
.testimonial-card .who b { font-size: 14px; } .testimonial-card .who small { color: var(--text-3); font-size: 12px; }

/* ---------- 页脚 ---------- */
.footer { padding: 64px 0 32px; border-top: 1px solid var(--border); margin-top: 64px; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 48px; }
.footer-brand p { color: var(--text-3); font-size: 14px; line-height: 1.7; margin-top: 16px; max-width: 320px; }
.footer-col h4 { font-size: 14px; font-weight: 600; margin-bottom: 16px; color: var(--text-1); }
.footer-col a { display: block; color: var(--text-3); font-size: 14px; padding: 6px 0; transition: color 0.2s; }
.footer-col a:hover { color: var(--brand-2); }
.footer-bottom { padding-top: 24px; border-top: 1px solid var(--border); display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 12px; color: var(--text-dim); font-size: 13px; }
.footer-bottom .seo { color: var(--text-3); }
.footer-bottom .seo b { color: var(--brand-2); font-weight: 600; }

/* ---------- 回到顶部 ---------- */
.to-top { position: fixed; bottom: 28px; right: 28px; width: 48px; height: 48px; border-radius: 14px; background: var(--brand-grad); display: grid; place-items: center; box-shadow: var(--shadow-brand); z-index: 90; opacity: 0; pointer-events: none; transform: translateY(16px); transition: all 0.3s var(--ease); }
.to-top.show { opacity: 1; pointer-events: auto; transform: translateY(0); }
.to-top svg { width: 22px; height: 22px; color: #2a0a14; }

/* ---------- 弹窗 ---------- */
.modal-mask { position: fixed; inset: 0; z-index: 200; background: rgba(8,5,14,0.7); backdrop-filter: blur(6px); display: none; align-items: center; justify-content: center; padding: 24px; }
.modal-mask.open { display: flex; animation: fadeIn 0.3s; }
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
.modal { width: 100%; max-width: 440px; background: linear-gradient(160deg, var(--bg-2), var(--bg-1)); border: 1px solid var(--border-strong); border-radius: var(--r-xl); padding: 40px 32px; position: relative; box-shadow: var(--shadow-2); animation: pop 0.4s var(--ease); }
@keyframes pop { from { transform: scale(0.92) translateY(20px); opacity: 0; } to { transform: scale(1) translateY(0); opacity: 1; } }
.modal-close { position: absolute; top: 16px; right: 16px; width: 36px; height: 36px; border-radius: 10px; background: var(--card); display: grid; place-items: center; font-size: 20px; color: var(--text-2); }
.modal h3 { font-family: var(--font-serif); font-size: 26px; margin-bottom: 12px; }
.modal p { color: var(--text-2); font-size: 15px; line-height: 1.7; margin-bottom: 24px; }

/* ---------- 滚动显现 ---------- */
.reveal { opacity: 0; transform: translateY(28px); transition: opacity 0.7s var(--ease), transform 0.7s var(--ease); }
.reveal.in { opacity: 1; transform: none; }
.reveal.d1 { transition-delay: 0.08s; } .reveal.d2 { transition-delay: 0.16s; } .reveal.d3 { transition-delay: 0.24s; } .reveal.d4 { transition-delay: 0.32s; }

/* ---------- 移动端导航抽屉 ---------- */
.mobile-menu { position: fixed; inset: 0 0 0 auto; width: min(82vw, 340px); z-index: 110; background: linear-gradient(180deg, var(--bg-2), var(--bg-1)); border-left: 1px solid var(--border-strong); transform: translateX(100%); transition: transform 0.4s var(--ease); padding: 90px 28px 40px; display: flex; flex-direction: column; gap: 6px; box-shadow: -20px 0 60px rgba(0,0,0,0.5); }
.mobile-menu.open { transform: translateX(0); }
.mobile-menu a { padding: 14px 16px; border-radius: 14px; font-size: 17px; color: var(--text-2); transition: background 0.2s; }
.mobile-menu a:hover, .mobile-menu a.active { background: var(--card); color: var(--text-1); }
.mobile-menu .btn { margin-top: 16px; }

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .video-grid { grid-template-columns: repeat(3, 1fr); }
  .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 32px; }
}
@media (max-width: 860px) {
  :root { --nav-h: 64px; }
  .nav-links, .nav-actions .btn { display: none; }
  .nav-toggle { display: grid; }
  .hero { padding: calc(var(--nav-h) + 48px) 0 56px; }
  .hero-grid { grid-template-columns: 1fr; gap: 40px; }
  .hero-visual { max-width: 360px; margin: 0 auto; order: -1; }
  .dl-grid { grid-template-columns: 1fr; gap: 40px; }
  .dl-visual { max-width: 320px; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
  .section { padding: 64px 0; }
  .float-chip { display: none; }
}
@media (max-width: 640px) {
  .container { padding: 0 18px; }
  .video-grid { grid-template-columns: repeat(2, 1fr); gap: 14px; }
  .steps { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .hero-stats { gap: 20px; }
  .stat-num { font-size: 28px; }
  .section-title { font-size: 26px; }
  .hero h1 { font-size: 38px; }
  .hero-cta { flex-direction: column; }
  .hero-cta .btn { width: 100%; }
  .filter-bar { gap: 8px; }
  .chip { padding: 8px 14px; font-size: 13px; }
  .stats-band { padding: 40px 0; }
  .to-top { bottom: 18px; right: 18px; }
}