/* ==========================================================================
   南宫看台 · Site Kit
   assets/site.css — reset / tokens / 中文排版 / header / footer / 通用组件
   ========================================================================== */

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

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 24px);
}

body {
  margin: 0;
  background: var(--ink);
  color: var(--white);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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 { display: block; max-width: 100%; }
img { height: auto; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
table { border-collapse: collapse; width: 100%; }
hr { border: 0; border-top: 1px solid var(--line); margin: 0; }

:focus-visible {
  outline: 2px solid var(--lime);
  outline-offset: 3px;
}
:focus:not(:focus-visible) { outline: none; }

::selection {
  background: var(--lime);
  color: var(--brown);
}

/* ---------- 2. Design tokens ---------- */
:root {
  /* 主色 */
  --ink: #07130F;          /* 看台墨绿 */
  --coal: #0B0F0D;         /* 夜场炭黑 */
  --cream: #F2E8D5;        /* 奶油纸 */
  --brown: #231A14;        /* 深棕黑 */
  --lime: #C9FF3F;         /* 荧光青柠 */
  --orange: #FF7A2F;       /* 暖橙 */
  --cyan: #5BD6C8;         /* 冷青 */
  --sage: #91A39A;         /* 灰绿 */
  --red: #D94A3D;          /* 出版红 */
  --white: #FFFFFF;

  /* 派生 */
  --ink-soft: #0E1D17;
  --coal-soft: #121714;
  --line: rgba(145, 163, 154, 0.28);
  --line-strong: rgba(145, 163, 154, 0.55);
  --line-dark: rgba(35, 26, 20, 0.18);

  /* 字体 */
  --font-display: 'Barlow Condensed', 'Oswald', 'Noto Sans SC', 'PingFang SC', sans-serif;
  --font-head: 'Noto Sans SC', 'Source Han Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-body: 'Source Han Sans SC', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-data: 'Roboto Mono', 'IBM Plex Mono', 'SFMono-Regular', Consolas, monospace;

  /* 尺度 */
  --gutter: clamp(20px, 4vw, 64px);
  --max-w: 1360px;
  --header-h: 72px;
  --step: 8px;

  /* 动效 */
  --dur: 160ms;
  --dur-slow: 420ms;
  --ease: cubic-bezier(0.2, 0.7, 0.3, 1);
}

/* ---------- 3. 中文排版基础 ---------- */
h1, h2, h3, h4 {
  font-family: var(--font-head);
  font-weight: 700;
  line-height: 1.22;
  letter-spacing: 0.01em;
  text-wrap: balance;
}

p { text-wrap: pretty; }

.container {
  width: 100%;
  max-width: var(--max-w);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.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;
}

/* ---------- 4. 跳转链接 ---------- */
.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 300;
  padding: 10px 18px;
  background: var(--lime);
  color: var(--brown);
  font-family: var(--font-head);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  transform: translateY(-180%);
  transition: transform var(--dur) var(--ease);
}
.skip-link:focus {
  transform: translateY(0);
}

/* ---------- 5. Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--ink);
  border-bottom: 1px solid var(--line);
}

.site-header::after {
  content: "";
  position: absolute;
  inset: auto 0 -1px 0;
  height: 1px;
  background: linear-gradient(90deg, var(--lime) 0 18%, transparent 18% 100%);
  opacity: 0.5;
  pointer-events: none;
}

.scroll-meter {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  overflow: hidden;
  pointer-events: none;
}
.scroll-meter > span {
  display: block;
  width: 0;
  height: 100%;
  background: var(--lime);
}

.header-inner {
  position: relative;
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 32px);
  width: 100%;
  max-width: var(--max-w);
  min-height: var(--header-h);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

/* 品牌 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
  padding-block: 12px;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  background: var(--lime);
  color: var(--brown);
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 800;
  letter-spacing: 0.02em;
  line-height: 1;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease);
}
.brand:hover .brand-mark {
  background: var(--white);
}

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 3px;
  line-height: 1.05;
}
.brand-name {
  font-family: var(--font-head);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--white);
}
.brand-line {
  font-family: var(--font-data);
  font-size: 10px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--sage);
  white-space: nowrap;
}

/* 轨道导航 */
.rail-nav {
  flex: 1 1 auto;
  display: flex;
  justify-content: flex-end;
}

.rail-list {
  display: flex;
  align-items: stretch;
  flex-wrap: nowrap;
}

.rail-item {
  display: flex;
}

.rail-link {
  position: relative;
  display: flex;
  align-items: baseline;
  gap: 7px;
  padding: 12px 13px;
  font-family: var(--font-head);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--sage);
  white-space: nowrap;
  transition: color var(--dur) var(--ease);
}

.rail-link::after {
  content: "";
  position: absolute;
  left: 13px;
  right: 13px;
  bottom: 6px;
  height: 2px;
  background: var(--lime);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform var(--dur) var(--ease);
}

.rail-num {
  font-family: var(--font-data);
  font-size: 10px;
  letter-spacing: 0.08em;
  color: var(--sage);
  opacity: 0.6;
  transition: color var(--dur) var(--ease), opacity var(--dur) var(--ease);
}

.rail-link:hover { color: var(--white); }
.rail-link:hover::after { transform: scaleX(1); }
.rail-link:hover .rail-num { color: var(--cyan); opacity: 1; }

.rail-link[aria-current="page"] { color: var(--lime); }
.rail-link[aria-current="page"]::after { transform: scaleX(1); }
.rail-link[aria-current="page"] .rail-num { color: var(--lime); opacity: 1; }

/* 头部右侧 */
.header-side {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
  margin-left: auto;
}

.quick-jump {
  display: flex;
  align-items: center;
  gap: 6px;
}

.quick-link {
  display: inline-flex;
  align-items: center;
  padding: 5px 10px;
  border: 1px solid var(--line);
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--sage);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}
.quick-link:hover {
  color: var(--ink);
  background: var(--cyan);
  border-color: var(--cyan);
}

/* 抽屉按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border: 1px solid var(--line-strong);
  color: var(--white);
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}
.nav-toggle:hover { border-color: var(--lime); color: var(--lime); }

.nav-toggle-bars {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
  transition: background var(--dur) var(--ease);
}
.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: currentColor;
  transition: transform var(--dur) var(--ease), top var(--dur) var(--ease);
}
.nav-toggle-bars::before { top: -6px; }
.nav-toggle-bars::after { top: 6px; }

.site-header[data-open] .nav-toggle-bars { background: transparent; }
.site-header[data-open] .nav-toggle-bars::before { top: 0; transform: rotate(45deg); }
.site-header[data-open] .nav-toggle-bars::after { top: 0; transform: rotate(-45deg); }

/* ---------- 6. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 20px;
  border: 1px solid transparent;
  border-radius: 0;
  font-family: var(--font-head);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.06em;
  line-height: 1.4;
  white-space: nowrap;
  cursor: pointer;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease),
              border-color var(--dur) var(--ease);
}

.btn-lime { background: var(--lime); color: var(--brown); border-color: var(--lime); }
.btn-lime:hover { background: var(--white); border-color: var(--white); color: var(--brown); }

.btn-orange { background: var(--orange); color: var(--brown); border-color: var(--orange); }
.btn-orange:hover { background: var(--lime); border-color: var(--lime); }

.btn-ghost { background: transparent; color: var(--white); border-color: var(--line-strong); }
.btn-ghost:hover { color: var(--lime); border-color: var(--lime); }

.header-cta { padding: 10px 18px; font-size: 13px; }

/* ---------- 7. Footer ---------- */
.site-footer {
  position: relative;
  background: var(--coal);
  color: var(--white);
  border-top: 1px solid var(--line);
  padding-top: clamp(48px, 7vw, 88px);
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 4px;
  background: linear-gradient(
    90deg,
    var(--lime) 0 22%,
    var(--cyan) 22% 46%,
    var(--orange) 46% 70%,
    var(--red) 70% 100%
  );
}

.footer-inner { padding-bottom: 0; }

.footer-top {
  display: grid;
  grid-template-columns: minmax(240px, 1.05fr) minmax(0, 2.55fr);
  gap: clamp(32px, 5vw, 72px);
  padding-bottom: clamp(40px, 6vw, 72px);
  border-bottom: 1px solid var(--line);
}

.footer-brand {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.footer-mark {
  display: block;
  font-family: var(--font-display);
  font-size: clamp(56px, 7vw, 92px);
  font-weight: 800;
  line-height: 0.86;
  letter-spacing: 0.02em;
  color: var(--lime);
}

.footer-brand-name {
  margin-top: 16px;
  font-family: var(--font-head);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.16em;
  color: var(--white);
}

.footer-brand-sub {
  margin-top: 6px;
  font-family: var(--font-data);
  font-size: 10px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--sage);
}

.footer-tagline {
  margin-top: 20px;
  max-width: 30ch;
  font-size: 14px;
  line-height: 1.8;
  color: var(--sage);
}

.footer-nav {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: clamp(20px, 2.6vw, 40px);
}

.footer-col { min-width: 0; }

.footer-col-title {
  padding-bottom: 10px;
  margin-bottom: 16px;
  border-bottom: 1px solid var(--line);
  font-family: var(--font-data);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cyan);
}

.footer-links {
  display: grid;
  gap: 10px;
}

.footer-links--contact { gap: 12px; }

.footer-link {
  display: inline-block;
  font-size: 14px;
  line-height: 1.6;
  color: var(--white);
  opacity: 0.82;
  transition: color var(--dur) var(--ease), opacity var(--dur) var(--ease);
}
.footer-link::before {
  content: "";
  display: inline-block;
  width: 0;
  height: 1px;
  margin-right: 0;
  background: var(--lime);
  vertical-align: middle;
  transition: width var(--dur) var(--ease), margin-right var(--dur) var(--ease);
}
.footer-link:hover {
  color: var(--lime);
  opacity: 1;
}
.footer-link:hover::before {
  width: 12px;
  margin-right: 8px;
}

.contact-line {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 8px;
  align-items: baseline;
}

.contact-label {
  font-family: var(--font-data);
  font-size: 10px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--sage);
  opacity: 0.85;
}

.contact-value {
  font-size: 13px;
  line-height: 1.7;
  color: var(--white);
  word-break: break-word;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 32px;
  padding-block: 24px 28px;
}

.footer-legal {
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--sage);
}

.footer-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
}

.footer-meta-link {
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--sage);
  transition: color var(--dur) var(--ease);
}
.footer-meta-link:hover { color: var(--lime); }

/* ---------- 8. 布局与章节原语 ---------- */
.section {
  padding-block: clamp(48px, 8vw, 112px);
}

.section--cream {
  background: var(--cream);
  color: var(--brown);
}
.section--cream .eyebrow { color: var(--red); }
.section--cream hr { border-top-color: var(--line-dark); }

.eyebrow {
  display: block;
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--cyan);
}

.band-num {
  display: block;
  font-family: var(--font-display);
  font-size: clamp(40px, 6vw, 84px);
  font-weight: 800;
  line-height: 0.9;
  letter-spacing: 0.02em;
  color: var(--red);
}

.divider {
  width: 100%;
  height: 1px;
  background: var(--line);
  margin-block: clamp(24px, 3vw, 40px);
}

.grid {
  display: grid;
  gap: clamp(16px, 2.2vw, 28px);
}
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--split { grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); }

/* ---------- 9. 通用内容组件 ---------- */
.card {
  position: relative;
  display: flex;
  flex-direction: column;
  background: var(--coal-soft);
  border: 1px solid var(--line);
  transition: border-color var(--dur) var(--ease);
}
.card:hover { border-color: var(--line-strong); }

.card__bar {
  height: 3px;
  background: var(--cyan);
}
.card__bar--cyan { background: var(--cyan); }
.card__bar--orange { background: var(--orange); }
.card__bar--lime { background: var(--lime); }
.card__bar--red { background: var(--red); }

.card__body {
  display: flex;
  flex-direction: column;
  gap: 12px;
  flex: 1 1 auto;
  padding: clamp(18px, 2.4vw, 28px);
}

.card__title {
  font-family: var(--font-head);
  font-size: clamp(18px, 1.8vw, 22px);
  font-weight: 700;
  line-height: 1.35;
  color: var(--white);
}

.card__meta {
  margin-top: auto;
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--sage);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  border: 1px solid currentColor;
  font-family: var(--font-data);
  font-size: 10px;
  letter-spacing: 0.12em;
  line-height: 1.7;
  text-transform: uppercase;
}
.tag--cyan { color: var(--cyan); }
.tag--orange { color: var(--orange); }
.tag--lime { color: var(--lime); }
.tag--red { color: var(--red); }
.tag--sage { color: var(--sage); }

.data-num {
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.01em;
}

.stat {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding-left: 12px;
  border-left: 2px solid var(--cyan);
}
.stat--orange { border-left-color: var(--orange); }

.prose {
  max-width: 68ch;
  font-size: 17px;
  line-height: 1.8;
}
.prose > * + * { margin-top: 20px; }
.prose h2 {
  font-size: clamp(26px, 3.2vw, 40px);
  line-height: 1.25;
  margin-top: 40px;
}
.prose h3 {
  font-size: clamp(20px, 2.2vw, 26px);
  margin-top: 32px;
}
.prose ul, .prose ol {
  padding-left: 1.4em;
  list-style: disc;
}
.prose ol { list-style: decimal; }
.prose li + li { margin-top: 8px; }
.prose a {
  text-decoration: underline;
  text-decoration-color: var(--cyan);
  text-underline-offset: 3px;
}
.prose strong { font-weight: 700; }

/* ---------- 10. 图片容器基础规则 ---------- */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  background: var(--ink-soft);
  border: 1px solid var(--line);
}
.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media-frame--16x9 { aspect-ratio: 16 / 9; }
.media-frame--4x3 { aspect-ratio: 4 / 3; }
.media-frame--3x4 { aspect-ratio: 3 / 4; }
.media-frame--1x1 { aspect-ratio: 1 / 1; }
.media-frame--wide { aspect-ratio: 21 / 9; }

.media-frame[data-placeholder]::after {
  content: attr(data-placeholder);
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  padding: 12px;
  text-align: center;
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--sage);
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 32px 32px;
  background-position: -1px -1px;
}

@media (max-width: 560px) {
  .media-frame--wide { aspect-ratio: 16 / 9; }
  .media-frame--3x4 { aspect-ratio: 4 / 5; }
}

/* ---------- 11. 显现动效协议 ---------- */
[data-reveal="pending"] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity var(--dur-slow) var(--ease), transform var(--dur-slow) var(--ease);
}
[data-reveal="done"] {
  opacity: 1;
  transform: none;
}

/* ---------- 12. 响应式：平板与移动 ---------- */
@media (max-width: 1180px) {
  .nav-toggle { display: inline-flex; }

  .quick-jump { display: none; }

  .rail-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    justify-content: flex-start;
    max-height: calc(100vh - var(--header-h));
    overflow-y: auto;
    padding: 8px var(--gutter) 28px;
    background: var(--coal);
    border-bottom: 1px solid var(--line);
    box-shadow: 0 24px 48px rgba(0, 0, 0, 0.45);
  }

  .site-header[data-open] .rail-nav { display: flex; }

  .rail-list {
    flex-direction: column;
    align-items: stretch;
  }

  .rail-item {
    border-bottom: 1px solid var(--line);
  }
  .rail-item:last-child { border-bottom: 0; }

  .rail-link {
    justify-content: flex-start;
    padding: 16px 4px;
    font-size: 17px;
    color: var(--white);
  }

  .rail-link::after {
    left: 4px;
    right: auto;
    bottom: 10px;
    width: 0;
    height: 2px;
    transform: none;
    transition: width var(--dur) var(--ease);
  }
  .rail-link:hover::after { transform: none; width: 24px; }

  .rail-link[aria-current="page"] {
    color: var(--lime);
  }
  .rail-link[aria-current="page"]::after {
    transform: none;
    width: 24px;
  }

  .rail-num {
    font-size: 11px;
    opacity: 0.7;
  }

  .footer-top {
    grid-template-columns: minmax(0, 1fr);
  }

  .footer-nav {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 32px;
  }

  .grid--split { grid-template-columns: minmax(0, 1fr); }
}

@media (max-width: 860px) {
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 720px) {
  :root { --header-h: 64px; }

  .brand-mark { width: 36px; height: 36px; font-size: 16px; }
  .brand-name { font-size: 16px; }
  .brand-line { display: none; }

  .header-inner { gap: 10px; }

  .header-cta { display: none; }

  .grid--2,
  .grid--3 { grid-template-columns: minmax(0, 1fr); }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 520px) {
  .footer-nav { grid-template-columns: minmax(0, 1fr); gap: 28px; }
  .contact-line { grid-template-columns: 40px minmax(0, 1fr); }
}

/* ---------- 13. 动效降级 ---------- */
@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;
    scroll-behavior: auto !important;
  }

  [data-reveal="pending"],
  [data-reveal="done"] {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .rail-link::after,
  .footer-link::before {
    transition: none;
  }
}