/* ============================================================
   万博最新版 · 共享站点样式 /assets/site.css
   结构：1 重置 2 变量 3 排版 4 头部 5 页脚 6 通用组件 7 响应式
   ============================================================ */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 120px;
}

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

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

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

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
}

a { color: inherit; text-decoration: none; }

/* ---------- 2. 变量 ---------- */
:root {
  --graphite: #0A1622;
  --abyss: #0F2136;
  --abyss-2: #16324F;
  --orange: #FF6B2C;
  --orange-soft: #FFA26B;
  --cyan: #2FE3D2;
  --ink: #E8EEF5;
  --ink-dim: #9FB0C2;
  --line: #5A6E82;
  --data-blue: #1B4A6B;

  --line-soft: rgba(90, 110, 130, 0.28);
  --line-mid: rgba(90, 110, 130, 0.48);
  --surface: rgba(15, 33, 54, 0.72);
  --surface-2: rgba(22, 50, 79, 0.66);

  --radius-sm: 12px;
  --radius-md: 18px;
  --radius-lg: 28px;
  --radius-xl: 36px;
  --pill: 999px;

  --gutter: clamp(16px, 4vw, 48px);
  --section-gap: clamp(48px, 8vw, 104px);
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);

  --font-display: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "IBM Plex Mono", "SFMono-Regular", Consolas, "Liberation Mono", "Courier New", ui-monospace, monospace;
}

/* ---------- 3. 排版与全局表面 ---------- */
body {
  min-height: 100vh;
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  font-weight: 400;
  line-height: 1.8;
  letter-spacing: 0.01em;
  background-color: var(--graphite);
  background-image:
    radial-gradient(1100px 620px at 88% -8%, rgba(27, 74, 107, 0.5), rgba(27, 74, 107, 0) 68%),
    radial-gradient(760px 480px at 2% 4%, rgba(47, 227, 210, 0.07), rgba(47, 227, 210, 0) 62%),
    linear-gradient(rgba(90, 110, 130, 0.05) 1px, rgba(90, 110, 130, 0) 1px),
    linear-gradient(90deg, rgba(90, 110, 130, 0.05) 1px, rgba(90, 110, 130, 0) 1px);
  background-size: auto, auto, 72px 72px, 72px 72px;
  background-repeat: no-repeat, no-repeat, repeat, repeat;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: var(--ink);
  text-wrap: pretty;
}

h1 { font-size: clamp(36px, 6vw, 56px); }
h2 { font-size: clamp(26px, 3.4vw, 36px); }
h3 { font-size: clamp(20px, 2.2vw, 26px); }
h4 { font-size: 20px; }

p { max-width: 68ch; }

::selection {
  background: rgba(47, 227, 210, 0.28);
  color: #FFFFFF;
}

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

.site-main { display: block; min-height: 50vh; }

/* ---------- 4. 头部 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 120;
  isolation: isolate;
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: background-color 0.22s ease, border-color 0.22s ease, box-shadow 0.22s ease;
}

.site-header::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background: linear-gradient(180deg, rgba(10, 22, 34, 0.9), rgba(10, 22, 34, 0));
  transition: opacity 0.22s ease;
}

.site-header.is-scrolled {
  background: rgba(10, 22, 34, 0.93);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  backdrop-filter: blur(14px) saturate(140%);
  border-bottom-color: var(--line-soft);
  box-shadow: 0 18px 42px -30px rgba(0, 0, 0, 0.95);
}

.site-header.is-scrolled::before { opacity: 0; }

.skip-link {
  position: absolute;
  left: 16px;
  top: -120px;
  z-index: 200;
  padding: 12px 22px;
  border-radius: 0 0 14px 14px;
  background: var(--orange);
  color: #0A1622;
  font-size: 14px;
  font-weight: 700;
  line-height: 1.2;
  transition: top 0.18s var(--ease);
}

.skip-link:focus { top: 0; }

.header-inner {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 32px);
  width: 100%;
  max-width: 1440px;
  margin-inline: auto;
  padding: clamp(11px, 1.5vw, 17px) var(--gutter);
}

/* 品牌轨道 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.brand-mark {
  display: inline-flex;
  align-items: flex-end;
  gap: 3px;
  height: 28px;
  flex-shrink: 0;
}

.brand-mark .brand-bar {
  display: block;
  width: 5px;
  height: 100%;
  border-radius: 3px;
  background: var(--orange);
}

.brand-mark .brand-bar:nth-child(2) {
  height: 66%;
  background: var(--orange-soft);
}

.brand-mark .brand-bar:nth-child(3) {
  height: 40%;
  background: var(--cyan);
}

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.brand-line {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: 0.02em;
  color: var(--ink);
  white-space: nowrap;
}

.brand-tagline {
  font-size: 11px;
  line-height: 1.3;
  letter-spacing: 0.16em;
  color: var(--ink-dim);
  white-space: nowrap;
}

/* 导航 */
.site-nav {
  margin-left: auto;
  min-width: 0;
}

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

.nav-item { display: flex; }

.nav-link {
  position: relative;
  display: inline-block;
  padding: 9px 13px;
  border-radius: var(--pill);
  font-size: 14px;
  font-weight: 500;
  line-height: 1.4;
  color: var(--ink-dim);
  white-space: nowrap;
  transition: color 0.18s ease, background-color 0.18s ease;
}

.nav-link:hover,
.nav-link:focus-visible {
  color: var(--ink);
  background: rgba(22, 50, 79, 0.66);
}

.nav-link[aria-current="page"] { color: var(--ink); }

.nav-link[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 13px;
  right: 13px;
  bottom: 3px;
  height: 2px;
  border-radius: 2px;
  background: var(--orange);
}

.nav-cta {
  display: none;
  align-items: center;
  justify-content: center;
  padding: 13px 22px;
  border-radius: var(--pill);
  background: var(--orange);
  color: #0A1622;
  font-size: 15px;
  font-weight: 700;
  line-height: 1.2;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.header-cta { display: inline-flex; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 20px;
  border-radius: var(--pill);
  border: 1px solid transparent;
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 700;
  line-height: 1.2;
  text-align: center;
  cursor: pointer;
  transition: background-color 0.18s ease, color 0.18s ease,
              border-color 0.18s ease, transform 0.18s ease,
              box-shadow 0.18s ease;
}

.btn-primary {
  background: var(--orange);
  color: #0A1622;
  box-shadow: 0 10px 26px -16px rgba(255, 107, 44, 0.95);
}

.btn-primary:hover,
.btn-primary:focus-visible {
  background: var(--orange-soft);
  transform: translateY(-1px);
}

.btn-ghost {
  background: rgba(15, 33, 54, 0.5);
  border-color: var(--line-mid);
  color: var(--ink);
}

.btn-ghost:hover,
.btn-ghost:focus-visible {
  border-color: var(--cyan);
  color: var(--cyan);
}

/* 移动菜单按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  border-radius: var(--pill);
  border: 1px solid var(--line-mid);
  background: rgba(15, 33, 54, 0.62);
  color: var(--ink);
  font-size: 13px;
  font-weight: 700;
  line-height: 1;
  cursor: pointer;
  transition: border-color 0.18s ease, color 0.18s ease;
}

.nav-toggle:hover,
.nav-toggle:focus-visible { border-color: var(--cyan); }

.nav-toggle-bars {
  display: inline-flex;
  flex-direction: column;
  gap: 4px;
  width: 16px;
}

.nav-toggle-bars span {
  display: block;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform 0.18s var(--ease), opacity 0.18s ease;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bars span:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bars span:nth-child(2) {
  opacity: 0;
}

.nav-toggle-label { display: inline-block; }

/* 批次说明行 */
.header-note {
  display: flex;
  align-items: center;
  gap: 10px;
  max-width: 1440px;
  margin-inline: auto;
  padding: 0 var(--gutter) 13px;
  max-height: 92px;
  overflow: hidden;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--ink-dim);
  transition: max-height 0.26s var(--ease), opacity 0.2s ease, padding 0.26s var(--ease);
}

.site-header.is-scrolled .header-note {
  max-height: 0;
  opacity: 0;
  padding-bottom: 0;
}

.note-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  flex-shrink: 0;
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(47, 227, 210, 0.16);
}

.header-note-text { min-width: 0; }

/* 阅读进度 */
.read-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: rgba(90, 110, 130, 0.16);
  overflow: hidden;
  pointer-events: none;
}

.read-progress-bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--orange) 0%, var(--orange-soft) 46%, var(--cyan) 100%);
  transition: width 0.08s linear;
}

/* ---------- 5. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(64px, 9vw, 120px);
  background:
    radial-gradient(720px 320px at 10% 0%, rgba(255, 107, 44, 0.1), rgba(255, 107, 44, 0) 70%),
    radial-gradient(620px 280px at 92% 8%, rgba(47, 227, 210, 0.07), rgba(47, 227, 210, 0) 70%),
    linear-gradient(180deg, #0C1B2B 0%, #081220 82%);
  border-top: 1px solid var(--line-soft);
  color: var(--ink-dim);
  font-size: 14px;
}

.site-footer::before {
  content: "";
  position: absolute;
  left: 50%;
  top: -1px;
  transform: translateX(-50%);
  width: min(1200px, 92vw);
  height: 1px;
  background: linear-gradient(90deg,
    rgba(255, 107, 44, 0) 0%,
    rgba(255, 107, 44, 0.85) 32%,
    rgba(47, 227, 210, 0.75) 68%,
    rgba(47, 227, 210, 0) 100%);
}

.footer-inner {
  max-width: 1280px;
  margin-inline: auto;
  padding: clamp(40px, 6vw, 72px) var(--gutter) clamp(24px, 4vw, 40px);
}

.footer-top {
  display: grid;
  grid-template-columns: minmax(220px, 1.35fr) minmax(0, 2fr);
  gap: clamp(28px, 4vw, 56px);
  padding-bottom: clamp(26px, 4vw, 40px);
  border-bottom: 1px solid var(--line-soft);
}

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

.footer-mark {
  display: inline-flex;
  align-items: flex-end;
  gap: 4px;
  height: 32px;
}

.footer-mark .brand-bar {
  display: block;
  width: 6px;
  height: 100%;
  border-radius: 3px;
  background: var(--orange);
}

.footer-mark .brand-bar:nth-child(2) {
  height: 66%;
  background: var(--orange-soft);
}

.footer-mark .brand-bar:nth-child(3) {
  height: 40%;
  background: var(--cyan);
}

.footer-brand-line {
  margin-top: 16px;
  font-family: var(--font-display);
  font-size: 26px;
  font-weight: 900;
  line-height: 1.2;
  color: var(--ink);
}

.footer-tagline {
  margin-top: 6px;
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--ink-dim);
}

.footer-cols {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(20px, 3vw, 40px);
}

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

.footer-col-title {
  margin-bottom: 14px;
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 700;
  line-height: 1.4;
  letter-spacing: 0.08em;
  color: var(--ink);
}

.footer-links li + li { margin-top: 10px; }

.footer-links a {
  font-size: 14px;
  line-height: 1.6;
  color: var(--ink-dim);
  transition: color 0.18s ease;
}

.footer-links a:hover,
.footer-links a:focus-visible { color: var(--cyan); }

.footer-contact {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 18px clamp(24px, 3vw, 40px);
  padding: clamp(20px, 3vw, 28px) 0;
  border-bottom: 1px solid var(--line-soft);
}

.footer-contact-item {
  display: flex;
  flex-direction: column;
  gap: 5px;
  min-width: 0;
}

.footer-contact-label {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.18em;
  color: var(--cyan);
}

.footer-contact-value {
  font-size: 14px;
  line-height: 1.65;
  color: var(--ink);
  word-break: break-word;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px clamp(16px, 3vw, 32px);
  padding-top: clamp(18px, 3vw, 28px);
  font-size: 12.5px;
  color: var(--ink-dim);
}

.footer-legal {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.03em;
  color: var(--ink-dim);
}

.footer-copyright { font-size: 12.5px; color: var(--ink-dim); }

.footer-note {
  flex-basis: 100%;
  max-width: 72ch;
  font-size: 12px;
  line-height: 1.75;
  color: rgba(159, 176, 194, 0.72);
}

/* ---------- 6. 通用组件 ---------- */
.container {
  width: 100%;
  max-width: 1240px;
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.container--narrow { max-width: 880px; }
.container--wide { max-width: 1440px; }

.breadcrumb { margin-bottom: clamp(18px, 3vw, 30px); }

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--ink-dim);
}

.breadcrumb-list li { display: flex; align-items: center; gap: 8px; }

.breadcrumb-list li + li::before {
  content: "/";
  color: var(--line);
}

.breadcrumb-list a { transition: color 0.18s ease; }

.breadcrumb-list a:hover,
.breadcrumb-list a:focus-visible { color: var(--cyan); }

.breadcrumb-list [aria-current="page"] { color: var(--ink); }

.grid {
  display: grid;
  gap: clamp(16px, 2.4vw, 28px);
}

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

.grid-main {
  grid-template-columns: minmax(0, 7fr) minmax(0, 3fr);
  align-items: start;
}

.card {
  position: relative;
  padding: clamp(18px, 2.4vw, 28px);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-lg);
  background: linear-gradient(160deg, var(--surface-2), var(--surface));
}

.card--flat {
  background: rgba(15, 33, 54, 0.58);
  border-radius: var(--radius-md);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 12px;
  border-radius: var(--pill);
  border: 1px solid var(--line-mid);
  background: rgba(15, 33, 54, 0.62);
  font-size: 12px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--ink-dim);
  white-space: nowrap;
}

.tag--accent {
  border-color: rgba(255, 107, 44, 0.55);
  background: rgba(255, 107, 44, 0.1);
  color: var(--orange-soft);
}

.tag--live {
  border-color: rgba(47, 227, 210, 0.5);
  background: rgba(47, 227, 210, 0.08);
  color: var(--cyan);
}

.tag[aria-pressed="true"] {
  border-color: var(--cyan);
  color: var(--cyan);
  box-shadow: inset 0 0 0 1px rgba(47, 227, 210, 0.35);
}

.mono {
  font-family: var(--font-mono);
  font-weight: 500;
  letter-spacing: 0.02em;
}

.code-tag {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.02em;
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
  text-decoration-color: rgba(47, 227, 210, 0.6);
}

.eyebrow {
  display: block;
  margin-bottom: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.22em;
  color: var(--cyan);
}

.section-head { margin-bottom: clamp(20px, 3vw, 32px); }

.lede {
  max-width: 62ch;
  font-size: clamp(16px, 1.6vw, 20px);
  line-height: 1.75;
  color: var(--ink-dim);
}

.link-arrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  font-weight: 700;
  color: var(--cyan);
  transition: gap 0.18s ease, color 0.18s ease;
}

.link-arrow::after {
  content: "\2192";
  font-family: var(--font-mono);
  font-size: 15px;
}

.link-arrow:hover,
.link-arrow:focus-visible {
  gap: 12px;
  color: var(--orange-soft);
}

/* 图片容器基础规则（页面阶段放置 img 占位） */
.media-frame {
  position: relative;
  width: 100%;
  overflow: hidden;
  border-radius: var(--radius-lg);
  border: 1px solid var(--line-soft);
  background:
    linear-gradient(150deg, rgba(22, 50, 79, 0.9), rgba(10, 22, 34, 0.9)),
    repeating-linear-gradient(90deg, rgba(90, 110, 130, 0.14) 0 1px, transparent 1px 40px);
}

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

.media-frame--wide { aspect-ratio: 16 / 9; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame--portrait { aspect-ratio: 4 / 5; }

.media-frame-caption {
  margin-top: 10px;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--ink-dim);
}

.stack > * + * { margin-top: clamp(16px, 2.4vw, 28px); }
.stack--tight > * + * { margin-top: 12px; }

.divider {
  height: 1px;
  border: 0;
  margin-block: clamp(28px, 4vw, 48px);
  background: linear-gradient(90deg, var(--line-soft), rgba(90, 110, 130, 0));
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

/* 入场动效 */
.reveal-ready [data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.45s var(--ease), transform 0.45s var(--ease);
}

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

/* ---------- 7. 响应式 ---------- */
@media (max-width: 1024px) {
  .nav-toggle { display: inline-flex; }
  .header-cta { display: none; }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    margin-left: 0;
    padding: 10px var(--gutter) 24px;
    max-height: calc(100vh - 90px);
    overflow-y: auto;
    background: rgba(10, 24, 38, 0.98);
    border-bottom: 1px solid var(--line-soft);
    box-shadow: 0 30px 60px -40px #000;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: opacity 0.18s ease, transform 0.18s var(--ease), visibility 0.18s linear;
  }

  .site-nav[data-open] {
    opacity: 1;
    visibility: visible;
    transform: none;
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
  }

  .nav-item { width: 100%; }

  .nav-link {
    display: block;
    width: 100%;
    padding: 14px 16px;
    border-radius: 14px;
    border: 1px solid transparent;
    font-size: 16px;
    color: var(--ink);
  }

  .nav-link[aria-current="page"] {
    background: rgba(22, 50, 79, 0.75);
    border-color: rgba(255, 107, 44, 0.45);
  }

  .nav-link[aria-current="page"]::after { display: none; }

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

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

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

@media (max-width: 760px) {
  body { font-size: 15.5px; }

  .brand-line { font-size: 18px; }
  .brand-tagline { font-size: 10px; letter-spacing: 0.12em; }

  .header-note {
    font-size: 12px;
    padding-bottom: 11px;
    max-height: 110px;
  }

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

  .footer-cols { grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); }

  .footer-brand-line { font-size: 22px; }

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

@media (max-width: 420px) {
  .nav-toggle-label { display: none; }
  .nav-toggle { padding: 11px 12px; }
}

@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;
  }

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

  .site-header.is-scrolled .header-note { transition: none; }
}