/* ============================================================
   欧宝赛场 / oubao-1978.com.cn
   共享样式表 /assets/site.css
   结构：变量 → reset → 中文排版 → 头部轨道 → 导航 → 页脚
        → 容器与网格 → 基础组件 → 图片容器 → 动效 → 响应式
   ============================================================ */

:root {
  --ink: #07130F;
  --panel: #0E2A20;
  --line: #1F4B39;
  --text: #E6F1E9;
  --muted: #8FA89A;
  --red: #FF5340;
  --orange: #FF9E2C;
  --yellow: #F0C34E;
  --blue: #4F93DE;
  --edge: #2C6A4F;

  --rail: 232px;
  --radius-lg: 22px;
  --radius-md: 14px;
  --radius-pill: 999px;

  --mono: ui-monospace, "JetBrains Mono", "IBM Plex Mono", "SFMono-Regular", Menlo, Consolas, monospace;
  --sans: system-ui, -apple-system, "PingFang SC", "Source Han Sans SC", "Noto Sans CJK SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

/* ---------- reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body, h1, h2, h3, h4, h5, p, ul, ol, figure, blockquote, dl, dd { margin: 0; }
ul, ol { padding: 0; list-style: none; }
img, svg, video { display: block; max-width: 100%; }
button { font: inherit; color: inherit; background: none; border: 0; }
table { border-collapse: collapse; width: 100%; }
a { color: inherit; }
:focus-visible {
  outline: 2px solid var(--edge);
  outline-offset: 2px;
  box-shadow: 0 0 0 3px rgba(126, 214, 168, 0.22);
}

/* ---------- 中文排版与底色 ---------- */
body {
  position: relative;
  min-height: 100%;
  background-color: var(--ink);
  color: var(--text);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
}
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  opacity: 0.55;
  background-image:
    linear-gradient(to right, rgba(31, 75, 57, 0.28) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(31, 75, 57, 0.28) 1px, transparent 1px);
  background-size: 84px 84px;
}
body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background:
    radial-gradient(120% 90% at 82% -12%, rgba(255, 83, 64, 0.07), transparent 60%),
    radial-gradient(100% 80% at -8% 104%, rgba(79, 147, 222, 0.07), transparent 58%);
}
html.ob-nav-open, html.ob-nav-open body { overflow: hidden; }

p { text-wrap: pretty; }
h1, h2, h3, h4 { font-weight: 500; line-height: 1.25; letter-spacing: -0.02em; text-wrap: balance; }

/* ---------- 跳转链接 ---------- */
.ob-skip {
  position: absolute;
  left: 12px;
  top: -80px;
  z-index: 120;
  padding: 10px 18px;
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  background: var(--text);
  color: var(--ink);
  font-size: 14px;
  text-decoration: none;
  transition: top 0.16s ease;
}
.ob-skip:focus { top: 0; }

/* ---------- 头部轨道 ---------- */
.ob-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: rgba(7, 19, 15, 0.94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(8px);
}
.ob-rail {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 16px;
}
@media (min-width: 1024px) {
  .ob-header {
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    width: var(--rail);
    border-bottom: 0;
    border-right: 1px solid var(--line);
    background: linear-gradient(180deg, #0A1C15 0%, #07130F 58%, #060F0C 100%);
    backdrop-filter: none;
  }
  .ob-rail {
    flex-direction: column;
    align-items: stretch;
    gap: 16px;
    height: 100%;
    padding: 24px 18px 18px;
    overflow-y: auto;
    scrollbar-width: thin;
  }
}

/* 品牌 */
.ob-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
  color: var(--text);
  text-decoration: none;
}
.ob-brand__mark {
  position: relative;
  flex: none;
  width: 36px;
  height: 36px;
  border-radius: 11px;
  border: 1px solid var(--edge);
  background: radial-gradient(120% 120% at 28% 22%, #173F2D 0%, #0A1D16 72%);
}
.ob-brand__mark::before {
  content: "";
  position: absolute;
  inset: 7px;
  border-radius: 6px;
  border: 1px solid rgba(44, 106, 79, 0.85);
}
.ob-brand__mark::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 9px;
  bottom: 9px;
  width: 1px;
  transform: translateX(-50%);
  background: rgba(240, 195, 78, 0.72);
}
.ob-brand__text { display: flex; flex-direction: column; min-width: 0; }
.ob-brand__name { font-size: 17px; letter-spacing: 0.06em; font-weight: 500; }
.ob-brand__sub {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.12em;
  color: var(--muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
@media (max-width: 1023px) {
  .ob-brand__sub { display: none; }
}

.ob-rail__anno { display: none; }
@media (min-width: 1024px) {
  .ob-rail__anno {
    display: block;
    margin: 0;
    padding-top: 12px;
    border-top: 1px solid var(--line);
    font-family: var(--mono);
    font-size: 11px;
    letter-spacing: 0.18em;
    color: var(--muted);
  }
}

/* 菜单按钮 */
.ob-nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-left: auto;
  padding: 8px 14px;
  border: 1px solid var(--edge);
  border-radius: var(--radius-pill);
  background: rgba(14, 42, 32, 0.72);
  color: var(--text);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  cursor: pointer;
  transition: border-color 0.16s ease, color 0.16s ease;
}
.ob-nav-toggle:hover { border-color: #59C08D; }
.ob-nav-toggle__bars { position: relative; display: block; width: 14px; height: 10px; }
.ob-nav-toggle__bars::before,
.ob-nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  height: 1px;
  background: var(--yellow);
}
.ob-nav-toggle__bars::before { top: 0; }
.ob-nav-toggle__bars::after { bottom: 0; }
@media (min-width: 1024px) {
  .ob-nav-toggle { display: none; }
}

/* ---------- 导航 ---------- */
.ob-nav {
  position: fixed;
  inset: 0;
  z-index: 80;
  display: flex;
  justify-content: flex-end;
  background: rgba(4, 10, 8, 0.72);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.2s ease, visibility 0.2s ease;
}
.ob-nav[data-open="true"] { opacity: 1; visibility: visible; }
.ob-nav__panel {
  display: flex;
  flex-direction: column;
  gap: 16px;
  width: min(88vw, 350px);
  height: 100%;
  padding: 22px 20px 30px;
  overflow-y: auto;
  background: var(--panel);
  border-left: 1px solid var(--line);
  transform: translateX(18px);
  transition: transform 0.24s ease;
}
.ob-nav[data-open="true"] .ob-nav__panel { transform: none; }
.ob-nav__head {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.22em;
  color: var(--muted);
}
.ob-nav__close {
  align-self: flex-start;
  padding: 6px 14px;
  border: 1px solid var(--edge);
  border-radius: var(--radius-pill);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--text);
  cursor: pointer;
}
.ob-nav__close:hover { border-color: #59C08D; }
.ob-nav__list { display: flex; flex-direction: column; gap: 2px; }
.ob-nav__link {
  position: relative;
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 11px 12px;
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  color: var(--text);
  text-decoration: none;
  transition: background-color 0.16s ease, border-color 0.16s ease, color 0.16s ease;
}
.ob-nav__link::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 2px;
  height: 0;
  transform: translateY(-50%);
  background: var(--yellow);
  transition: height 0.18s ease;
}
.ob-nav__link:hover { background: rgba(31, 75, 57, 0.4); border-color: var(--line); }
.ob-nav__link:hover::before { height: 40%; }
.ob-nav__link[aria-current="page"],
.ob-nav__link.is-current {
  background: rgba(31, 75, 57, 0.55);
  border-color: var(--edge);
  color: #FFFFFF;
}
.ob-nav__link[aria-current="page"]::before,
.ob-nav__link.is-current::before { height: 58%; }
.ob-nav__link[aria-current="page"] .ob-nav__idx,
.ob-nav__link.is-current .ob-nav__idx { color: var(--yellow); }
.ob-nav__idx {
  flex: none;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--muted);
}
.ob-nav__label { font-size: 15px; letter-spacing: 0.02em; }

@media (min-width: 1024px) {
  .ob-nav {
    position: static;
    inset: auto;
    z-index: auto;
    display: block;
    flex: 1 1 auto;
    min-height: 0;
    overflow-y: auto;
    scrollbar-width: thin;
    background: none;
    opacity: 1;
    visibility: visible;
    transition: none;
  }
  .ob-nav__panel {
    display: flex;
    flex-direction: column;
    gap: 14px;
    width: auto;
    height: 100%;
    padding: 0;
    overflow: visible;
    background: none;
    border: 0;
    transform: none;
    transition: none;
  }
  .ob-nav__close { display: none; }
}

/* 行动胶囊 */
.ob-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 18px;
  border: 1px solid var(--edge);
  border-radius: var(--radius-pill);
  background: linear-gradient(180deg, rgba(31, 75, 57, 0.75), rgba(14, 42, 32, 0.85));
  color: var(--text);
  font-size: 14px;
  letter-spacing: 0.04em;
  text-decoration: none;
  transition: border-color 0.18s ease, color 0.18s ease, background-color 0.18s ease;
}
.ob-cta::after { content: "→"; font-family: var(--mono); font-size: 13px; color: var(--yellow); }
.ob-cta:hover { border-color: #59C08D; color: #FFFFFF; }
.ob-cta--quiet { background: none; border-color: var(--line); color: var(--muted); }
.ob-cta--quiet:hover { color: var(--text); }
@media (min-width: 1024px) {
  .ob-nav__panel .ob-cta { margin-top: auto; }
}

/* 口径与状态 */
.ob-caliber { display: flex; flex-wrap: wrap; gap: 8px; }
.ob-caliber__item {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 5px 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--muted);
}
.ob-caliber__item--league {
  color: var(--yellow);
  border-color: rgba(240, 195, 78, 0.42);
  background: rgba(240, 195, 78, 0.07);
}
.ob-caliber__item--cup {
  color: var(--blue);
  border-color: rgba(79, 147, 222, 0.42);
  background: rgba(79, 147, 222, 0.08);
}
.ob-caliber__dot {
  width: 6px;
  height: 6px;
  flex: none;
  border-radius: 50%;
  background: currentColor;
  box-shadow: 0 0 10px currentColor;
}
.ob-status {
  display: flex;
  align-items: center;
  gap: 8px;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--muted);
}
.ob-status__dot {
  width: 7px;
  height: 7px;
  flex: none;
  border-radius: 50%;
  background: var(--red);
  animation: ob-ping 2.6s ease-out infinite;
}
@keyframes ob-ping {
  0% { box-shadow: 0 0 0 0 rgba(255, 83, 64, 0.55); }
  70% { box-shadow: 0 0 0 9px rgba(255, 83, 64, 0); }
  100% { box-shadow: 0 0 0 0 rgba(255, 83, 64, 0); }
}

/* 阅读进度 */
.ob-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 90;
  height: 2px;
  pointer-events: none;
  background: rgba(31, 75, 57, 0.5);
}
.ob-progress__bar {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--blue), var(--yellow), var(--red));
}
@media (min-width: 1024px) {
  .ob-progress { left: var(--rail); }
}

/* ---------- 主内容区 ---------- */
#main-content { position: relative; z-index: 1; display: block; }
@media (min-width: 1024px) {
  #main-content { margin-left: var(--rail); }
}

/* ---------- 页脚 ---------- */
.ob-footer {
  position: relative;
  z-index: 1;
  margin-top: 72px;
  border-top: 1px solid var(--line);
  background: linear-gradient(180deg, #08170F, #050D0A);
}
@media (min-width: 1024px) {
  .ob-footer { margin-left: var(--rail); }
}
.ob-footer__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px 24px;
  padding: 48px 0 34px;
}
@media (min-width: 640px) {
  .ob-footer__grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (min-width: 1024px) {
  .ob-footer__grid {
    grid-template-columns: 1.5fr 1fr 1fr 1.2fr;
    padding: 56px 0 38px;
  }
}
.ob-footer__col { min-width: 0; }
.ob-footer__title {
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted);
}
.ob-footer__text {
  margin-top: 16px;
  max-width: 34ch;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}
.ob-footer__list { display: flex; flex-direction: column; gap: 9px; font-size: 14px; }
.ob-footer__list a {
  color: var(--text);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.16s ease, border-color 0.16s ease;
}
.ob-footer__list a:hover { color: #FFFFFF; border-color: var(--edge); }
.ob-footer__list--plain li {
  font-family: var(--mono);
  font-size: 12.5px;
  letter-spacing: 0.02em;
  color: var(--muted);
  word-break: break-word;
}
.ob-footer__base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 24px;
  padding: 18px 0 26px;
  border-top: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--muted);
}
.ob-footer__legal { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; }
.ob-footer__legal a {
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  padding-bottom: 2px;
  transition: color 0.16s ease, border-color 0.16s ease;
}
.ob-footer__legal a:hover { color: var(--text); border-color: var(--edge); }
.ob-footer__sep { color: var(--line); }
.ob-footer__meta { color: var(--muted); }
.ob-brand--footer .ob-brand__name { font-size: 16px; }

/* ---------- 容器与网格 ---------- */
.ob-wrap {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}
@media (min-width: 1024px) {
  .ob-wrap { padding: 0 40px; }
}
.ob-grid {
  display: grid;
  gap: 20px;
  grid-template-columns: repeat(4, minmax(0, 1fr));
}
@media (min-width: 768px) {
  .ob-grid { grid-template-columns: repeat(8, minmax(0, 1fr)); gap: 24px; }
}
@media (min-width: 1024px) {
  .ob-grid { grid-template-columns: repeat(12, minmax(0, 1fr)); gap: 24px; }
}
[class*="ob-span-"] { grid-column: 1 / -1; }
@media (min-width: 1024px) {
  .ob-span-3 { grid-column: span 3; }
  .ob-span-4 { grid-column: span 4; }
  .ob-span-5 { grid-column: span 5; }
  .ob-span-6 { grid-column: span 6; }
  .ob-span-7 { grid-column: span 7; }
  .ob-span-8 { grid-column: span 8; }
  .ob-span-9 { grid-column: span 9; }
  .ob-span-12 { grid-column: span 12; }
}

/* ---------- 章节块 ---------- */
.ob-section {
  position: relative;
  padding: 56px 0;
  border-top: 1px solid var(--line);
}
.ob-section:first-of-type { border-top: 0; }
@media (min-width: 1024px) {
  .ob-section { padding: 72px 0; }
}
.ob-section__head {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  margin-bottom: 26px;
}
.ob-section__idx {
  padding-top: 8px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--muted);
}
.ob-section__title {
  font-size: 26px;
  font-weight: 500;
  line-height: 1.3;
  letter-spacing: -0.02em;
}
@media (min-width: 1024px) {
  .ob-section__title { font-size: 34px; }
}

/* 整宽横条 */
.ob-band {
  position: relative;
  margin: 40px 0;
  padding: 26px 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: linear-gradient(120deg, rgba(14, 42, 32, 0.95), rgba(7, 19, 15, 0.9));
  overflow: hidden;
}
.ob-band::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0.5;
  background-image: repeating-linear-gradient(90deg, rgba(31, 75, 57, 0.5) 0 1px, transparent 1px 64px);
}

/* ---------- 文字层级 ---------- */
.ob-num {
  font-family: var(--mono);
  font-weight: 700;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
  color: var(--text);
}
.ob-num--xl { font-size: 64px; line-height: 1; }
.ob-num--l { font-size: 48px; line-height: 1; }
.ob-num--m { font-size: 32px; line-height: 1.1; }
@media (max-width: 767px) {
  .ob-num--xl { font-size: 44px; }
  .ob-num--l { font-size: 34px; }
}
.ob-display {
  font-size: 32px;
  font-weight: 500;
  line-height: 1.2;
  letter-spacing: -0.03em;
}
@media (min-width: 768px) { .ob-display { font-size: 40px; } }
@media (min-width: 1024px) { .ob-display { font-size: 52px; } }
.ob-anno {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--muted);
}
.ob-anno--vertical { writing-mode: vertical-rl; text-orientation: mixed; }
.ob-rule { height: 1px; margin: 0; border: 0; background: var(--line); }
.ob-prose { max-width: 600px; font-size: 16px; line-height: 1.75; color: var(--text); }
.ob-prose p + p { margin-top: 14px; }
.ob-prose h3 { margin: 26px 0 10px; font-size: 20px; font-weight: 500; }

/* ---------- 胶囊与标签 ---------- */
.ob-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  background: rgba(14, 42, 32, 0.65);
  color: var(--muted);
  font-size: 13px;
  text-decoration: none;
  cursor: pointer;
  transition: color 0.16s ease, border-color 0.16s ease, background-color 0.16s ease;
}
.ob-pill:hover { color: var(--text); border-color: var(--edge); }
.ob-pill.is-active,
.ob-pill[aria-pressed="true"] {
  color: var(--ink);
  background: var(--yellow);
  border-color: var(--yellow);
  font-weight: 500;
}
.ob-pill--cup.is-active,
.ob-pill--cup[aria-pressed="true"] {
  background: var(--blue);
  border-color: var(--blue);
  color: #05121F;
}
.ob-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  border: 1px solid currentColor;
  border-radius: var(--radius-pill);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.ob-tag--league { color: var(--yellow); }
.ob-tag--cup { color: var(--blue); }
.ob-tag--extra { color: var(--red); }
.ob-tag--window { color: var(--orange); }

/* ---------- 面包屑 ---------- */
.ob-crumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 18px 0;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}
.ob-crumb a {
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.16s ease, border-color 0.16s ease;
}
.ob-crumb a:hover { color: var(--text); border-color: var(--edge); }
.ob-crumb__sep { color: var(--line); }

/* ---------- 图片容器 ---------- */
.ob-figure {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--panel);
}
.ob-figure__media {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  background: linear-gradient(140deg, #123A29 0%, #07130F 72%);
}
.ob-figure__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.5) contrast(1.06) brightness(0.92);
}
.ob-figure__media--wide { aspect-ratio: 21 / 9; }
.ob-figure__media--tall { aspect-ratio: 3 / 4; }
.ob-figure__scan {
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0.7;
  background-image:
    linear-gradient(to right, rgba(31, 75, 57, 0.45) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(31, 75, 57, 0.45) 1px, transparent 1px);
  background-size: 48px 48px;
}
.ob-figure__tag {
  position: absolute;
  top: 12px;
  left: 12px;
  z-index: 1;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border: 1px solid var(--edge);
  border-radius: var(--radius-pill);
  background: rgba(7, 19, 15, 0.78);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--text);
}
.ob-figure__cap {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 16px;
  padding: 12px 16px;
  border-top: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

/* ---------- 返回顶部 ---------- */
.ob-to-top {
  position: fixed;
  right: 16px;
  bottom: 16px;
  z-index: 70;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  border: 1px solid var(--edge);
  border-radius: var(--radius-pill);
  background: rgba(10, 28, 21, 0.92);
  color: var(--text);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s ease, border-color 0.2s ease;
}
.ob-to-top[data-visible="true"] { opacity: 1; visibility: visible; transform: none; }
.ob-to-top:hover { border-color: #59C08D; }
@media (min-width: 1024px) {
  .ob-to-top { right: 28px; bottom: 28px; }
}

/* ---------- 动效 ---------- */
.ob-reveal {
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}
.ob-reveal.is-in { opacity: 1; transform: none; }

@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;
  }
  .ob-reveal { opacity: 1; transform: none; }
}