/* ==========================================================================
   博亚娱乐 · /assets/site.css
   共享外壳：reset / 变量 / 中文排版 / 页头 / 页脚 / 通用组件
   视觉语言：墨蓝明档操作台 × 编辑部目录版式
   ========================================================================== */

/* ---------- 1. 变量 ---------- */
:root {
  --ink: #0B1B2B;
  --panel: #10243A;
  --line: #1B3A57;
  --amber: #E8A33D;
  --amber-lt: #F5C56B;
  --cinnabar: #C7452A;
  --celadon: #4C9A8E;
  --cream: #F4F0E6;
  --smoke: #9AA7B4;
  --black: #050B12;
  --body-text: #D9D3C6;

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

  --maxw: 1220px;
  --gutter: clamp(18px, 4vw, 44px);
  --notch: 18px;
  --radius: 3px;
  --shadow: 0 24px 60px rgba(0, 0, 0, .45);
  --ease: cubic-bezier(.22, .78, .26, 1);
}

/* ---------- 2. Reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

@media (prefers-reduced-motion: no-preference) {
  html { scroll-behavior: smooth; }
}

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

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

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

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

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

input, select, textarea { font: inherit; color: inherit; }

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

/* ---------- 3. 基础中文排版 ---------- */
body {
  background-color: var(--ink);
  background-image:
    radial-gradient(90% 55% at 6% 0%, rgba(232, 163, 61, .075), transparent 60%),
    radial-gradient(72% 48% at 100% 10%, rgba(76, 154, 142, .06), transparent 58%);
  background-repeat: no-repeat;
  color: var(--body-text);
  font-family: var(--font-body);
  font-size: 16px;
  font-weight: 400;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

@media (min-width: 768px) {
  body { font-size: 17px; }
}

h1, h2, h3, h4 {
  font-family: var(--font-head);
  font-weight: 900;
  letter-spacing: -.02em;
  line-height: 1.14;
  color: var(--cream);
  text-wrap: balance;
}

p { text-wrap: pretty; }

[id] { scroll-margin-top: 84px; }

#main-content { scroll-margin-top: 70px; }

/* ---------- 4. 布局容器与工具类 ---------- */
.container {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section { padding: clamp(48px, 7vw, 96px) 0; }
.section--tight { padding: clamp(30px, 4vw, 54px) 0; }
.section--flush { padding-top: 0; }

.section--band {
  background: var(--panel);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

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

.band {
  position: relative;
  background: var(--panel);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.band--amber {
  background:
    linear-gradient(90deg, rgba(232, 163, 61, .16), rgba(232, 163, 61, 0) 62%),
    var(--panel);
}

.slash-divider {
  height: 1px;
  border: 0;
  background: linear-gradient(90deg, transparent, var(--line) 12%, var(--line) 88%, transparent);
}

.grid { display: grid; gap: clamp(16px, 2.4vw, 28px); }
.grid--2 { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.grid--3 { grid-template-columns: repeat(auto-fit, minmax(228px, 1fr)); }
.grid--4 { grid-template-columns: repeat(auto-fit, minmax(186px, 1fr)); }

.stack > * + * { margin-top: var(--stack, 16px); }
.text-center { text-align: center; }

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

/* 排版工具 */
.h1 { font-size: clamp(34px, 6.2vw, 64px); }
.h2 { font-size: clamp(26px, 4vw, 42px); }
.h3 { font-size: clamp(19px, 2.4vw, 26px); font-weight: 700; letter-spacing: -.01em; }

.lead {
  font-size: clamp(16px, 1.9vw, 19px);
  line-height: 1.9;
  color: var(--body-text);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-num);
  font-size: 11px;
  letter-spacing: .34em;
  text-transform: uppercase;
  color: var(--amber);
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--amber);
}

.num {
  font-family: var(--font-num);
  font-variant-numeric: tabular-nums;
  letter-spacing: .04em;
}

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

.note-vertical {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-size: 12px;
  letter-spacing: .32em;
  color: var(--smoke);
}

/* ---------- 5. 切角面板与标签 ---------- */
.panel {
  position: relative;
  background:
    linear-gradient(180deg, rgba(232, 163, 61, .06), rgba(232, 163, 61, 0) 44%),
    var(--panel);
  padding: clamp(20px, 2.6vw, 30px);
  clip-path: polygon(
    0 0,
    calc(100% - var(--notch)) 0,
    100% var(--notch),
    100% 100%,
    var(--notch) 100%,
    0 calc(100% - var(--notch))
  );
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 11px;
  letter-spacing: .16em;
  padding: 4px 10px;
  border-radius: 2px;
  background: rgba(232, 163, 61, .12);
  color: var(--amber-lt);
  border: 1px solid rgba(232, 163, 61, .3);
}

.tag--green {
  background: rgba(76, 154, 142, .14);
  color: #7FC4B7;
  border-color: rgba(76, 154, 142, .36);
}

.tag--red {
  background: rgba(199, 69, 42, .16);
  color: #E58063;
  border-color: rgba(199, 69, 42, .4);
}

.tag--ghost {
  background: transparent;
  color: var(--smoke);
  border-color: var(--line);
}

/* ---------- 6. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 20px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: .06em;
  line-height: 1.2;
  white-space: nowrap;
  transition: background-color .24s var(--ease), color .24s var(--ease),
              border-color .24s var(--ease), transform .24s var(--ease);
}

.btn:hover { transform: translateY(-1px); }
.btn:active { transform: translateY(0); }

.btn--gold {
  background: var(--amber);
  color: #191206;
}

.btn--gold:hover { background: var(--amber-lt); }

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

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

.btn--red {
  background: var(--cinnabar);
  color: #FFF4F0;
}

.btn--red:hover { background: #D85536; }

.btn--sm {
  padding: 9px 15px;
  font-size: 13px;
}

/* ---------- 7. 跳转链接 ---------- */
.skip-link {
  position: absolute;
  left: 50%;
  top: 0;
  z-index: 300;
  transform: translate(-50%, -140%);
  background: var(--amber);
  color: #191206;
  padding: 10px 22px;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: .08em;
  border-radius: 0 0 var(--radius) var(--radius);
  transition: transform .22s var(--ease);
}

.skip-link:focus {
  transform: translate(-50%, 0);
}

/* ---------- 8. 页头 ---------- */
.site-header {
  position: relative;
  background:
    radial-gradient(120% 90% at 50% -30%, rgba(232, 163, 61, .1), transparent 62%),
    linear-gradient(180deg, #0B1B2B 0%, #0A1826 100%);
  border-bottom: 1px solid var(--line);
}

.site-header::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--amber), transparent);
  opacity: .5;
  pointer-events: none;
}

/* 顶栏状态带 */
.header-strip {
  background: rgba(5, 11, 18, .55);
  border-bottom: 1px solid rgba(27, 58, 87, .7);
}

.header-strip__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 38px;
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--smoke);
}

.header-strip__state {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  color: var(--body-text);
}

.header-strip__dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--celadon);
  box-shadow: 0 0 0 4px rgba(76, 154, 142, .16);
  flex: none;
}

.header-strip__meta {
  font-family: var(--font-num);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--smoke);
}

/* 刊头 */
.masthead {
  position: relative;
  padding: clamp(20px, 3vw, 36px) 0 clamp(16px, 2.2vw, 26px);
}

.masthead__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
  align-items: center;
  gap: clamp(14px, 2vw, 32px);
}

.masthead__note {
  justify-self: start;
  position: relative;
  padding-left: 16px;
  font-size: 12px;
  letter-spacing: .34em;
  color: var(--smoke);
  white-space: nowrap;
}

.masthead__note::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 9px;
  height: 1px;
  background: var(--amber);
  transform: translateY(-50%);
}

.masthead__brand {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 7px;
  text-align: center;
}

.masthead__mark {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(28px, 4.6vw, 46px);
  line-height: 1.05;
  letter-spacing: -.01em;
  color: var(--cream);
  transition: color .24s var(--ease);
}

.masthead__brand:hover .masthead__mark { color: var(--amber-lt); }

.masthead__sub {
  font-family: var(--font-num);
  font-size: 10px;
  letter-spacing: .42em;
  padding-left: .42em;
  color: var(--amber);
  text-transform: uppercase;
}

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

/* 导航 */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 90;
  background: rgba(7, 15, 25, .92);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.site-nav__inner {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 54px;
}

.site-nav__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: clamp(8px, 2.2vw, 26px);
}

.site-nav__item {
  display: flex;
  align-items: center;
}

.site-nav__item + .site-nav__item::before {
  content: "";
  width: 1px;
  height: 12px;
  background: var(--line);
  flex: none;
}

.site-nav__link {
  position: relative;
  display: inline-block;
  padding: 6px 2px;
  font-size: 15px;
  font-weight: 500;
  letter-spacing: .14em;
  color: var(--smoke);
  transition: color .22s var(--ease);
}

.site-nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: var(--amber);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .28s var(--ease);
}

.site-nav__link:hover { color: var(--cream); }
.site-nav__link:hover::after { transform: scaleX(1); }

.site-nav__link[aria-current="page"] { color: var(--amber-lt); }
.site-nav__link[aria-current="page"]::after { transform: scaleX(1); }

/* 汉堡按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  background: var(--panel);
  color: var(--cream);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-size: 13px;
  letter-spacing: .16em;
  transition: border-color .22s var(--ease), background-color .22s var(--ease);
}

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

.nav-toggle__bars {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  gap: 3px;
  width: 16px;
  flex: none;
}

.nav-toggle__bars i {
  display: block;
  height: 2px;
  width: 100%;
  background: var(--amber);
  transition: transform .26s var(--ease), opacity .2s 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);
}

/* ---------- 9. 移动端页头 ---------- */
@media (max-width: 899px) {
  .header-strip__inner { justify-content: flex-start; }
  .header-strip__meta { display: none; }

  .masthead { padding: clamp(16px, 5vw, 26px) 0 clamp(14px, 4vw, 22px); }

  .masthead__inner {
    display: block;
    text-align: center;
  }

  .masthead__note { display: none; }

  .masthead__brand { align-items: center; }

  .masthead__actions {
    justify-content: center;
    margin-top: 16px;
  }

  .nav-toggle {
    display: inline-flex;
    position: absolute;
    top: clamp(14px, 4vw, 20px);
    right: var(--gutter);
  }

  .site-nav__inner {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: none;
    min-height: 0;
    max-width: none;
    margin: 0;
    padding: 12px var(--gutter) 26px;
    background: var(--black);
    border-bottom: 1px solid var(--line);
    box-shadow: var(--shadow);
    max-height: min(72vh, 560px);
    overflow-y: auto;
  }

  .site-nav[data-open] .site-nav__inner { display: block; }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .site-nav__item + .site-nav__item {
    border-top: 1px solid rgba(27, 58, 87, .6);
  }

  .site-nav__item + .site-nav__item::before { display: none; }

  .site-nav__link {
    display: block;
    padding: 15px 4px;
    font-size: 17px;
    letter-spacing: .08em;
  }

  .site-nav__link::after { display: none; }
}

@media (max-width: 460px) {
  .nav-toggle__label { display: none; }
  .nav-toggle { padding: 10px 12px; }
  .masthead__actions .btn { flex: 1 1 auto; }
}

/* ---------- 10. 页脚 ---------- */
.site-footer {
  position: relative;
  background: var(--black);
  color: var(--smoke);
  border-top: 1px solid var(--line);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--amber) 0%, var(--cinnabar) 48%, var(--celadon) 100%);
  opacity: .85;
}

.footer__grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1.25fr;
  gap: clamp(24px, 3.4vw, 48px);
  padding: clamp(42px, 6vw, 74px) 0 clamp(28px, 4vw, 46px);
}

.footer__mark {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(22px, 2.6vw, 30px);
  line-height: 1.2;
  letter-spacing: .01em;
  color: var(--cream);
}

.footer__tagline {
  margin-top: 14px;
  max-width: 34ch;
  font-size: 14px;
  line-height: 1.9;
  color: var(--smoke);
}

.footer__stamp {
  margin-top: 18px;
  font-family: var(--font-num);
  font-size: 10px;
  letter-spacing: .28em;
  color: var(--smoke);
  opacity: .68;
}

.footer__heading {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 12px;
  letter-spacing: .28em;
  color: var(--amber-lt);
  padding-bottom: 12px;
  margin-bottom: 16px;
  border-bottom: 1px solid rgba(27, 58, 87, .8);
}

.footer__list {
  display: flex;
  flex-direction: column;
  gap: 11px;
}

.footer__list a {
  position: relative;
  display: inline-block;
  font-size: 14px;
  letter-spacing: .04em;
  color: var(--smoke);
  transition: color .22s var(--ease);
}

.footer__list a::before {
  content: "›";
  margin-right: 8px;
  color: var(--amber);
  opacity: .75;
}

.footer__list a:hover { color: var(--cream); }

.footer__list--meta li {
  display: grid;
  grid-template-columns: 46px minmax(0, 1fr);
  gap: 10px;
  align-items: baseline;
}

.footer__list--meta a::before { content: none; }

.footer__label {
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--smoke);
  opacity: .7;
}

.footer__value {
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--body-text);
  word-break: break-word;
}

.footer__bottom {
  background: rgba(11, 27, 43, .6);
  border-top: 1px solid rgba(27, 58, 87, .8);
}

.footer__bottom-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 20px;
  padding: 18px 0;
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--smoke);
}

.footer__icp {
  font-family: var(--font-num);
  letter-spacing: .1em;
}

.footer__note { color: var(--smoke); opacity: .82; }

@media (max-width: 1080px) {
  .footer__grid { grid-template-columns: 1.4fr 1fr 1.2fr; }
}

@media (max-width: 760px) {
  .footer__grid { grid-template-columns: 1fr 1fr; }
  .footer__brand { grid-column: 1 / -1; }
  .footer__tagline { max-width: none; }
}

@media (max-width: 480px) {
  .footer__grid { grid-template-columns: 1fr; }
  .footer__bottom-inner { flex-direction: column; align-items: flex-start; }
}

/* ---------- 11. 返回顶部与进度条 ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  z-index: 200;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--amber), var(--cinnabar));
  pointer-events: none;
  will-change: transform;
}

.to-top {
  position: fixed;
  right: clamp(14px, 3vw, 30px);
  bottom: clamp(14px, 3vw, 30px);
  z-index: 110;
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 11px 13px;
  background: var(--panel);
  color: var(--cream);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  opacity: 0;
  visibility: hidden;
  transform: translateY(14px);
  transition: opacity .3s var(--ease), transform .3s var(--ease),
              background-color .24s var(--ease), color .24s var(--ease),
              border-color .24s var(--ease), visibility .3s;
}

.to-top.is-shown {
  opacity: 1;
  visibility: visible;
  transform: none;
}

.to-top:hover {
  background: var(--amber);
  border-color: var(--amber);
  color: #191206;
}

.to-top__arrow {
  font-size: 15px;
  line-height: 1;
}

.to-top__label {
  writing-mode: vertical-rl;
  font-size: 10px;
  letter-spacing: .22em;
}

/* ---------- 12. 内容组件 ---------- */
.prose {
  max-width: 74ch;
  font-size: clamp(15.5px, 1.7vw, 17px);
  line-height: 1.95;
  color: var(--body-text);
}

.prose > * + * { margin-top: 1.05em; }

.prose h2,
.prose h3 {
  font-family: var(--font-head);
  font-weight: 900;
  letter-spacing: -.01em;
  line-height: 1.32;
  color: var(--cream);
  margin-top: 1.9em;
}

.prose h2 { font-size: clamp(21px, 2.6vw, 28px); }
.prose h3 { font-size: clamp(17px, 2vw, 21px); }

.prose a {
  color: var(--amber-lt);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 4px;
}

.prose ul { padding-left: 1.3em; }

.prose ul li {
  position: relative;
  list-style: none;
  padding-left: 1.1em;
}

.prose ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .86em;
  width: 6px;
  height: 6px;
  background: var(--amber);
  transform: rotate(45deg);
}

.prose ol {
  list-style: decimal;
  padding-left: 1.5em;
}

.prose li + li { margin-top: .45em; }

.prose blockquote {
  padding: 6px 0 6px 20px;
  border-left: 2px solid var(--amber);
  color: var(--cream);
}

.prose code {
  font-family: var(--font-num);
  font-size: .9em;
  padding: 2px 6px;
  border-radius: 2px;
  background: var(--panel);
  color: var(--amber-lt);
}

.prose hr {
  height: 1px;
  border: 0;
  margin: 2em 0;
  background: linear-gradient(90deg, var(--line), transparent);
}

/* 面包屑 */
.breadcrumb { padding: 18px 0 0; }

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--smoke);
}

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

.breadcrumb__list li + li::before {
  content: "›";
  margin: 0 10px;
  font-size: 13px;
  color: var(--line);
}

.breadcrumb__list a { color: var(--smoke); }
.breadcrumb__list a:hover { color: var(--amber-lt); }
.breadcrumb__list [aria-current="page"] { color: var(--body-text); }

/* 章节目录 */
.toc {
  display: flex;
  flex-direction: column;
  gap: 2px;
  font-size: 13.5px;
}

.toc__link {
  display: block;
  padding: 9px 12px;
  border-left: 2px solid transparent;
  color: var(--smoke);
  letter-spacing: .06em;
  transition: color .22s var(--ease), background-color .22s var(--ease),
              border-color .22s var(--ease);
}

.toc__link:hover {
  color: var(--cream);
  background: rgba(232, 163, 61, .06);
}

.toc__link[aria-current] {
  color: var(--amber-lt);
  border-left-color: var(--amber);
  background: rgba(232, 163, 61, .1);
}

/* 响应式图片容器 */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background:
    linear-gradient(135deg, #10243A 0%, #0E2033 62%, #12293F 100%);
}

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

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(158deg, rgba(232, 163, 61, .08), transparent 46%);
}

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame--portrait { aspect-ratio: 3 / 4; }
.media-frame--fill { aspect-ratio: auto; height: 100%; }

.media-frame__cap {
  position: absolute;
  left: 0;
  bottom: 0;
  z-index: 2;
  padding: 8px 14px;
  background: rgba(5, 11, 18, .88);
  color: var(--body-text);
  font-size: 12px;
  letter-spacing: .12em;
  border-top-right-radius: var(--radius);
}

/* 滚动显现（斜线轨迹） */
.reveal {
  opacity: 0;
  transform: translate3d(16px, 12px, 0);
  transition: opacity .55s var(--ease), transform .68s var(--ease);
}

.reveal.is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 13. 降低动态效果 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

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

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

  .to-top {
    transition: opacity .001ms, visibility .001ms;
    transform: none;
  }

  .btn:hover { transform: none; }
}