/* =========================================================
   乐投游艺 · 共享样式 /assets/site.css
   结构：变量 → 基础 → 布局 → 按钮标签 → 卡片图片 → 页头 → 页脚 → 响应式 → 动效
   ========================================================= */

/* ---------- 01. 设计变量 ---------- */
:root {
  --ink: #0B1F33;
  --navy: #123A5A;
  --cyan: #18C8D8;
  --cyan-soft: #8CE8EF;
  --coral: #FF6B4A;
  --coral-deep: #7A2E1D;
  --paper: #F7F3EA;
  --card: #FFFDF8;
  --slate: #4A5A6A;
  --mist: #D7E3E6;

  --line-ink: rgba(11, 31, 51, .16);
  --line-soft: rgba(11, 31, 51, .09);
  --on-dark: rgba(247, 243, 234, .72);
  --on-dark-strong: rgba(247, 243, 234, .92);

  --font-sans: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "IBM Plex Mono", "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;

  --shell: 1240px;
  --gutter: clamp(18px, 4vw, 48px);
  --radius: 2px;
  --ease: cubic-bezier(.22, .61, .36, 1);
  --shadow-lift: 0 12px 24px -14px rgba(11, 31, 51, .55);
}

/* ---------- 02. 基础重置 ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: clamp(16px, 0.95rem + 0.15vw, 17.5px);
  line-height: 1.75;
  font-weight: 400;
  letter-spacing: .01em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0 0 .5em;
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -.005em;
  text-wrap: balance;
}

h1 { font-size: clamp(2.15rem, 1.35rem + 3.4vw, 4.2rem); line-height: 1.08; }
h2 { font-size: clamp(1.5rem, 1.2rem + 1.2vw, 2.4rem); }
h3 { font-size: clamp(1.15rem, 1.05rem + .5vw, 1.5rem); }
h4 { font-size: 1.05rem; }

p { margin: 0 0 1em; }
p:last-child { margin-bottom: 0; }

a {
  color: inherit;
  text-decoration: none;
  transition: color .16s var(--ease);
}

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

button {
  font: inherit;
  color: inherit;
  margin: 0;
}

ul, ol { margin: 0 0 1em; padding-left: 1.3em; }

blockquote { margin: 0; }

hr {
  border: 0;
  border-top: 1px solid var(--line-ink);
  margin: 2em 0;
}

:focus-visible {
  outline: 3px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 1px;
}

.site-footer :focus-visible {
  outline-color: var(--cyan-soft);
}

.visually-hidden {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.nav-locked { overflow: hidden; }

/* ---------- 03. 布局容器 ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section {
  padding-block: clamp(44px, 6vw, 92px);
}

.section--tight {
  padding-block: clamp(28px, 3.5vw, 52px);
}

.section-head {
  display: grid;
  gap: .55em;
  margin-bottom: clamp(22px, 3vw, 40px);
  max-width: 62ch;
}

.section-head__title { margin: 0; }

.section-head__note {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--slate);
  max-width: 56ch;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: .6em;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--navy);
}

.rule {
  width: 56px;
  height: 3px;
  background: var(--cyan);
  border: 0;
  margin: 0 0 1.2em;
}

.grid {
  display: grid;
  gap: clamp(20px, 3vw, 36px);
}

.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--split { grid-template-columns: minmax(0, 220px) minmax(0, 1fr); }

/* ---------- 04. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5em;
  padding: .72em 1.15em;
  font-family: var(--font-sans);
  font-size: 15px;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: .02em;
  border: 2px solid transparent;
  border-radius: var(--radius);
  cursor: pointer;
  text-align: center;
  transition: transform .18s var(--ease), background-color .16s var(--ease),
              color .16s var(--ease), border-color .16s var(--ease), box-shadow .18s var(--ease);
}

.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0); }

.btn--sm {
  font-size: 13px;
  padding: .5em .82em;
  border-width: 1px;
}

.btn--solid {
  background: var(--ink);
  color: var(--paper);
  border-color: var(--ink);
}
.btn--solid:hover { background: var(--navy); border-color: var(--navy); color: var(--paper); }

.btn--cyan {
  background: var(--cyan);
  color: var(--ink);
  border-color: var(--cyan);
}
.btn--cyan:hover { background: var(--cyan-soft); border-color: var(--cyan-soft); color: var(--ink); }

.btn--coral {
  background: var(--coral);
  color: var(--ink);
  border-color: var(--coral);
}
.btn--coral:hover { background: #FF8A6E; border-color: #FF8A6E; color: var(--ink); }

.btn--outline {
  background: transparent;
  color: var(--ink);
  border-color: var(--ink);
}
.btn--outline:hover { background: var(--ink); color: var(--paper); }

.btn--ghost {
  background: transparent;
  color: var(--paper);
  border-color: rgba(247, 243, 234, .38);
}
.btn--ghost:hover {
  color: var(--cyan-soft);
  border-color: var(--cyan-soft);
  background: rgba(24, 200, 216, .12);
}

/* ---------- 05. 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: .4em;
  padding: .26em .62em;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .07em;
  line-height: 1.5;
  color: var(--ink);
  background: var(--mist);
  border: 1px solid var(--line-ink);
  border-radius: var(--radius);
}

.tag--cyan { background: rgba(24, 200, 216, .16); border-color: rgba(24, 200, 216, .5); color: var(--navy); }
.tag--coral { background: rgba(255, 107, 74, .16); border-color: rgba(255, 107, 74, .55); color: var(--coral-deep); }
.tag--ink { background: var(--ink); border-color: var(--ink); color: var(--paper); }
.tag--soft { background: var(--card); border-color: var(--line-soft); color: var(--slate); }

/* ---------- 06. 卡片与面板 ---------- */
.card {
  background: var(--card);
  border: 1px solid var(--line-ink);
  border-radius: var(--radius);
  padding: clamp(18px, 2.4vw, 30px);
  transition: transform .2s var(--ease), box-shadow .2s var(--ease), border-color .2s var(--ease);
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lift);
  border-color: rgba(24, 200, 216, .55);
}

.card--ink {
  background: var(--navy);
  border-color: var(--navy);
  color: var(--on-dark-strong);
}
.card--ink h2, .card--ink h3, .card--ink h4 { color: var(--paper); }

.card--cyan {
  background: rgba(140, 232, 239, .22);
  border-color: rgba(24, 200, 216, .5);
}

.panel {
  position: relative;
  background: var(--card);
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  padding: clamp(18px, 2.4vw, 32px);
  box-shadow: 8px 8px 0 rgba(11, 31, 51, .07);
}

/* ---------- 07. 图片容器基础规则 ---------- */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  background: var(--mist);
  border: 1px solid var(--line-ink);
  border-radius: var(--radius);
}

.media > img,
.media > picture > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media--frame {
  border: 2px solid var(--ink);
  box-shadow: 8px 8px 0 rgba(11, 31, 51, .08);
}

.media--16x9 { aspect-ratio: 16 / 9; }
.media--4x3 { aspect-ratio: 4 / 3; }
.media--3x2 { aspect-ratio: 3 / 2; }
.media--1x1 { aspect-ratio: 1 / 1; }

.media__caption {
  margin-top: .6em;
  font-size: 13px;
  line-height: 1.55;
  color: var(--slate);
}

/* ---------- 08. 正文与面包屑 ---------- */
.prose {
  max-width: 72ch;
  font-size: 1.01rem;
}

.prose > * + * { margin-top: 1em; }

.prose h2 {
  margin-top: 2em;
  font-size: clamp(1.4rem, 1.15rem + .8vw, 1.85rem);
}

.prose h3 {
  margin-top: 1.6em;
  font-size: clamp(1.12rem, 1.03rem + .4vw, 1.32rem);
}

.prose ul, .prose ol { padding-left: 1.4em; }
.prose li + li { margin-top: .4em; }

.prose a,
.link-underline {
  text-decoration: underline;
  text-decoration-color: var(--cyan);
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
}
.prose a:hover { color: var(--navy); text-decoration-color: var(--coral); }

.prose blockquote {
  margin: 1.8em 0;
  padding: 16px 20px;
  border-left: 4px solid var(--cyan);
  background: var(--card);
  color: var(--navy);
}

.prose code {
  font-family: var(--font-mono);
  font-size: .9em;
  padding: .14em .4em;
  background: rgba(11, 31, 51, .06);
  border-radius: 1px;
}

.breadcrumbs {
  font-size: 13px;
  color: var(--slate);
}

.breadcrumbs ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .5em;
  margin: 0;
  padding: 0;
  list-style: none;
}

.breadcrumbs li { display: inline-flex; align-items: center; gap: .5em; }

.breadcrumbs li + li::before {
  content: "/";
  color: rgba(11, 31, 51, .3);
  font-family: var(--font-mono);
}

.breadcrumbs a:hover { color: var(--navy); }

/* ---------- 09. 页头 ---------- */
.skip-link {
  position: absolute;
  top: 8px;
  left: var(--gutter);
  z-index: 500;
  padding: .65em 1.1em;
  font-size: 14px;
  font-weight: 700;
  color: var(--paper);
  background: var(--ink);
  border: 2px solid var(--cyan);
  border-radius: var(--radius);
  transform: translateY(-180%);
  transition: transform .18s var(--ease);
}

.skip-link:focus { transform: translateY(0); color: var(--paper); }

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 400;
  pointer-events: none;
}

.scroll-progress__bar {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--cyan) 0%, var(--cyan-soft) 55%, var(--coral) 100%);
  transition: width .12s linear;
}

.site-header {
  position: relative;
  z-index: 200;
  background: var(--card);
}

/* 上层：品牌说明带 */
.header-upper {
  background: var(--navy);
  color: var(--paper);
  border-bottom: 1px solid rgba(24, 200, 216, .38);
}

.header-upper__inner {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: clamp(14px, 2.4vw, 36px);
  min-height: 58px;
  padding-block: 9px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
  color: var(--paper);
}

.brand:hover { color: var(--cyan-soft); }

.brand__mark {
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  width: 36px;
  height: 36px;
  font-size: 19px;
  font-weight: 900;
  line-height: 1;
  color: var(--ink);
  background: var(--cyan);
  border-radius: 1px;
  box-shadow: 3px 3px 0 rgba(11, 31, 51, .5);
}

.brand__text {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.brand__name {
  font-size: 17px;
  font-weight: 800;
  line-height: 1.25;
  letter-spacing: .04em;
}

.brand__line {
  font-size: 11.5px;
  line-height: 1.4;
  letter-spacing: .05em;
  color: rgba(247, 243, 234, .66);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.header-note {
  margin: 0;
  font-size: 13px;
  line-height: 1.5;
  letter-spacing: .04em;
  color: var(--on-dark);
  text-align: center;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

/* 下层：栏目导航带 */
.header-main {
  background: var(--card);
  border-bottom: 2px solid var(--ink);
}

.header-main__inner {
  display: flex;
  align-items: stretch;
  gap: clamp(16px, 3vw, 40px);
  padding-block: 2px;
}

.header-main__label {
  align-self: center;
  flex: 0 0 auto;
  margin: 0;
  padding-left: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .18em;
  color: var(--slate);
  border-left: 3px solid var(--coral);
  line-height: 1.4;
}

.primary-nav { margin-left: auto; }

.nav-list {
  display: flex;
  align-items: stretch;
  gap: clamp(2px, 1.2vw, 18px);
  margin: 0;
  padding: 0;
  list-style: none;
}

.nav-link {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 2px;
  padding: 13px 4px 11px;
  font-size: 15px;
  font-weight: 600;
  color: var(--ink);
  border-bottom: 3px solid transparent;
  transition: color .16s var(--ease), border-color .16s var(--ease), background-color .16s var(--ease);
}

.nav-index {
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 600;
  line-height: 1;
  letter-spacing: .12em;
  color: var(--slate);
  transition: color .16s var(--ease);
}

.nav-link:hover {
  color: var(--navy);
  background: rgba(140, 232, 239, .16);
  border-bottom-color: var(--cyan-soft);
}

.nav-link:hover .nav-index { color: var(--navy); }

.nav-link[aria-current="page"] {
  color: var(--navy);
  border-bottom-color: var(--cyan);
}

.nav-link[aria-current="page"] .nav-index { color: var(--coral-deep); }

/* 移动菜单按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  margin-left: auto;
  align-self: center;
  padding: 12px 2px;
  background: transparent;
  border: 0;
  border-bottom: 3px solid transparent;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--ink);
  cursor: pointer;
  transition: color .16s var(--ease), border-color .16s var(--ease);
}

.nav-toggle:hover { color: var(--navy); border-bottom-color: var(--cyan); }

.nav-toggle__bars {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  width: 20px;
  height: 14px;
}

.nav-toggle__bars span {
  display: block;
  width: 100%;
  height: 2px;
  background: currentColor;
  transition: transform .2s var(--ease), opacity .2s var(--ease);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

.nav-scrim {
  position: fixed;
  inset: 0;
  z-index: 60;
  background: rgba(11, 31, 51, .62);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity .22s var(--ease), visibility .22s var(--ease);
}

/* ---------- 10. 页脚 ---------- */
.site-footer {
  position: relative;
  background: var(--ink);
  color: var(--on-dark);
  font-size: 15px;
}

.site-footer::before {
  content: "";
  display: block;
  height: 6px;
  background: linear-gradient(90deg,
    #0B1F33 0 20%, #123A5A 20% 40%, #18C8D8 40% 60%,
    #8CE8EF 60% 80%, #FF6B4A 80% 100%);
}

.footer-top {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(0, .7fr) minmax(0, .7fr) minmax(0, 1.15fr);
  gap: clamp(24px, 3vw, 48px);
  padding-block: clamp(38px, 5vw, 68px);
}

.footer-brand__name {
  margin: 0 0 .5em;
  font-size: 21px;
  font-weight: 800;
  letter-spacing: .04em;
  color: var(--paper);
}

.footer-brand__summary {
  margin: 0 0 1.1em;
  max-width: 34ch;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--on-dark);
}

.footer-brand__meta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: rgba(247, 243, 234, .55);
}

.footer-brand__dot {
  width: 7px;
  height: 7px;
  background: var(--cyan);
  border-radius: 50%;
  box-shadow: 0 0 0 3px rgba(24, 200, 216, .22);
}

.footer-col__title {
  margin: 0 0 1em;
  padding-bottom: .55em;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .16em;
  color: var(--cyan-soft);
  border-bottom: 1px solid rgba(247, 243, 234, .16);
}

.footer-links {
  margin: 0;
  padding: 0;
  list-style: none;
}

.footer-links li + li { margin-top: 4px; }

.footer-links a {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding-block: 4px;
  font-size: 15px;
  color: rgba(247, 243, 234, .84);
  border-bottom: 1px solid transparent;
  transition: color .16s var(--ease), border-color .16s var(--ease);
}

.footer-links a::before {
  content: "";
  flex: 0 0 auto;
  width: 10px;
  height: 2px;
  background: var(--cyan);
  transform: scaleX(.55);
  transform-origin: left center;
  transition: transform .18s var(--ease);
}

.footer-links a:hover {
  color: var(--cyan-soft);
  border-bottom-color: rgba(140, 232, 239, .45);
}

.footer-links a:hover::before { transform: scaleX(1); }

.contact-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.contact-item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: baseline;
  gap: 10px;
  padding-block: 9px;
  border-bottom: 1px dashed rgba(247, 243, 234, .16);
}

.contact-item__label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: rgba(247, 243, 234, .5);
}

.contact-item__value {
  font-size: 14.5px;
  line-height: 1.6;
  color: var(--on-dark-strong);
  word-break: break-word;
}

.copy-btn {
  padding: .26em .6em;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--cyan-soft);
  background: transparent;
  border: 1px solid rgba(140, 232, 239, .45);
  border-radius: var(--radius);
  cursor: pointer;
  transition: background-color .16s var(--ease), color .16s var(--ease), border-color .16s var(--ease);
}

.copy-btn:hover,
.copy-btn[data-copied] {
  color: var(--ink);
  background: var(--cyan);
  border-color: var(--cyan);
}

.footer-contact__note {
  margin: 1em 0 0;
  font-size: 13px;
  line-height: 1.65;
  color: rgba(247, 243, 234, .58);
}

.footer-subscribe-band {
  background: var(--navy);
  border-top: 1px solid rgba(24, 200, 216, .22);
  border-bottom: 1px solid rgba(24, 200, 216, .22);
}

.footer-subscribe {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto auto;
  align-items: center;
  gap: clamp(16px, 3vw, 40px);
  padding-block: clamp(20px, 2.6vw, 32px);
}

.footer-subscribe__head { min-width: 0; }

.footer-subscribe__title {
  margin: 0 0 .25em;
  font-size: 17px;
  font-weight: 800;
  letter-spacing: .04em;
  color: var(--paper);
}

.footer-subscribe__note {
  margin: 0;
  font-size: 13px;
  line-height: 1.6;
  color: var(--on-dark);
}

.subscribe-steps {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.subscribe-step {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 8px 14px;
  background: rgba(247, 243, 234, .07);
  border: 1px solid rgba(247, 243, 234, .2);
  border-radius: var(--radius);
}

.subscribe-step__num {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .1em;
  color: var(--coral);
}

.subscribe-step__label {
  font-size: 14px;
  line-height: 1.4;
  color: var(--on-dark-strong);
}

.footer-bottom {
  padding-block: 20px 28px;
}

.footer-bottom__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 26px;
  font-size: 13px;
  color: rgba(247, 243, 234, .6);
}

.footer-copy { margin: 0; }

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 22px;
}

.footer-legal a {
  color: rgba(247, 243, 234, .78);
  border-bottom: 1px solid transparent;
  padding-bottom: 1px;
}

.footer-legal a:hover {
  color: var(--cyan-soft);
  border-bottom-color: var(--cyan-soft);
}

.footer-icp {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .05em;
  color: rgba(247, 243, 234, .5);
}

/* ---------- 11. 平板断点 ---------- */
@media (max-width: 1180px) {
  .header-note { display: none; }
  .header-upper__inner { grid-template-columns: auto minmax(0, 1fr); }
  .header-actions { grid-column: 2; }
  .footer-top { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-brand { grid-column: 1 / -1; }
  .footer-subscribe { grid-template-columns: minmax(0, 1fr) auto; }
  .footer-subscribe__head { grid-column: 1 / -1; }
}

@media (max-width: 1024px) {
  .nav-link { font-size: 14px; padding-inline: 2px; }
  .footer-subscribe { grid-template-columns: minmax(0, 1fr); }
  .footer-subscribe .btn { justify-self: start; }
}

/* ---------- 12. 手机断点：导航抽屉 ---------- */
@media (max-width: 900px) {
  .header-main__label { display: none; }

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

  .primary-nav {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    z-index: 70;
    width: min(340px, 86vw);
    margin-left: 0;
    padding: 78px 10px 40px;
    background: var(--card);
    border-left: 3px solid var(--cyan);
    box-shadow: -22px 0 48px -28px rgba(11, 31, 51, .85);
    overflow-y: auto;
    overscroll-behavior: contain;
    transform: translateX(102%);
    visibility: hidden;
    transition: transform .22s var(--ease), visibility .22s var(--ease);
  }

  .site-header[data-open] .primary-nav {
    transform: translateX(0);
    visibility: visible;
  }

  .site-header[data-open] .nav-scrim {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
  }

  .nav-list {
    flex-direction: column;
    gap: 0;
  }

  .nav-link {
    flex-direction: row;
    align-items: baseline;
    gap: 14px;
    padding: 15px 16px;
    font-size: 17px;
    border-bottom: 1px solid var(--line-soft);
    border-bottom-color: var(--line-soft);
  }

  .nav-link:hover {
    background: rgba(140, 232, 239, .18);
    border-bottom-color: var(--line-soft);
  }

  .nav-link[aria-current="page"] {
    background: rgba(24, 200, 216, .12);
    border-bottom-color: var(--line-soft);
    box-shadow: inset 4px 0 0 var(--cyan);
  }

  .nav-link[aria-current="page"] .nav-index { color: var(--coral-deep); }

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

@media (max-width: 720px) {
  .header-upper__inner {
    grid-template-columns: minmax(0, 1fr);
    gap: 10px;
    padding-block: 11px;
  }

  .header-actions { grid-column: 1; justify-content: flex-start; }

  .brand__line { white-space: normal; }

  .footer-top { grid-template-columns: minmax(0, 1fr); gap: 28px; }

  .footer-bottom__inner { flex-direction: column; align-items: flex-start; }

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

  .media--frame { box-shadow: 4px 4px 0 rgba(11, 31, 51, .08); }
}

@media (max-width: 520px) {
  .btn--sm { font-size: 12.5px; padding: .48em .7em; }
  .header-actions { gap: 6px; }
  .subscribe-step { width: 100%; }
  .footer-subscribe .btn { width: 100%; }
}

/* ---------- 13. 动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }

  .btn:hover,
  .card:hover { transform: none; }

  .primary-nav,
  .nav-scrim,
  .scroll-progress__bar { transition: none !important; }
}