/* ============================================================
   6号平台中心 · /assets/site.css
   共享层：reset / 变量 / 中文排版 / 页头 / 页脚 / 通用组件
   ============================================================ */

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

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

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

ul, ol { padding: 0; list-style: none; }

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

button { font: inherit; color: inherit; }

/* ---------- 2. 变量 ---------- */
:root {
  --paper: #F7F4EE;
  --paper-2: #EFEAE0;
  --ink: #14161A;
  --ink-soft: #2A2D33;
  --orange: #E2601C;
  --orange-deep: #A63F0D;
  --orange-soft: #FBEDE3;
  --ice: #6FB7C9;
  --ice-soft: #EAF4F7;
  --ice-deep: #2E6B7A;
  --forest: #123A32;
  --forest-deep: #0C2A24;
  --forest-ink: #DCE7E2;
  --forest-muted: #9CB3AB;
  --gold: #C79A44;
  --gray: #6B6F76;
  --line: #D8D2C6;

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

  --h1: clamp(34px, 5.6vw, 72px);
  --h2: clamp(26px, 3.2vw, 40px);
  --h3: clamp(20px, 1.6vw, 26px);

  --shell: 1280px;
  --gutter: clamp(16px, 4vw, 40px);
  --gap-block: clamp(48px, 7vw, 96px);
  --radius: 2px;
  --dur: .22s;
  --ease: cubic-bezier(.2, .7, .25, 1);
}

/* ---------- 3. 中文排版基底 ---------- */
body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: -.02em;
}

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

p { max-width: 68ch; }

a { color: inherit; }

::selection { background: var(--orange); color: #fff; }

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

#main-content { display: block; scroll-margin-top: 96px; }

/* ---------- 4. 布局容器与网格 ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.grid {
  display: grid;
  gap: 20px;
  grid-template-columns: minmax(0, 1fr);
}

.split {
  display: grid;
  gap: clamp(24px, 4vw, 56px);
  grid-template-columns: minmax(0, 1fr);
}

.stack > * + * { margin-top: 14px; }

.rule { height: 1px; background: var(--line); border: 0; }

@media (min-width: 680px) {
  .grid-2,
  .grid-3,
  .grid-4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (min-width: 1040px) {
  .grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .grid-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

  .split { grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); }
  .split-4-8 { grid-template-columns: minmax(0, 4fr) minmax(0, 8fr); }
  .split-aside { position: sticky; top: 104px; align-self: start; }
}

/* ---------- 5. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 20px;
  border: 1px solid var(--ink);
  border-radius: var(--radius);
  background: var(--paper);
  color: var(--ink);
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: .04em;
  text-decoration: none;
  cursor: pointer;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease),
              border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.btn:hover { background: var(--ink); color: var(--paper); }
.btn:active { transform: translateY(1px); }

.btn-primary {
  background: var(--orange);
  border-color: var(--orange-deep);
  color: #fff;
  font-weight: 600;
}

.btn-primary:hover {
  background: var(--orange-deep);
  border-color: var(--orange-deep);
  color: #fff;
}

.btn-ghost { background: transparent; border-color: var(--line); }
.btn-ghost:hover { background: var(--ice-deep); border-color: var(--ice-deep); color: var(--paper); }

.btn-sm { padding: 8px 14px; font-size: 12px; }

/* ---------- 6. 跳转链接 ---------- */
.skip-link {
  position: absolute;
  left: 16px;
  top: -72px;
  z-index: 200;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--mono);
  font-size: 13px;
  padding: 10px 16px;
  text-decoration: none;
  transition: top var(--dur) var(--ease);
}

.skip-link:focus { top: 8px; }

/* ---------- 7. 页头 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: var(--paper);
  border-bottom: 1px solid var(--line);
  color: var(--ink);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 64px;
  padding-block: 10px;
  transition: min-height var(--dur) var(--ease), padding var(--dur) var(--ease);
}

.header-rule {
  height: 3px;
  background: linear-gradient(90deg, var(--orange) 0 72px, var(--line) 72px 100%);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
  text-decoration: none;
  color: var(--ink);
}

.brand-mark {
  position: relative;
  width: 16px;
  height: 16px;
  flex: 0 0 auto;
  background: var(--orange);
  border: 1px solid var(--orange-deep);
}

.brand-mark::after {
  content: "";
  position: absolute;
  inset: 4px;
  background: var(--paper);
}

.brand-text { display: block; }

.brand-name {
  display: block;
  font-size: 19px;
  font-weight: 900;
  letter-spacing: -.01em;
  line-height: 1.15;
}

.brand-sub {
  display: block;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .18em;
  line-height: 1.5;
  color: var(--gray);
  text-transform: uppercase;
}

.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 8px 12px;
  border: 1px solid var(--ink);
  border-radius: var(--radius);
  background: transparent;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .08em;
  cursor: pointer;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease);
}

.nav-toggle:hover { background: var(--ink); color: var(--paper); }

.nav-toggle-bars {
  position: relative;
  width: 16px;
  height: 10px;
  flex: 0 0 auto;
}

.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  height: 2px;
  background: currentColor;
  transition: transform var(--dur) var(--ease);
}

.nav-toggle-bars::before { top: 0; }
.nav-toggle-bars::after { bottom: 0; }

.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before { transform: translateY(4px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after { transform: translateY(-4px) rotate(-45deg); }

.site-nav {
  position: absolute;
  left: 0;
  right: 0;
  top: 100%;
  display: none;
  padding: 12px var(--gutter) 24px;
  background: var(--paper);
  border-bottom: 1px solid var(--ink);
  box-shadow: 0 26px 40px -32px rgba(20, 22, 26, .7);
}

.site-nav[data-open="true"] { display: block; }

.nav-list {
  counter-reset: nav-i;
  display: flex;
  flex-direction: column;
}

.nav-list li { counter-increment: nav-i; }
.nav-list li + li { border-top: 1px solid var(--line); }

.nav-list a {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 14px 2px;
  color: var(--ink);
  font-family: var(--mono);
  font-size: 14px;
  letter-spacing: .02em;
  text-decoration: none;
  transition: color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.nav-list a::before {
  content: counter(nav-i, decimal-leading-zero);
  flex: 0 0 auto;
  font-size: 11px;
  color: var(--gray);
}

.nav-list a:hover { color: var(--orange-deep); }

.nav-list a[aria-current="page"] {
  color: var(--orange-deep);
  background: linear-gradient(transparent 60%, var(--orange-soft) 60%);
}

.nav-list a[aria-current="page"]::before { color: var(--orange); font-weight: 700; }

.nav-cta { margin-top: 16px; width: 100%; }

@media (min-width: 900px) {
  .header-inner { min-height: 84px; padding-block: 14px; }
  .header-rule { height: 4px; }

  .nav-toggle { display: none; }

  .site-nav,
  .site-nav[data-open] {
    position: static;
    display: flex;
    align-items: center;
    gap: clamp(14px, 2vw, 30px);
    padding: 0;
    background: transparent;
    border: 0;
    box-shadow: none;
  }

  .nav-list { flex-direction: row; align-items: center; gap: clamp(10px, 1.6vw, 22px); }
  .nav-list li + li { border-top: 0; }

  .nav-list a { padding: 6px 2px; font-size: 13px; gap: 6px; }

  .nav-list a[aria-current="page"] { background: none; border-bottom: 2px solid var(--orange); }

  .nav-cta { margin-top: 0; width: auto; }

  [data-scrolled="true"] .header-inner { min-height: 66px; padding-block: 8px; }
  [data-scrolled="true"] .nav-list a { font-size: 12px; }
  [data-scrolled="true"] .brand-name { font-size: 17px; }
  [data-scrolled="true"] .brand-sub { font-size: 9px; letter-spacing: .14em; }
}

/* ---------- 8. 页脚 ---------- */
.site-footer {
  margin-top: var(--gap-block);
  background: var(--forest);
  color: var(--forest-ink);
  border-top: 3px solid var(--orange);
}

.footer-inner {
  display: grid;
  gap: 32px;
  grid-template-columns: minmax(0, 1fr);
  padding-block: clamp(40px, 6vw, 68px);
}

.footer-brand-name {
  font-size: 24px;
  font-weight: 900;
  letter-spacing: -.01em;
  color: var(--paper);
  line-height: 1.2;
}

.footer-brand-tag {
  margin-top: 8px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--gold);
  text-transform: uppercase;
}

.footer-brand-copy {
  margin-top: 14px;
  max-width: 34ch;
  font-size: 14px;
  line-height: 1.7;
  color: var(--forest-muted);
}

.footer-col-title {
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .2em;
  color: var(--gold);
  text-transform: uppercase;
  padding-bottom: 12px;
  border-bottom: 1px solid rgba(247, 244, 238, .18);
}

.footer-list li { border-bottom: 1px solid rgba(247, 244, 238, .1); }

.footer-list a {
  display: block;
  padding: 10px 0;
  color: var(--forest-ink);
  font-size: 14px;
  text-decoration: none;
  transition: color var(--dur) var(--ease), padding-left var(--dur) var(--ease);
}

.footer-list a:hover { color: var(--orange); padding-left: 6px; }

.footer-contact-item {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  max-width: none;
  padding: 11px 0;
  border-bottom: 1px solid rgba(247, 244, 238, .1);
  font-size: 14px;
  line-height: 1.65;
  color: var(--forest-ink);
}

.footer-contact-key {
  flex: 0 0 48px;
  padding-top: 3px;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .14em;
  color: var(--gold);
}

.footer-contact-val { word-break: break-word; }

.footer-base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 24px;
  padding-block: 18px;
  border-top: 1px solid rgba(247, 244, 238, .18);
  font-family: var(--mono);
  font-size: 12px;
  line-height: 1.7;
}

.footer-legal { color: var(--forest-muted); max-width: none; }
.footer-note { color: var(--gold); max-width: 46ch; }

@media (min-width: 760px) {
  .footer-inner { grid-template-columns: 1.4fr 1fr 1fr; }
}

@media (min-width: 1040px) {
  .footer-inner { grid-template-columns: 1.6fr 1fr .9fr 1.4fr; gap: 40px; }
}

/* ---------- 9. 页面通用排版组件 ---------- */
.page-head { padding-block: clamp(28px, 4vw, 52px) 0; }

.page-title {
  font-size: var(--h1);
  font-weight: 900;
  line-height: 1.06;
  letter-spacing: -.02em;
}

.section { padding-block: clamp(40px, 6vw, 76px); }

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 12px 24px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--ink);
}

.section-title { font-size: var(--h2); }

.eyebrow {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--orange-deep);
}

.lede { font-size: clamp(17px, 1.3vw, 19px); color: var(--ink-soft); max-width: 60ch; }

.muted { color: var(--gray); }

.meta {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--gray);
}

.index-no {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--orange);
}

.v-note {
  writing-mode: vertical-rl;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .3em;
  text-transform: uppercase;
  color: var(--gray);
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--gray);
}

.breadcrumb a {
  color: var(--gray);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.breadcrumb a:hover { color: var(--orange-deep); border-color: var(--orange); }

.breadcrumb-sep { color: var(--line); }

/* ---------- 10. 内容容器与索引组件 ---------- */
.card {
  display: block;
  padding: clamp(18px, 2.2vw, 26px);
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: inherit;
  text-decoration: none;
  transition: border-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease),
              transform var(--dur) var(--ease);
}

.card:hover {
  border-color: var(--ink);
  box-shadow: 6px 6px 0 var(--orange-soft);
  transform: translate(-2px, -2px);
}

.paper {
  padding: clamp(18px, 2.2vw, 26px);
  background: var(--paper);
  border: 1px solid var(--ink);
  border-radius: var(--radius);
  box-shadow: 5px 5px 0 var(--line);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 9px;
  background: var(--orange-soft);
  border: 1px solid var(--orange);
  border-radius: var(--radius);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--orange-deep);
}

.tag-ice { background: var(--ice-soft); border-color: var(--ice); color: var(--ice-deep); }

.tag-dark { background: transparent; border-color: var(--gold); color: var(--gold); }

.ledger { border-top: 1px solid var(--ink); }

.ledger-row {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 16px;
  padding: 14px 4px;
  border-bottom: 1px solid var(--line);
  color: inherit;
  text-decoration: none;
  transition: background var(--dur) var(--ease), padding-left var(--dur) var(--ease);
}

.ledger-row:hover { background: var(--orange-soft); padding-left: 12px; }

.ledger-row .index-no { flex: 0 0 42px; }

.timeline {
  position: relative;
  padding-left: 28px;
  border-left: 1px solid var(--line);
}

.timeline-item { position: relative; padding-bottom: 30px; }

.timeline-item::before {
  content: "";
  position: absolute;
  left: -34px;
  top: 8px;
  width: 9px;
  height: 9px;
  background: var(--paper);
  border: 2px solid var(--line);
  transition: border-color 200ms var(--ease), background 200ms var(--ease);
}

.timeline-item[data-current="true"]::before,
.timeline-item:hover::before { border-color: var(--orange); background: var(--orange); }

.panel-dark {
  padding: clamp(24px, 3vw, 44px);
  background: var(--forest);
  border: 1px solid var(--forest-deep);
  color: var(--forest-ink);
}

.panel-dark .section-title,
.panel-dark h2,
.panel-dark h3 { color: var(--paper); }

.panel-dark .muted,
.panel-dark .meta { color: var(--forest-muted); }

.panel-dark a { color: var(--gold); }

.diag-block {
  position: relative;
  overflow: hidden;
  padding: clamp(24px, 4vw, 48px);
  background: var(--orange);
  color: #fff;
  clip-path: polygon(0 0, 100% 0, 100% 82%, 0 100%);
}

/* ---------- 11. 图片容器基础（页面阶段投放占位） ---------- */
.media-frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  border: 1px solid var(--ink);
  border-radius: var(--radius);
  background-color: var(--ice-soft);
  background-image:
    linear-gradient(135deg, var(--paper-2) 0 25%, transparent 25% 50%, var(--paper-2) 50% 75%, transparent 75%);
  background-size: 16px 16px;
}

.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 5px;
  background: linear-gradient(90deg, var(--orange) 0 40%, var(--gold) 40% 70%, var(--ice) 70% 100%);
}

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

.figure-caption {
  margin-top: 8px;
  font-family: var(--mono);
  font-size: 12px;
  line-height: 1.6;
  color: var(--gray);
}

/* ---------- 12. 分段控件 ---------- */
.tabs {
  display: flex;
  overflow-x: auto;
  border-bottom: 1px solid var(--ink);
  box-shadow: inset -22px 0 16px -20px rgba(20, 22, 26, .45);
  scrollbar-width: thin;
  -webkit-overflow-scrolling: touch;
}

.tab {
  flex: 0 0 auto;
  padding: 12px 16px;
  border: 0;
  border-bottom: 3px solid transparent;
  background: transparent;
  color: var(--gray);
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: .04em;
  white-space: nowrap;
  cursor: pointer;
  transition: color var(--dur) var(--ease), background var(--dur) var(--ease),
              border-color var(--dur) var(--ease);
}

.tab:hover { color: var(--ink); background: var(--paper-2); }

.tab[aria-selected="true"] {
  color: var(--ink);
  background: var(--orange-soft);
  border-bottom-color: var(--orange);
}

.tabpanel { padding-top: 24px; }
.tabpanel[hidden] { display: none; }
.tabpanel:not([hidden]) { animation: fade-up 120ms var(--ease) both; }

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

/* ---------- 13. 滚动进度 ---------- */
.scroll-progress {
  position: fixed;
  left: 0;
  right: 0;
  top: 0;
  z-index: 120;
  height: 3px;
  pointer-events: none;
}

.scroll-progress > span {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--orange), var(--gold));
}

/* ---------- 14. 进入视口显现 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity .5s var(--ease), transform .5s var(--ease);
}

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

html:not(.js) [data-reveal] { opacity: 1; transform: none; }

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

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