/* =========================================================
   boxi-zone.com.cn — 共享外壳样式 /assets/site.css
   北境数据场：近单色冰蓝体系 + 荧光橙路径
   ========================================================= */

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

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

body,
h1, h2, h3, h4, h5, h6,
p, figure, blockquote, dl, dd, ol, ul, pre {
  margin: 0;
}

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

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

button, input, select, textarea { font: inherit; color: inherit; }

a { color: inherit; }

/* ---------- 2. Tokens ---------- */
:root {
  --ink: #07171A;
  --deep: #0F332E;
  --ice: #2E7C9B;
  --frost: #8FD0DF;
  --snow: #EDF4F5;
  --path: #FF6A1A;
  --warm: #FFB27A;
  --data: #7E9298;
  --water: #174A63;
  --hi: #FFFFFF;

  --font-display: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans SC", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-mono: ui-monospace, "SF Mono", "JetBrains Mono", "Cascadia Mono", Consolas, "Liberation Mono", Menlo, monospace;

  --shell: 1280px;
  --gutter: clamp(16px, 4vw, 48px);
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
  --cut: 12px;

  --rule: 1px solid rgba(46, 124, 155, 0.38);
  --rule-soft: 1px solid rgba(46, 124, 155, 0.22);
}

/* ---------- 3. 中文排版基线 ---------- */
body {
  background-color: var(--ink);
  background-image:
    linear-gradient(180deg, rgba(15, 51, 46, 0.55) 0%, rgba(7, 23, 26, 0) 42%),
    linear-gradient(90deg, rgba(143, 208, 223, 0.045) 1px, transparent 1px),
    linear-gradient(180deg, rgba(143, 208, 223, 0.045) 1px, transparent 1px);
  background-size: 100% 100%, 34px 34px, 34px 34px;
  color: var(--snow);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.8;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.16;
  letter-spacing: -0.02em;
  color: var(--snow);
}

p { max-width: 34em; }

a { text-decoration: none; }

::selection {
  background: var(--path);
  color: var(--ink);
}

/* ---------- 4. 焦点可见 ---------- */
:focus { outline: none; }

a:focus-visible,
button:focus-visible,
summary:focus-visible,
[tabindex]:focus-visible {
  outline: 2px solid var(--warm);
  outline-offset: 3px;
}

/* ---------- 5. 通用工具 ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.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;
}

.eyebrow {
  display: inline-block;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.26em;
  color: var(--path);
  text-transform: uppercase;
}

.num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
  letter-spacing: -0.01em;
}

/* 显现 */
[data-reveal] {
  opacity: 0;
  transform: translate3d(0, 12px, 0);
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
  will-change: opacity, transform;
}

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

/* 筛选重排淡入 */
.is-refreshed { animation: bx-fade-in 0.3s var(--ease) both; }

@keyframes bx-fade-in {
  from { opacity: 0.12; }
  to { opacity: 1; }
}

/* ---------- 6. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 13px 22px;
  font-size: 14.5px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  clip-path: polygon(0 0, calc(100% - 11px) 0, 100% 11px, 100% 100%, 11px 100%, 0 calc(100% - 11px));
  transition: transform 0.18s var(--ease), filter 0.18s var(--ease),
              background-color 0.18s var(--ease), color 0.18s var(--ease),
              border-color 0.18s var(--ease);
}

.btn--primary {
  background: linear-gradient(120deg, var(--path), var(--warm));
  color: var(--ink);
}

.btn--primary:hover { filter: brightness(1.08); transform: translateY(-2px); }

.btn--ghost {
  background: rgba(46, 124, 155, 0.16);
  border-color: rgba(143, 208, 223, 0.45);
  color: var(--snow);
}

.btn--ghost:hover {
  background: rgba(46, 124, 155, 0.32);
  transform: translateY(-2px);
}

/* ---------- 7. 面包屑 ---------- */
.breadcrumb {
  padding-block: 14px 0;
  font-size: 13px;
  letter-spacing: 0.04em;
}

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.breadcrumb__list li {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--data);
}

.breadcrumb__list li + li::before {
  content: "";
  width: 14px;
  height: 1px;
  background: var(--path);
  transform: skewX(-32deg);
  flex: none;
}

.breadcrumb a { color: var(--frost); }

.breadcrumb a:hover { color: var(--path); }

/* ---------- 8. 图片容器（页面阶段放图） ---------- */
.media-frame {
  position: relative;
  display: block;
  width: 100%;
  overflow: hidden;
  border: 1px solid rgba(46, 124, 155, 0.35);
  background:
    linear-gradient(135deg, var(--deep) 0%, var(--ink) 55%, var(--water) 100%);
  clip-path: polygon(0 0, calc(100% - 18px) 0, 100% 18px, 100% 100%, 18px 100%, 0 calc(100% - 18px));
  isolation: isolate;
}

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 2;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(143, 208, 223, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(143, 208, 223, 0.07) 1px, transparent 1px);
  background-size: 30px 30px;
}

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

.media-frame > picture { height: 100%; }

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

.media-frame__caption {
  position: absolute;
  left: 0;
  bottom: 0;
  z-index: 3;
  padding: 8px 14px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--frost);
  background: rgba(7, 23, 26, 0.82);
  border-top: 1px solid rgba(46, 124, 155, 0.45);
  border-right: 1px solid rgba(46, 124, 155, 0.45);
}

/* ---------- 9. 主题筛选 ---------- */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding-block: 12px;
  border-top: 1px solid rgba(46, 124, 155, 0.3);
  border-bottom: 1px solid rgba(46, 124, 155, 0.3);
}

.filter-btn {
  padding: 8px 15px;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--frost);
  background: transparent;
  border: 1px solid rgba(46, 124, 155, 0.42);
  cursor: pointer;
  clip-path: polygon(0 0, calc(100% - 9px) 0, 100% 9px, 100% 100%, 0 100%);
  transition: color 0.18s var(--ease), background-color 0.18s var(--ease),
              border-color 0.18s var(--ease);
}

.filter-btn:hover {
  color: var(--snow);
  border-color: var(--frost);
  background: rgba(46, 124, 155, 0.18);
}

.filter-btn[aria-pressed="true"],
.filter-btn.is-active {
  color: var(--ink);
  font-weight: 700;
  background: var(--path);
  border-color: var(--path);
}

/* ---------- 10. Skip Link ---------- */
.skip-link {
  position: fixed;
  left: 12px;
  top: -80px;
  z-index: 200;
  padding: 11px 18px;
  font-size: 14px;
  font-weight: 700;
  color: var(--ink);
  background: var(--path);
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 0 100%);
  transition: top 0.2s var(--ease);
}

.skip-link:focus {
  top: 12px;
}

/* ---------- 11. Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: linear-gradient(180deg, #07171A 0%, #0C2A28 100%);
  border-bottom: 1px solid rgba(46, 124, 155, 0.48);
}

.site-header::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: -1px;
  width: min(260px, 32vw);
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--path));
  pointer-events: none;
}

.site-header__frame {
  position: relative;
  display: flex;
  align-items: center;
  gap: clamp(14px, 2.4vw, 32px);
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding: 14px var(--gutter);
  transition: padding 0.24s var(--ease);
}

.site-header[data-condensed] .site-header__frame {
  padding-top: 7px;
  padding-bottom: 7px;
}

/* 品牌 */
.brand-lockup {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
  color: inherit;
  text-decoration: none;
}

.brand-lockup__mark {
  flex: none;
  width: 28px;
  height: 34px;
  background: linear-gradient(160deg, var(--path) 0 42%, var(--ice) 42% 100%);
  clip-path: polygon(0 0, 100% 6px, 100% 100%, 0 calc(100% - 8px));
  transition: height 0.24s var(--ease);
}

.site-header[data-condensed] .brand-lockup__mark {
  height: 28px;
}

.brand-lockup__text {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.brand-lockup__name {
  display: block;
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 800;
  letter-spacing: 0.04em;
  color: var(--snow);
  transition: font-size 0.24s var(--ease);
}

.site-header[data-condensed] .brand-lockup__name {
  font-size: 17px;
}

.brand-lockup__line {
  display: block;
  max-height: 22px;
  overflow: hidden;
  font-size: 11.5px;
  letter-spacing: 0.16em;
  color: var(--data);
  transition: opacity 0.22s var(--ease), max-height 0.22s var(--ease),
              transform 0.22s var(--ease);
}

.site-header[data-condensed] .brand-lockup__line {
  opacity: 0;
  max-height: 0;
  transform: translateY(-4px);
}

/* 移动导航按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--snow);
  background: rgba(46, 124, 155, 0.2);
  border: 1px solid rgba(143, 208, 223, 0.5);
  cursor: pointer;
  clip-path: polygon(0 0, calc(100% - 9px) 0, 100% 9px, 100% 100%, 0 100%);
  transition: background-color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.nav-toggle:hover {
  background: rgba(46, 124, 155, 0.36);
  border-color: var(--frost);
}

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
  transition: background-color 0.18s var(--ease);
}

.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: currentColor;
  transition: transform 0.22s var(--ease), top 0.22s 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 { top: 0; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after { top: 0; transform: rotate(-45deg); }

/* 导航：作为页面边框的一部分 */
.site-nav {
  margin-left: auto;
  padding: 5px;
  background: rgba(7, 23, 26, 0.6);
  border: 1px solid rgba(46, 124, 155, 0.5);
  clip-path: polygon(0 0, calc(100% - 14px) 0, 100% 14px, 100% 100%, 14px 100%, 0 calc(100% - 14px));
}

.site-nav__list {
  display: flex;
  align-items: center;
  gap: 3px;
}

.site-nav__link {
  position: relative;
  display: block;
  padding: 10px 14px 11px;
  font-size: 14.5px;
  letter-spacing: 0.05em;
  color: var(--frost);
  border: 1px solid transparent;
  clip-path: polygon(0 0, calc(100% - 9px) 0, 100% 9px, 100% 100%, 0 100%);
  transition: color 0.18s var(--ease), background-color 0.18s var(--ease),
              border-color 0.18s var(--ease);
}

.site-nav__link::after {
  content: "";
  position: absolute;
  left: 14px;
  right: 9px;
  bottom: 5px;
  height: 2px;
  background: var(--path);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.24s var(--ease);
}

.site-nav__link:hover,
.site-nav__link:focus-visible {
  color: var(--snow);
  background: rgba(46, 124, 155, 0.2);
  border-color: rgba(143, 208, 223, 0.4);
}

.site-nav__link:hover::after { transform: scaleX(1); }

.site-nav__link[aria-current="page"] {
  color: var(--hi);
  font-weight: 700;
  background: linear-gradient(150deg, var(--water), var(--ice));
  border-color: rgba(143, 208, 223, 0.6);
}

.site-nav__link[aria-current="page"]::after { transform: scaleX(1); }

/* 小屏版快捷入口 */
.quick-entry {
  flex: none;
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 11px 16px;
  font-size: 13.5px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--ink);
  background: linear-gradient(120deg, var(--path), var(--warm));
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
  transition: filter 0.18s var(--ease), transform 0.18s var(--ease);
}

.quick-entry:hover {
  filter: brightness(1.08);
  transform: translateY(-1px);
}

.quick-entry__dot {
  flex: none;
  width: 8px;
  height: 8px;
  background: var(--ink);
  clip-path: polygon(50% 0, 100% 50%, 50% 100%, 0 50%);
}

/* 平板 */
@media (max-width: 1080px) {
  .site-nav__link {
    padding-inline: 11px;
    font-size: 13.5px;
    letter-spacing: 0.02em;
  }
  .quick-entry { padding: 10px 13px; font-size: 12.5px; }
}

/* 移动 */
@media (max-width: 900px) {
  .site-header__frame {
    flex-wrap: wrap;
    row-gap: 10px;
    padding-block: 10px;
  }

  .brand-lockup { order: 1; }
  .brand-lockup__line { display: none; }

  .quick-entry {
    order: 2;
    margin-left: auto;
    padding: 9px 12px;
    font-size: 12px;
  }

  .nav-toggle { order: 3; display: inline-flex; }

  .site-nav {
    order: 4;
    flex-basis: 100%;
    margin-left: 0;
    padding: 0;
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    border-color: transparent;
    background: transparent;
    clip-path: none;
    transition: max-height 0.3s var(--ease), opacity 0.22s var(--ease),
                border-color 0.22s var(--ease), background-color 0.22s var(--ease);
  }

  .site-nav[data-open] {
    max-height: 560px;
    opacity: 1;
    padding: 8px;
    border: 1px solid rgba(46, 124, 155, 0.5);
    background: rgba(7, 23, 26, 0.78);
  }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 3px;
  }

  .site-nav__link {
    padding: 13px 15px;
    font-size: 15px;
    border-color: rgba(46, 124, 155, 0.28);
  }

  .site-nav__link::after { left: 15px; right: 9px; bottom: 8px; }
}

@media (max-width: 420px) {
  .brand-lockup__name { font-size: 16.5px; }
  .brand-lockup__mark { width: 22px; height: 27px; }
  .nav-toggle__label { display: none; }
}

/* ---------- 12. Footer ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(56px, 8vw, 120px);
  background: linear-gradient(180deg, var(--deep) 0%, var(--ink) 100%);
  border-top: 1px solid rgba(46, 124, 155, 0.45);
  color: var(--frost);
}

.site-footer__inner {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding: clamp(38px, 5vw, 68px) var(--gutter) clamp(20px, 3vw, 32px);
}

.footer-archive {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) repeat(2, minmax(0, 0.95fr)) minmax(0, 1.4fr);
  gap: clamp(22px, 3vw, 44px);
}

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

@media (min-width: 641px) {
  .footer-cell + .footer-cell {
    padding-left: clamp(14px, 2vw, 26px);
    border-left: 1px solid rgba(46, 124, 155, 0.28);
  }
}

.footer-cell__title {
  margin: 0 0 14px;
  font-family: var(--font-body);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.24em;
  color: var(--data);
  text-transform: uppercase;
}

.footer-brand {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 800;
  letter-spacing: 0.03em;
  color: var(--snow);
  margin: 0 0 12px;
}

.footer-lede {
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--frost);
  margin: 0 0 10px;
  max-width: 28em;
}

.footer-note {
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--data);
  margin: 0;
}

.footer-links {
  display: grid;
  gap: 9px;
  font-size: 14.5px;
}

.footer-links a {
  color: var(--frost);
  transition: color 0.18s var(--ease);
}

.footer-links a::before {
  content: "";
  display: inline-block;
  width: 0;
  height: 2px;
  margin-right: 0;
  background: var(--path);
  vertical-align: middle;
  transform: skewX(-30deg);
  transition: width 0.2s var(--ease), margin-right 0.2s var(--ease);
}

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

.footer-links a:hover::before,
.footer-links a:focus-visible::before {
  width: 12px;
  margin-right: 8px;
}

/* 备案与联系 —— 可折叠 */
.footer-cell--legal > summary {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0;
  cursor: pointer;
  list-style: none;
  user-select: none;
}

.footer-cell--legal > summary::-webkit-details-marker { display: none; }

.footer-cell--legal > summary::after {
  content: "";
  flex: none;
  width: 8px;
  height: 8px;
  margin-top: -4px;
  border-right: 2px solid var(--path);
  border-bottom: 2px solid var(--path);
  transform: rotate(45deg);
  transition: transform 0.22s var(--ease), margin-top 0.22s var(--ease);
}

.footer-cell--legal[open] > summary::after {
  transform: rotate(-135deg);
  margin-top: 3px;
}

.footer-cell--legal[open] > summary { margin-bottom: 14px; }

.footer-meta {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 7px 14px;
  font-size: 13.5px;
  line-height: 1.7;
}

.footer-meta dt {
  color: var(--data);
  letter-spacing: 0.1em;
  white-space: nowrap;
}

.footer-meta dd {
  margin: 0;
  color: var(--frost);
  font-variant-numeric: tabular-nums;
  overflow-wrap: anywhere;
}

/* 路径线 */
.footer-trace {
  height: 3px;
  margin: clamp(28px, 4vw, 42px) 0 clamp(14px, 2vw, 20px);
  transform: skewX(-30deg);
  transform-origin: left center;
  background: linear-gradient(
    90deg,
    var(--path) 0%,
    var(--warm) 28%,
    rgba(46, 124, 155, 0.32) 28.4%,
    rgba(46, 124, 155, 0.32) 100%
  );
}

.footer-base {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 24px;
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--data);
}

.footer-base p { margin: 0; max-width: none; }

.footer-base__copy { font-variant-numeric: tabular-nums; }

@media (max-width: 1023px) {
  .footer-archive { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 640px) {
  .footer-archive { grid-template-columns: minmax(0, 1fr); gap: 22px; }
  .footer-brand { font-size: 20px; }
  .footer-meta { grid-template-columns: minmax(0, 1fr); gap: 2px; }
  .footer-meta dt { margin-top: 8px; }
  .footer-base { flex-direction: column; }
}

/* ---------- 13. 动效退化 ---------- */
@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;
  }

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

  .btn:hover,
  .quick-entry:hover { transform: none; }
}