/* ==========================================================================
   AIMP 中文站 · 全站样式
   品牌色取自 AIMP 官方标识：#F7CA00 / #F7A200 / #000000
   ========================================================================== */

/* 1. 设计令牌
   ========================================================================== */
:root {
  --brand: #f7ca00;
  --brand-strong: #f7a200;
  --brand-soft: #fff6cc;

  --ink: #0a0a0b;
  --ink-2: #141519;
  --ink-3: #212228;

  --paper: #faf9f5;
  --surface: #ffffff;
  --surface-2: #f3f2ec;

  --line: #e4e2d9;
  --line-strong: #cfccc0;
  --line-dark: rgba(255, 255, 255, 0.1);

  --text: #121316;
  --muted: #5d5f67;
  --muted-dark: #a3a5ad;

  --radius-lg: 18px;
  --radius: 14px;
  --radius-sm: 10px;

  --shadow-sm: 0 1px 2px rgba(14, 14, 18, 0.05);
  --shadow-md: 0 2px 4px rgba(14, 14, 18, 0.04), 0 18px 40px -22px rgba(14, 14, 18, 0.35);
  --shadow-lg: 0 40px 80px -32px rgba(0, 0, 0, 0.85);

  --wrap: 1180px;
  --header-h: 74px;

  --font-sans: "Segoe UI", -apple-system, BlinkMacSystemFont, "Helvetica Neue",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC",
    "Noto Sans CJK SC", sans-serif;
  --font-mono: ui-monospace, "SFMono-Regular", "Cascadia Mono", "Segoe UI Mono",
    Consolas, "Liberation Mono", monospace;
}

/* 2. 基础重置
   ========================================================================== */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 24px);
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body.is-locked {
  overflow: hidden;
}

h1,
h2,
h3,
h4,
p,
figure,
blockquote,
dl,
dd {
  margin: 0;
}

ul,
ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

img,
svg,
video {
  display: block;
  max-width: 100%;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
  color: inherit;
  border: 0;
  background: none;
  cursor: pointer;
}

code,
kbd,
samp {
  font-family: var(--font-mono);
  font-size: 0.92em;
}

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

:focus-visible {
  outline: 2px solid var(--ink);
  outline-offset: 3px;
  border-radius: 4px;
}

.dark :focus-visible,
.hero :focus-visible,
.footer :focus-visible,
.band :focus-visible,
.skins :focus-visible,
.modal :focus-visible {
  outline-color: var(--brand);
}

/* 3. 排版与通用布局
   ========================================================================== */
.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: 24px;
}

.section {
  padding-block: 96px;
}

.section--tight {
  padding-block: 68px;
}

.section--flush-top {
  padding-top: 0;
}

.section--paper {
  background: var(--paper);
}

.section--white {
  background: var(--surface);
}

.dark {
  background: var(--ink);
  color: #fff;
}

.eyebrow {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 18px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted);
}

.eyebrow::before {
  content: "";
  width: 8px;
  height: 8px;
  flex: none;
  background: var(--brand);
}

.dark .eyebrow {
  color: var(--muted-dark);
}

.h2 {
  font-size: clamp(28px, 3.5vw, 44px);
  font-weight: 800;
  line-height: 1.14;
  letter-spacing: -0.022em;
}

.h3 {
  font-size: clamp(20px, 1.6vw, 23px);
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: -0.01em;
}

.lead {
  margin-top: 18px;
  max-width: 62ch;
  font-size: 17px;
  line-height: 1.8;
  color: var(--muted);
}

.dark .lead {
  color: var(--muted-dark);
}

.muted {
  color: var(--muted);
}

.mono {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
}

.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 48px;
  margin-bottom: 52px;
}

.section-head .lead {
  margin-top: 14px;
}

.section-head__aside {
  flex: none;
  max-width: 300px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
  text-align: right;
}

.accent {
  color: var(--brand);
}

.skip-link {
  position: absolute;
  left: 16px;
  top: -80px;
  z-index: 100;
  padding: 10px 18px;
  background: var(--brand);
  color: var(--ink);
  font-weight: 700;
  border-radius: 0 0 8px 8px;
  transition: top 0.18s ease;
}

.skip-link:focus {
  top: 0;
}

/* 4. 按钮
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  height: 48px;
  padding-inline: 24px;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.01em;
  white-space: nowrap;
  transition: background-color 0.18s ease, color 0.18s ease,
    border-color 0.18s ease, transform 0.18s ease;
}

.btn svg {
  width: 18px;
  height: 18px;
  flex: none;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn:active {
  transform: translateY(0);
}

.btn--primary {
  background: var(--brand);
  color: var(--ink);
}

.btn--primary:hover {
  background: #ffd521;
}

.btn--dark {
  background: var(--ink);
  color: #fff;
}

.btn--dark:hover {
  background: var(--ink-3);
}

.btn--ghost {
  border-color: var(--line-strong);
  color: var(--text);
}

.btn--ghost:hover {
  border-color: var(--ink);
}

.btn--on-dark {
  border-color: rgba(255, 255, 255, 0.24);
  color: #fff;
}

.btn--on-dark:hover {
  border-color: rgba(255, 255, 255, 0.6);
  background: rgba(255, 255, 255, 0.05);
}

.btn--sm {
  height: 40px;
  padding-inline: 18px;
  font-size: 14px;
}

.btn--block {
  width: 100%;
}

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 32px;
}

.link-arrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  font-weight: 700;
  border-bottom: 2px solid var(--brand);
  padding-bottom: 3px;
  transition: gap 0.18s ease;
}

.link-arrow:hover {
  gap: 12px;
}

.link-arrow svg {
  width: 15px;
  height: 15px;
}

/* 5. 站点头部
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  border-bottom: 1px solid var(--line);
  backdrop-filter: saturate(160%) blur(14px);
  transition: box-shadow 0.2s ease;
}

.site-header.is-scrolled {
  box-shadow: 0 1px 0 rgba(14, 14, 18, 0.06), 0 12px 28px -22px rgba(14, 14, 18, 0.45);
}

.header__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
  align-items: center;
  gap: 24px;
  height: var(--header-h);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex: none;
  justify-self: start;
}

.brand__mark {
  width: 30px;
  height: 30px;
}

.brand__name {
  font-size: 19px;
  font-weight: 800;
  letter-spacing: 0.04em;
  line-height: 1;
}

.brand__tag {
  padding-left: 10px;
  margin-left: 2px;
  border-left: 1px solid var(--line-strong);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.nav {
  display: flex;
  align-items: center;
  justify-self: center;
  gap: 4px;
}

.nav a {
  position: relative;
  padding: 8px 12px;
  border-radius: 6px;
  font-size: 14.5px;
  font-weight: 500;
  color: var(--muted);
  transition: color 0.16s ease, background-color 0.16s ease;
}

.nav a:hover {
  color: var(--text);
  background: var(--surface-2);
}

.nav a[aria-current="page"] {
  color: var(--text);
  font-weight: 700;
}

.nav a[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 12px;
  right: 12px;
  bottom: 1px;
  height: 2px;
  background: var(--brand);
}

.header__actions {
  display: flex;
  align-items: center;
  justify-self: end;
  gap: 10px;
}

.header__version {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.04em;
  color: var(--muted);
  padding-right: 4px;
}

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line-strong);
  border-radius: 8px;
}

.nav-toggle svg {
  width: 20px;
  height: 20px;
}

.nav-toggle .icon-close {
  display: none;
}

[data-nav-open="true"] .nav-toggle .icon-menu {
  display: none;
}

[data-nav-open="true"] .nav-toggle .icon-close {
  display: block;
}

/* 6. 首页 Hero
   ========================================================================== */
.hero {
  position: relative;
  overflow: hidden;
  background: var(--ink);
  color: #fff;
  padding-block: 88px 96px;
}

.hero::before {
  content: "";
  position: absolute;
  top: -320px;
  right: -180px;
  width: 760px;
  height: 760px;
  background: radial-gradient(circle, rgba(247, 202, 0, 0.2) 0%, rgba(247, 202, 0, 0) 62%);
  pointer-events: none;
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(rgba(255, 255, 255, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.035) 1px, transparent 1px);
  background-size: 72px 72px;
  mask-image: radial-gradient(circle at 20% 10%, #000 0%, transparent 72%);
  -webkit-mask-image: radial-gradient(circle at 20% 10%, #000 0%, transparent 72%);
  pointer-events: none;
}

.hero__inner {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 1.02fr) minmax(0, 0.98fr);
  align-items: center;
  gap: 64px;
}

.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  margin-bottom: 26px;
  padding: 7px 13px;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.04em;
  color: #dedfe3;
}

.hero__badge b {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--brand);
}

.hero h1 {
  font-size: clamp(38px, 5vw, 54px);
  font-weight: 800;
  line-height: 1.06;
  letter-spacing: -0.03em;
}

.hero h1 span {
  display: block;
  color: var(--brand);
}

.hero__lead {
  margin-top: 24px;
  max-width: 33em;
  font-size: 16.5px;
  line-height: 1.85;
  color: #b9bbc2;
}

.hero__facts {
  display: flex;
  flex-wrap: wrap;
  gap: 28px;
  margin-top: 38px;
  padding-top: 26px;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
}

.hero__fact strong {
  display: block;
  font-size: 25px;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.01em;
}

.hero__fact span {
  display: block;
  margin-top: 2px;
  font-size: 12px;
  letter-spacing: 0.04em;
  color: #8f9199;
}

.hero__note {
  margin-top: 22px;
  font-size: 12.5px;
  color: #83858d;
}

/* 7. 播放器界面示意
   ========================================================================== */
.hero__visual {
  position: relative;
}

.player {
  position: relative;
  z-index: 2;
  width: 100%;
  background: #0f1014;
  border: 1px solid rgba(255, 255, 255, 0.09);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
}

.player__bar {
  display: flex;
  align-items: center;
  gap: 7px;
  height: 38px;
  padding-inline: 14px;
  background: #16171c;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.player__dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #2c2e36;
}

.player__bar-title {
  margin-left: 8px;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  color: #6e7079;
}

.player__body {
  padding: 22px 22px 18px;
}

.player__now {
  display: flex;
  align-items: center;
  gap: 16px;
}

.player__cover {
  position: relative;
  width: 86px;
  height: 86px;
  flex: none;
  border-radius: 10px;
  background: radial-gradient(circle at 50% 50%, #1b1c22 0 17%, #f7ca00 17% 20%, #101116 20% 34%, #1b1c22 34% 36%, #101116 36% 52%, #1b1c22 52% 54%, #101116 54% 100%);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.08);
}

.player__cover::after {
  content: "";
  position: absolute;
  inset: 41px;
  border-radius: 50%;
  background: #f7ca00;
}

.player__meta {
  min-width: 0;
}

.player__track {
  font-size: 15px;
  font-weight: 700;
  color: #f4f4f6;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.player__artist {
  margin-top: 3px;
  font-size: 11.5px;
  color: #8b8d95;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.player__eq {
  display: flex;
  align-items: flex-end;
  gap: 3px;
  height: 26px;
  margin-top: 12px;
}

.player__eq i {
  width: 3px;
  height: 30%;
  background: var(--brand);
  transform-origin: bottom;
  animation: eq 1.15s ease-in-out infinite alternate;
}

.player__eq i:nth-child(2) { height: 62%; animation-delay: -0.15s; }
.player__eq i:nth-child(3) { height: 44%; animation-delay: -0.4s; }
.player__eq i:nth-child(4) { height: 82%; animation-delay: -0.05s; }
.player__eq i:nth-child(5) { height: 55%; animation-delay: -0.55s; }
.player__eq i:nth-child(6) { height: 92%; animation-delay: -0.3s; }
.player__eq i:nth-child(7) { height: 40%; animation-delay: -0.7s; }
.player__eq i:nth-child(8) { height: 70%; animation-delay: -0.2s; }
.player__eq i:nth-child(9) { height: 50%; animation-delay: -0.62s; }
.player__eq i:nth-child(10) { height: 86%; animation-delay: -0.12s; }
.player__eq i:nth-child(11) { height: 34%; animation-delay: -0.48s; }
.player__eq i:nth-child(12) { height: 66%; animation-delay: -0.34s; }

@keyframes eq {
  from { transform: scaleY(0.35); }
  to { transform: scaleY(1); }
}

.player__seek {
  position: relative;
  height: 4px;
  margin-top: 20px;
  border-radius: 2px;
  background: rgba(255, 255, 255, 0.12);
}

.player__seek span {
  position: absolute;
  inset: 0 auto 0 0;
  width: 38%;
  border-radius: 2px;
  background: var(--brand);
}

.player__seek span::after {
  content: "";
  position: absolute;
  right: -4px;
  top: -3px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #fff;
}

.player__times {
  display: flex;
  justify-content: space-between;
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: 10px;
  color: #767882;
}

.player__controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  margin-top: 14px;
}

.player__controls span {
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  color: #8e9098;
}

.player__controls span svg {
  width: 16px;
  height: 16px;
}

.player__play {
  width: 42px !important;
  height: 42px !important;
  border-radius: 50%;
  background: var(--brand);
  color: var(--ink) !important;
}

.player__play svg {
  width: 17px !important;
  height: 17px !important;
}

.player__list {
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  padding: 8px;
}

.player__list li {
  display: grid;
  grid-template-columns: 26px minmax(0, 1fr) auto;
  align-items: center;
  gap: 10px;
  padding: 9px 10px;
  border-radius: 8px;
  font-size: 12px;
  color: #a4a6ae;
}

.player__list li.is-active {
  background: rgba(247, 202, 0, 0.1);
  color: #fff;
}

.player__list .idx {
  font-family: var(--font-mono);
  font-size: 10px;
  color: #6c6e77;
}

.player__list li.is-active .idx {
  color: var(--brand);
}

.player__list .t {
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}

.player__list .d {
  font-family: var(--font-mono);
  font-size: 10px;
  color: #6c6e77;
}

.hero__chip {
  position: absolute;
  z-index: 3;
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 11px 15px;
  background: #fff;
  color: var(--ink);
  border-radius: 10px;
  box-shadow: 0 18px 40px -18px rgba(0, 0, 0, 0.9);
  font-size: 12px;
  font-weight: 700;
  white-space: nowrap;
}

.hero__chip svg {
  width: 16px;
  height: 16px;
  color: var(--brand-strong);
}

.hero__chip--a {
  top: 34px;
  right: -22px;
}

.hero__chip--b {
  bottom: -34px;
  left: -26px;
}

/* 8. 数据条
   ========================================================================== */
.factbar {
  background: var(--surface);
  border-bottom: 1px solid var(--line);
}

.factbar__grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.factbar__item {
  padding: 30px 26px;
  border-left: 1px solid var(--line);
}

.factbar__item:first-child {
  border-left: 0;
  padding-left: 0;
}

.factbar__item strong {
  display: block;
  font-size: 27px;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.factbar__item strong em {
  font-style: normal;
  font-size: 15px;
  font-weight: 600;
  margin-left: 2px;
  color: var(--muted);
}

.factbar__item span {
  display: block;
  margin-top: 4px;
  font-size: 12.5px;
  color: var(--muted);
}

/* 9. 卡片网格
   ========================================================================== */
.grid {
  display: grid;
  gap: 20px;
}

.grid--3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.grid--2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.grid--4 {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.card {
  position: relative;
  padding: 28px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.card:hover {
  border-color: var(--line-strong);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.card__icon {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  margin-bottom: 20px;
  border-radius: 9px;
  background: var(--ink);
  color: var(--brand);
}

.card__icon svg {
  width: 21px;
  height: 21px;
}

.card .h3 {
  margin-bottom: 9px;
}

.card p {
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--muted);
}

.card__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 18px;
}

.tag {
  display: inline-flex;
  align-items: center;
  height: 24px;
  padding-inline: 9px;
  border: 1px solid var(--line);
  border-radius: 5px;
  background: var(--paper);
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.03em;
  color: var(--muted);
}

.tag--brand {
  background: var(--brand-soft);
  border-color: #f0dfa0;
  color: #6b5400;
}

.card--flat:hover {
  transform: none;
  box-shadow: none;
}

/* 10. 使用场景
   ========================================================================== */
.scenarios {
  display: grid;
  grid-template-columns: minmax(0, 0.82fr) minmax(0, 1.18fr);
  gap: 72px;
  align-items: start;
}

.scenarios__intro {
  position: sticky;
  top: calc(var(--header-h) + 40px);
}

.scenario {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr);
  gap: 8px 20px;
  padding-block: 26px;
  border-top: 1px solid var(--line);
}

.scenario:first-child {
  border-top: 0;
  padding-top: 0;
}

.scenario__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--brand-strong);
  padding-top: 4px;
}

.scenario h3 {
  font-size: 17.5px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.scenario p {
  grid-column: 2;
  margin-top: 6px;
  max-width: 46em;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--muted);
}

/* 11. 皮肤区块
   ========================================================================== */
.skins {
  position: relative;
  overflow: hidden;
}

.skins__grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.skin {
  padding: 14px;
  background: #111216;
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius);
  transition: transform 0.2s ease, border-color 0.2s ease;
}

.skin:hover {
  transform: translateY(-3px);
  border-color: rgba(247, 202, 0, 0.45);
}

.skin__preview {
  height: 158px;
  border-radius: 8px;
  padding: 12px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  overflow: hidden;
}

.skin__bar {
  display: flex;
  align-items: center;
  gap: 5px;
}

.skin__bar i {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: currentColor;
  opacity: 0.35;
}

.skin__line {
  height: 6px;
  border-radius: 3px;
  background: currentColor;
  opacity: 0.16;
}

.skin__line--w60 { width: 60%; }
.skin__line--w40 { width: 40%; }
.skin__line--w80 { width: 80%; }

.skin__wave {
  display: flex;
  align-items: flex-end;
  gap: 3px;
  height: 44px;
  margin-top: auto;
}

.skin__wave i {
  flex: 1;
  height: 28%;
  background: currentColor;
  border-radius: 1px;
}

.skin__wave i:nth-child(2) { height: 64%; }
.skin__wave i:nth-child(3) { height: 42%; }
.skin__wave i:nth-child(4) { height: 88%; }
.skin__wave i:nth-child(5) { height: 56%; }
.skin__wave i:nth-child(6) { height: 74%; }
.skin__wave i:nth-child(7) { height: 36%; }
.skin__wave i:nth-child(8) { height: 66%; }
.skin__wave i:nth-child(9) { height: 48%; }
.skin__wave i:nth-child(10) { height: 80%; }
.skin__wave i:nth-child(11) { height: 30%; }
.skin__wave i:nth-child(12) { height: 58%; }

.skin--charm .skin__preview {
  background: #16171c;
  color: var(--brand);
  border: 1px solid rgba(255, 255, 255, 0.07);
}

.skin--bliss .skin__preview {
  background: #e8eef3;
  color: #2b5f78;
  border: 1px solid rgba(0, 0, 0, 0.08);
}

.skin--pandemic .skin__preview {
  background: #2b2f2c;
  color: #c8d0c4;
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.skin__name {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 4px 4px;
}

.skin__name h3 {
  font-size: 15px;
  font-weight: 700;
}

.skin__name span {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.05em;
  color: #85878f;
}

.skin__desc {
  padding-inline: 4px;
  font-size: 12.5px;
  line-height: 1.65;
  color: #9a9ca4;
}

/* 12. 黄色下载横幅
   ========================================================================== */
.band {
  position: relative;
  background: var(--brand);
  color: var(--ink);
  padding-block: 72px;
  overflow: hidden;
}

.band::after {
  content: "";
  position: absolute;
  right: -60px;
  top: -60px;
  width: 320px;
  height: 320px;
  border: 1px solid rgba(10, 10, 11, 0.16);
  border-radius: 50%;
  box-shadow: 0 0 0 40px rgba(10, 10, 11, 0.06), 0 0 0 80px rgba(10, 10, 11, 0.04);
  pointer-events: none;
}

.band__inner {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 48px;
}

.band h2 {
  font-size: clamp(26px, 3.2vw, 40px);
  font-weight: 800;
  line-height: 1.16;
  letter-spacing: -0.02em;
}

.band p {
  margin-top: 12px;
  max-width: 46ch;
  font-size: 15px;
  line-height: 1.75;
  color: rgba(10, 10, 11, 0.72);
}

.band__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  margin-top: 18px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: rgba(10, 10, 11, 0.72);
}

.band__action {
  flex: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
  align-items: flex-start;
}

.band__action .mono {
  font-size: 11px;
  color: rgba(10, 10, 11, 0.72);
}

.band .btn--ghost {
  border-color: rgba(10, 10, 11, 0.38);
  color: var(--ink);
}

.band .btn--ghost:hover {
  border-color: var(--ink);
}

/* 13. FAQ
   ========================================================================== */
.faq-list {
  max-width: 900px;
  border-top: 1px solid var(--line);
}

.faq {
  border-bottom: 1px solid var(--line);
}

.faq summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding-block: 22px;
  font-size: 16.5px;
  font-weight: 600;
  letter-spacing: -0.005em;
  cursor: pointer;
  list-style: none;
}

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

.faq summary::after {
  content: "";
  width: 14px;
  height: 14px;
  flex: none;
  border-right: 2px solid var(--muted);
  border-bottom: 2px solid var(--muted);
  transform: rotate(45deg) translateY(-3px);
  transition: transform 0.2s ease;
}

.faq[open] summary::after {
  transform: rotate(-135deg) translateY(-3px);
}

.faq__body {
  padding-bottom: 24px;
  max-width: 72ch;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--muted);
}

.faq__body p + p {
  margin-top: 10px;
}

.faq__body a {
  color: var(--text);
  border-bottom: 1px solid var(--brand);
}

/* 14. 内页头部
   ========================================================================== */
.page-head {
  position: relative;
  padding-block: 64px 58px;
  background: var(--ink);
  color: #fff;
  overflow: hidden;
}

.page-head::before {
  content: "";
  position: absolute;
  right: -120px;
  top: -220px;
  width: 560px;
  height: 560px;
  background: radial-gradient(circle, rgba(247, 202, 0, 0.16) 0%, transparent 64%);
}

.page-head::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: rgba(255, 255, 255, 0.1);
}

.page-head__inner {
  position: relative;
  z-index: 1;
  max-width: 860px;
}

.page-head h1 {
  font-size: clamp(32px, 4.2vw, 52px);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.025em;
}

.page-head p {
  margin-top: 18px;
  max-width: 60ch;
  font-size: 16px;
  line-height: 1.8;
  color: #b4b6bd;
}

.page-head__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 28px;
  margin-top: 28px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: #8d8f97;
}

.page-head__meta b {
  color: var(--brand);
  font-weight: 600;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-bottom: 22px;
  font-size: 12px;
  color: #8d8f97;
}

.breadcrumb a:hover {
  color: #fff;
}

.breadcrumb span {
  color: #9a9ca4;
}

.breadcrumb i {
  font-style: normal;
  color: #74767e;
  font-size: 11px;
}

.dark .section-head__aside {
  border-top-color: rgba(255, 255, 255, 0.16);
}

/* 15. 下载页
   ========================================================================== */
.dl-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

.dl-card {
  display: flex;
  flex-direction: column;
  padding: 30px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.dl-card:hover {
  border-color: var(--line-strong);
  box-shadow: var(--shadow-md);
}

.dl-card--featured {
  border-color: #e6cf70;
  background: linear-gradient(180deg, #fffdf2 0%, #ffffff 42%);
}

.dl-card__top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
}

.dl-card__platform {
  display: flex;
  align-items: center;
  gap: 12px;
}

.dl-card__platform svg {
  width: 26px;
  height: 26px;
  color: var(--ink);
}

.dl-card__os {
  font-size: 12px;
  color: var(--muted);
  letter-spacing: 0.02em;
}

.dl-card__name {
  font-size: 19px;
  font-weight: 800;
  letter-spacing: -0.01em;
  line-height: 1.3;
}

.badge {
  display: inline-flex;
  align-items: center;
  height: 23px;
  padding-inline: 9px;
  border-radius: 4px;
  font-size: 10.5px;
  font-weight: 700;
  letter-spacing: 0.06em;
  background: var(--ink);
  color: var(--brand);
  white-space: nowrap;
}

.badge--soft {
  background: var(--surface-2);
  color: var(--muted);
  border: 1px solid var(--line);
}

.badge--warn {
  background: #fff2d6;
  color: #7a5200;
  border: 1px solid #f0dcae;
}

.dl-card__specs {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px 20px;
  margin-top: 22px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}

.dl-card__specs dt {
  font-size: 11.5px;
  color: var(--muted);
}

.dl-card__specs dd {
  margin-top: 1px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--text);
  word-break: break-all;
}

.dl-card__foot {
  margin-top: auto;
  padding-top: 24px;
}

.dl-card__hint {
  margin-top: 10px;
  font-size: 11.5px;
  line-height: 1.6;
  color: var(--muted);
  text-align: center;
}

.notice {
  display: flex;
  gap: 16px;
  margin-top: 24px;
  padding: 20px 22px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-left: 3px solid var(--brand);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.notice svg {
  width: 20px;
  height: 20px;
  flex: none;
  margin-top: 2px;
  color: var(--brand-strong);
}

.notice h3 {
  font-size: 14.5px;
  font-weight: 700;
  margin-bottom: 4px;
}

.notice p {
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--muted);
}

.spec-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}

.spec-table caption {
  text-align: left;
  font-size: 12px;
  color: var(--muted);
  padding-bottom: 12px;
}

.spec-table th,
.spec-table td {
  padding: 15px 16px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--line);
}

.spec-table th {
  width: 190px;
  font-weight: 600;
  color: var(--muted);
  background: var(--paper);
}

.spec-table td {
  color: var(--text);
}

.spec-table tr:last-child th,
.spec-table tr:last-child td {
  border-bottom: 0;
}

.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.table-wrap .spec-table th:first-child,
.table-wrap .spec-table td:first-child {
  padding-left: 24px;
}

.table-wrap .spec-table th:last-child,
.table-wrap .spec-table td:last-child {
  padding-right: 24px;
}

.hash {
  display: flex;
  align-items: flex-start;
  gap: 10px;
}

.hash code {
  flex: 1;
}

.hash code {
  font-size: 11.5px;
  word-break: break-all;
  color: var(--muted);
}

.copy-btn {
  flex: none;
  margin-left: auto;
  display: inline-grid;
  place-items: center;
  width: 28px;
  height: 28px;
  border: 1px solid var(--line);
  border-radius: 5px;
  color: var(--muted);
  transition: color 0.16s ease, border-color 0.16s ease;
}

.copy-btn:hover {
  color: var(--ink);
  border-color: var(--ink);
}

.copy-btn svg {
  width: 13px;
  height: 13px;
}

.copy-btn.is-done {
  color: #1f7a45;
  border-color: #b7e0c6;
}

.steps {
  counter-reset: step;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.step {
  background: var(--surface);
  padding: 26px 24px 30px;
}

.step::before {
  counter-increment: step;
  content: "0" counter(step);
  display: block;
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--brand-strong);
}

.step h3 {
  font-size: 15.5px;
  font-weight: 700;
  margin-bottom: 6px;
}

.step p {
  font-size: 13.5px;
  line-height: 1.72;
  color: var(--muted);
}

/* 16. 功能页
   ========================================================================== */
.feature-block {
  display: grid;
  grid-template-columns: minmax(0, 0.72fr) minmax(0, 1.28fr);
  gap: 56px;
  padding-block: 56px;
  border-top: 1px solid var(--line);
}

.feature-block:first-of-type {
  border-top: 0;
  padding-top: 0;
}

.feature-block__aside {
  position: sticky;
  top: calc(var(--header-h) + 36px);
}

.feature-block__aside .mono {
  color: var(--brand-strong);
  letter-spacing: 0.1em;
}

.feature-block__aside h2 {
  margin-top: 10px;
  font-size: clamp(24px, 2.4vw, 30px);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.feature-block__aside p {
  margin-top: 12px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

.feature-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.feature-list li {
  background: var(--surface);
  padding: 20px 22px;
}

.feature-list h3 {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14.5px;
  font-weight: 700;
  margin-bottom: 5px;
}

.feature-list h3::before {
  content: "";
  width: 5px;
  height: 5px;
  flex: none;
  background: var(--brand);
}

.feature-list p {
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

.format-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
}

.format {
  display: inline-flex;
  align-items: center;
  height: 30px;
  padding-inline: 11px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 5px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.02em;
  color: var(--text);
}

.format--brand {
  background: var(--brand);
  border-color: var(--brand);
  font-weight: 700;
  color: var(--ink);
}

/* 17. 指南页
   ========================================================================== */
.guide-grid {
  display: grid;
  grid-template-columns: 240px minmax(0, 1fr);
  gap: 64px;
  align-items: start;
}

.toc {
  position: sticky;
  top: calc(var(--header-h) + 36px);
  padding: 22px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.toc p {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 12px;
}

.toc ol {
  display: grid;
  gap: 2px;
  counter-reset: toc;
}

.toc a {
  display: block;
  padding: 7px 8px;
  border-radius: 5px;
  font-size: 13.5px;
  color: var(--muted);
  transition: color 0.16s ease, background-color 0.16s ease;
}

.toc a:hover {
  color: var(--ink);
  background: var(--surface-2);
}

.toc a::before {
  counter-increment: toc;
  content: counter(toc, decimal-leading-zero);
  margin-right: 8px;
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--brand-strong);
}

.prose {
  max-width: 780px;
}

.prose > section {
  padding-block: 40px;
  border-top: 1px solid var(--line);
}

.prose > section:first-child {
  border-top: 0;
  padding-top: 0;
}

.prose h2 {
  font-size: clamp(22px, 2.2vw, 28px);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.25;
  margin-bottom: 8px;
}

.prose h3 {
  margin-top: 28px;
  margin-bottom: 6px;
  font-size: 16px;
  font-weight: 700;
}

.prose p {
  margin-top: 12px;
  font-size: 15px;
  line-height: 1.9;
  color: #3f4148;
}

.prose ul {
  margin-top: 14px;
  display: grid;
  gap: 8px;
}

.prose ul li {
  position: relative;
  padding-left: 20px;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--muted);
}

.prose ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 11px;
  width: 6px;
  height: 6px;
  background: var(--brand);
}

.prose .note-inline {
  margin-top: 20px;
  padding: 16px 18px;
  background: var(--surface-2);
  border-radius: var(--radius-sm);
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--muted);
}

.prose .note-inline strong {
  color: var(--ink);
}

/* 18. 关于页
   ========================================================================== */
.about-lead {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(0, 0.75fr);
  gap: 64px;
  align-items: start;
}

.about-lead .h2 {
  max-width: 18em;
}

.quote {
  padding: 24px 26px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-left: 3px solid var(--brand);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--muted);
}

.quote cite {
  display: block;
  margin-top: 12px;
  font-style: normal;
  font-size: 12px;
  font-family: var(--font-mono);
  color: var(--muted);
}

.timeline {
  position: relative;
  margin-top: 8px;
  border-left: 1px solid var(--line-strong);
  padding-left: 32px;
  display: grid;
  gap: 34px;
}

.timeline__item {
  position: relative;
}

.timeline__item::before {
  content: "";
  position: absolute;
  left: -37px;
  top: 9px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--brand);
  box-shadow: 0 0 0 4px var(--paper);
}

.timeline__year {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--brand-strong);
}

.timeline__item h3 {
  margin-top: 3px;
  font-size: 16.5px;
  font-weight: 700;
}

.timeline__item p {
  margin-top: 4px;
  max-width: 60ch;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

.source-list {
  display: grid;
  gap: 0;
  margin-top: 20px;
  border-top: 1px solid var(--line);
}

.source-list li {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding-block: 13px;
  border-bottom: 1px solid var(--line);
  font-size: 13.5px;
}

.source-list span:last-child {
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--muted);
  white-space: nowrap;
}

.about-aside {
  display: grid;
  gap: 16px;
}

.about-facts {
  margin-top: 0;
  border-top: 1px solid var(--line);
}

.about-facts li {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding-block: 11px;
  border-bottom: 1px solid var(--line);
  font-size: 12.5px;
  color: var(--muted);
}

.about-facts strong {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  color: var(--text);
  letter-spacing: 0.02em;
}

.author-box {
  display: flex;
  gap: 18px;
  padding: 24px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.author-box__avatar {
  display: grid;
  place-items: center;
  width: 52px;
  height: 52px;
  flex: none;
  border-radius: 50%;
  background: var(--brand);
  color: var(--ink);
  font-weight: 800;
  font-size: 18px;
}

.author-box h3 {
  font-size: 15px;
  font-weight: 700;
}

.author-box p {
  margin-top: 4px;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--muted);
}

/* 19. 页脚
   ========================================================================== */
.footer {
  background: var(--ink);
  color: #fff;
  padding-block: 64px 32px;
}

.footer__top {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) repeat(4, minmax(0, 0.62fr));
  gap: 40px;
  padding-bottom: 48px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer__brand .brand__name {
  color: #fff;
}

.footer__brand p {
  margin-top: 16px;
  max-width: 34ch;
  font-size: 13.5px;
  line-height: 1.8;
  color: #8f9199;
}

.footer__col h4 {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #8a8c94;
  margin-bottom: 14px;
}

.footer__col ul {
  display: grid;
  gap: 9px;
}

.footer__col a {
  font-size: 13.5px;
  color: #b9bbc2;
  transition: color 0.16s ease;
}

.footer__col a:hover {
  color: var(--brand);
}

.footer__bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 16px;
  padding-top: 26px;
  font-size: 11.5px;
  line-height: 1.8;
  color: #8a8c94;
}

.footer__bottom p {
  max-width: 76ch;
}

.footer__legal {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

/* 20. 弹窗
   ========================================================================== */
.modal {
  position: fixed;
  inset: 0;
  z-index: 120;
  display: grid;
  place-items: center;
  padding: 20px;
}

.modal[hidden] {
  display: none;
}

.modal__backdrop {
  position: absolute;
  inset: 0;
  background: rgba(6, 6, 8, 0.66);
  backdrop-filter: blur(3px);
  animation: fade 0.18s ease-out;
}

.modal__panel {
  position: relative;
  width: 100%;
  max-width: 560px;
  max-height: calc(100dvh - 40px);
  overflow-y: auto;
  background: var(--surface);
  border-radius: var(--radius-lg);
  box-shadow: 0 40px 100px -30px rgba(0, 0, 0, 0.7);
  animation: pop 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes fade {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes pop {
  from { opacity: 0; transform: translateY(10px) scale(0.985); }
  to { opacity: 1; transform: none; }
}

.modal__head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 20px;
  padding: 26px 28px 0;
}

.modal__head h2 {
  font-size: 21px;
  font-weight: 800;
  letter-spacing: -0.01em;
}

.modal__head p {
  margin-top: 6px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

.modal__close {
  flex: none;
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--muted);
  transition: color 0.16s ease, border-color 0.16s ease, background-color 0.16s ease;
}

.modal__close:hover {
  color: var(--ink);
  border-color: var(--ink);
  background: var(--paper);
}

.modal__close svg {
  width: 16px;
  height: 16px;
}

.modal__body {
  padding: 22px 28px 26px;
}

.qr-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.qr {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.qr__box {
  position: relative;
  display: grid;
  place-items: center;
  width: 100%;
  aspect-ratio: 1 / 1;
  padding: 12px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
}

.qr__box img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.qr__label {
  font-size: 13px;
  font-weight: 700;
  text-align: center;
  letter-spacing: 0.01em;
}

.qr__sub {
  font-size: 11.5px;
  color: var(--muted);
  text-align: center;
}

.modal__note {
  display: flex;
  gap: 10px;
  margin-top: 20px;
  padding: 12px 14px;
  background: var(--paper);
  border-radius: 8px;
  font-size: 12px;
  line-height: 1.75;
  color: var(--muted);
}

.modal__note svg {
  width: 15px;
  height: 15px;
  flex: none;
  margin-top: 2px;
  color: var(--brand-strong);
}

.modal__foot {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px;
  padding: 16px 28px;
  border-top: 1px solid var(--line);
  background: var(--paper);
  font-family: var(--font-mono);
  font-size: 10.5px;
  color: var(--muted);
}

/* 21. 进场动画
   ========================================================================== */
.js .reveal.reveal-armed {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.6s ease, transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.js .reveal.reveal-armed.is-in {
  opacity: 1;
  transform: none;
}

/* 22. 响应式
   ========================================================================== */
@media (max-width: 1080px) {
  .header__inner {
    gap: 16px;
  }

  .hero__inner {
    grid-template-columns: 1fr;
    gap: 52px;
  }

  .hero__visual {
    max-width: 560px;
  }

  .hero__lead {
    max-width: 40em;
  }

  .hero__chip--a {
    right: 0;
  }

  .scenarios {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .scenarios__intro {
    position: static;
  }

  .feature-block {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .feature-block__aside {
    position: static;
  }

  .guide-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .toc {
    position: static;
  }

  .about-lead {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .footer__top {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 36px;
  }

  .footer__brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 900px) {
  .header__inner {
    display: flex;
    justify-content: space-between;
  }

  .nav {
    position: absolute;
    top: 100%;
    right: 0;
    bottom: auto;
    left: 0;
    width: 100%;
    justify-self: auto;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    padding: 14px 24px 22px;
    background: var(--surface);
    border-bottom: 1px solid var(--line);
    box-shadow: 0 24px 40px -28px rgba(14, 14, 18, 0.5);
  }

  [data-nav-open="true"] .nav {
    display: flex;
  }

  .nav a {
    padding: 12px 10px;
    font-size: 15px;
    border-radius: 8px;
  }

  .nav a[aria-current="page"] {
    background: var(--surface-2);
  }

  .nav a[aria-current="page"]::after {
    display: none;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .header__version {
    display: none;
  }

  .grid--3,
  .grid--4 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .skins__grid {
    grid-template-columns: 1fr;
  }

  .steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .section {
    padding-block: 72px;
  }

  .section-head {
    flex-direction: column;
    align-items: flex-start;
    gap: 20px;
    margin-bottom: 40px;
  }

  .section-head__aside {
    text-align: left;
    max-width: none;
  }

  .band__inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 28px;
  }

  .factbar__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .factbar__item:nth-child(3) {
    border-left: 0;
    padding-left: 0;
  }

  .factbar__item:nth-child(1),
  .factbar__item:nth-child(2) {
    border-bottom: 1px solid var(--line);
  }
}

@media (max-width: 680px) {
  :root {
    --header-h: 66px;
  }

  body {
    font-size: 15.5px;
  }

  .wrap {
    padding-inline: 18px;
  }

  .section {
    padding-block: 56px;
  }

  .brand__tag {
    display: none;
  }

  .brand__name {
    font-size: 17px;
  }

  .hero {
    padding-block: 56px 64px;
  }

  .hero__lead {
    font-size: 15.5px;
  }

  .hero__facts {
    gap: 20px;
  }

  .hero__fact strong {
    font-size: 21px;
  }

  .hero__chip--a {
    top: -14px;
    right: 8px;
  }

  .hero__chip--b {
    bottom: -30px;
    left: 8px;
  }

  .hero__facts {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px 20px;
  }

  .section-head__aside {
    border-top: 1px solid var(--line);
    padding-top: 16px;
  }

  .band__meta {
    display: grid;
    gap: 6px;
    font-size: 11px;
  }

  .skin__preview {
    height: 142px;
  }

  .grid--3,
  .grid--4,
  .grid--2,
  .dl-grid,
  .feature-list,
  .qr-grid,
  .steps {
    grid-template-columns: 1fr;
  }

  .qr__box {
    max-width: 240px;
  }

  .factbar__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .factbar__item {
    border-left: 1px solid var(--line);
    padding: 18px 16px;
    border-bottom: 1px solid var(--line);
  }

  .factbar__item:nth-child(odd) {
    border-left: 0;
    padding-left: 0;
  }

  .factbar__item:nth-child(even) {
    padding-right: 0;
  }

  .factbar__item:nth-child(3),
  .factbar__item:nth-child(4) {
    border-bottom: 0;
  }

  .card {
    padding: 22px;
  }

  .scenario {
    grid-template-columns: 40px minmax(0, 1fr);
    padding-block: 20px;
  }

  .dl-card {
    padding: 22px;
  }

  .dl-card__specs {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px 14px;
  }

  .spec-table th {
    width: 120px;
  }

  .spec-table th,
  .spec-table td {
    padding: 12px;
    font-size: 13px;
  }

  .table-wrap .spec-table th:first-child,
  .table-wrap .spec-table td:first-child {
    padding-left: 16px;
  }

  .footer__top {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .footer {
    padding-top: 48px;
  }

  .modal {
    padding: 10px;
  }

  .modal__head {
    padding: 22px 20px 0;
  }

  .modal__body {
    padding: 18px 20px 22px;
  }

  .qr__box {
    max-width: 190px;
  }

  .qr {
    gap: 10px;
  }

  .modal__foot {
    padding: 14px 20px;
  }

  .band {
    padding-block: 52px;
  }

  .page-head {
    padding-block: 40px 36px;
  }

  .toc {
    padding: 18px;
  }

  .toc ol {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .toc a {
    padding: 6px 6px;
    font-size: 12.5px;
  }

  .btn {
    height: 46px;
    padding-inline: 20px;
  }

  .btn-row .btn {
    flex: 1 1 100%;
  }

  .author-box {
    flex-direction: column;
  }
}

/* 23. 无障碍与偏好
   ========================================================================== */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }

  .js .reveal.reveal-armed {
    opacity: 1;
    transform: none;
  }
}

@media (prefers-contrast: more) {
  :root {
    --line: #b8b5a8;
    --muted: #3f4147;
  }
}

.visually-hidden {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}


/* 19. 相关专题（站内内链模块）
   ========================================================================== */
.next-read {
  padding-block: 64px 72px;
  background: var(--paper);
  border-top: 1px solid var(--line);
}

.next-read__head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 32px;
  margin-bottom: 30px;
}

.next-read__note {
  max-width: 26em;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
  text-align: right;
}

.next-read__grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border-top: 1px solid var(--line-strong);
}

.next-read__item {
  position: relative;
  display: grid;
  align-content: start;
  gap: 7px;
  padding: 26px 30px 30px 0;
  border-bottom: 1px solid var(--line);
}

.next-read__item + .next-read__item {
  padding-left: 30px;
  border-left: 1px solid var(--line);
}

.next-read__kicker {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  color: var(--brand-strong);
}

.next-read__title {
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.next-read__desc {
  padding-right: 26px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--muted);
}

.next-read__arrow {
  position: absolute;
  right: 28px;
  bottom: 30px;
  display: inline-flex;
  color: var(--line-strong);
  transition: color 0.18s ease, transform 0.18s ease;
}

.next-read__arrow svg {
  width: 18px;
  height: 18px;
}

.next-read__item:hover .next-read__title {
  text-decoration: underline;
  text-decoration-color: var(--brand);
  text-underline-offset: 4px;
}

.next-read__item:hover .next-read__arrow {
  color: var(--ink);
  transform: translateX(3px);
}

/* 20. 正文内链与有序列表
   ========================================================================== */
.prose a {
  color: var(--ink);
  border-bottom: 1px solid var(--brand);
  transition: background-color 0.16s ease;
}

.prose a:hover {
  background: var(--brand-soft);
}

.prose ol {
  margin-top: 14px;
  display: grid;
  gap: 10px;
  counter-reset: prose-step;
}

.prose ol li {
  position: relative;
  padding-left: 34px;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--muted);
  counter-increment: prose-step;
}

.prose ol li::before {
  content: counter(prose-step, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 2px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  color: var(--brand-strong);
}

@media (max-width: 900px) {
  .next-read {
    padding-block: 48px 56px;
  }

  .next-read__head {
    display: block;
    margin-bottom: 22px;
  }

  .next-read__note {
    max-width: none;
    margin-top: 10px;
    text-align: left;
  }

  .next-read__grid {
    grid-template-columns: 1fr;
  }

  .next-read__item {
    padding: 20px 0 22px;
  }

  .next-read__item + .next-read__item {
    padding-left: 0;
    border-left: 0;
  }

  .next-read__arrow {
    right: 0;
    bottom: 24px;
  }
}