/* ============================================================
   /assets/site.css — 十八游戏站 共享外壳
   夜间指挥舱 · 深墨蓝地面 / 霓虹青行动 / 荧光橙断点
   ============================================================ */

/* ---------- 01. reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

body, h1, h2, h3, h4, h5, h6, p, ul, ol, li, figure, blockquote, dl, dd {
  margin: 0;
  padding: 0;
}

ul, ol { list-style: none; }

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

a { color: inherit; }

button { font: inherit; color: inherit; }

/* ---------- 02. 变量 ---------- */
:root {
  --ink-900: #070E1A;
  --ink-800: #0D1A2B;
  --ink-700: #122540;
  --line: #1C3350;
  --line-soft: rgba(28, 51, 80, 0.62);

  --text: #E8F1FF;
  --muted: #93A9C6;

  --cyan: #2FF3E1;
  --cyan-ink: #061019;
  --orange: #FF8A3D;
  --grad: linear-gradient(135deg, #7C4DFF 0%, #E23E9C 100%);
  --green: #46E08A;
  --warn: #FFC857;

  --wrap: 1240px;
  --gutter: clamp(1.1rem, 4vw, 2.6rem);

  --radius-s: 6px;
  --radius-m: 14px;
  --radius-l: 26px;

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

  --dur: 240ms;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* ---------- 03. 基础排版 ---------- */
body {
  min-height: 100vh;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.9;
  color: var(--text);
  background-color: var(--ink-900);
  background-image:
    radial-gradient(940px 540px at 84% -12%, rgba(47, 243, 225, 0.10), transparent 62%),
    radial-gradient(780px 480px at 4% 4%, rgba(124, 77, 255, 0.16), transparent 60%),
    radial-gradient(620px 420px at 96% 88%, rgba(255, 138, 61, 0.08), transparent 64%);
  background-repeat: no-repeat;
  -webkit-font-smoothing: antialiased;
}

/* 舱体网格：低对比、向下淡出 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(28, 51, 80, 0.55) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(28, 51, 80, 0.55) 1px, transparent 1px);
  background-size: 72px 72px;
  opacity: 0.34;
  -webkit-mask-image: radial-gradient(130% 92% at 50% 0%, #000 0%, transparent 78%);
  mask-image: radial-gradient(130% 92% at 50% 0%, #000 0%, transparent 78%);
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 800;
  line-height: 1.25;
  letter-spacing: -0.01em;
}

h1 { font-size: clamp(2.4rem, 6vw, 5rem); font-weight: 900; letter-spacing: -0.02em; line-height: 1.06; }
h2 { font-size: clamp(1.4rem, 2.6vw, 2.2rem); font-weight: 800; }
h3 { font-size: clamp(1.125rem, 1.8vw, 1.4rem); font-weight: 700; }

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

/* ---------- 04. 焦点与可访问性 ---------- */
:where(a, button, summary, [tabindex]):focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 4px;
}

#main-content:focus { outline: none; }

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 200;
  padding: 0.7rem 1.15rem;
  border-radius: 0 0 10px 0;
  background: var(--cyan);
  color: var(--cyan-ink);
  font-weight: 700;
  font-size: 0.9375rem;
  text-decoration: none;
}

.skip-link:focus,
.skip-link:focus-visible {
  left: 0;
  outline: 2px solid var(--text);
  outline-offset: -4px;
}

/* ---------- 05. 工具类 ---------- */
.mono {
  font-family: var(--font-mono);
  font-weight: 500;
  letter-spacing: 0.04em;
}

.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.rule {
  height: 1px;
  border: 0;
  margin-block: clamp(1.2rem, 3vw, 1.9rem);
  background: linear-gradient(90deg, var(--line), rgba(28, 51, 80, 0));
}

.prose { max-width: 38em; }
.prose p {
  max-width: 34em;
  margin-bottom: 1.1em;
  color: var(--muted);
  line-height: 1.9;
}
.prose p:last-child { margin-bottom: 0; }
.prose h2,
.prose h3 { margin-block: 1.6em 0.6em; color: var(--text); }
.prose strong { color: var(--text); font-weight: 700; }
.prose a { color: var(--cyan); text-underline-offset: 3px; }

/* ---------- 06. 头部外壳 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: rgba(7, 14, 26, 0.9);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}

/* 状态条 */
.status-bar {
  border-bottom: 1px solid var(--line-soft);
  background-image: linear-gradient(
    90deg,
    rgba(124, 77, 255, 0.18),
    rgba(47, 243, 225, 0.12) 52%,
    rgba(255, 138, 61, 0.16)
  );
}

.status-bar__inner {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding: 0.42rem var(--gutter);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.05em;
  color: var(--muted);
}

.status-bar__dot {
  flex: none;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 0 3px rgba(70, 224, 138, 0.16);
  animation: pulse 3.2s var(--ease) infinite;
}

@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 3px rgba(70, 224, 138, 0.16); }
  50% { box-shadow: 0 0 0 6px rgba(70, 224, 138, 0.05); }
}

.status-bar__text {
  flex: 1 1 auto;
  min-width: 0;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}

.status-bar__meta {
  flex: none;
  padding: 0.05rem 0.5rem;
  border: 1px solid rgba(47, 243, 225, 0.4);
  border-radius: 999px;
  color: var(--cyan);
  font-size: 0.625rem;
  letter-spacing: 0.14em;
}

@media (max-width: 479px) {
  .status-bar__meta { display: none; }
}

/* 主导航行 */
.header-main__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-block: 0.7rem;
  padding-inline: var(--gutter);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  order: 1;
  text-decoration: none;
  color: var(--text);
}

.brand__mark {
  display: grid;
  place-items: center;
  flex: none;
  width: 38px;
  height: 38px;
  border-radius: 11px;
  background: var(--cyan);
  color: var(--cyan-ink);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.9375rem;
  letter-spacing: 0.02em;
  box-shadow: inset 0 0 0 1px rgba(6, 16, 25, 0.35);
}

.brand__text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.brand__name {
  font-size: 1.0625rem;
  font-weight: 800;
  letter-spacing: 0.02em;
}

.brand__domain {
  font-size: 0.625rem;
  letter-spacing: 0.08em;
  color: var(--muted);
}

/* 移动端菜单按钮 */
.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  order: 2;
  padding: 0.48rem 0.85rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: transparent;
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  cursor: pointer;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

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

.nav-toggle__bars {
  display: grid;
  gap: 3px;
  width: 16px;
}

.nav-toggle__bars i {
  display: block;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(1) {
  transform: translateY(5px) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(2) {
  opacity: 0;
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(3) {
  transform: translateY(-5px) rotate(-45deg);
}

/* ---------- 07. 导航（移动端为抽屉） ---------- */
.site-nav {
  display: none;
  flex: 1 0 100%;
  order: 3;
  margin-inline: calc(var(--gutter) * -1);
  padding: 0.35rem var(--gutter) 1.15rem;
  border-top: 1px solid var(--line);
  background: var(--ink-800);
}

.site-nav[data-open] {
  display: block;
  animation: navIn var(--dur) var(--ease) both;
}

@keyframes navIn {
  from { opacity: 0; transform: translateY(-6px); }
  to { opacity: 1; transform: none; }
}

.site-nav__list {
  display: block;
}

.site-nav__list li + li {
  border-top: 1px solid var(--line-soft);
}

.site-nav__list a {
  display: block;
  padding: 0.9rem 0.4rem;
  font-size: 1rem;
  font-weight: 700;
  color: var(--muted);
  text-decoration: none;
  transition: color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.site-nav__list a:hover,
.site-nav__list a:focus-visible {
  color: var(--text);
  background: rgba(47, 243, 225, 0.06);
}

.site-nav__list a[aria-current="page"] {
  color: var(--cyan);
  background: rgba(47, 243, 225, 0.09);
  box-shadow: inset 3px 0 0 var(--cyan);
}

.site-nav__cta {
  display: grid;
  gap: 0.6rem;
  margin-top: 1rem;
}

.site-nav__cta .btn { width: 100%; }

/* ---------- 08. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  padding: 0.72rem 1.15rem;
  border: 1px solid transparent;
  border-radius: 999px;
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  text-decoration: none;
  cursor: pointer;
  transition:
    transform var(--dur) var(--ease),
    background-color var(--dur) var(--ease),
    color var(--dur) var(--ease),
    border-color var(--dur) var(--ease),
    box-shadow var(--dur) var(--ease);
}

.btn--primary {
  background: var(--cyan);
  color: var(--cyan-ink);
  box-shadow: 0 6px 22px rgba(47, 243, 225, 0.22);
}

.btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 28px rgba(47, 243, 225, 0.34);
}

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

.btn--ghost:hover {
  transform: translateY(-2px);
  color: var(--orange);
  border-color: var(--orange);
}

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

/* 阅读进度 */
.header-progress {
  position: relative;
  height: 2px;
  background: var(--line-soft);
}

.header-progress__bar {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--cyan), var(--orange));
}

/* ---------- 09. 桌面导航（≥1080px 左右分置） ---------- */
@media (min-width: 1080px) {
  .header-main__inner {
    flex-wrap: nowrap;
    padding-block: 0.8rem;
  }

  .nav-toggle { display: none; }

  .site-nav,
  .site-nav[data-open] {
    display: flex;
    flex: 0 1 auto;
    align-items: center;
    gap: 0.9rem;
    margin-inline: 0;
    padding: 0;
    border-top: 0;
    background: transparent;
    animation: none;
  }

  .site-nav__list {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.1rem;
  }

  .site-nav__list li + li { border-top: 0; }

  .site-nav__list a {
    position: relative;
    display: inline-block;
    padding: 0.5rem 0.55rem;
    font-size: 0.875rem;
    font-weight: 600;
    background: none;
    box-shadow: none;
  }

  .site-nav__list a::after {
    content: "";
    position: absolute;
    left: 0.55rem;
    right: 0.55rem;
    bottom: 0.12rem;
    height: 2px;
    border-radius: 2px;
    background: var(--cyan);
    transform: scaleX(0);
    transform-origin: 0 50%;
    transition: transform var(--dur) var(--ease), background var(--dur) var(--ease);
  }

  .site-nav__list a:hover,
  .site-nav__list a:focus-visible {
    color: var(--text);
    background: none;
  }

  .site-nav__list a:hover::after,
  .site-nav__list a:focus-visible::after { transform: scaleX(1); }

  .site-nav__list a[aria-current="page"] {
    color: var(--cyan);
    background: none;
    box-shadow: none;
  }

  .site-nav__list a[aria-current="page"]::after {
    transform: scaleX(1);
    background: linear-gradient(90deg, var(--cyan), var(--orange));
  }

  .site-nav__cta {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-top: 0;
    padding-left: 0.9rem;
    border-left: 1px solid var(--line);
  }

  .site-nav__cta .btn {
    width: auto;
    padding: 0.55rem 0.95rem;
    font-size: 0.8125rem;
  }
}

/* ---------- 10. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(3rem, 8vw, 6rem);
  background-image: linear-gradient(180deg, rgba(13, 26, 43, 0.72), var(--ink-900) 42%);
  border-top: 1px solid var(--line);
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0 0 auto;
  height: 3px;
  background: linear-gradient(90deg, transparent, var(--cyan), var(--orange), transparent);
  opacity: 0.7;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding: clamp(2.2rem, 6vw, 3.6rem) var(--gutter) 1.9rem;
}

.footer-brand__name {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 900;
  letter-spacing: -0.01em;
  line-height: 1.2;
}

.footer-brand__tag {
  margin-top: 0.55rem;
  max-width: 22em;
  font-size: 0.9375rem;
  color: var(--muted);
  line-height: 1.8;
}

.footer-brand__region {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  margin-top: 0.9rem;
  padding: 0.2rem 0.65rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 0.6875rem;
  letter-spacing: 0.1em;
  color: var(--muted);
}

.footer-brand__region::before {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--cyan);
}

.footer-col__title {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.9rem;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

.footer-col__title::before {
  content: "";
  flex: none;
  width: 8px;
  height: 8px;
  border-radius: 2px;
  background: var(--orange);
}

.footer-col__list {
  display: grid;
  gap: 0.5rem;
}

.footer-col__list a {
  position: relative;
  display: inline-block;
  padding-left: 0;
  font-size: 0.9375rem;
  color: var(--text);
  text-decoration: none;
  transition: color var(--dur) var(--ease), padding-left var(--dur) var(--ease);
}

.footer-col__list a::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 0;
  height: 1px;
  background: var(--cyan);
  transition: width var(--dur) var(--ease);
}

.footer-col__list a:hover,
.footer-col__list a:focus-visible {
  color: var(--cyan);
  padding-left: 0.95rem;
}

.footer-col__list a:hover::before,
.footer-col__list a:focus-visible::before { width: 0.62rem; }

.footer-contact {
  position: relative;
  padding: clamp(1rem, 2.2vw, 1.35rem);
  border: 1px solid var(--line);
  border-radius: var(--radius-m);
  background-image: linear-gradient(160deg, rgba(47, 243, 225, 0.08), rgba(13, 26, 43, 0.92) 46%);
}

.footer-contact__list {
  display: grid;
  gap: 0.7rem;
}

.footer-contact__row {
  display: grid;
  grid-template-columns: 2.9rem minmax(0, 1fr);
  gap: 0.6rem;
  align-items: start;
}

.footer-contact__label {
  padding-top: 0.14rem;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.1em;
  color: var(--muted);
}

.footer-contact__value {
  font-size: 0.875rem;
  line-height: 1.75;
  color: var(--text);
  overflow-wrap: anywhere;
}

.footer-contact__note {
  margin-top: 0.95rem;
  padding-top: 0.85rem;
  border-top: 1px dashed var(--line);
  font-size: 0.8125rem;
  line-height: 1.8;
  color: var(--muted);
}

.footer-legal {
  border-top: 1px solid var(--line);
  background: rgba(7, 14, 26, 0.6);
}

.footer-legal__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem 1.4rem;
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding: 1.05rem var(--gutter) 1.5rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  color: var(--muted);
}

.footer-legal__icp {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
}

.footer-legal__icp::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cyan);
}

@media (min-width: 720px) {
  .footer-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 2.2rem 1.8rem;
  }
  .footer-contact { grid-column: 1 / -1; }
}

@media (min-width: 1024px) {
  .footer-grid {
    grid-template-columns: 1.4fr 0.8fr 0.8fr 1.4fr;
    gap: 2rem;
  }
  .footer-contact { grid-column: auto; }
}

/* ---------- 11. 章节与容器 ---------- */
.section {
  padding-block: clamp(2.4rem, 6vw, 4.5rem);
}

.section--tight {
  padding-block: clamp(1.3rem, 3vw, 2.2rem);
}

.section__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.5rem 1.2rem;
  margin-bottom: clamp(1.1rem, 2.6vw, 1.7rem);
  padding-bottom: 0.85rem;
  border-bottom: 1px solid var(--line);
}

.section__title {
  font-size: clamp(1.4rem, 2.6vw, 2.1rem);
  font-weight: 800;
  line-height: 1.25;
}

.section__meta {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--cyan);
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 2px;
  background: var(--cyan);
}

.lede {
  max-width: 34em;
  font-size: clamp(1rem, 1.5vw, 1.125rem);
  line-height: 1.85;
  color: var(--muted);
}

/* 面包屑 */
.breadcrumb {
  padding-block: 1.1rem 0;
}

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.breadcrumb__list li {
  display: flex;
  align-items: center;
  gap: 0.45rem;
}

.breadcrumb__list li + li::before {
  content: "/";
  color: var(--line);
}

.breadcrumb__list a {
  color: var(--muted);
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}

.breadcrumb__list a:hover,
.breadcrumb__list a:focus-visible { color: var(--cyan); }

.breadcrumb__list [aria-current="page"] { color: var(--text); }

/* ---------- 12. 网格 ---------- */
.grid {
  display: grid;
  gap: clamp(1rem, 2.4vw, 1.6rem);
}

.grid--2 { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.grid--3 { grid-template-columns: repeat(auto-fit, minmax(224px, 1fr)); }
.grid--rail { grid-template-columns: minmax(0, 1fr); }

@media (min-width: 1024px) {
  .grid--rail {
    grid-template-columns: minmax(0, 3fr) minmax(0, 9fr);
    gap: 2.6rem;
  }
}

/* ---------- 13. 面板 ---------- */
.panel {
  position: relative;
  padding: clamp(1.05rem, 2.4vw, 1.6rem);
  border: 1px solid var(--line);
  border-radius: var(--radius-m);
  background-image: linear-gradient(180deg, rgba(13, 26, 43, 0.94), rgba(13, 26, 43, 0.6));
}

.panel__title {
  margin-bottom: 0.5rem;
  font-size: 1.0625rem;
  font-weight: 800;
  color: var(--text);
}

.panel--accent {
  border-color: rgba(47, 243, 225, 0.42);
  box-shadow: inset 0 0 0 1px rgba(47, 243, 225, 0.06);
}

/* ---------- 14. 折叠问答 ---------- */
.fold {
  display: grid;
  gap: 0.6rem;
}

.fold__item {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius-m);
  background: var(--ink-800);
  transition: border-color var(--dur) var(--ease);
}

.fold__item[data-open] { border-color: rgba(47, 243, 225, 0.46); }

.fold__trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  width: 100%;
  padding: 1rem 1.1rem;
  border: 0;
  background: none;
  color: var(--text);
  font-family: inherit;
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.6;
  text-align: left;
  cursor: pointer;
  transition: color var(--dur) var(--ease);
}

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

.fold__icon {
  display: grid;
  place-items: center;
  flex: none;
  width: 22px;
  height: 22px;
  border: 1px solid var(--line);
  border-radius: 50%;
  color: var(--orange);
  font-size: 0.875rem;
  line-height: 1;
  transition: transform var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.fold__trigger[aria-expanded="true"] .fold__icon {
  transform: rotate(45deg);
  border-color: var(--orange);
}

.fold__panel {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows var(--dur) var(--ease);
}

.fold__panel > * {
  min-height: 0;
  overflow: hidden;
}

.fold__item[data-open] .fold__panel { grid-template-rows: 1fr; }

.fold__inner {
  padding: 0 1.1rem 1.15rem;
  font-size: 0.9375rem;
  line-height: 1.9;
  color: var(--muted);
}

/* ---------- 15. 标签 ---------- */
.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.28rem 0.72rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  color: var(--muted);
  text-decoration: none;
  transition:
    transform var(--dur) var(--ease),
    color var(--dur) var(--ease),
    border-color var(--dur) var(--ease);
}

.tag:hover,
.tag:focus-visible {
  transform: translateY(-2px);
  color: var(--text);
  border-color: var(--cyan);
}

.tag--grad {
  border-color: transparent;
  color: #fff;
  font-weight: 600;
  background-image:
    linear-gradient(135deg, rgba(7, 14, 26, 0.3), rgba(7, 14, 26, 0.18)),
    var(--grad);
}

.tag--grad:hover,
.tag--grad:focus-visible { color: #fff; }

.tag--cyan {
  border-color: transparent;
  background: var(--cyan);
  color: var(--cyan-ink);
  font-weight: 600;
}

.tag--cyan:hover { color: var(--cyan-ink); }

.tag--orange {
  border-color: transparent;
  background: var(--orange);
  color: var(--cyan-ink);
  font-weight: 600;
}

.tag--orange:hover { color: var(--cyan-ink); }

/* ---------- 16. 横幅 ---------- */
.banner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: clamp(1rem, 2.4vw, 1.5rem) clamp(1.1rem, 3vw, 2rem);
  border: 1px solid rgba(255, 138, 61, 0.5);
  border-radius: var(--radius-m);
  background-image: linear-gradient(
    100deg,
    rgba(255, 138, 61, 0.15),
    rgba(124, 77, 255, 0.16) 58%,
    rgba(13, 26, 43, 0)
  );
}

.banner__label {
  display: block;
  margin-bottom: 0.25rem;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--orange);
}

.banner__text {
  max-width: 46em;
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--text);
}

/* ---------- 17. 图片容器 ---------- */
.media-frame {
  position: relative;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius-m);
  background-color: var(--ink-800);
  background-image:
    radial-gradient(120% 92% at 18% 0%, rgba(47, 243, 225, 0.14), transparent 62%),
    radial-gradient(100% 82% at 100% 100%, rgba(255, 138, 61, 0.16), transparent 64%);
}

.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0.42;
  background-image:
    linear-gradient(to right, rgba(28, 51, 80, 0.7) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(28, 51, 80, 0.7) 1px, transparent 1px);
  background-size: 34px 34px;
}

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame--tall { aspect-ratio: 3 / 4; }

.media-frame__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 1;
  padding: 0.75rem 1rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  color: var(--muted);
  background-image: linear-gradient(180deg, rgba(7, 14, 26, 0), rgba(7, 14, 26, 0.92));
}

/* ---------- 18. 进场显现 ---------- */
.js [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 520ms var(--ease), transform 520ms var(--ease);
}

.js [data-reveal].is-in {
  opacity: 1;
  transform: none;
}

/* ---------- 19. 降级动效 ---------- */
@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;
  }

  .status-bar__dot { animation: none; }

  .js [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .site-nav[data-open] { animation: none; }
}