/* ================================================
   体坛速递 · 全站共享样式 /assets/site.css
   设计语言：编辑部目录 + 现代粗野主义 + 赛场能量
   ================================================ */

/* ---------- 设计变量 ---------- */
:root {
  --c-ink: #0A1B2A;
  --c-navy: #0B2545;
  --c-volt: #D7FF00;
  --c-orange: #FF5C00;
  --c-paper: #F2F4F8;
  --c-steel: #3A4A5A;
  --c-white: #FFFFFF;
  --c-line: #0B2545;
  --c-muted: #8A97A5;

  --font-title: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", "Helvetica Neue", Arial, sans-serif;
  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, "SF Mono", "SFMono-Regular", "Cascadia Code", Consolas, "Liberation Mono", monospace;

  --border-thick: 4px solid var(--c-ink);
  --border-medium: 3px solid var(--c-ink);
  --border-thin: 2px solid var(--c-ink);
  --shadow-card: 8px 8px 0 rgba(10, 27, 42, 0.18);
  --shadow-btn: 4px 4px 0 var(--c-ink);
  --shadow-btn-hover: 6px 6px 0 var(--c-ink);

  --container-max: 1280px;
  --header-h: 72px;
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 16px;
  --space-4: 24px;
  --space-5: 32px;
  --space-6: 48px;
  --space-7: 64px;
  --space-8: 96px;
}

/* ---------- Reset & 基础 ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

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

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.8;
  color: var(--c-ink);
  background: var(--c-paper);
  min-height: 100vh;
}

img { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }
button { font-family: inherit; }
a { color: var(--c-navy); }

body.nav-locked { overflow: hidden; }

/* ---------- 焦点可见 ---------- */
:focus-visible {
  outline: 3px solid var(--c-orange);
  outline-offset: 2px;
}

/* ---------- 容器与网格 ---------- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding-left: var(--space-4);
  padding-right: var(--space-4);
}

.grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: var(--space-4);
}
.col-3 { grid-column: span 3; }
.col-4 { grid-column: span 4; }
.col-5 { grid-column: span 5; }
.col-6 { grid-column: span 6; }
.col-7 { grid-column: span 7; }
.col-8 { grid-column: span 8; }
.col-9 { grid-column: span 9; }
.col-12 { grid-column: span 12; }

.content-main {
  max-width: 46em;
  margin: 0 auto;
}

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

.diagonal-lines {
  background-image: repeating-linear-gradient(
    -45deg,
    rgba(10, 27, 42, 0.06) 0,
    rgba(10, 27, 42, 0.06) 1px,
    transparent 1px,
    transparent 12px
  );
}

/* ---------- 排版组件 ---------- */
.page-title {
  font-size: clamp(40px, 6vw, 72px);
  font-weight: 900;
  font-style: italic;
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--c-ink);
  margin: 0;
}

.lead {
  font-size: 18px;
  line-height: 1.75;
  color: var(--c-steel);
  max-width: 48em;
}

.prose {
  font-size: 16px;
  line-height: 1.8;
  color: var(--c-ink);
  max-width: 46em;
}
.prose p { margin: 0 0 1.2em; }
.prose h2 {
  font-size: 26px;
  font-weight: 800;
  line-height: 1.3;
  margin: 2em 0 0.6em;
  color: var(--c-navy);
}
.prose h3 {
  font-size: 20px;
  font-weight: 700;
  margin: 1.5em 0 0.5em;
}
.prose a {
  color: var(--c-navy);
  text-decoration: underline;
  text-decoration-color: var(--c-volt);
  text-decoration-thickness: 3px;
  text-underline-offset: 2px;
}
.prose a:hover { color: var(--c-orange); }

.index-num {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--c-orange);
  text-transform: uppercase;
}

.section-head {
  margin-bottom: var(--space-5);
}
.section-head__index {
  display: block;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--c-orange);
  margin-bottom: var(--space-2);
  text-transform: uppercase;
}
.section-head__title {
  font-size: clamp(28px, 4vw, 48px);
  font-weight: 900;
  font-style: italic;
  line-height: 1.15;
  color: var(--c-ink);
  margin: 0;
}
.section-head__desc {
  max-width: 48em;
  font-size: 16px;
  color: var(--c-steel);
  line-height: 1.7;
  margin-top: var(--space-2);
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: 12px 28px;
  border: var(--border-medium);
  font-family: var(--font-title);
  font-size: 16px;
  font-weight: 700;
  line-height: 1;
  text-decoration: none;
  cursor: pointer;
  box-shadow: var(--shadow-btn);
  transition: transform 150ms ease, box-shadow 150ms ease, background 150ms ease;
  color: var(--c-ink);
  background: var(--c-white);
}
.btn:hover {
  transform: translate(-2px, -2px);
  box-shadow: var(--shadow-btn-hover);
}
.btn:active {
  transform: translate(2px, 2px);
  box-shadow: 2px 2px 0 var(--c-ink);
}
.btn--volt { background: var(--c-volt); color: var(--c-ink); }
.btn--navy { background: var(--c-navy); color: var(--c-white); }
.btn--orange { background: var(--c-orange); color: var(--c-white); }
.btn--ghost {
  background: transparent;
  color: var(--c-ink);
  box-shadow: none;
}
.btn--ghost:hover {
  background: var(--c-paper);
  transform: none;
  box-shadow: none;
}
.btn--sm { padding: 8px 16px; font-size: 14px; }

/* ---------- 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-muted);
  margin-bottom: var(--space-5);
}
.breadcrumb li + li::before {
  content: "/";
  color: var(--c-muted);
  margin-right: var(--space-2);
}
.breadcrumb a {
  color: var(--c-navy);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  padding-bottom: 1px;
}
.breadcrumb a:hover { border-bottom-color: var(--c-volt); }

/* ---------- 卡片与标注 ---------- */
.panel {
  background: var(--c-white);
  border: var(--border-thick);
  box-shadow: var(--shadow-card);
  padding: var(--space-5);
}
.panel--navy {
  background: var(--c-navy);
  color: var(--c-white);
  border-color: var(--c-ink);
}
.panel--volt {
  background: var(--c-volt);
  color: var(--c-ink);
}

.side-note {
  border-left: 4px solid var(--c-orange);
  padding-left: var(--space-3);
  color: var(--c-steel);
  font-size: 14px;
  line-height: 1.7;
  margin: 0;
}

.tag-chip {
  display: inline-block;
  padding: 4px 12px;
  border: var(--border-thin);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.04em;
  background: var(--c-white);
  color: var(--c-ink);
  text-transform: uppercase;
}

/* ---------- 图片容器 ---------- */
.image-frame {
  position: relative;
  overflow: hidden;
  display: block;
  width: 100%;
  background: var(--c-navy);
  border: var(--border-thick);
  box-shadow: var(--shadow-card);
}
.image-frame--16x9 { aspect-ratio: 16 / 9; }
.image-frame--4x3 { aspect-ratio: 4 / 3; }
.image-frame--1x1 { aspect-ratio: 1 / 1; }
.image-frame--21x9 { aspect-ratio: 21 / 9; }
.image-frame > img {
  position: relative;
  z-index: 1;
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.image-frame::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  background: repeating-linear-gradient(
    -45deg,
    var(--c-navy) 0,
    var(--c-navy) 12px,
    rgba(215, 255, 0, 0.07) 12px,
    rgba(215, 255, 0, 0.07) 14px
  );
}
.image-frame::after {
  content: "IMG";
  position: absolute;
  left: 10px;
  bottom: 10px;
  z-index: 2;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  color: var(--c-volt);
  background: var(--c-ink);
  border: 2px solid var(--c-ink);
  padding: 3px 8px;
  letter-spacing: 0.08em;
}
.image-frame[data-label]::after {
  content: "IMG/" attr(data-label);
}
.image-frame:has(img)::before,
.image-frame:has(img)::after {
  content: none;
}

/* ---------- 章节目录 ---------- */
.toc {
  position: sticky;
  top: calc(var(--header-h) + 48px);
  margin: 0;
  padding: 0;
  list-style: none;
  border-left: 4px solid var(--c-navy);
  padding-left: var(--space-3);
}
.toc__link {
  display: block;
  padding: 7px 0;
  font-size: 15px;
  line-height: 1.4;
  color: var(--c-steel);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: color 150ms ease, border-color 150ms ease, font-weight 150ms ease;
}
.toc__link:hover { color: var(--c-ink); border-bottom-color: var(--c-volt); }
.toc__link.is-active {
  color: var(--c-navy);
  font-weight: 700;
  border-bottom-color: var(--c-orange);
}

/* ---------- 手风琴 ---------- */
.accordion {
  border: var(--border-medium);
  border-bottom: none;
  background: var(--c-white);
  box-shadow: var(--shadow-card);
  margin-bottom: var(--space-4);
}
.accordion__toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 16px 20px;
  background: transparent;
  border: none;
  border-bottom: var(--border-medium);
  text-align: left;
  font-family: var(--font-title);
  font-size: 16px;
  font-weight: 700;
  color: var(--c-ink);
  cursor: pointer;
  transition: background 150ms ease, color 150ms ease;
}
.accordion__toggle:hover { background: var(--c-paper); color: var(--c-navy); }
.accordion__toggle::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 400;
  color: var(--c-orange);
  transition: transform 200ms ease;
}
.accordion__toggle[aria-expanded="true"]::after { content: "–"; }
.accordion__panel {
  display: none;
  padding: 20px 24px;
  border-bottom: var(--border-medium);
  background: var(--c-paper);
  font-size: 15px;
  line-height: 1.75;
  color: var(--c-ink);
}
.accordion__panel[data-open] { display: block; }

/* ================================================
   头部
   ================================================ */
.skip-link {
  position: absolute;
  top: -64px;
  left: var(--space-3);
  z-index: 3000;
  background: var(--c-volt);
  color: var(--c-ink);
  font-weight: 700;
  font-size: 14px;
  padding: 12px 20px;
  border: var(--border-medium);
  box-shadow: var(--shadow-btn);
  text-decoration: none;
  transition: top 150ms ease;
}
.skip-link:focus-visible { top: 12px; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--c-navy);
  border-bottom: var(--border-thick);
}

.progress-track {
  height: 5px;
  background: var(--c-ink);
  position: relative;
  overflow: hidden;
}
.progress-track__bar {
  position: absolute;
  top: 0;
  left: 0;
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--c-volt) 0%, var(--c-orange) 100%);
  transition: width 80ms linear;
  will-change: width;
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: var(--header-h);
  gap: var(--space-3);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  flex-shrink: 0;
}
.brand__mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 52px;
  height: 32px;
  padding: 0 10px;
  background: var(--c-volt);
  color: var(--c-ink);
  font-weight: 900;
  font-size: 17px;
  font-style: italic;
  line-height: 1;
  border: var(--border-medium);
  box-shadow: 3px 3px 0 var(--c-ink);
  transform: rotate(-4deg);
}
.brand__text {
  font-size: 18px;
  font-weight: 800;
  color: var(--c-white);
  white-space: nowrap;
  letter-spacing: 0.02em;
}
.brand__text em {
  font-style: normal;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--c-volt);
  letter-spacing: 1.5px;
  margin-left: 2px;
}

/* 导航 */
.site-nav__list {
  display: flex;
  align-items: center;
  gap: 2px;
}
.site-nav__link {
  display: inline-flex;
  align-items: baseline;
  gap: 4px;
  padding: 10px 10px 8px;
  color: var(--c-white);
  text-decoration: none;
  font-size: 15px;
  font-weight: 500;
  border-bottom: 3px solid transparent;
  transition: color 150ms ease, border-color 150ms ease, background 150ms ease;
}
.site-nav__link:hover {
  color: var(--c-volt);
  border-bottom-color: var(--c-volt);
}
.site-nav__num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--c-muted);
  font-weight: 400;
}
.site-nav__link[aria-current="page"] {
  color: var(--c-volt);
  border-bottom-color: var(--c-volt);
  font-weight: 700;
}
.site-nav__link[aria-current="page"] .site-nav__num { color: var(--c-volt); }

/* 移动导航按钮 */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 46px;
  height: 46px;
  padding: 10px;
  background: var(--c-volt);
  border: var(--border-medium);
  box-shadow: 3px 3px 0 var(--c-ink);
  cursor: pointer;
  position: relative;
  z-index: 1002;
  transition: background 150ms ease, transform 150ms ease;
}
.nav-toggle:hover {
  background: var(--c-orange);
  transform: rotate(-3deg);
}
.nav-toggle__line {
  display: block;
  width: 20px;
  height: 3px;
  background: var(--c-ink);
  transition: transform 200ms ease, opacity 200ms ease;
  pointer-events: none;
}
.nav-toggle.is-active .nav-toggle__line:nth-child(1) { transform: translateY(8px) rotate(45deg); }
.nav-toggle.is-active .nav-toggle__line:nth-child(2) { opacity: 0; }
.nav-toggle.is-active .nav-toggle__line:nth-child(3) { transform: translateY(-8px) rotate(-45deg); }

/* ================================================
   页脚
   ================================================ */
.site-footer {
  background: var(--c-navy);
  color: var(--c-white);
  border-top: var(--border-thick);
  position: relative;
}
.site-footer::before {
  content: "";
  position: absolute;
  top: -4px;
  left: 0;
  width: 33.333%;
  height: 4px;
  background: var(--c-volt);
}
.site-footer__inner {
  padding-top: var(--space-7);
  padding-bottom: var(--space-5);
}
.site-footer__grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1.2fr;
  gap: var(--space-6);
  margin-bottom: var(--space-6);
}
.site-footer__brand {
  font-size: 40px;
  font-weight: 900;
  font-style: italic;
  line-height: 1.1;
  color: var(--c-white);
  margin: 0 0 12px;
  letter-spacing: -0.02em;
}
.site-footer__brand-dot { color: var(--c-volt); }
.site-footer__desc {
  color: var(--c-muted);
  font-size: 14px;
  line-height: 1.7;
  max-width: 22em;
  margin: 0;
}
.site-footer__col-title {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--c-volt);
  margin: 0 0 14px;
  padding-bottom: 8px;
  border-bottom: 2px solid rgba(10, 27, 42, 0.55);
}
.site-footer__link {
  display: block;
  color: rgba(255, 255, 255, 0.92);
  text-decoration: none;
  font-size: 15px;
  padding: 5px 0;
  transition: color 150ms ease, padding-left 150ms ease, border-color 150ms ease;
  border-bottom: 1px solid transparent;
}
.site-footer__link:hover {
  color: var(--c-volt);
  padding-left: 8px;
  border-bottom-color: rgba(215, 255, 0, 0.4);
}
.site-footer__contact {
  color: var(--c-muted);
  font-size: 14px;
  line-height: 1.7;
  margin: 0 0 4px;
}
.site-footer__bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-3);
  padding-top: var(--space-4);
  border-top: 2px solid rgba(10, 27, 42, 0.55);
}
.site-footer__copy {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-muted);
}
.site-footer__legal {
  display: flex;
  gap: var(--space-4);
}
.site-footer__legal a {
  color: var(--c-muted);
  text-decoration: none;
  font-size: 13px;
  border-bottom: 2px solid transparent;
  padding-bottom: 2px;
  transition: color 150ms ease, border-bottom-color 150ms ease;
}
.site-footer__legal a:hover {
  color: var(--c-volt);
  border-bottom-color: var(--c-volt);
}

/* ---------- 返回顶部 ---------- */
.back-top {
  position: fixed;
  right: 20px;
  bottom: 20px;
  z-index: 999;
  width: 50px;
  height: 50px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--c-orange);
  border: var(--border-medium);
  box-shadow: 4px 4px 0 var(--c-ink);
  cursor: pointer;
  color: var(--c-white);
  font-size: 20px;
  line-height: 1;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity 200ms ease, transform 200ms ease, visibility 200ms ease, box-shadow 200ms ease;
}
.back-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.back-top:hover {
  transform: translateY(-2px) rotate(-3deg);
  box-shadow: 6px 6px 0 var(--c-ink);
}
.back-top:active {
  transform: translateY(2px) translateX(2px);
  box-shadow: 2px 2px 0 var(--c-ink);
}
.back-top__icon {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 18px;
}

/* ================================================
   响应式
   ================================================ */
@media (max-width: 960px) {
  .site-footer__grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-5);
  }
  .site-footer__brand-col {
    grid-column: 1 / -1;
  }
  .col-3, .col-4 { grid-column: span 6; }
  .col-5, .col-7 { grid-column: span 12; }
  .col-6, .col-8, .col-9, .col-12 { grid-column: span 12; }
}

@media (max-width: 820px) {
  .container {
    padding-left: var(--space-3);
    padding-right: var(--space-3);
  }

  .site-header__inner {
    min-height: 60px;
  }

  .brand__mark {
    min-width: 44px;
    height: 28px;
    font-size: 14px;
    padding: 0 7px;
  }
  .brand__text {
    font-size: 15px;
  }
  .brand__text em {
    font-size: 11px;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    width: min(86vw, 360px);
    background: var(--c-volt);
    border-left: var(--border-thick);
    box-shadow: -8px 8px 0 rgba(10, 27, 42, 0.3);
    padding: 88px var(--space-4) var(--space-5);
    transform: translateX(100%);
    visibility: hidden;
    transition: transform 220ms ease-out, visibility 220ms;
    z-index: 1000;
    overflow-y: auto;
  }
  .site-nav[data-open] {
    transform: translateX(0);
    visibility: visible;
  }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }
  .site-nav__item {
    border-bottom: 1px solid rgba(10, 27, 42, 0.18);
  }
  .site-nav__link {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 15px 10px;
    font-size: 18px;
    font-weight: 700;
    color: var(--c-ink);
    border-bottom: none;
    border-left: 4px solid transparent;
  }
  .site-nav__link:hover {
    background: var(--c-ink);
    color: var(--c-volt);
    border-left-color: var(--c-orange);
  }
  .site-nav__link[aria-current="page"] {
    background: var(--c-ink);
    color: var(--c-volt);
    border-left-color: var(--c-orange);
    border-bottom: none;
    font-weight: 800;
  }
  .site-nav__link[aria-current="page"] .site-nav__num { color: var(--c-orange); }
  .site-nav__num {
    color: var(--c-orange);
    font-size: 12px;
  }
  .site-nav__link:hover .site-nav__num { color: var(--c-volt); }
}

@media (max-width: 640px) {
  .site-footer__grid {
    grid-template-columns: 1fr;
    gap: var(--space-5);
  }
  .site-footer__bottom {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-2);
  }
  .site-footer__legal {
    gap: var(--space-3);
  }
  .back-top {
    right: 14px;
    bottom: 14px;
    width: 44px;
    height: 44px;
    font-size: 17px;
  }
  .col-3, .col-4, .col-5, .col-6, .col-7, .col-8, .col-9, .col-12 {
    grid-column: span 12;
  }
}

/* ================================================
   无障碍：减少动态
   ================================================ */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  .site-nav {
    transition: none;
  }
  .progress-track__bar {
    transition: none;
  }
}