/* ==========================================================================
   BOB看台 / assets/site.css
   共享：reset · 变量 · 中文排版 · 头部 · 页脚 · 通用按钮 · 网格 · 基础组件
   ========================================================================== */

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

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

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

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

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

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

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

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

a { color: inherit; }

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

/* ---------- 变量 ---------- */
:root {
  --ink: #061713;
  --pitch: #0C2A22;
  --panel: #123B31;
  --grid: #1E4A3E;
  --cyan: #35F2D0;
  --cyan-soft: #9BFFEA;
  --orange: #FF8A3D;
  --amber: #FFC46B;
  --mist: #E9F3F0;
  --dim: #8AA6A0;
  --alert: #E4573D;

  --sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC",
          system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --serif: "Songti SC", "Source Han Serif SC", "Noto Serif SC", Georgia, "Times New Roman", serif;
  --mono: ui-monospace, "SFMono-Regular", "SF Mono", "Roboto Mono", Menlo, Consolas,
          "Courier New", monospace;

  --shell: 1320px;
  --gutter: clamp(18px, 4vw, 44px);
  --ease: cubic-bezier(.22, .61, .36, 1);
  --header-h: 174px;
}

body[data-mode="elevated"] {
  --ink: #08201A;
  --pitch: #0F352B;
  --panel: #164A3D;
  --grid: #276055;
}

/* ---------- 基础排版 ---------- */
body {
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.75;
  color: var(--mist);
  background-color: var(--ink);
  background-image: radial-gradient(1180px 640px at 78% -8%, rgba(53, 242, 208, .085), transparent 62%);
  background-attachment: fixed;
  min-height: 100vh;
  overflow-x: hidden;
}

h1, h2, h3 { font-family: var(--serif); font-weight: 700; letter-spacing: -.01em; }

strong { color: var(--cyan-soft); font-weight: 600; }

code, kbd, samp { font-family: var(--mono); }

:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

#main-content { scroll-margin-top: calc(var(--header-h) + 12px); }

.site-main { display: block; position: relative; z-index: 1; }

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

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

.skip-link {
  position: fixed;
  left: 16px;
  top: 0;
  z-index: 200;
  padding: 13px 20px;
  background: var(--cyan);
  color: var(--ink);
  font: 600 14px/1 var(--sans);
  letter-spacing: .08em;
  text-decoration: none;
  transform: translateY(-130%);
  transition: transform .18s var(--ease);
}

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

/* ---------- 头部：第一层 品牌署名 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: var(--ink);
  border-bottom: 1px solid var(--grid);
}

.topbar {
  background: var(--ink);
  border-bottom: 1px solid var(--grid);
}

.topbar__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: clamp(16px, 3vw, 40px);
  min-height: 66px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  min-width: 0;
  text-decoration: none;
}

.brand__mark {
  flex: none;
  display: grid;
  place-items: center;
  width: 54px;
  height: 34px;
  background: var(--cyan);
  color: var(--ink);
  font: 700 14px/1 var(--mono);
  letter-spacing: .16em;
}

.brand__text {
  display: flex;
  flex-direction: column;
  gap: 3px;
  min-width: 0;
}

.brand__name {
  font-family: var(--serif);
  font-size: 24px;
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: .02em;
  color: var(--mist);
}

.brand__line {
  font-size: 12px;
  line-height: 1.3;
  letter-spacing: .1em;
  color: var(--dim);
}

.topbar__side {
  flex: none;
  display: flex;
  align-items: center;
  gap: 14px;
}

.topbar__stamp {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font: 600 12px/1 var(--mono);
  letter-spacing: .14em;
  color: var(--amber);
}

.dot {
  flex: none;
  width: 6px;
  height: 6px;
  background: currentColor;
  box-shadow: 0 0 8px currentColor;
}

.theme-switch {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border: 1px solid var(--grid);
  color: var(--dim);
  font: 600 12px/1 var(--sans);
  letter-spacing: .1em;
  transition: border-color .18s var(--ease), color .18s var(--ease);
}

.theme-switch:hover { border-color: var(--cyan); color: var(--cyan); }

.theme-switch[aria-pressed="true"] { border-color: var(--cyan); color: var(--cyan); }

.theme-switch__dot {
  flex: none;
  width: 8px;
  height: 8px;
  border: 1px solid currentColor;
  background: transparent;
  transition: background .18s var(--ease);
}

.theme-switch[aria-pressed="true"] .theme-switch__dot { background: var(--cyan); }

/* ---------- 头部：第二层 主栏目 ---------- */
.navbar {
  position: relative;
  background: var(--pitch);
  border-bottom: 1px solid var(--grid);
}

.navbar__inner {
  display: flex;
  align-items: center;
  gap: clamp(14px, 2.6vw, 36px);
  min-height: 58px;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  border: 1px solid var(--grid);
  color: var(--mist);
  font: 600 12px/1 var(--sans);
  letter-spacing: .14em;
}

.nav-toggle__label { display: block; }

.nav-toggle__bars {
  display: grid;
  gap: 4px;
  width: 18px;
}

.nav-toggle__bars i {
  display: block;
  height: 1px;
  background: currentColor;
}

.primary-nav {
  flex: 1 1 auto;
  min-width: 0;
}

.primary-nav__list {
  display: flex;
  align-items: center;
  gap: clamp(10px, 2vw, 30px);
}

.primary-nav__list a {
  position: relative;
  display: inline-block;
  padding: 18px 2px;
  color: var(--dim);
  font-size: 14px;
  letter-spacing: .12em;
  text-decoration: none;
  transition: color .16s var(--ease);
}

.primary-nav__list a::after {
  content: "";
  position: absolute;
  left: 0; right: 0;
  bottom: 10px;
  height: 2px;
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .2s var(--ease);
}

.primary-nav__list a:hover { color: var(--cyan-soft); }
.primary-nav__list a:hover::after { transform: scaleX(1); }

.primary-nav__list a[aria-current="page"] { color: var(--cyan); }
.primary-nav__list a[aria-current="page"]::after { transform: scaleX(1); }

.navbar__cta {
  flex: none;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  border: 1px solid var(--cyan);
  color: var(--cyan);
  font: 600 12px/1 var(--sans);
  letter-spacing: .14em;
  text-decoration: none;
  transition: background .18s var(--ease), color .18s var(--ease);
}

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

/* ---------- 比赛日切换条 ---------- */
.daybar {
  background: var(--ink);
  border-top: 1px solid var(--grid);
}

.daybar__inner {
  display: flex;
  align-items: center;
  gap: 16px;
  min-height: 50px;
}

.daybar__label {
  flex: none;
  font: 600 12px/1 var(--mono);
  letter-spacing: .2em;
  color: var(--cyan);
}

.daybar__scroller {
  flex: 1 1 auto;
  min-width: 0;
  overflow-x: auto;
  overflow-y: hidden;
  scrollbar-color: var(--grid) transparent;
  scrollbar-width: thin;
}

.daybar__scroller::-webkit-scrollbar { height: 4px; }
.daybar__scroller::-webkit-scrollbar-track { background: transparent; }
.daybar__scroller::-webkit-scrollbar-thumb { background: var(--grid); }

.daybar__list {
  display: flex;
  align-items: center;
  gap: 8px;
  width: max-content;
  padding: 10px 2px;
}

.daybar__item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  white-space: nowrap;
  padding: 7px 13px;
  border: 1px solid var(--grid);
  color: var(--dim);
  font: 600 12px/1 var(--mono);
  letter-spacing: .08em;
  transition: border-color .16s var(--ease), color .16s var(--ease), background .16s var(--ease);
}

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

.daybar__item.is-active {
  border-color: var(--cyan);
  color: var(--cyan);
  background: rgba(53, 242, 208, .1);
}

.daybar__date { color: var(--amber); }

.daybar__state {
  flex: none;
  min-width: 52px;
  text-align: right;
  font: 600 12px/1 var(--mono);
  letter-spacing: .08em;
  color: var(--amber);
}

/* ---------- 滚动进度 ---------- */
.scroll-progress {
  position: absolute;
  left: 0; right: 0; bottom: -1px;
  height: 2px;
  pointer-events: none;
}

.scroll-progress__bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--cyan), var(--amber));
}

/* ---------- 头部滚动压缩态 ---------- */
.site-header[data-scrolled] .navbar__inner { min-height: 48px; }
.site-header[data-scrolled] .primary-nav__list a { padding-block: 12px; }
.site-header[data-scrolled] .primary-nav__list a::after { bottom: 5px; }
.site-header[data-scrolled] .daybar__list { padding-block: 6px; }

/* ---------- 页脚 ---------- */
.site-footer {
  position: relative;
  z-index: 1;
  background: var(--ink);
  border-top: 1px solid var(--grid);
  margin-top: clamp(56px, 9vw, 140px);
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) repeat(2, minmax(0, .9fr)) minmax(0, 1.2fr);
  gap: clamp(24px, 4vw, 64px);
  padding-block: clamp(44px, 6vw, 76px) clamp(32px, 4vw, 52px);
}

.footer-brand__mark {
  font-family: var(--serif);
  font-size: 32px;
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: .02em;
  color: var(--mist);
}

.footer-brand__line {
  margin-top: 14px;
  max-width: 34ch;
  font-size: 16px;
  line-height: 1.7;
  color: var(--dim);
}

.footer-brand__meta {
  margin-top: 18px;
  font: 600 12px/1.6 var(--mono);
  letter-spacing: .12em;
  color: var(--cyan);
}

.footer-col__title {
  margin-bottom: 18px;
  font: 600 12px/1 var(--mono);
  letter-spacing: .2em;
  color: var(--amber);
}

.footer-list { display: grid; gap: 11px; }

.footer-list a {
  color: var(--dim);
  font-size: 15px;
  text-decoration: none;
  transition: color .16s var(--ease);
}

.footer-list a:hover { color: var(--cyan); }

.footer-list--contact { color: var(--dim); font-size: 15px; }

.footer-list__label {
  display: block;
  margin-bottom: 3px;
  font: 600 12px/1 var(--mono);
  letter-spacing: .12em;
  color: var(--dim);
  opacity: .78;
}

.footer-list__value {
  display: block;
  color: var(--mist);
  font-size: 15px;
  line-height: 1.6;
  word-break: break-word;
}

.footer-bar {
  background: var(--pitch);
  border-top: 1px solid var(--grid);
}

.footer-bar__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 18px;
  min-height: 62px;
  font: 600 12px/1.6 var(--mono);
  letter-spacing: .1em;
  color: var(--dim);
}

.footer-bar__domain { color: var(--cyan); }
.footer-bar__sep { color: var(--grid); }
.footer-bar__year { margin-left: auto; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 26px;
  border: 1px solid var(--cyan);
  background: transparent;
  color: var(--cyan);
  font: 600 14px/1 var(--sans);
  letter-spacing: .12em;
  text-decoration: none;
  transition: background .18s var(--ease), color .18s var(--ease),
              border-color .18s var(--ease), transform .18s var(--ease);
}

.btn:hover { background: rgba(53, 242, 208, .12); color: var(--cyan-soft); border-color: var(--cyan-soft); }
.btn:active { transform: translateY(1px); }

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

.btn--ghost { border-color: var(--grid); color: var(--dim); }
.btn--ghost:hover { border-color: var(--cyan); color: var(--cyan); background: transparent; }

.btn--small { padding: 10px 18px; font-size: 12px; }

/* ---------- 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  font: 600 12px/1.6 var(--mono);
  letter-spacing: .14em;
  color: var(--dim);
}

.breadcrumb a { color: var(--dim); text-decoration: none; }
.breadcrumb a:hover { color: var(--cyan); }
.breadcrumb__sep { color: var(--grid); }
.breadcrumb > [aria-current="page"] { color: var(--mist); }

/* ---------- 章节与正文 ---------- */
.section { padding-block: clamp(48px, 7vw, 104px); }

.section__eyebrow {
  display: flex;
  align-items: center;
  gap: 12px;
  font: 600 12px/1 var(--mono);
  letter-spacing: .24em;
  text-transform: uppercase;
  color: var(--cyan);
}

.section__eyebrow::before {
  content: "";
  width: 28px;
  height: 1px;
  background: var(--cyan);
}

.section__title {
  margin-top: 14px;
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(32px, 4.4vw, 48px);
  line-height: 1.14;
  letter-spacing: -.01em;
  color: var(--mist);
}

.section__lead {
  margin-top: 14px;
  max-width: 62ch;
  color: var(--dim);
}

.prose { max-width: 72ch; }

.prose p { margin-bottom: 1.15em; }

.prose h2 {
  margin: 1.7em 0 .6em;
  font-size: clamp(24px, 3vw, 32px);
  line-height: 1.28;
  color: var(--mist);
}

.prose h3 {
  margin: 1.5em 0 .5em;
  font-size: 24px;
  line-height: 1.35;
  color: var(--mist);
}

.prose a {
  color: var(--cyan);
  text-decoration: underline;
  text-underline-offset: 4px;
}

.prose ul { display: grid; gap: .5em; margin-bottom: 1.2em; }

.prose li {
  position: relative;
  padding-left: 20px;
}

.prose li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .72em;
  width: 8px;
  height: 1px;
  background: var(--cyan);
}

/* ---------- 网格 / 面板 / 标签 ---------- */
.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(16px, 2.4vw, 32px);
}

.panel {
  border: 1px solid var(--grid);
  background: var(--panel);
  padding: clamp(20px, 2.6vw, 32px);
}

.hairline {
  height: 1px;
  border: 0;
  background: var(--grid);
  margin: 0;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  border: 1px solid var(--grid);
  background: rgba(18, 59, 49, .6);
  color: var(--dim);
  font: 600 12px/1 var(--mono);
  letter-spacing: .12em;
}

.tag--cyan { border-color: rgba(53, 242, 208, .42); color: var(--cyan); }
.tag--amber { border-color: rgba(255, 196, 107, .42); color: var(--amber); }
.tag--orange { border-color: rgba(255, 138, 61, .45); color: var(--orange); }

/* ---------- 图片容器（页面阶段放置图片） ---------- */
.media-frame {
  position: relative;
  display: block;
  width: 100%;
  overflow: hidden;
  border: 1px solid var(--grid);
  background:
    linear-gradient(140deg, rgba(53, 242, 208, .1), transparent 46%),
    linear-gradient(0deg, var(--panel), var(--pitch));
}

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 2;
  pointer-events: none;
  opacity: .55;
  background-image:
    linear-gradient(to right, rgba(30, 74, 62, .5) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(30, 74, 62, .5) 1px, transparent 1px);
  background-size: 44px 44px;
}

.media-frame > img,
.media-frame > picture > img {
  position: relative;
  z-index: 1;
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(.72) contrast(1.06);
}

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--16-9 { aspect-ratio: 16 / 9; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame--tall { aspect-ratio: 3 / 4; }

.media-frame__glow {
  position: absolute;
  z-index: 1;
  right: -10%;
  bottom: -40%;
  width: 60%;
  height: 80%;
  pointer-events: none;
  background: radial-gradient(closest-side, rgba(53, 242, 208, .35), transparent 100%);
}

.media-frame__tag {
  position: absolute;
  z-index: 3;
  left: 0;
  bottom: 0;
  padding: 8px 14px;
  background: var(--ink);
  border-top: 1px solid var(--grid);
  border-right: 1px solid var(--grid);
  font: 600 12px/1 var(--mono);
  letter-spacing: .14em;
  color: var(--amber);
}

/* ---------- 入场动效协议 ---------- */
.reveal,
[data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .34s var(--ease), transform .34s var(--ease);
}

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

/* ---------- 平板 ---------- */
@media (max-width: 1024px) {
  .navbar__cta { display: none; }
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

/* ---------- 移动端导航 ---------- */
@media (max-width: 900px) {
  :root { --header-h: 158px; }

  .topbar__inner { min-height: 58px; }
  .topbar__stamp { display: none; }
  .brand__line { display: none; }

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

  .primary-nav {
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    z-index: 5;
    display: none;
    max-height: min(72vh, 560px);
    overflow-y: auto;
    padding: 8px var(--gutter) 22px;
    background: var(--panel);
    border-bottom: 1px solid var(--grid);
    box-shadow: 0 26px 52px rgba(0, 0, 0, .55);
  }

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

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

  .primary-nav__list li + li { border-top: 1px solid var(--grid); }

  .primary-nav__list a {
    display: block;
    padding: 16px 4px;
    font-size: 16px;
    letter-spacing: .06em;
  }

  .primary-nav__list a::after { display: none; }

  .daybar__state { display: none; }
}

/* ---------- 手机 ---------- */
@media (max-width: 620px) {
  :root { --gutter: 16px; --header-h: 150px; }

  body { font-size: 16px; }

  .brand__mark { width: 46px; height: 30px; font-size: 12px; }
  .brand__name { font-size: 18px; }
  .theme-switch { padding: 7px 11px; }

  .daybar__label { display: none; }
  .daybar__list { padding-block: 8px; }

  .footer-grid { grid-template-columns: minmax(0, 1fr); }
  .footer-bar__year { margin-left: 0; width: 100%; }
}

/* ---------- 降低动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    scroll-behavior: auto !important;
  }

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

  .scroll-progress { display: none; }
}