/* Covera 官网：落地页 + 隐私 / 协议 / 支持。颜色取自品牌标志（珊瑚 → 玫红 → 紫）。 */
:root {
  --bg: #fbfaf8;
  --bg-soft: #f3f1ee;
  --card: #ffffff;
  --text: #1c1a1f;
  --text-2: #5d5863;
  --text-3: #8b8690;
  --line: rgba(28, 26, 31, 0.1);
  --coral: #ff6a55;
  --rose: #f23d6d;
  --violet: #7a5cf0;
  --brand: linear-gradient(135deg, var(--coral) 0%, var(--rose) 45%, var(--violet) 100%);
  --accent: #e2335f;
  --radius: 18px;
  --max: 1120px;
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --display: -apple-system, BlinkMacSystemFont, "SF Pro Display", "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #111014;
    --bg-soft: #18161c;
    --card: #1d1b22;
    --text: #f3f1f5;
    --text-2: #b4afba;
    --text-3: #847f8b;
    --line: rgba(255, 255, 255, 0.1);
    --accent: #ff6f8f;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
a { color: var(--accent); text-underline-offset: 3px; }
img, svg { max-width: 100%; }
.wrap { width: 100%; max-width: var(--max); margin: 0 auto; padding: 0 24px; }
@media (max-width: 600px) { .wrap { padding: 0 16px; } }
.skip { position: absolute; left: -9999px; }
.skip:focus { left: 16px; top: 12px; z-index: 99; background: var(--card); padding: 8px 12px; border-radius: 8px; }

/* ---------- 页头 ---------- */
.site-header {
  position: sticky; top: 0; z-index: 20;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(160%) blur(14px);
  -webkit-backdrop-filter: saturate(160%) blur(14px);
  border-bottom: 1px solid var(--line);
}
.site-header .wrap { display: flex; align-items: center; gap: 16px; height: 60px; }
.brand { display: flex; align-items: center; flex-shrink: 0; }
.brand img { height: 30px; width: auto; display: block; }
.brand .logo-dark { display: none; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .brand .logo-light { display: none; }
  :root:not([data-theme="light"]) .brand .logo-dark { display: block; }
}
.nav { display: flex; align-items: center; gap: 4px; margin-left: auto; }
.nav a {
  color: var(--text-2); text-decoration: none; font-size: 14px;
  padding: 6px 10px; border-radius: 8px; white-space: nowrap;
}
.nav a:hover { color: var(--text); background: var(--bg-soft); }
.nav a[aria-current="page"] { color: var(--text); font-weight: 600; }
.nav .lang { border: 1px solid var(--line); margin-left: 6px; }
@media (max-width: 640px) {
  .nav .hide-sm { display: none; }
  .brand img { height: 26px; }
}

/* ---------- 首屏 ---------- */
.hero { position: relative; padding: 72px 0 40px; overflow: hidden; }
.hero::before {
  content: ""; position: absolute; inset: -30% -10% auto -10%; height: 560px; z-index: -1;
  background:
    radial-gradient(40% 60% at 25% 40%, rgba(255, 106, 85, 0.22), transparent 70%),
    radial-gradient(40% 60% at 70% 30%, rgba(122, 92, 240, 0.2), transparent 70%),
    radial-gradient(30% 50% at 50% 60%, rgba(242, 61, 109, 0.14), transparent 70%);
  filter: blur(10px);
}
.hero-grid { display: grid; grid-template-columns: 1fr; gap: 48px; align-items: center; }
.hero-copy { text-align: center; max-width: 720px; margin: 0 auto; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 13px; font-weight: 600; color: var(--text-2);
  background: var(--card); border: 1px solid var(--line);
  padding: 5px 12px 5px 6px; border-radius: 999px;
}
.eyebrow .dot { width: 20px; height: 20px; border-radius: 6px; background: var(--brand); display: inline-block; }
.hero h1 {
  font-family: var(--display);
  font-size: clamp(38px, 7vw, 68px); line-height: 1.08; letter-spacing: -0.02em;
  margin: 22px 0 18px; font-weight: 800;
}
.hero h1 .grad { background: var(--brand); -webkit-background-clip: text; background-clip: text; color: transparent; }
h1, h2, .lede, .section-head p { text-wrap: balance; }
.lede { font-size: clamp(17px, 2.2vw, 20px); color: var(--text-2); margin: 0 auto; max-width: 600px; }
.cta { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; margin-top: 30px; }
.btn {
  display: inline-flex; align-items: center; gap: 10px;
  height: 50px; padding: 0 22px; border-radius: 14px;
  font-size: 16px; font-weight: 600; text-decoration: none; white-space: nowrap;
}
.btn-store { background: var(--text); color: var(--bg); }
.btn-store small { display: block; font-size: 11px; font-weight: 500; opacity: 0.7; line-height: 1.1; }
.btn-store span { line-height: 1.15; text-align: left; }
.btn-store[aria-disabled="true"] { cursor: default; }
.btn-ghost { color: var(--text); background: var(--card); border: 1px solid var(--line); }
.btn-ghost:hover { border-color: color-mix(in srgb, var(--text) 30%, transparent); }
.meta-line { margin-top: 16px; font-size: 13px; color: var(--text-3); }

/* ---------- 首屏产品示意（纯 CSS 画的听歌模式，不用真实专辑封面） ---------- */
.device {
  position: relative; width: 100%; max-width: 980px; margin: 0 auto;
  aspect-ratio: 16 / 10; border-radius: 16px; overflow: hidden;
  box-shadow: 0 40px 80px -30px rgba(60, 20, 90, 0.45), 0 0 0 1px rgba(0, 0, 0, 0.08);
  background: #3a1830; color: #fff; isolation: isolate;
  display: flex; flex-direction: column;
  font-family: var(--font);
}
.device .bg { position: absolute; inset: -20%; z-index: -1; filter: blur(60px) saturate(140%); }
.device .blob { position: absolute; border-radius: 50%; animation: drift 18s ease-in-out infinite alternate; }
.device .b1 { width: 60%; height: 70%; left: 5%; top: 5%; background: #ff6a55; }
.device .b2 { width: 55%; height: 65%; right: 0; top: 20%; background: #7a5cf0; animation-delay: -6s; }
.device .b3 { width: 45%; height: 55%; left: 30%; bottom: 0; background: #f23d6d; animation-delay: -11s; }
.device .shade { position: absolute; inset: 0; z-index: -1; background: linear-gradient(180deg, rgba(0,0,0,.05), rgba(0,0,0,.35)); }
@keyframes drift {
  0% { transform: translate(0, 0) rotate(0) scale(1); }
  100% { transform: translate(8%, -6%) rotate(25deg) scale(1.12); }
}
@media (prefers-reduced-motion: reduce) { .device .blob { animation: none; } }
.d-bar { display: flex; align-items: center; gap: 7px; padding: 2.2% 2.4%; font-size: clamp(8px, 1.2vw, 13px); }
.d-bar i { width: 1.2em; height: 1.2em; border-radius: 50%; background: rgba(255,255,255,.35); display: inline-block; }
.d-bar i:nth-child(1) { background: #ff5f57; } .d-bar i:nth-child(2) { background: #febc2e; } .d-bar i:nth-child(3) { background: #28c840; }
.d-bar .src { margin: 0 auto; opacity: .8; }
.d-bar .pill { background: rgba(255,255,255,.16); padding: .3em .8em; border-radius: 999px; }
.d-main { flex: 1; display: flex; flex-direction: column; align-items: center; justify-content: center; min-height: 0; }
.d-cover {
  width: 21%; aspect-ratio: 1; border-radius: 6%; position: relative; overflow: hidden;
  background: linear-gradient(135deg, #ffb199, #ff5e7e 45%, #6f4ff0);
  box-shadow: 0 20px 40px -10px rgba(0,0,0,.45);
}
.d-cover::before { content: ""; position: absolute; width: 70%; height: 70%; left: -10%; top: -15%; border-radius: 50%; background: rgba(255, 214, 165, .55); filter: blur(10px); }
.d-title { margin-top: 2.2%; font-weight: 700; font-size: clamp(11px, 1.9vw, 22px); }
.d-sub { opacity: .75; font-size: clamp(9px, 1.3vw, 14px); }
.d-lyric { margin-top: 1.6%; font-size: clamp(8px, 1.2vw, 13px); background: rgba(255,255,255,.14); padding: .35em 1em; border-radius: 999px; display: grid; overflow: hidden; }
.d-seek { width: 46%; height: 4px; border-radius: 4px; background: rgba(255,255,255,.25); margin-top: 3%; position: relative; }
.d-seek::after { content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 38%; animation: seek 24s linear infinite; border-radius: 4px; background: #fff; }
.d-ctrl { display: flex; align-items: center; gap: 5%; margin-top: 2%; width: 30%; justify-content: center; }
.d-ctrl span { width: 7%; aspect-ratio: 1; }
.d-ctrl .prev, .d-ctrl .next { width: 0; height: 0; border-top: .55em solid transparent; border-bottom: .55em solid transparent; font-size: clamp(8px, 1.4vw, 16px); }
.d-ctrl .prev { border-right: .8em solid #fff; }
.d-ctrl .next { border-left: .8em solid #fff; }
.d-ctrl .play { width: 17%; aspect-ratio: 1; border-radius: 50%; background: #fff; display: grid; place-items: center; }
.d-ctrl .play::before { content: ""; width: 22%; height: 36%; border-left: 3px solid #d7336a; border-right: 3px solid #d7336a; }
.d-next { padding: 0 0 3.5%; display: flex; gap: 1.6%; justify-content: center; }
.d-next div { width: 12%; aspect-ratio: 2.6; border-radius: 8px; background: rgba(255,255,255,.12); display: flex; align-items: center; gap: 8%; padding: 0 3%; }
.d-next div::before { content: ""; height: 70%; aspect-ratio: 1; border-radius: 4px; background: var(--c, #ffb199); }
.d-next div::after { content: ""; height: 14%; flex: 1; border-radius: 4px; background: rgba(255,255,255,.4); }
.d-next-label { text-align: center; margin: 2.2% 0 1.2%; font-size: clamp(7px, 1vw, 11px); opacity: .65; letter-spacing: .08em; }
.d-cover, .d-title, .d-sub, .d-lyric, .d-seek, .d-ctrl { flex-shrink: 0; }
@media (max-width: 600px) {
  .device { aspect-ratio: 4 / 3.6; border-radius: 12px; }
  .d-cover { width: 34%; }
  .d-seek { width: 64%; }
  .d-ctrl { width: 44%; }
  .d-next div { width: 15%; }
  .d-bar .pill { display: none; }
}
.meta-line span { white-space: nowrap; display: inline-block; margin: 0 10px; }
.hero-note { text-align: center; font-size: 12px; color: var(--text-3); margin-top: 12px; }

/* ---------- 区块 ---------- */
.section { padding: 88px 0; }
.section.alt { background: var(--bg-soft); }
.section-head { max-width: 640px; margin: 0 auto 48px; text-align: center; }
.section-head h2 { font-family: var(--display); font-size: clamp(28px, 4.4vw, 40px); line-height: 1.2; letter-spacing: -0.01em; margin: 0 0 12px; }
.section-head p { color: var(--text-2); margin: 0; font-size: 17px; }
.features { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
@media (max-width: 900px) { .features { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 600px) { .features { grid-template-columns: 1fr; } }
.feature { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 26px 24px; }
.feature .ic {
  width: 42px; height: 42px; border-radius: 12px; display: grid; place-items: center;
  background: var(--brand); color: #fff; margin-bottom: 16px;
}
.feature .ic svg { width: 22px; height: 22px; }
.feature h3 { margin: 0 0 6px; font-size: 18px; }
.feature p { margin: 0; color: var(--text-2); font-size: 15px; }

.promise { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
@media (max-width: 800px) { .promise { grid-template-columns: 1fr; } }
.promise div { padding: 4px 0; }
.promise strong { display: block; font-size: 17px; margin-bottom: 4px; }
.promise span { color: var(--text-2); font-size: 15px; }

.req { max-width: 760px; margin: 0 auto; background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 8px 28px; }
.req dl { margin: 0; }
.req .row { display: grid; grid-template-columns: 160px 1fr; gap: 16px; padding: 16px 0; border-bottom: 1px solid var(--line); }
.req .row:last-child { border-bottom: 0; }
.req dt { font-weight: 600; }
.req dd { margin: 0; color: var(--text-2); }
@media (max-width: 600px) { .req { padding: 4px 18px; } .req .row { grid-template-columns: 1fr; gap: 2px; } }

.closing { text-align: center; }
.closing img { width: 88px; height: 88px; }
.closing h2 { font-family: var(--display); font-size: clamp(26px, 4vw, 36px); margin: 18px 0 8px; }
.closing p { color: var(--text-2); margin: 0; }

/* ---------- 文档页（隐私 / 协议 / 支持） ---------- */
.doc { padding: 56px 0 88px; }
.doc .wrap { max-width: 780px; }
.doc h1 { font-family: var(--display); font-size: clamp(30px, 5vw, 42px); line-height: 1.2; margin: 0 0 8px; letter-spacing: -0.01em; }
.doc .updated { color: var(--text-3); font-size: 14px; margin: 0 0 32px; }
.doc .summary { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px 24px; margin-bottom: 36px; }
.doc .summary h2 { margin-top: 0; font-size: 17px; }
.doc .summary ul { margin-bottom: 0; }
.doc h2 { font-size: 22px; margin: 40px 0 12px; line-height: 1.35; }
.doc h3 { font-size: 17px; margin: 24px 0 8px; }
.doc p, .doc li { color: var(--text-2); }
.doc strong { color: var(--text); }
.doc ul, .doc ol { padding-left: 1.3em; }
.doc li { margin: 6px 0; }
.doc table { width: 100%; border-collapse: collapse; margin: 16px 0; font-size: 15px; }
.doc th, .doc td { text-align: left; vertical-align: top; padding: 12px 10px; border-bottom: 1px solid var(--line); }
.doc th { color: var(--text); font-weight: 600; white-space: nowrap; }
.doc td { color: var(--text-2); }
.table-scroll { overflow-x: auto; -webkit-overflow-scrolling: touch; }
@media (max-width: 600px) {
  .doc table.stack thead { display: none; }
  .doc table.stack tr { display: block; padding: 12px 0; border-bottom: 1px solid var(--line); }
  .doc table.stack td { display: block; border: 0; padding: 2px 0; }
  .doc table.stack td:first-child { color: var(--text); font-weight: 600; }
}
.doc .toc { font-size: 15px; }
.doc details { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 14px 18px; margin: 10px 0; }
.doc details summary { cursor: pointer; font-weight: 600; color: var(--text); }
.doc details[open] summary { margin-bottom: 6px; }
.doc details p { margin: 6px 0; }
.contact-card { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px 24px; margin: 8px 0 32px; }
.contact-card .grow { flex: 1; min-width: 200px; }
.contact-card strong { display: block; font-size: 17px; }
.contact-card span { color: var(--text-2); font-size: 15px; }

/* ---------- 页脚 ---------- */
.site-footer { border-top: 1px solid var(--line); padding: 36px 0 44px; font-size: 14px; color: var(--text-3); }
.site-footer .wrap { display: flex; flex-wrap: wrap; gap: 16px 28px; align-items: flex-start; justify-content: space-between; }
.site-footer nav { display: flex; flex-wrap: wrap; gap: 8px 20px; }
.site-footer a { color: var(--text-2); text-decoration: none; }
.site-footer a:hover { color: var(--text); text-decoration: underline; }
.site-footer .legal { max-width: 620px; font-size: 12px; line-height: 1.6; }

/* ================= 动画 =================
   所有动效都尊重系统「减弱动态效果」；滚动出现的效果只在脚本可用时才先隐藏，脚本失败时内容照常可见。 */

/* 首屏依次浮现 */
@keyframes rise { from { opacity: 0; transform: translateY(18px); } to { opacity: 1; transform: none; } }
.hero .eyebrow, .hero h1, .hero .lede, .hero .cta, .hero .meta-line { animation: rise .8s cubic-bezier(.2,.8,.2,1) both; }
.hero h1 { animation-delay: .08s; }
.hero .lede { animation-delay: .16s; }
.hero .cta { animation-delay: .24s; }
.hero .meta-line { animation-delay: .32s; }

/* 标题渐变缓慢流动 */
.hero h1 .grad { background-size: 200% 100%; animation: sheen 8s ease-in-out infinite alternate; }
@keyframes sheen { from { background-position: 0% 50%; } to { background-position: 100% 50%; } }
.eyebrow .dot { background-size: 200% 200%; animation: sheen 5s ease-in-out infinite alternate; }

/* 示意图：从倾斜到摆正地升起 */
.device { transition: transform 1.1s cubic-bezier(.2,.8,.2,1), opacity 1s ease; }
.js .device:not(.in) { opacity: 0; transform: perspective(1400px) rotateX(14deg) translateY(40px) scale(.95); }

/* 封面：轻微呼吸 + 五根跳动的音量条（品牌标志里的元素） */
.d-cover { animation: breathe 6s ease-in-out infinite; }
@keyframes breathe { 50% { transform: scale(1.025); } }
.d-cover .eq { position: absolute; left: 30%; right: 22%; top: 30%; bottom: 30%; display: flex; align-items: center; gap: 9%; }
.d-cover .eq i { flex: 1; background: #fff; border-radius: 99px; height: var(--h); animation: eq 1.1s ease-in-out infinite alternate; transform-origin: center; box-shadow: 0 4px 10px rgba(120,30,80,.3); }
.d-cover .eq i:nth-child(1) { --h: 100%; animation-delay: -.2s; }
.d-cover .eq i:nth-child(2) { --h: 82%; animation-delay: -.7s; }
.d-cover .eq i:nth-child(3) { --h: 64%; animation-delay: -.4s; }
.d-cover .eq i:nth-child(4) { --h: 46%; animation-delay: -.9s; }
.d-cover .eq i:nth-child(5) { --h: 30%; animation-delay: -.1s; }
@keyframes eq { from { transform: scaleY(.45); } to { transform: scaleY(1); } }

/* 歌词：三句轮流上滚 */
.d-lyric span { grid-area: 1 / 1; text-align: center; opacity: 0; animation: lyric 12s infinite; }
.d-lyric span:nth-child(2) { animation-delay: 4s; }
.d-lyric span:nth-child(3) { animation-delay: 8s; }
@keyframes lyric {
  0% { opacity: 0; transform: translateY(80%); }
  4%, 30% { opacity: 1; transform: none; }
  34%, 100% { opacity: 0; transform: translateY(-80%); }
}

/* 进度条走动、播放键外圈脉动、「接下来」依次亮起 */
@keyframes seek { from { width: 8%; } to { width: 92%; } }
.d-ctrl .play { position: relative; }
.d-ctrl .play::after { content: ""; position: absolute; inset: 0; border-radius: 50%; border: 2px solid rgba(255,255,255,.7); animation: ring 2.4s ease-out infinite; }
@keyframes ring { from { transform: scale(1); opacity: .8; } to { transform: scale(1.4); opacity: 0; } }
.d-next div { animation: cardglow 10s ease-in-out infinite; }
.d-next div:nth-child(2) { animation-delay: 2s; }
.d-next div:nth-child(3) { animation-delay: 4s; }
.d-next div:nth-child(4) { animation-delay: 6s; }
.d-next div:nth-child(5) { animation-delay: 8s; }
@keyframes cardglow { 0%, 20%, 100% { background: rgba(255,255,255,.12); transform: none; } 8% { background: rgba(255,255,255,.26); transform: translateY(-8%); } }

/* 滚动到视野里时浮现（按同组顺序错开） */
.reveal { transition: opacity .8s ease, transform .8s cubic-bezier(.2,.8,.2,1); transition-delay: var(--d, 0s); }
.js .reveal:not(.in) { opacity: 0; transform: translateY(26px); }

/* 卡片与按钮的悬停反馈 */
.feature { transition: transform .35s cubic-bezier(.2,.8,.2,1), box-shadow .35s, border-color .35s; }
.feature:hover { transform: translateY(-4px); box-shadow: 0 18px 40px -20px rgba(80, 40, 120, .35); border-color: color-mix(in srgb, var(--rose) 30%, var(--line)); }
.feature .ic { transition: transform .45s cubic-bezier(.3,1.6,.5,1); }
.feature:hover .ic { transform: rotate(-8deg) scale(1.1); }
.btn { transition: transform .2s, box-shadow .2s, border-color .2s; }
a.btn:hover { transform: translateY(-2px); box-shadow: 0 10px 24px -12px rgba(0,0,0,.35); }
a.btn:active { transform: translateY(0) scale(.98); }
.doc details { transition: border-color .25s, box-shadow .25s; }
.doc details:hover { border-color: color-mix(in srgb, var(--rose) 30%, var(--line)); }
.doc details[open] > p { animation: rise .45s ease both; }

/* 结尾标志缓慢漂浮 */
.closing img { animation: float 5s ease-in-out infinite; }
@keyframes float { 50% { transform: translateY(-8px) rotate(-3deg); } }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .js .reveal:not(.in), .js .device:not(.in) { opacity: 1; transform: none; }
  .d-lyric span:first-child { opacity: 1; }
}