/* 抖阴官方站 — 深色品牌视觉 */
:root {
  --bg-deep: #07070c;
  --bg-base: #0d0d14;
  --bg-elevated: #15151f;
  --bg-card: #1a1a26;
  --bg-soft: #22222f;
  --line: rgba(255, 255, 255, 0.08);
  --line-strong: rgba(255, 255, 255, 0.14);
  --text: #f4f4f7;
  --text-secondary: #a8a8b8;
  --text-muted: #6f6f82;
  --accent: #ff2d6a;
  --accent-hot: #ff4d8d;
  --accent-soft: rgba(255, 45, 106, 0.16);
  --cyan: #25f4ee;
  --cyan-soft: rgba(37, 244, 238, 0.14);
  --magenta: #fe2c55;
  --grad-brand: linear-gradient(135deg, #fe2c55 0%, #ff6b9d 42%, #25f4ee 100%);
  --grad-cta: linear-gradient(90deg, #fe2c55, #ff4d8d);
  --grad-hero: radial-gradient(ellipse 80% 60% at 70% 20%, rgba(254, 44, 85, 0.28), transparent 55%),
    radial-gradient(ellipse 55% 45% at 15% 70%, rgba(37, 244, 238, 0.12), transparent 50%),
    linear-gradient(180deg, #0d0d14 0%, #07070c 100%);
  --shadow-phone: 0 28px 60px rgba(0, 0, 0, 0.55), 0 0 0 1px rgba(255, 255, 255, 0.06);
  --radius: 16px;
  --radius-sm: 10px;
  --nav-h: 64px;
  --ad-h: 0px;
  --font-display: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-body: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --max: 1120px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

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

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

body {
  margin: 0;
  font-family: var(--font-body);
  background: var(--bg-deep);
  color: var(--text);
  line-height: 1.75;
  font-size: 15px;
  padding-top: var(--nav-h);
  overflow-x: hidden;
}

body.has-site-ads {
  padding-top: calc(var(--nav-h) + var(--ad-h));
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: var(--accent-hot);
  text-decoration: none;
  transition: color 0.2s var(--ease);
}

a:hover {
  color: var(--cyan);
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  line-height: 1.35;
  margin: 0 0 0.75em;
  font-weight: 700;
  letter-spacing: 0.01em;
}

h1 { font-size: clamp(1.75rem, 5vw, 2.75rem); }
h2 { font-size: clamp(1.4rem, 3.5vw, 2rem); }
h3 { font-size: clamp(1.1rem, 2.5vw, 1.35rem); }

p { margin: 0 0 1.1em; color: var(--text-secondary); }

ul, ol { color: var(--text-secondary); }

.container {
  width: min(100% - 2rem, var(--max));
  margin-inline: auto;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

/* —— 顶栏 —— */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(7, 7, 12, 0.86);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--line);
}

.nav-bar {
  height: var(--nav-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  color: var(--text);
  flex-shrink: 0;
}

.brand img {
  height: 36px;
  width: auto;
}

.brand-name {
  font-size: 1.15rem;
  font-weight: 800;
  background: var(--grad-brand);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.nav-links {
  display: none;
  align-items: center;
  gap: 0.25rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  color: var(--text-secondary);
  padding: 0.45rem 0.75rem;
  border-radius: 999px;
  font-size: 0.92rem;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--text);
  background: var(--accent-soft);
}

.nav-toggle {
  width: 44px;
  height: 44px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--bg-elevated);
  color: var(--text);
  display: grid;
  place-items: center;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
  position: relative;
}

.nav-toggle span::before,
.nav-toggle span::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: currentColor;
}

.nav-toggle span::before { top: -6px; }
.nav-toggle span::after { top: 6px; }

.nav-drawer {
  display: none;
  border-top: 1px solid var(--line);
  background: var(--bg-base);
  padding: 0.75rem 0 1rem;
}

.nav-drawer.open { display: block; }

.nav-drawer a {
  display: block;
  padding: 0.75rem 1rem;
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
}

.nav-drawer a:hover { background: var(--bg-elevated); color: var(--text); }

/* —— 固定广告位（读取 myads.html） —— */
.site-ads-bar {
  position: fixed;
  top: var(--nav-h);
  left: 0;
  right: 0;
  z-index: 999;
  background: #f7f7f9;
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}

.site-ads-bar #applist {
  padding: 0.35rem 0.75rem 0.55rem;
}

.site-ads-bar .applist-title {
  color: #333;
  font-size: 0.85rem;
  font-weight: 700;
  margin-bottom: 0.15rem;
}

.site-ads-bar #ads {
  margin: 4px 0 0;
  gap: 0.35rem 0.5rem;
}

.site-ads-bar #ads figure {
  margin: 0;
}

/* —— Hero —— */
.hero {
  position: relative;
  padding: 2.5rem 0 3rem;
  background: var(--grad-hero);
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 30%, #000 20%, transparent 75%);
  pointer-events: none;
}

.hero-grid {
  position: relative;
  display: grid;
  gap: 2.5rem;
  align-items: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.3rem 0.75rem;
  border-radius: 999px;
  background: var(--cyan-soft);
  border: 1px solid rgba(37, 244, 238, 0.25);
  color: var(--cyan);
  font-size: 0.78rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

.hero h1 {
  margin-bottom: 0.65rem;
  background: linear-gradient(120deg, #fff 20%, #ffb0c8 55%, #25f4ee 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-lead {
  font-size: 1.05rem;
  color: var(--text);
  margin-bottom: 1rem;
  max-width: 36em;
}

.hero-desc {
  max-width: 40em;
  margin-bottom: 1.25rem;
}

.hero-points {
  list-style: none;
  padding: 0;
  margin: 0 0 1.5rem;
  display: grid;
  gap: 0.55rem;
}

.hero-points li {
  display: flex;
  align-items: flex-start;
  gap: 0.55rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.hero-points li::before {
  content: "";
  width: 8px;
  height: 8px;
  margin-top: 0.55rem;
  border-radius: 50%;
  background: var(--grad-brand);
  flex-shrink: 0;
  box-shadow: 0 0 12px rgba(254, 44, 85, 0.6);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  padding: 0.85rem 1.4rem;
  border-radius: 999px;
  font-weight: 700;
  font-size: 0.95rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.2s var(--ease), box-shadow 0.2s, background 0.2s;
}

.btn:hover { transform: translateY(-2px); }

.btn-primary {
  background: var(--grad-cta);
  color: #fff !important;
  box-shadow: 0 12px 32px rgba(254, 44, 85, 0.4);
}

.btn-ghost {
  background: rgba(255, 255, 255, 0.04);
  border-color: var(--line-strong);
  color: var(--text) !important;
}

.phone-stack {
  position: relative;
  height: 420px;
  max-width: 320px;
  margin: 0 auto;
}

.phone {
  position: absolute;
  width: 210px;
  border-radius: 28px;
  overflow: hidden;
  box-shadow: var(--shadow-phone);
  background: #000;
  border: 2px solid rgba(255, 255, 255, 0.1);
}

.phone img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  aspect-ratio: 9 / 19.5;
}

.phone-main {
  right: 8%;
  top: 0;
  z-index: 2;
  transform: rotate(2deg);
  animation: floatMain 5.5s ease-in-out infinite;
}

.phone-sub {
  left: 0;
  top: 48px;
  z-index: 1;
  opacity: 0.88;
  filter: saturate(0.95) brightness(0.92);
  transform: rotate(-8deg) scale(0.92);
  animation: floatSub 6.5s ease-in-out infinite;
}

.phone-glow {
  position: absolute;
  width: 220px;
  height: 220px;
  right: 10%;
  top: 20%;
  background: radial-gradient(circle, rgba(254, 44, 85, 0.35), transparent 70%);
  filter: blur(20px);
  z-index: 0;
  pointer-events: none;
}

@keyframes floatMain {
  0%, 100% { transform: rotate(2deg) translateY(0); }
  50% { transform: rotate(2deg) translateY(-12px); }
}

@keyframes floatSub {
  0%, 100% { transform: rotate(-8deg) scale(0.92) translateY(0); }
  50% { transform: rotate(-8deg) scale(0.92) translateY(10px); }
}

/* —— 通用区块 —— */
.section {
  padding: 3.5rem 0;
  position: relative;
}

.section-alt {
  background: linear-gradient(180deg, rgba(21, 21, 31, 0.55), transparent);
}

.section-head {
  margin-bottom: 2rem;
  max-width: 42rem;
}

.section-eyebrow {
  display: inline-block;
  color: var(--cyan);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 0.5rem;
}

.section-head p {
  margin-bottom: 0;
}

.prose {
  max-width: 48rem;
}

.prose p,
.prose li {
  font-size: 0.98rem;
}

.prose h2,
.prose h3 {
  margin-top: 1.75em;
  color: var(--text);
}

.inline-link {
  color: var(--accent-hot);
  border-bottom: 1px solid rgba(255, 77, 141, 0.35);
}

.inline-link:hover {
  border-bottom-color: var(--cyan);
}

/* —— 优势网格 —— */
.feature-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: 1fr;
}

.feature-item {
  padding: 1.35rem 1.25rem;
  border-radius: var(--radius);
  background: var(--bg-elevated);
  border: 1px solid var(--line);
  position: relative;
  overflow: hidden;
}

.feature-item::after {
  content: "";
  position: absolute;
  inset: auto -20% -40% auto;
  width: 120px;
  height: 120px;
  background: radial-gradient(circle, rgba(254, 44, 85, 0.18), transparent 70%);
  pointer-events: none;
}

.feature-item h3 {
  margin-bottom: 0.45rem;
  font-size: 1.05rem;
}

.feature-item p {
  margin: 0;
  font-size: 0.92rem;
}

.feature-num {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 800;
  color: var(--accent-hot);
  margin-bottom: 0.55rem;
  letter-spacing: 0.06em;
}

/* —— 视频 / 图文 —— */
.video-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: 1fr;
}

.video-card {
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--bg-card);
  border: 1px solid var(--line);
  transition: transform 0.25s var(--ease), border-color 0.25s;
}

.video-card:hover {
  transform: translateY(-4px);
  border-color: rgba(254, 44, 85, 0.4);
}

.video-card .thumb {
  aspect-ratio: 16 / 10;
  overflow: hidden;
  background: #111;
}

.video-card .thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.45s var(--ease);
}

.video-card:hover .thumb img {
  transform: scale(1.05);
}

.video-card .body {
  padding: 0.9rem 1rem 1.1rem;
}

.video-card h3 {
  font-size: 0.95rem;
  margin-bottom: 0.35rem;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.video-card p {
  margin: 0;
  font-size: 0.82rem;
  color: var(--text-muted);
}

/* —— 功能图文 —— */
.split {
  display: grid;
  gap: 1.75rem;
  align-items: center;
  margin-bottom: 2.75rem;
}

.split:last-child { margin-bottom: 0; }

.split-media {
  border-radius: 20px;
  overflow: hidden;
  border: 1px solid var(--line);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.35);
  background: var(--bg-card);
}

.split-media img {
  width: 100%;
  display: block;
}

.split-copy h3 { margin-bottom: 0.6rem; }

/* —— 特色标签 —— */
.chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin: 1rem 0 0;
}

.chip {
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  background: var(--bg-soft);
  border: 1px solid var(--line);
  color: var(--text-secondary);
  font-size: 0.8rem;
}

/* —— CTA —— */
.cta-band {
  padding: 3rem 0;
  background:
    radial-gradient(ellipse 60% 80% at 50% 100%, rgba(254, 44, 85, 0.22), transparent 60%),
    var(--bg-elevated);
  border-block: 1px solid var(--line);
  text-align: center;
}

.cta-band h2 { margin-bottom: 0.5rem; }
.cta-band p {
  max-width: 36rem;
  margin: 0 auto 1.5rem;
}

.cta-apps {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.75rem;
}

/* —— FAQ —— */
.faq-list {
  display: grid;
  gap: 0.75rem;
}

.faq-item {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg-elevated);
  overflow: hidden;
}

.faq-item summary {
  list-style: none;
  cursor: pointer;
  padding: 1rem 1.15rem;
  font-weight: 700;
  color: var(--text);
  position: relative;
  padding-right: 2.5rem;
}

.faq-item summary::-webkit-details-marker { display: none; }

.faq-item summary::after {
  content: "+";
  position: absolute;
  right: 1.15rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--accent-hot);
  font-size: 1.25rem;
}

.faq-item[open] summary::after { content: "–"; }

.faq-item .faq-body {
  padding: 0 1.15rem 1.15rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* —— 面包屑 —— */
.breadcrumb {
  padding: 1.25rem 0 0;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.breadcrumb a { color: var(--text-secondary); }
.breadcrumb span { margin: 0 0.35rem; color: var(--text-muted); }

.page-hero {
  padding: 1.5rem 0 2rem;
  border-bottom: 1px solid var(--line);
  background: var(--grad-hero);
}

.page-hero h1 {
  margin-bottom: 0.5rem;
}

/* —— 下载页 —— */
.download-grid {
  display: grid;
  gap: 1rem;
}

.download-card {
  display: grid;
  grid-template-columns: 72px 1fr;
  gap: 1rem;
  align-items: center;
  padding: 1.25rem;
  border-radius: var(--radius);
  background: var(--bg-elevated);
  border: 1px solid var(--line);
}

.download-card.featured {
  border-color: rgba(254, 44, 85, 0.45);
  background: linear-gradient(135deg, rgba(254, 44, 85, 0.12), rgba(21, 21, 31, 0.9));
}

.download-card img {
  width: 72px;
  height: 72px;
  border-radius: 16px;
  object-fit: cover;
}

.download-card h3 { margin-bottom: 0.25rem; font-size: 1.1rem; }
.download-card p { margin-bottom: 0.75rem; font-size: 0.88rem; }

/* —— 相关推荐 —— */
.related {
  display: grid;
  gap: 0.75rem;
}

.related a {
  display: block;
  padding: 0.9rem 1rem;
  border-radius: var(--radius-sm);
  background: var(--bg-elevated);
  border: 1px solid var(--line);
  color: var(--text-secondary);
}

.related a:hover {
  border-color: rgba(37, 244, 238, 0.35);
  color: var(--text);
}

/* —— Footer —— */
.site-footer {
  padding: 3rem 0 2rem;
  background: #050508;
  border-top: 1px solid var(--line);
}

.footer-grid {
  display: grid;
  gap: 2rem;
}

.footer-brand img {
  height: 32px;
  margin-bottom: 0.75rem;
}

.footer-brand p {
  font-size: 0.9rem;
  max-width: 28rem;
}

.footer-links h4 {
  font-size: 0.85rem;
  margin-bottom: 0.75rem;
  color: var(--text);
}

.footer-links ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 0.45rem;
}

.footer-links a {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.footer-links a:hover { color: var(--text); }

.footer-bottom {
  margin-top: 2.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--line);
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.25rem;
  justify-content: space-between;
  color: var(--text-muted);
  font-size: 0.8rem;
}

/* —— 错误页 —— */
.error-page {
  min-height: 70vh;
  display: grid;
  place-items: center;
  text-align: center;
  padding: 3rem 1rem;
}

.error-code {
  font-size: clamp(4rem, 18vw, 7rem);
  font-weight: 900;
  line-height: 1;
  background: var(--grad-brand);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  margin-bottom: 0.5rem;
}

/* —— 动效入场 —— */
.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}

.reveal.in {
  opacity: 1;
  transform: none;
}

/* —— 响应式 —— */
@media (min-width: 640px) {
  .feature-grid { grid-template-columns: 1fr 1fr; }
  .video-grid { grid-template-columns: 1fr 1fr; }
  .download-grid { grid-template-columns: 1fr 1fr; }
  .footer-grid { grid-template-columns: 1.4fr 1fr 1fr; }
}

@media (min-width: 900px) {
  body { font-size: 16px; }
  .nav-links { display: flex; }
  .nav-toggle { display: none; }
  .hero { padding: 4rem 0 5rem; }
  .hero-grid { grid-template-columns: 1.1fr 0.9fr; gap: 2rem; }
  .phone-stack { height: 480px; max-width: 380px; }
  .phone { width: 240px; }
  .feature-grid { grid-template-columns: repeat(3, 1fr); }
  .video-grid { grid-template-columns: repeat(3, 1fr); }
  .split { grid-template-columns: 1fr 1fr; gap: 2.5rem; }
  .split.reverse .split-media { order: 2; }
  .split.reverse .split-copy { order: 1; }
  .section { padding: 4.5rem 0; }
}