/* ==========================================================================
   sun-king-taiyang.com.cn — 共享样式表 /assets/site.css
   设计原点：日冕放射 + 堆叠面板 + 展签标签
   ========================================================================== */

/* ---------- 1. Reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

body {
  margin: 0;
  overflow-x: clip;
  background-color: var(--space);
  background-image:
    radial-gradient(920px 540px at 80% -12%, rgba(255, 138, 61, 0.20), transparent 62%),
    radial-gradient(680px 460px at 4% 6%, rgba(43, 210, 196, 0.10), transparent 60%),
    radial-gradient(520px 380px at 50% 118%, rgba(255, 75, 43, 0.14), transparent 65%);
  background-repeat: no-repeat;
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  font-weight: 400;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6, p, figure, blockquote, dl, dd {
  margin: 0;
}

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

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

a {
  color: inherit;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

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

input, select, textarea {
  font: inherit;
}

hr {
  border: 0;
  margin: 0;
}

table {
  border-collapse: collapse;
  width: 100%;
}

/* ---------- 2. 设计令牌 ---------- */
:root {
  /* 品牌色 */
  --sun: #FFB020;
  --flare: #FF4B2B;
  --amber: #FF8A3D;
  --space: #0B1226;
  --panel: #16203A;
  --line: #24304D;
  --paper: #FFF6E8;
  --ink: #1A1F2B;
  --muted: #9AA4B8;
  --cyan: #2BD2C4;

  /* 文字 */
  --text: #E6ECF8;
  --text-dim: #C9D3E8;
  --text-on-sun: #1A1205;

  /* 结构 */
  --shell: 1200px;
  --radius: 14px;
  --radius-sm: 10px;
  --shadow-panel: 0 22px 44px -30px rgba(0, 0, 0, 0.95);
  --shadow-lift: 0 30px 60px -34px rgba(0, 0, 0, 1);

  /* 字体 */
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
    "Source Han Sans SC", "Noto Sans CJK SC", "Helvetica Neue", Arial, sans-serif;

  /* 动效 */
  --ease-out: cubic-bezier(0.2, 0.7, 0.3, 1);
}

/* ---------- 3. 中文排版基础 ---------- */
.prose {
  max-width: min(100%, 40em);
  color: var(--text-dim);
  line-height: 1.8;
}

.prose h2 {
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 900;
  letter-spacing: -0.01em;
  line-height: 1.3;
  color: #FFF6E8;
  margin-bottom: 0.6em;
}

.prose h3 {
  font-size: clamp(18px, 2.2vw, 22px);
  font-weight: 800;
  color: var(--sun);
  margin-top: 1.6em;
  margin-bottom: 0.5em;
}

.prose p + p { margin-top: 1em; }
.prose ul,
.prose ol {
  margin-top: 1em;
  padding-left: 1.2em;
  display: grid;
  gap: 0.5em;
}
.prose ul { list-style: none; padding-left: 0; }
.prose ul li {
  position: relative;
  padding-left: 1.4em;
}
.prose ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 7px;
  height: 2px;
  border-radius: 2px;
  background: var(--amber);
}
.prose ol { list-style: decimal; }
.prose strong { color: #FFF6E8; font-weight: 800; }
.prose a {
  color: var(--sun);
  text-decoration: underline;
}
.prose a:hover { color: var(--amber); }

.panel--paper .prose,
.panel--paper .prose h2,
.panel--paper .prose strong { color: var(--ink); }
.panel--paper .prose h3 { color: #B2541A; }
.panel--paper .prose a { color: #B2541A; }

/* ---------- 4. 布局容器 ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: 20px;
}

#main-content {
  display: block;
}

.section {
  padding-block: 56px;
}

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

@media (min-width: 1024px) {
  .section { padding-block: 78px; }
}

.grid {
  display: grid;
  gap: 20px;
}

.grid--2 { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.grid--3 { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.grid--tight { gap: 14px; }

/* 堆叠画板：奇偶错位 */
.stack {
  display: grid;
  gap: 30px;
}

@media (min-width: 768px) {
  .stack > .panel:nth-child(even) { margin-left: clamp(0px, 4vw, 52px); }
  .stack > .panel:nth-child(odd) { margin-right: clamp(0px, 4vw, 52px); }
}

/* ---------- 5. 标题与展签 ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.16em;
  color: var(--amber);
}

.eyebrow::before {
  content: "";
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--amber), var(--flare));
}

.section-title {
  display: block;
  font-size: clamp(28px, 4.6vw, 44px);
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: #FFF6E8;
  transform: skewX(-2deg);
  transform-origin: left center;
  margin-top: 10px;
}

.section-title--center {
  transform-origin: center center;
  text-align: center;
}

.section-head {
  display: flex;
  flex-wrap: wrap;
  gap: 16px 28px;
  align-items: flex-end;
  justify-content: space-between;
  margin-bottom: 28px;
}

.plate {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 13px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(22, 32, 58, 0.68);
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  line-height: 1.4;
  white-space: nowrap;
}

.plate__num {
  font-variant-numeric: tabular-nums;
  font-weight: 900;
  color: var(--sun);
}

.plate--hot {
  color: #FFD9CB;
  border-color: rgba(255, 75, 43, 0.55);
  background: rgba(255, 75, 43, 0.14);
}

.plate--cyan {
  color: #BEF7F2;
  border-color: rgba(43, 210, 196, 0.45);
  background: rgba(43, 210, 196, 0.12);
}

/* ---------- 6. 面板（堆叠画板） ---------- */
.panel {
  position: relative;
  z-index: 0;
  padding: 24px;
  border: 2px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  background-image: linear-gradient(160deg, rgba(255, 255, 255, 0.035), transparent 46%);
  box-shadow: var(--shadow-panel);
  color: var(--text);
}

.panel--paper {
  background: var(--paper);
  background-image: none;
  border-color: #E7D8BE;
  color: var(--ink);
  box-shadow: 0 24px 48px -32px rgba(0, 0, 0, 0.85);
}

.panel--hot {
  border-color: rgba(255, 138, 61, 0.5);
  background-image:
    radial-gradient(120% 140% at 100% 0%, rgba(255, 75, 43, 0.24), transparent 58%),
    linear-gradient(160deg, rgba(255, 176, 32, 0.10), transparent 50%);
}

.panel--stack::after {
  content: "";
  position: absolute;
  inset: 10px -8px -10px 8px;
  border: 2px solid var(--line);
  border-radius: var(--radius);
  z-index: -1;
  pointer-events: none;
}

.panel--paper.panel--stack::after { border-color: #DCC9A8; }

.panel__pad { padding: 24px; }

@media (min-width: 768px) {
  .panel { padding: 30px; }
}

.panel__title {
  font-size: clamp(20px, 2.6vw, 25px);
  font-weight: 900;
  letter-spacing: -0.01em;
  line-height: 1.25;
  color: #FFF6E8;
}

.panel--paper .panel__title { color: var(--ink); }

.panel__rule {
  height: 2px;
  border: 0;
  margin: 20px 0;
  background-image: repeating-linear-gradient(90deg, var(--line) 0 10px, transparent 10px 18px);
}

.panel--paper .panel__rule {
  background-image: repeating-linear-gradient(90deg, #DCC9A8 0 10px, transparent 10px 18px);
}

.panel__meta {
  font-size: 13px;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

.panel--paper .panel__meta { color: #7A6547; }

/* ---------- 7. 按钮 ---------- */
.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 48px;
  padding: 0 26px;
  border: 2px solid transparent;
  border-radius: 999px;
  font-size: 16px;
  font-weight: 800;
  letter-spacing: 0.01em;
  text-decoration: none;
  cursor: pointer;
  overflow: hidden;
  isolation: isolate;
  transition: transform 0.2s var(--ease-out), background-color 0.2s ease,
    border-color 0.2s ease, color 0.2s ease;
}

.btn::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background: linear-gradient(100deg, transparent 20%, rgba(255, 255, 255, 0.62), transparent 80%);
  transform: translateX(-130%);
  transition: transform 0.6s var(--ease-out);
  pointer-events: none;
}

.btn:hover::after,
.btn:focus-visible::after { transform: translateX(130%); }

.btn:active { transform: translateY(1px) scale(0.99); }

.btn--primary {
  background: linear-gradient(118deg, var(--sun), var(--amber) 92%);
  color: var(--text-on-sun);
  box-shadow: 0 14px 32px -18px rgba(255, 138, 61, 0.95);
}

.btn--primary:hover {
  background: linear-gradient(118deg, #FFC24D, var(--amber) 92%);
}

.btn--ghost {
  border-color: rgba(154, 164, 184, 0.42);
  color: #FFF6E8;
  background: rgba(255, 255, 255, 0.03);
}

.btn--ghost:hover {
  border-color: var(--sun);
  color: var(--sun);
  background: rgba(255, 176, 32, 0.09);
}

.btn--hot {
  background: linear-gradient(118deg, var(--flare), #FF7A38);
  color: #FFF6E8;
}

.btn--sm {
  min-height: 44px;
  padding: 0 18px;
  font-size: 14px;
}

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

/* ---------- 8. 头部 ---------- */
.skip-link {
  position: fixed;
  top: -70px;
  left: 16px;
  z-index: 200;
  padding: 11px 20px;
  border-radius: 0 0 12px 12px;
  background: var(--sun);
  color: var(--text-on-sun);
  font-size: 15px;
  font-weight: 800;
  text-decoration: none;
  transition: top 0.2s var(--ease-out);
}

.skip-link:focus {
  top: 0;
  outline: 3px solid #FFF6E8;
  outline-offset: 2px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: rgba(11, 18, 38, 0.96);
  backdrop-filter: blur(10px);
  border-bottom: 2px solid var(--line);
}

.site-header::before {
  content: "";
  display: block;
  height: 3px;
  background: linear-gradient(90deg,
    rgba(255, 176, 32, 0.12) 0%,
    var(--sun) 20%,
    var(--amber) 52%,
    var(--flare) 78%,
    rgba(255, 75, 43, 0.12) 100%);
}

.header-shell {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 14px;
  padding-block: 10px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  text-decoration: none;
  color: #FFF6E8;
  font-size: 19px;
  font-weight: 900;
  letter-spacing: -0.015em;
}

.brand__mark {
  flex: none;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: radial-gradient(circle at 34% 32%, #FFF3D0 0%, var(--sun) 46%, var(--flare) 100%);
  box-shadow: 0 0 0 1px rgba(255, 176, 32, 0.45), 0 0 20px rgba(255, 138, 61, 0.55);
}

.brand__name {
  display: inline-block;
  transform: skewX(-2deg);
}

.version-badge {
  display: inline-flex;
  align-items: center;
  padding: 5px 12px;
  border: 1px solid rgba(255, 176, 32, 0.45);
  border-radius: 999px;
  background: rgba(255, 176, 32, 0.10);
  color: var(--sun);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.08em;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.nav-toggle {
  margin-left: auto;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  padding: 0 16px;
  border: 2px solid rgba(255, 176, 32, 0.5);
  border-radius: 999px;
  background: rgba(255, 176, 32, 0.10);
  color: var(--sun);
  font-size: 14px;
  font-weight: 800;
  cursor: pointer;
  transition: background-color 0.2s ease, border-color 0.2s ease;
}

.nav-toggle:hover { background: rgba(255, 176, 32, 0.2); }

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
}

.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform 0.2s var(--ease-out);
}

.nav-toggle__bars::before { top: -6px; }
.nav-toggle__bars::after { top: 6px; }

.nav-toggle[aria-expanded="true"] .nav-toggle__bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after { transform: translateY(-6px) rotate(-45deg); }

.header-panel {
  display: none;
  flex: 1 0 100%;
  flex-direction: column;
  gap: 4px;
}

.header-panel[data-open] {
  display: flex;
  animation: panel-drop 0.26s var(--ease-out);
}

@keyframes panel-drop {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: none; }
}

.header-tier {
  border-top: 1px solid var(--line);
  padding-block: 10px;
}

.header-tier--top {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 20px;
}

.header-tier--main {
  padding-bottom: 4px;
}

.mini-nav__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 2px 20px;
}

.mini-nav a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.mini-nav a:hover {
  color: #FFF6E8;
  border-bottom-color: var(--sun);
}

.site-nav__list {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 6px;
}

.site-nav a {
  position: relative;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 15px;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  color: var(--text-dim);
  font-size: 15px;
  font-weight: 700;
  text-decoration: none;
  transition: color 0.2s ease, background-color 0.2s ease, border-color 0.2s ease;
}

.site-nav a::after {
  content: "";
  position: absolute;
  left: 15px;
  right: 15px;
  bottom: 7px;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--sun), var(--amber));
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.25s var(--ease-out);
}

.site-nav a:hover {
  color: #FFF6E8;
  background: rgba(255, 176, 32, 0.08);
}

.site-nav a:hover::after { transform: scaleX(1); }

.site-nav a[aria-current="page"] {
  color: var(--text-on-sun);
  background: linear-gradient(118deg, var(--sun), var(--amber));
  border-color: rgba(255, 255, 255, 0.22);
}

.site-nav a[aria-current="page"]::after { transform: scaleX(0); }

@media (min-width: 900px) {
  .nav-toggle { display: none; }

  .header-shell {
    flex-wrap: nowrap;
    align-items: center;
    gap: 12px;
    padding-block: 8px 10px;
  }

  .header-panel {
    display: flex;
    flex: 1 1 auto;
    margin-left: auto;
    max-width: 760px;
  }

  .header-tier { border-top: 0; padding-block: 0; }

  .header-tier--top {
    justify-content: flex-end;
    padding-bottom: 2px;
  }

  .header-tier--main {
    justify-content: flex-end;
    padding-bottom: 0;
  }

  .mini-nav__list { justify-content: flex-end; }
  .site-nav__list { justify-content: flex-end; }
}

/* ---------- 9. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: 68px;
  overflow: hidden;
  background: #0A1020;
  border-top: 2px solid var(--line);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: -200px;
  left: 50%;
  width: 130%;
  height: 380px;
  transform: translateX(-50%);
  background: radial-gradient(closest-side, rgba(255, 138, 61, 0.22), transparent 72%);
  pointer-events: none;
}

.footer-grid {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  padding-block: 48px 32px;
}

@media (min-width: 720px) {
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 36px; }
}

@media (min-width: 1024px) {
  .footer-grid {
    grid-template-columns: 1.1fr 1.5fr 1.2fr;
    gap: 48px;
    padding-block: 60px 40px;
  }
}

.footer-col { position: relative; }

.footer-title {
  display: flex;
  align-items: center;
  gap: 9px;
  margin-bottom: 14px;
  color: var(--sun);
  font-size: 13px;
  font-weight: 900;
  letter-spacing: 0.14em;
}

.footer-title::before {
  content: "";
  width: 14px;
  height: 2px;
  border-radius: 2px;
  background: var(--flare);
}

.footer-links {
  display: grid;
  gap: 2px;
}

.footer-links a {
  display: inline-flex;
  align-items: center;
  width: fit-content;
  min-height: 44px;
  color: var(--text-dim);
  font-size: 15px;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.2s ease, transform 0.2s var(--ease-out);
}

.footer-links a:hover {
  color: var(--sun);
  transform: translateX(4px);
}

.footer-contact {
  display: grid;
  gap: 10px;
  color: var(--text-dim);
  font-size: 14px;
  line-height: 1.65;
}

.footer-contact li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
}

.footer-contact li::before {
  content: "";
  flex: none;
  width: 6px;
  height: 6px;
  margin-top: 9px;
  border-radius: 50%;
  background: var(--amber);
  box-shadow: 0 0 10px rgba(255, 138, 61, 0.75);
}

.footer-legal {
  color: var(--text-dim);
  font-size: 14px;
  font-variant-numeric: tabular-nums;
}

.footer-version {
  margin-top: 6px;
  color: var(--muted);
  font-size: 13px;
  font-variant-numeric: tabular-nums;
}

.footer-version__num {
  color: var(--sun);
  font-weight: 900;
  font-size: 16px;
}

.footer-legal-links {
  display: flex;
  flex-wrap: wrap;
  gap: 2px 18px;
  margin-top: 12px;
}

.footer-legal-links a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  color: var(--muted);
  font-size: 13px;
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  transition: color 0.2s ease, border-color 0.2s ease;
}

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

.footer-base {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 24px;
  padding-block: 18px 26px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
}

/* ---------- 10. 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding-block: 20px;
  color: var(--muted);
  font-size: 13px;
}

.breadcrumb a {
  color: var(--text-dim);
  text-decoration: none;
  transition: color 0.2s ease;
}

.breadcrumb a:hover { color: var(--sun); }

.breadcrumb__sep {
  color: var(--line);
  user-select: none;
}

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

/* ---------- 11. 图片容器基础规则 ---------- */
.figure {
  display: block;
  margin: 0;
}

.figure__frame {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  border: 2px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
  background-image:
    radial-gradient(120% 120% at 14% 8%, rgba(255, 138, 61, 0.34), transparent 56%),
    radial-gradient(90% 90% at 86% 92%, rgba(43, 210, 196, 0.20), transparent 62%),
    linear-gradient(160deg, #1B2745, #0B1226);
}

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

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

.figure__cap {
  display: flex;
  align-items: flex-start;
  gap: 9px;
  margin-top: 10px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.6;
}

.figure__cap::before {
  content: "";
  flex: none;
  width: 6px;
  height: 6px;
  margin-top: 8px;
  border-radius: 50%;
  background: var(--amber);
}

.panel--paper .figure__frame { border-color: #DCC9A8; }

/* ---------- 12. 工具类 ---------- */
.text-sun { color: var(--sun); }
.text-flare { color: var(--flare); }
.text-cyan { color: var(--cyan); }
.text-muted { color: var(--muted); }
.text-center { text-align: center; }
.mt-0 { margin-top: 0; }
.mt-sm { margin-top: 12px; }
.mt-md { margin-top: 20px; }
.mt-lg { margin-top: 32px; }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* ---------- 13. JS 注入组件 ---------- */
.scroll-ray {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 120;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--sun), var(--amber) 55%, var(--flare));
  box-shadow: 0 0 14px rgba(255, 138, 61, 0.7);
  pointer-events: none;
  will-change: transform;
}

.to-top {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 90;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border: 2px solid rgba(255, 176, 32, 0.55);
  border-radius: 50%;
  background: rgba(11, 18, 38, 0.92);
  color: var(--sun);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity 0.25s ease, transform 0.25s var(--ease-out),
    visibility 0.25s ease, background-color 0.2s ease;
}

.to-top[data-visible] {
  opacity: 1;
  visibility: visible;
  transform: none;
}

.to-top:hover { background: rgba(255, 176, 32, 0.18); }

.to-top__glyph {
  width: 12px;
  height: 12px;
  margin-top: 4px;
  border-top: 2px solid currentColor;
  border-right: 2px solid currentColor;
  transform: rotate(-45deg);
}

/* ---------- 14. 滚动显现协议 ---------- */
.reveal-ready [data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.45s ease, transform 0.45s var(--ease-out);
  transition-delay: var(--reveal-delay, 0ms);
  will-change: opacity, transform;
}

.reveal-ready [data-reveal].is-revealed {
  opacity: 1;
  transform: none;
}

/* ---------- 15. 聚焦可见 ---------- */
:focus-visible {
  outline: 3px solid var(--sun);
  outline-offset: 3px;
  border-radius: 4px;
}

.btn:focus-visible,
.nav-toggle:focus-visible,
.to-top:focus-visible,
.site-nav a:focus-visible {
  outline: 3px solid #FFF6E8;
  outline-offset: 3px;
}

/* ---------- 16. 降低动效偏好 ---------- */
@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;
    transition-delay: 0ms !important;
  }

  .reveal-ready [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
  }

  .btn::after { display: none; }
  .scroll-ray { display: none; }
}