/* =========================================================
   利博看台 LB303 · /assets/site.css
   共享层：reset / 变量 / 中文排版 / 头部 / 页脚 / 通用组件
   ========================================================= */

/* ---------- 1. 设计变量 ---------- */
:root {
  --c-deep: #0B1F2A;
  --c-near: #143140;
  --c-green: #0E2E2A;
  --c-indigo: #4C4A8C;
  --c-wine: #7A2E3B;
  --c-signal: #FF7A18;
  --c-signal-hi: #FF9245;
  --c-gold: #C9A227;
  --c-paper: #F3F5F2;
  --c-sand: #E8DFCB;
  --c-tide: #6E8B85;
  --c-mute: #9AA6A2;
  --c-ink: #12262F;

  --line: rgba(110, 139, 133, .26);
  --line-strong: rgba(110, 139, 133, .5);
  --panel: rgba(20, 49, 64, .72);
  --header-bg: rgba(20, 49, 64, .94);
  --signal-soft: rgba(255, 122, 24, .12);
  --signal-line: rgba(255, 122, 24, .42);

  --font-head: "PingFang SC", "Hiragino Sans GB", "Source Han Sans SC", "Noto Sans CJK SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Heiti SC", system-ui, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", "Courier New", monospace;

  --fs-1: 56px;
  --fs-2: 40px;
  --fs-3: 28px;
  --fs-4: 20px;
  --fs-5: 16px;
  --fs-6: 14px;
  --fs-7: 12px;

  --shell: 1320px;
  --gutter: clamp(16px, 4vw, 40px);
  --radius-lg: 32px;
  --radius-md: 20px;
  --radius-sm: 12px;
  --radius-pill: 999px;
  --ease: cubic-bezier(.22, .61, .36, 1);
}

/* ---------- 2. Reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 124px;
}

body {
  margin: 0;
  background: var(--c-deep);
  color: var(--c-paper);
  font-family: var(--font-body);
  font-size: var(--fs-5);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

main { display: block; }

h1, h2, h3, h4, h5, h6 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -.02em;
}

p { margin: 0 0 .9em; }
ul, ol { margin: 0; padding: 0; }
li { list-style: none; }
img, svg, video { display: block; max-width: 100%; }
a { color: inherit; }
button { font: inherit; color: inherit; background: none; border: 0; }
hr { border: 0; }

::selection { background: var(--c-signal); color: var(--c-deep); }

:focus-visible {
  outline: 2px solid var(--c-signal);
  outline-offset: 2px;
  border-radius: 6px;
}

/* ---------- 3. 跳转链接 ---------- */
.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 200;
  padding: 10px 20px;
  border-radius: var(--radius-pill);
  background: var(--c-signal);
  color: var(--c-deep);
  font-family: var(--font-head);
  font-size: var(--fs-6);
  font-weight: 800;
  text-decoration: none;
  transform: translateY(-180%);
  transition: transform .2s var(--ease);
}
.skip-link:focus { transform: translateY(0); }

/* ---------- 4. 头部：悬浮胶囊浮岛 ---------- */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 70;
  padding: clamp(10px, 1.6vw, 16px) var(--gutter);
  pointer-events: none;
}

.header-shell {
  position: relative;
  pointer-events: auto;
  max-width: var(--shell);
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: clamp(10px, 2vw, 28px);
  padding: 10px 10px 10px clamp(14px, 2vw, 24px);
  background: var(--header-bg);
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  box-shadow: 0 10px 30px rgba(3, 12, 18, .42);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}

.brand {
  flex: 0 0 auto;
  display: flex;
  flex-direction: column;
  gap: 2px;
  text-decoration: none;
  color: var(--c-paper);
}
.brand__name {
  font-family: var(--font-head);
  font-size: 19px;
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: .02em;
  transition: color .18s var(--ease);
}
.brand__sub {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--c-tide);
}
.brand:hover .brand__name { color: var(--c-signal); }

.site-nav {
  flex: 1 1 auto;
  min-width: 0;
  display: flex;
  justify-content: center;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
}

.nav-link {
  display: inline-block;
  padding: 8px 12px;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  color: var(--c-paper);
  font-family: var(--font-head);
  font-size: var(--fs-6);
  font-weight: 600;
  text-decoration: none;
  white-space: nowrap;
  transition: color .18s var(--ease), background-color .18s var(--ease), border-color .18s var(--ease);
}
.nav-link:hover {
  background: rgba(243, 245, 242, .09);
  color: #fff;
}
.nav-link[aria-current="page"] {
  color: var(--c-signal);
  background: var(--signal-soft);
  border-color: var(--signal-line);
}

.header-action {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 18px;
  border-radius: var(--radius-pill);
  background: var(--c-signal);
  color: var(--c-deep);
  font-family: var(--font-head);
  font-size: var(--fs-6);
  font-weight: 800;
  text-decoration: none;
  white-space: nowrap;
  transition: background-color .18s var(--ease);
}
.header-action::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--c-deep);
  opacity: .5;
}
.header-action:hover { background: var(--c-signal-hi); }

.nav-toggle {
  display: none;
  flex: 0 0 auto;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line-strong);
  border-radius: 50%;
  color: var(--c-paper);
  cursor: pointer;
  transition: border-color .18s var(--ease), background-color .18s var(--ease);
}
.nav-toggle:hover { border-color: var(--c-signal); background: var(--signal-soft); }

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
}
.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform .2s var(--ease);
}
.nav-toggle__bars::before { top: -6px; }
.nav-toggle__bars::after { top: 6px; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after { transform: translateY(-6px) rotate(-45deg); }

.read-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--c-signal), var(--c-gold));
  pointer-events: none;
  z-index: 90;
}

@keyframes nav-in {
  from { opacity: 0; transform: translateY(-6px); }
  to { opacity: 1; transform: none; }
}

/* ---------- 5. 页脚 ---------- */
.site-footer {
  margin-top: clamp(48px, 8vw, 120px);
  background: var(--c-green);
  border-top: 2px solid var(--line-strong);
  color: var(--c-paper);
}

.footer-shell {
  max-width: var(--shell);
  margin: 0 auto;
  padding: clamp(36px, 5vw, 72px) var(--gutter) 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.1fr 1fr 1.2fr .9fr;
  gap: clamp(24px, 3vw, 48px);
}

.footer-col { display: flex; flex-direction: column; gap: 14px; }

.footer-col__title {
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: var(--fs-7);
  font-weight: 600;
  letter-spacing: .18em;
  color: var(--c-gold);
}

.footer-list { display: flex; flex-direction: column; gap: 8px; }
.footer-list--contact { gap: 12px; }

.footer-link {
  display: inline-flex;
  align-items: baseline;
  gap: 10px;
  color: var(--c-paper);
  font-size: var(--fs-6);
  text-decoration: none;
  transition: color .18s var(--ease);
}
.footer-link__num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .06em;
  color: var(--c-tide);
  transition: color .18s var(--ease);
}
.footer-link:hover { color: var(--c-signal); }
.footer-link:hover .footer-link__num { color: var(--c-gold); }

.footer-item {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 10px;
}
.footer-item__key {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: var(--fs-7);
  letter-spacing: .1em;
  color: var(--c-tide);
}
.footer-item__val {
  font-size: var(--fs-6);
  color: var(--c-paper);
  word-break: break-word;
}

.footer-text {
  margin: 0;
  font-size: var(--fs-6);
  line-height: 1.7;
  color: var(--c-mute);
}

.footer-base {
  margin-top: clamp(32px, 4vw, 56px);
  padding: 20px 0 28px;
  border-top: 1px solid var(--line);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  font-family: var(--font-mono);
  font-size: var(--fs-7);
  letter-spacing: .06em;
  color: var(--c-mute);
}
.footer-base__line { margin: 0; }
.footer-base__brand { color: var(--c-paper); }

/* ---------- 6. 布局容器与网格 ---------- */
.site-main { padding-top: clamp(104px, 11vw, 140px); }

.container {
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding: 0 var(--gutter);
}
.container--narrow { max-width: 920px; }

.section { padding: clamp(40px, 6vw, 88px) 0; }
.section--tight { padding: clamp(24px, 3vw, 40px) 0; }
.section--dark { background: var(--c-deep); }
.section--green {
  background: var(--c-green);
  border-top: 2px solid var(--line);
  border-bottom: 2px solid var(--line);
}
.section--paper {
  background: var(--c-sand);
  color: var(--c-ink);
  --line: rgba(11, 31, 42, .18);
  --line-strong: rgba(11, 31, 42, .34);
  --c-mute: #5C6B66;
  --c-tide: #7C8985;
}

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: clamp(16px, 2.4vw, 32px);
}
.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-12 { grid-column: span 12; }

/* ---------- 7. 排版工具 ---------- */
.eyebrow {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: var(--fs-7);
  letter-spacing: .18em;
  color: var(--c-gold);
  text-transform: uppercase;
}

.section-title {
  margin: 0 0 16px;
  font-size: var(--fs-2);
}

.lede {
  max-width: 640px;
  margin: 0 0 20px;
  font-size: var(--fs-4);
  line-height: 1.6;
  color: var(--c-paper);
  opacity: .9;
}

.prose { max-width: 660px; }
.prose p { margin: 0 0 .9em; }
.prose h3 { margin: 1.6em 0 .5em; font-size: var(--fs-3); }

.mono {
  font-family: var(--font-mono);
  font-size: var(--fs-6);
  letter-spacing: .06em;
}

.num-tag {
  font-family: var(--font-mono);
  font-size: var(--fs-7);
  letter-spacing: .08em;
  color: var(--c-gold);
}

/* ---------- 8. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 26px;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  font-family: var(--font-head);
  font-size: var(--fs-6);
  font-weight: 800;
  text-decoration: none;
  cursor: pointer;
  transition: background-color .18s var(--ease), color .18s var(--ease), border-color .18s var(--ease), transform .18s var(--ease);
}
.btn--primary { background: var(--c-signal); color: var(--c-deep); }
.btn--primary:hover { background: var(--c-signal-hi); transform: translateY(-1px); }
.btn--ghost { border-color: var(--line-strong); color: var(--c-paper); }
.btn--ghost:hover { border-color: var(--c-signal); color: var(--c-signal); background: var(--signal-soft); }
.btn--quiet { background: rgba(243, 245, 242, .08); color: var(--c-paper); }
.btn--quiet:hover { background: rgba(243, 245, 242, .16); }

/* ---------- 9. 面包屑 ---------- */
.breadcrumbs { padding: 18px 0 0; }
.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: var(--fs-7);
  letter-spacing: .06em;
  color: var(--c-mute);
}
.breadcrumb-list > li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--c-tide);
}
.breadcrumb-link {
  color: var(--c-mute);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .18s var(--ease), border-color .18s var(--ease);
}
.breadcrumb-link:hover { color: var(--c-signal); border-bottom-color: var(--c-signal); }
.breadcrumb-list [aria-current="page"] { color: var(--c-paper); }

/* ---------- 10. 索引卡片 / 标签 / 分隔 / 提醒 ---------- */
.index-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--panel);
  color: var(--c-paper);
  text-decoration: none;
  transition: border-color .18s var(--ease), background-color .18s var(--ease), transform .18s var(--ease);
}
.index-card:hover {
  border-color: var(--c-signal);
  background: rgba(20, 49, 64, .95);
  transform: translateY(-2px);
}
.index-card__num {
  font-family: var(--font-mono);
  font-size: var(--fs-7);
  letter-spacing: .08em;
  color: var(--c-gold);
}
.index-card__title { font-size: var(--fs-4); font-weight: 700; }
.index-card__desc { margin: 0; font-size: var(--fs-6); color: var(--c-mute); }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: var(--fs-7);
  letter-spacing: .06em;
  color: var(--c-mute);
}
.tag--signal {
  border-color: var(--signal-line);
  background: var(--signal-soft);
  color: var(--c-signal);
}

.rule { width: 100%; height: 1px; background: var(--line); }
.rule--strong { height: 2px; background: var(--line-strong); }

.status-note {
  display: block;
  padding: 14px 18px;
  border-left: 3px solid var(--c-wine);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  background: rgba(122, 46, 59, .18);
  font-size: var(--fs-6);
  color: var(--c-paper);
}

/* ---------- 11. 复制编号 ---------- */
.copy-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 4px 12px;
  border: 1px dashed rgba(201, 162, 39, .5);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: var(--fs-7);
  letter-spacing: .08em;
  color: var(--c-gold);
  cursor: pointer;
  transition: color .18s var(--ease), border-color .18s var(--ease), background-color .18s var(--ease);
}
.copy-chip:hover {
  border-color: var(--c-gold);
  background: rgba(201, 162, 39, .12);
}
.copy-chip.is-copied {
  border-style: solid;
  border-color: var(--c-gold);
  background: var(--c-gold);
  color: var(--c-ink);
}

/* ---------- 12. 图片容器基础规则（页面阶段放置图片） ---------- */
.media-frame {
  position: relative;
  display: block;
  width: 100%;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--c-near);
}
.media-frame img,
.media-frame__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media-frame--wide { aspect-ratio: 21 / 9; }
.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__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 14px 18px;
  background: linear-gradient(180deg, rgba(11, 31, 42, 0), rgba(11, 31, 42, .88));
  font-family: var(--font-mono);
  font-size: var(--fs-7);
  letter-spacing: .06em;
  color: var(--c-sand);
}

@supports not (aspect-ratio: 1 / 1) {
  .media-frame::before {
    content: "";
    display: block;
    padding-top: 62%;
  }
  .media-frame > img,
  .media-frame > .media-frame__img {
    position: absolute;
    inset: 0;
  }
}

/* ---------- 13. 响应式 ---------- */
@media (max-width: 1080px) {
  .brand__sub { display: none; }
  .header-shell { gap: 10px; padding-left: 16px; }
  .header-action { margin-left: auto; padding: 8px 14px; font-size: var(--fs-7); }
  .nav-toggle { display: inline-flex; }

  .site-nav {
    position: absolute;
    top: calc(100% + 12px);
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    padding: 10px;
    background: var(--c-near);
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    box-shadow: 0 18px 44px rgba(3, 12, 18, .5);
    max-height: min(72vh, 560px);
    overflow-y: auto;
  }
  .site-nav[data-open] {
    display: flex;
    animation: nav-in .2s var(--ease);
  }
  .nav-list { flex-direction: column; align-items: stretch; gap: 4px; }
  .nav-link {
    display: block;
    padding: 12px 14px;
    border-radius: var(--radius-md);
    font-size: var(--fs-5);
    white-space: normal;
  }
}

@media (max-width: 1024px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 980px) {
  .grid-12 { grid-template-columns: repeat(6, 1fr); }
  .col-3, .col-4, .col-5, .col-6, .col-7, .col-8 { grid-column: span 6; }
  .lede { font-size: var(--fs-5); }
}

@media (max-width: 760px) {
  :root {
    --fs-1: 34px;
    --fs-2: 26px;
    --fs-3: 22px;
    --fs-4: 18px;
    --fs-5: 15px;
    --fs-6: 13px;
    --fs-7: 11px;
  }
  .footer-base { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 640px) {
  .grid-12 { grid-template-columns: 1fr; }
  .col-3, .col-4, .col-5, .col-6, .col-7, .col-8 { grid-column: span 1; }
}

@media (max-width: 600px) {
  .footer-grid { grid-template-columns: 1fr; }
}

/* ---------- 14. 无障碍与动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
}