/* ==========================================================================
   OG视讯厅 / site.css —— 共享外壳与基础组件
   夜色播控台 × 档案库：深墨蓝底、信号橙锚点、荧光青标签、蓝图网格
   ========================================================================== */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 132px;
}

body,
h1, h2, h3, h4, p, ul, ol, figure, blockquote {
  margin: 0;
}

ul, ol { padding: 0; }

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

button { font: inherit; }

a { color: inherit; }

/* ---------- 变量 ---------- */
:root {
  --ink-900: #061220;
  --ink-800: #0B1D30;
  --ink-700: #142A42;
  --ink-600: #1F3D5C;
  --signal: #FF6B2C;
  --signal-soft: #FF8A55;
  --cyan: #2CE5C8;
  --amber: #FFC24B;
  --violet: #8B7BFF;
  --mint: #5BE39A;
  --fog: #E8EEF4;
  --slate: #8FA3B8;
  --paper: #F4F6F8;
  --paper-ink: #0A1523;
  --paper-sub: #3D4E60;

  --radius-lg: 28px;
  --radius-md: 18px;
  --radius-pill: 999px;

  --wrap: 1180px;
  --gutter: clamp(16px, 4vw, 40px);

  --fs-xs: 0.8125rem;
  --fs-body: 1rem;
  --fs-h3: 1.25rem;
  --fs-h2: clamp(1.5rem, 3.2vw, 1.75rem);
  --fs-h1: clamp(2rem, 5.2vw, 2.75rem);

  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui,
    -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Courier New", monospace;

  --ease: cubic-bezier(0.2, 0.7, 0.3, 1);
  --dur: 200ms;
}

/* ---------- 基础排版 ---------- */
body {
  min-height: 100%;
  background-color: var(--ink-900);
  background-image:
    linear-gradient(to right, rgba(20, 42, 66, 0.55) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(20, 42, 66, 0.55) 1px, transparent 1px);
  background-size: 80px 80px;
  color: var(--fog);
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-weight: 800;
  line-height: 1.25;
  letter-spacing: -0.01em;
  color: var(--fog);
}

h1 { font-size: var(--fs-h1); }
h2 { font-size: var(--fs-h2); }
h3 { font-size: var(--fs-h3); }

p + p { margin-top: 1em; }

a {
  color: var(--cyan);
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}

a:hover { color: var(--signal); }

:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 6px;
}

::selection {
  background: rgba(255, 107, 44, 0.35);
  color: var(--fog);
}

/* ---------- 工具类 ---------- */
.wrap {
  width: min(100% - (var(--gutter) * 2), var(--wrap));
  margin-inline: auto;
}

.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

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

/* ---------- 跳转链接 ---------- */
.skip-link {
  position: absolute;
  left: 16px;
  top: -72px;
  z-index: 200;
  padding: 10px 20px;
  border-radius: var(--radius-pill);
  background: var(--signal);
  color: var(--paper-ink);
  font-size: var(--fs-body);
  font-weight: 700;
  transition: top var(--dur) var(--ease);
}

.skip-link:focus {
  top: 14px;
  color: var(--paper-ink);
}

/* ==========================================================================
   头部
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: rgba(6, 18, 32, 0.94);
  border-bottom: 1px solid var(--ink-700);
  backdrop-filter: blur(10px);
}

.header-utility {
  border-bottom: 1px solid var(--ink-700);
}

.header-utility__inner {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: clamp(12px, 2.4vw, 32px);
  min-height: 66px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
  color: var(--fog);
}

.brand:hover { color: var(--fog); }

.brand__mark {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  flex: 0 0 auto;
  border-radius: 12px;
  background: var(--signal);
  color: #08111D;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  font-weight: 700;
  letter-spacing: 0.06em;
}

.brand__text {
  display: flex;
  flex-direction: column;
  min-width: 0;
  line-height: 1.25;
}

.brand__name {
  font-size: 1.125rem;
  font-weight: 900;
  letter-spacing: 0.02em;
}

.brand__tag {
  font-size: var(--fs-xs);
  color: var(--slate);
}

.header-status {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  justify-self: start;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  color: var(--slate);
}

.header-status__dot {
  width: 7px;
  height: 7px;
  flex: 0 0 auto;
  border-radius: 50%;
  background: var(--mint);
  box-shadow: 0 0 0 4px rgba(91, 227, 154, 0.14);
  animation: statusPulse 2.6s var(--ease) infinite;
}

.header-status__text { white-space: nowrap; }

@keyframes statusPulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.35; }
}

.header-search {
  display: inline-flex;
  align-items: center;
  padding: 8px 18px;
  border: 1px solid var(--ink-600);
  border-radius: var(--radius-pill);
  color: var(--cyan);
  font-size: var(--fs-xs);
  font-weight: 700;
  letter-spacing: 0.04em;
  white-space: nowrap;
  transition: border-color var(--dur) var(--ease),
    background-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.header-search:hover {
  border-color: var(--cyan);
  background: rgba(44, 229, 200, 0.09);
  color: var(--cyan);
}

.header-nav__inner {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 56px;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  flex: 0 0 auto;
  padding: 9px 16px;
  border: 1px solid var(--ink-600);
  border-radius: var(--radius-pill);
  background: var(--ink-800);
  color: var(--fog);
  font-size: var(--fs-xs);
  font-weight: 700;
  cursor: pointer;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.nav-toggle__bars {
  display: grid;
  gap: 3px;
  width: 16px;
}

.nav-toggle__bars span {
  display: block;
  height: 2px;
  border-radius: 2px;
  background: var(--cyan);
  transition: background-color var(--dur) var(--ease);
}

.nav-toggle__label { white-space: nowrap; }

.nav-toggle[aria-expanded="true"] {
  border-color: var(--signal);
  color: var(--signal);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars span { background: var(--signal); }

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

.site-nav__list {
  display: flex;
  align-items: stretch;
  gap: 2px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-nav__list a {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 16px 14px;
  border-bottom: 2px solid transparent;
  color: var(--slate);
  font-size: var(--fs-body);
  font-weight: 700;
  white-space: nowrap;
  transition: color var(--dur) var(--ease),
    border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.site-nav__list a:hover {
  color: var(--fog);
  background: rgba(255, 107, 44, 0.07);
}

.site-nav__idx {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  font-variant-numeric: tabular-nums;
  color: var(--amber);
  transition: color var(--dur) var(--ease);
}

.site-nav__list a[aria-current="page"] {
  color: var(--fog);
  border-bottom-color: var(--signal);
}

.site-nav__list a[aria-current="page"] .site-nav__idx { color: var(--signal); }

.read-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  overflow: hidden;
  background: transparent;
}

.read-progress__bar {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--signal), var(--amber));
  transition: transform 120ms linear;
}

/* ==========================================================================
   页脚
   ========================================================================== */
.site-footer {
  margin-top: clamp(48px, 8vw, 96px);
  background: var(--ink-800);
  border-top: 1px solid var(--ink-700);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1.3fr;
  gap: clamp(20px, 4vw, 44px);
  padding: clamp(36px, 6vw, 64px) 0;
}

.footer-col {
  display: flex;
  flex-direction: column;
  gap: 12px;
  min-width: 0;
}

.footer-col--brand { gap: 14px; }

.footer-brand {
  font-size: 1.375rem;
  font-weight: 900;
  letter-spacing: 0.02em;
  color: var(--fog);
}

.footer-desc {
  color: var(--slate);
  font-size: var(--fs-body);
  line-height: 1.7;
}

.footer-desc--mono {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  color: var(--cyan);
}

.footer-title {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--amber);
}

.footer-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer-list a {
  color: var(--fog);
  font-size: var(--fs-body);
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.footer-list a:hover {
  color: var(--signal);
  border-bottom-color: var(--signal);
}

.footer-list--plain li {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  line-height: 1.8;
  color: var(--slate);
  word-break: break-word;
}

.footer-base {
  background: var(--ink-900);
  border-top: 1px solid var(--ink-700);
  padding: 18px 0;
}

.footer-base__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 24px;
}

.footer-base__inner p {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  color: var(--slate);
}

/* ==========================================================================
   内容骨架
   ========================================================================== */
.band {
  position: relative;
  padding: clamp(32px, 5vw, 56px) 0;
  border-top: 1px solid var(--ink-700);
  border-bottom: 1px solid var(--ink-700);
}

.band--paper {
  background: var(--paper);
  color: var(--paper-ink);
}

.band--paper h1,
.band--paper h2,
.band--paper h3 { color: var(--paper-ink); }

.band--paper .section__lead,
.band--paper .card__body,
.band--paper p { color: var(--paper-sub); }

.band--paper .section__idx { color: var(--signal); }

.band--paper a { color: #0F6E60; }

.section {
  position: relative;
  padding: clamp(40px, 6vw, 72px) 0;
  border-top: 1px solid var(--ink-700);
}

.section__head {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: clamp(20px, 3vw, 32px);
}

.section__idx {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.2em;
  color: var(--amber);
}

.section__title {
  font-size: var(--fs-h2);
  transition: color var(--dur) var(--ease);
}

.section.is-lit .section__title { color: var(--signal); }

.section__lead {
  max-width: 64ch;
  color: var(--slate);
}

.breadcrumb { margin-bottom: 18px; }

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  color: var(--slate);
}

.breadcrumb__item a { color: var(--slate); }

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

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

.breadcrumb__sep {
  color: var(--ink-600);
  font-family: var(--font-mono);
}

/* ==========================================================================
   网格 / 卡片 / 索引
   ========================================================================== */
.grid {
  display: grid;
  gap: clamp(14px, 2vw, 22px);
}

.grid--2 { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }

.grid--3 { grid-template-columns: repeat(auto-fit, minmax(232px, 1fr)); }

.layout-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 292px;
  gap: clamp(20px, 3vw, 40px);
  align-items: start;
}

.layout-split__aside {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: clamp(18px, 2.4vw, 26px);
  border: 1px solid var(--ink-700);
  border-radius: var(--radius-lg);
  background: var(--ink-800);
  color: var(--fog);
  text-decoration: none;
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease),
    background-color var(--dur) var(--ease);
}

a.card:hover {
  border-color: var(--ink-600);
  background: #0E2238;
  color: var(--fog);
  transform: translateY(-2px);
}

.card__title {
  font-size: var(--fs-h3);
  font-weight: 800;
}

.card__meta {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  color: var(--slate);
}

.card__body {
  color: var(--slate);
}

.side-index {
  position: sticky;
  top: 140px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 20px;
  border: 1px solid var(--ink-700);
  border-radius: var(--radius-md);
  background: rgba(11, 29, 48, 0.72);
}

.side-index__title {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  font-weight: 700;
  letter-spacing: 0.18em;
  color: var(--cyan);
}

.side-index__list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.side-index__list a {
  display: block;
  padding-left: 12px;
  border-left: 2px solid var(--ink-700);
  color: var(--slate);
  font-size: var(--fs-body);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.side-index__list a:hover { color: var(--fog); }

.side-index__list a.is-active,
.side-index__list a[aria-current="true"] {
  color: var(--signal);
  border-left-color: var(--signal);
}

/* ==========================================================================
   按钮与标签
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  border: 1px solid var(--ink-700);
  border-radius: var(--radius-pill);
  background: var(--ink-800);
  color: var(--fog);
  font-size: var(--fs-body);
  font-weight: 700;
  text-decoration: none;
  transition: background-color var(--dur) var(--ease),
    border-color var(--dur) var(--ease), color var(--dur) var(--ease),
    transform var(--dur) var(--ease);
}

.btn:hover {
  border-color: var(--cyan);
  color: var(--cyan);
  transform: translateY(-1px);
}

.btn--signal {
  border-color: var(--signal);
  background: var(--signal);
  color: #08111D;
}

.btn--signal:hover {
  border-color: var(--signal-soft);
  background: var(--signal-soft);
  color: #08111D;
}

.btn--ghost {
  background: transparent;
  color: var(--cyan);
  border-color: var(--ink-600);
}

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

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border: 1px solid currentColor;
  border-radius: var(--radius-pill);
  font-size: var(--fs-xs);
  font-weight: 700;
  letter-spacing: 0.04em;
  white-space: nowrap;
}

.tag--orange { color: var(--signal); }
.tag--cyan { color: var(--cyan); }
.tag--amber { color: var(--amber); }
.tag--violet { color: var(--violet); }
.tag--mint { color: var(--mint); }

/* ==========================================================================
   图像容器（页面阶段放置素材）
   ========================================================================== */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  border: 1px solid var(--ink-700);
  border-radius: var(--radius-lg);
  background: var(--ink-800);
}

.media__frame {
  display: block;
  width: 100%;
  height: 100%;
}

.media img,
.media svg,
.media__frame img,
.media__frame svg {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media--16x9 { aspect-ratio: 16 / 9; }
.media--4x3 { aspect-ratio: 4 / 3; }
.media--1x1 { aspect-ratio: 1 / 1; }
.media--21x9 { aspect-ratio: 21 / 9; }

.media__texture {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(90deg, rgba(44, 229, 200, 0.16) 0 1px, transparent 1px 14px),
    repeating-linear-gradient(0deg, rgba(20, 42, 66, 0.85) 0 1px, transparent 1px 44px);
}

.media__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 14px 18px;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  color: var(--fog);
  background: linear-gradient(to top, rgba(6, 18, 32, 0.92), rgba(6, 18, 32, 0));
}

/* ==========================================================================
   动效工具
   ========================================================================== */
.reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 320ms var(--ease), transform 320ms var(--ease);
  transition-delay: calc(var(--i, 0) * 60ms);
}

.reveal.is-in {
  opacity: 1;
  transform: none;
}

/* ==========================================================================
   响应式
   ========================================================================== */
@media (max-width: 1000px) {
  .layout-split { grid-template-columns: minmax(0, 1fr); }
  .side-index { position: static; top: auto; }
}

@media (max-width: 900px) {
  html { scroll-padding-top: 108px; }

  .header-utility__inner {
    grid-template-columns: 1fr auto;
    min-height: 58px;
  }

  .header-status { display: none; }

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

  .site-nav {
    overflow-x: auto;
    scrollbar-width: none;
    -webkit-overflow-scrolling: touch;
  }

  .site-nav::-webkit-scrollbar { display: none; }

  .site-nav__list a {
    padding: 14px 12px;
    font-size: var(--fs-body);
  }

  .site-header[data-open] .header-nav__inner { flex-wrap: wrap; }

  .site-header[data-open] .site-nav {
    flex-basis: 100%;
    overflow: visible;
  }

  .site-header[data-open] .site-nav__list {
    flex-wrap: wrap;
    gap: 0;
    width: 100%;
  }

  .site-header[data-open] .site-nav__list li { flex: 1 1 100%; }

  .site-header[data-open] .site-nav__list a {
    border-bottom: 1px solid var(--ink-700);
    border-radius: 0;
  }

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

@media (max-width: 620px) {
  .brand__mark { width: 34px; height: 34px; border-radius: 10px; }
  .brand__tag { display: none; }
  .header-search { padding: 7px 14px; }
  .footer-grid { grid-template-columns: minmax(0, 1fr); }
  .footer-base__inner { justify-content: flex-start; }
}

/* ==========================================================================
   降低动效
   ========================================================================== */
@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;
  }

  .reveal {
    opacity: 1;
    transform: none;
    transition-delay: 0ms !important;
  }

  .read-progress__bar { transition: none; }

  .header-status__dot { animation: none; }
}