/* ==========================================================================
   火博体育 · 共享样式表 /assets/site.css
   骨架：深空黑竖向索引轨道 + 顶部阅读进度 + 米白岩层连续画布
   ========================================================================== */

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

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

body { margin: 0; }

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, canvas { display: block; max-width: 100%; }

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

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

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

/* ---------- 02. 设计令牌 ---------- */
:root {
  /* 色彩体系 */
  --c-clay: #D2401E;
  --c-gold: #F2A03D;
  --c-lava: #8E2412;
  --c-deep: #121316;
  --c-cream: #F5F0E6;
  --c-terra: #B4633A;
  --c-moss: #2F6B4F;
  --c-turf: #35D07F;
  --c-stone: #6E6A63;
  --c-stone-ink: #4A4640;
  --c-mist: #FFFCF6;
  --c-frost: #C9C4BA;

  /* 尺寸与节奏 */
  --rail: 116px;
  --header-h: 58px;
  --progress-h: 3px;
  --shell-max: 1440px;
  --gutter: clamp(20px, 4vw, 56px);
  --radius-lg: 26px;
  --radius-md: 18px;
  --radius-sm: 10px;
  --radius-pill: 999px;

  /* 字体 */
  --font-display: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "Roboto Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, "Courier New", monospace;

  /* 动效 */
  --ease-out: cubic-bezier(.22, .8, .28, 1);
}

/* ---------- 03. 基础排版 ---------- */
body {
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.85;
  font-weight: 400;
  color: var(--c-deep);
  background-color: var(--c-cream);
  padding-top: var(--header-h);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  line-height: 1.24;
  letter-spacing: -0.02em;
  font-weight: 700;
}

h1 {
  font-size: clamp(34px, 6vw, 76px);
  font-weight: 900;
  line-height: 1.08;
}

h2 { font-size: clamp(24px, 3vw, 34px); }

h3 {
  font-size: clamp(19px, 2vw, 24px);
  line-height: 1.35;
}

p { line-height: 1.85; }

strong { font-weight: 700; }

::selection {
  background: var(--c-clay);
  color: var(--c-mist);
}

.mono,
[data-num] {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
}

.eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--c-clay);
}

.has-dark {
  background-color: var(--c-deep);
  color: var(--c-mist);
}

/* ---------- 04. 焦点与无障碍 ---------- */
:focus-visible {
  outline: 2px solid var(--c-turf);
  outline-offset: 3px;
  border-radius: 4px;
}

.skip-link {
  position: absolute;
  top: -72px;
  left: 12px;
  z-index: 200;
  display: inline-block;
  padding: 10px 20px;
  border-radius: var(--radius-pill);
  background: var(--c-gold);
  color: var(--c-deep);
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 700;
  transition: top .24s var(--ease-out);
}

.skip-link:focus {
  top: 12px;
}

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

/* ---------- 05. 布局容器与网格 ---------- */
.shell {
  width: min(100%, var(--shell-max));
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(16px, 2vw, 28px);
}

.span-3, .span-4, .span-5, .span-6,
.span-7, .span-8, .span-9, .span-12 { grid-column: 1 / -1; }

/* ---------- 06. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5em;
  padding: 12px 24px;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .01em;
  line-height: 1.2;
  cursor: pointer;
  transition: background-color .24s var(--ease-out),
              color .24s var(--ease-out),
              border-color .24s var(--ease-out),
              transform .24s var(--ease-out);
}

.btn--ember {
  background-image: linear-gradient(118deg, var(--c-clay) 0%, var(--c-gold) 100%);
  background-color: var(--c-clay);
  color: var(--c-deep);
}

.btn--ember:hover {
  background-image: linear-gradient(118deg, var(--c-gold) 0%, var(--c-clay) 100%);
  transform: translateY(-1px);
}

.btn--ghost {
  border-color: rgba(201, 196, 186, .42);
  color: var(--c-mist);
}

.btn--ghost:hover {
  border-color: var(--c-gold);
  color: var(--c-gold);
}

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

/* ---------- 07. 面包屑 ---------- */
.breadcrumb {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--c-stone-ink);
  margin-bottom: 20px;
}

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.breadcrumb__item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  color: var(--c-frost);
}

.breadcrumb__item[aria-current="page"] { color: var(--c-deep); }

.breadcrumb__link:hover { color: var(--c-clay); }

/* ---------- 08. 正文容器 ---------- */
.prose {
  max-width: 44em;
}

.prose > * + * { margin-top: 1.15em; }

.prose h2 {
  margin-top: 2.2em;
  padding-top: 1em;
  border-top: 1px solid rgba(110, 106, 99, .28);
}

.prose h3 { margin-top: 1.8em; }

.prose ul > li,
.prose ol > li {
  position: relative;
  padding-left: 1.5em;
}

.prose ul > li + li,
.prose ol > li + li { margin-top: .5em; }

.prose ul > li::before {
  content: "—";
  position: absolute;
  left: 0;
  color: var(--c-clay);
  font-family: var(--font-mono);
}

.prose ol { counter-reset: prose-ol; }

.prose ol > li::before {
  counter-increment: prose-ol;
  content: counter(prose-ol, decimal-leading-zero);
  position: absolute;
  left: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-clay);
}

/* ---------- 09. 图片容器（页面阶段使用） ---------- */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  border-radius: var(--radius-lg);
  background-color: var(--c-deep);
  aspect-ratio: 16 / 9;
  isolation: isolate;
}

.media-frame::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  background-image:
    radial-gradient(120% 90% at 12% 6%, rgba(242, 160, 61, .34), transparent 58%),
    radial-gradient(90% 76% at 88% 98%, rgba(210, 64, 30, .42), transparent 62%),
    conic-gradient(from 208deg at 64% 34%,
      rgba(53, 208, 127, .18), transparent 38%,
      rgba(142, 36, 18, .55) 62%, transparent 78%);
  background-color: var(--c-deep);
}

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 2;
  background-image: repeating-linear-gradient(
    -32deg,
    rgba(255, 252, 246, .05) 0 1px,
    transparent 1px 9px);
  pointer-events: none;
}

.media-frame img {
  position: relative;
  z-index: 1;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame figcaption {
  position: absolute;
  z-index: 3;
  left: 18px;
  bottom: 16px;
  max-width: calc(100% - 36px);
  padding: 5px 12px;
  border-radius: var(--radius-pill);
  background: rgba(18, 19, 22, .78);
  color: var(--c-frost);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .04em;
  line-height: 1.6;
}

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

/* ---------- 10. 框架母题工具 ---------- */
.frame-corners {
  position: relative;
}

.frame-corners::before,
.frame-corners::after {
  content: "";
  position: absolute;
  width: 15px;
  height: 15px;
  border: 1px solid var(--c-clay);
  pointer-events: none;
}

.frame-corners::before {
  top: -1px;
  left: -1px;
  border-right: 0;
  border-bottom: 0;
}

.frame-corners::after {
  right: -1px;
  bottom: -1px;
  border-left: 0;
  border-top: 0;
}

.divider-slant {
  height: 1px;
  border: 0;
  background-image: linear-gradient(90deg, transparent, var(--c-lava) 22%, var(--c-clay) 50%, var(--c-lava) 78%, transparent);
}

.rule-tick {
  height: 0;
  border: 0;
  border-top: 1px dashed rgba(110, 106, 99, .45);
}

/* ---------- 11. 头部：框架式索引轨道 ---------- */
.read-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--progress-h);
  z-index: 120;
  background: rgba(18, 19, 22, .38);
  pointer-events: none;
}

.read-progress__fill {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(0);
  transform-origin: left center;
  background-image: linear-gradient(90deg, var(--c-clay) 0%, var(--c-gold) 58%, var(--c-turf) 100%);
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 110;
  background-color: var(--c-deep);
  color: var(--c-mist);
  border-bottom: 1px solid rgba(201, 196, 186, .18);
}

.site-header__frame {
  position: relative;
  z-index: 2;
  display: flex;
  align-items: center;
  gap: 12px;
  width: 100%;
  max-width: var(--shell-max);
  min-height: var(--header-h);
  margin-inline: auto;
  padding: 8px clamp(14px, 4vw, 24px);
}

/* 品牌锁定 */
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
}

.brand__flame {
  position: relative;
  flex: none;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background-image: conic-gradient(from 0deg,
    var(--c-clay) 0deg,
    var(--c-gold) 130deg,
    var(--c-lava) 232deg,
    var(--c-clay) 360deg);
}

.brand__flame::before {
  content: "";
  position: absolute;
  inset: 6px;
  border-radius: 50%;
  background-color: var(--c-deep);
}

.brand__flame::after {
  content: "";
  position: absolute;
  inset: 11px;
  border-radius: 50%;
  background-image: radial-gradient(circle at 38% 32%, var(--c-gold), var(--c-clay) 72%);
}

.brand__flame--lg {
  width: 46px;
  height: 46px;
}

.brand__text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
  line-height: 1.15;
}

.brand__name {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--c-mist);
  white-space: nowrap;
}

.brand__sub {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .07em;
  color: var(--c-frost);
  white-space: nowrap;
}

/* 移动导航按钮 */
.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  margin-left: auto;
  padding: 8px 14px;
  border: 1px solid rgba(201, 196, 186, .38);
  border-radius: var(--radius-pill);
  color: var(--c-mist);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  transition: border-color .24s var(--ease-out), color .24s var(--ease-out);
}

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

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 16px;
  height: 11px;
}

.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  height: 1.5px;
  background-color: currentColor;
  transition: transform .28s var(--ease-out), top .28s var(--ease-out), bottom .28s var(--ease-out);
}

.nav-toggle__bars::before { top: 1px; }
.nav-toggle__bars::after { bottom: 1px; }

.site-header[data-nav-open] .nav-toggle__bars::before {
  top: 4.75px;
  transform: rotate(45deg);
}

.site-header[data-nav-open] .nav-toggle__bars::after {
  bottom: 4.75px;
  transform: rotate(-45deg);
}

/* 导航：移动端抽屉 */
.site-nav {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 130;
  max-height: 82vh;
  overflow-y: auto;
  padding: 20px clamp(16px, 5vw, 30px) calc(26px + env(safe-area-inset-bottom, 0px));
  background-color: var(--c-deep);
  border-top: 1px solid rgba(210, 64, 30, .55);
  box-shadow: 0 -18px 44px rgba(18, 19, 22, .55);
  transform: translateY(103%);
  transition: transform .42s var(--ease-out);
}

.site-nav[data-open] { transform: translateY(0); }

.site-nav__list {
  display: grid;
  gap: 2px;
}

.site-nav__link {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 12px 12px;
  border-left: 2px solid transparent;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  color: var(--c-frost);
  transition: background-color .22s var(--ease-out), color .22s var(--ease-out), border-color .22s var(--ease-out);
}

.site-nav__link:hover {
  background-color: rgba(210, 64, 30, .18);
  color: var(--c-mist);
}

.site-nav__link[aria-current="page"] {
  border-left-color: var(--c-clay);
  background-color: rgba(210, 64, 30, .16);
  color: var(--c-mist);
}

.site-nav__link[aria-current="page"] .site-nav__num { color: var(--c-gold); }

.site-nav__num {
  flex: none;
  width: 22px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-variant-numeric: tabular-nums;
  letter-spacing: .1em;
  color: var(--c-stone);
}

.site-nav__label {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  letter-spacing: .01em;
}

.site-nav__cta { margin-top: 16px; }

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

/* 抽屉遮罩 */
.nav-scrim {
  position: fixed;
  inset: 0;
  z-index: 125;
  background-color: rgba(18, 19, 22, .62);
  opacity: 0;
  pointer-events: none;
  transition: opacity .3s var(--ease-out);
}

.site-header[data-nav-open] .nav-scrim {
  opacity: 1;
  pointer-events: auto;
}

body[data-nav-open] { overflow: hidden; }

/* ---------- 12. 页脚 ---------- */
.site-footer {
  position: relative;
  padding: clamp(44px, 6vw, 76px) 0 28px;
  background-color: var(--c-deep);
  color: var(--c-frost);
  border-top: 1px solid rgba(210, 64, 30, .55);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 7px;
  background-image: repeating-linear-gradient(90deg,
    rgba(242, 160, 61, .55) 0 1px,
    transparent 1px 15px);
  opacity: .6;
  pointer-events: none;
}

.site-footer__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 46px);
  width: min(100%, var(--shell-max));
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.site-footer__brand {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 12px;
}

.site-footer__name {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--c-mist);
}

.site-footer__tag {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: rgba(201, 196, 186, .78);
}

.site-footer__col { min-width: 0; }

.site-footer__title {
  display: flex;
  align-items: baseline;
  gap: 9px;
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px dashed rgba(201, 196, 186, .26);
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--c-mist);
}

.site-footer__num {
  font-family: var(--font-mono);
  font-size: 10px;
  font-variant-numeric: tabular-nums;
  letter-spacing: .12em;
  color: var(--c-gold);
}

.site-footer__list {
  display: grid;
  gap: 9px;
}

.site-footer__link {
  display: inline-block;
  font-size: 14px;
  line-height: 1.6;
  color: rgba(201, 196, 186, .86);
  transition: color .22s var(--ease-out), padding-left .22s var(--ease-out);
}

.site-footer__link:hover {
  color: var(--c-gold);
  padding-left: 5px;
}

.site-footer__base {
  display: grid;
  gap: 9px;
  width: min(100%, var(--shell-max));
  margin: clamp(32px, 5vw, 58px) auto 0;
  padding: 20px var(--gutter) 0;
  border-top: 1px solid rgba(201, 196, 186, .18);
  font-size: 13px;
  line-height: 1.75;
  color: rgba(201, 196, 186, .74);
}

.site-footer__legal {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .05em;
  color: rgba(201, 196, 186, .82);
}

.site-footer__contact { max-width: 82ch; }

.site-footer__note {
  max-width: 78ch;
  font-size: 12px;
  color: rgba(201, 196, 186, .58);
}

.site-footer__copy {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .05em;
  color: rgba(201, 196, 186, .52);
}

/* ---------- 13. 滚动显现 ---------- */
.js [data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity .62s var(--ease-out), transform .62s var(--ease-out);
}

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

/* ---------- 14. 平板与桌面 ---------- */
@media (min-width: 760px) {
  .site-footer__grid {
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
  }

  .site-footer__base {
    grid-template-columns: 1fr;
  }
}

@media (min-width: 900px) {
  body {
    padding-top: 0;
    padding-left: var(--rail);
  }

  #main-content { scroll-margin-top: 16px; }

  .skip-link { left: calc(var(--rail) + 16px); }

  .read-progress { left: var(--rail); }

  .site-header {
    right: auto;
    bottom: 0;
    width: var(--rail);
    border-bottom: 0;
    border-right: 1px solid rgba(201, 196, 186, .22);
  }

  .site-header__frame {
    flex-direction: column;
    align-items: center;
    gap: 14px;
    width: 100%;
    height: 100%;
    max-width: none;
    padding: 18px 12px 16px;
  }

  .brand {
    flex-direction: column;
    gap: 9px;
    width: 100%;
    text-align: center;
  }

  .brand__text {
    align-items: center;
    gap: 3px;
  }

  .brand__name {
    font-size: 15px;
    letter-spacing: 0;
  }

  .brand__sub {
    font-size: 9px;
    letter-spacing: .05em;
    text-align: center;
    white-space: normal;
  }

  .nav-toggle { display: none; }

  .nav-scrim { display: none; }

  .site-nav {
    position: static;
    flex: 1 1 auto;
    display: flex;
    flex-direction: column;
    width: 100%;
    max-height: none;
    overflow: visible;
    padding: 0;
    background-color: transparent;
    border-top: 0;
    box-shadow: none;
    transform: none;
  }

  .site-nav__list { gap: 1px; }

  .site-nav__link {
    flex-direction: column;
    align-items: flex-start;
    gap: 1px;
    padding: 9px 12px;
    border-left: 2px solid transparent;
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
  }

  .site-nav__num { width: auto; font-size: 10px; }

  .site-nav__label {
    font-size: 13.5px;
    line-height: 1.35;
    white-space: nowrap;
  }

  .site-nav__cta {
    margin-top: auto;
    padding-top: 14px;
  }

  .site-nav__cta .btn {
    width: 100%;
    padding: 10px 6px;
    font-size: 12px;
    letter-spacing: .01em;
  }

  body[data-nav-open] { overflow: auto; }

  .span-3 { grid-column: span 3; }
  .span-4 { grid-column: span 4; }
  .span-5 { grid-column: span 5; }
  .span-6 { grid-column: span 6; }
  .span-7 { grid-column: span 7; }
  .span-8 { grid-column: span 8; }
  .span-9 { grid-column: span 9; }
  .span-12 { grid-column: span 12; }
}

@media (min-width: 1200px) {
  .site-footer__grid { gap: 56px; }
}

/* 矮屏桌面：压缩轨道纵向占用 */
@media (min-width: 900px) and (max-height: 820px) {
  .brand__flame { width: 30px; height: 30px; }
  .brand__name { font-size: 14px; }
  .brand__sub { font-size: 8.5px; }
  .site-nav__link { padding: 7px 12px; }
  .site-nav__label { font-size: 12.5px; }
  .site-nav__cta .btn { padding: 8px 6px; font-size: 11px; }
}

/* ---------- 15. 减弱动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    scroll-behavior: auto !important;
  }

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

  .read-progress__fill { transition: none; }

  .site-nav { transition: none; }

  .btn:hover { transform: none; }

  .site-footer__link:hover { padding-left: 0; }
}