/* ============================================================
   site.css — 四季 / 中国站 共享样式
   ============================================================ */

:root {
  /* 四季色彩 */
  --spring: #7BC96F;
  --summer: #2F9E6E;
  --autumn: #E08A3C;
  --winter: #6C8FB8;
  --paper: #FBF7EE;
  --card: #FFFDF7;
  --ink: #163B32;
  --ink-btn: #1F5E48;
  --amber: #D98B16;
  --mist: #E7E3D8;

  /* 尺寸 */
  --rail-w: 120px;
  --header-h: 64px;
  --hair: 3px;

  /* 字体 */
  --font-display: "DeyiHei", "Noto Sans SC", "HarmonyOS Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  /* 阴影 */
  --shadow-hard: 5px 5px 0 var(--ink);
  --shadow-soft: 6px 6px 0 rgba(22, 59, 50, 0.13);
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 20px);
}

body, h1, h2, h3, h4, h5, p, figure, blockquote, ul, ol, dl, dd { margin: 0; }
ul, ol { padding: 0; list-style: none; }
img, svg, video { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font: inherit; color: inherit; }
button { border: 0; background: none; cursor: pointer; }

:focus-visible {
  outline: 3px solid var(--amber);
  outline-offset: 3px;
}

/* ========== 2. 基础排版 ========== */
body {
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.8;
  color: var(--ink);
  background-color: var(--paper);
  background-image:
    radial-gradient(120% 70% at 100% 0%, rgba(123, 201, 111, 0.10), transparent 62%),
    radial-gradient(90% 60% at 0% 100%, rgba(108, 143, 184, 0.10), transparent 58%);
  background-repeat: no-repeat;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.25;
  letter-spacing: -0.005em;
  color: var(--ink);
  text-wrap: balance;
}
h1 { font-size: clamp(30px, 4.6vw, 52px); }
h2 { font-size: clamp(23px, 3vw, 34px); }
h3 { font-size: clamp(18px, 2vw, 22px); }
p { text-wrap: pretty; }

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}
.mono {
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
}

/* ========== 3. 头部 ========== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
}

.skip-link {
  position: absolute;
  top: -120px;
  left: 12px;
  z-index: 130;
  padding: 10px 18px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.05em;
  color: var(--card);
  background: var(--ink);
  border: var(--hair) solid var(--amber);
  transition: top 0.18s ease;
}
.skip-link:focus,
.skip-link:focus-visible { top: 10px; }

.header-bar {
  position: relative;
  display: flex;
  align-items: center;
  gap: 14px;
  min-height: var(--header-h);
  padding: 10px clamp(16px, 3vw, 30px);
  background: rgba(251, 247, 238, 0.95);
  border-bottom: var(--hair) solid var(--ink);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.brand {
  display: inline-flex;
  flex-direction: column;
  gap: 3px;
  flex: 0 0 auto;
}
.brand-mark {
  align-self: flex-start;
  padding: 2px 10px 3px;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--card);
  background: var(--ink);
  border: var(--hair) solid var(--ink);
  box-shadow: 3px 3px 0 var(--amber);
  transition: transform 0.16s ease, box-shadow 0.16s ease;
}
.brand:hover .brand-mark,
.brand:focus-visible .brand-mark {
  transform: translate(-1px, -1px);
  box-shadow: 5px 5px 0 var(--amber);
}
.brand-descriptor {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.03em;
  color: rgba(22, 59, 50, 0.64);
  white-space: nowrap;
}

.header-tools {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-left: auto;
}
.tool-link {
  display: inline-block;
  padding: 6px 12px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.02em;
  color: var(--ink-btn);
  border: 2px solid transparent;
  border-radius: 2px;
  transition: background 0.16s ease, border-color 0.16s ease, color 0.16s ease;
}
.tool-link:hover {
  background: rgba(47, 158, 110, 0.14);
  border-color: rgba(22, 59, 50, 0.22);
}
.tool-link--accent {
  color: var(--card);
  background: var(--ink-btn);
  border-color: var(--ink);
  box-shadow: 2px 2px 0 rgba(22, 59, 50, 0.28);
}
.tool-link--accent:hover {
  color: var(--ink);
  background: var(--amber);
  border-color: var(--ink);
}

.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 8px 13px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--ink);
  background: var(--card);
  border: var(--hair) solid var(--ink);
  box-shadow: 3px 3px 0 var(--ink);
  transition: transform 0.14s ease, box-shadow 0.14s ease;
}
.nav-toggle:hover {
  transform: translate(-1px, -1px);
  box-shadow: 4px 4px 0 var(--ink);
}
.nav-toggle-bars {
  position: relative;
  display: inline-block;
  width: 18px;
  height: 13px;
}
.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--ink);
  transition: transform 0.2s ease, top 0.2s ease, bottom 0.2s ease;
}
.nav-toggle-bars::before { top: 1px; }
.nav-toggle-bars::after { bottom: 1px; }
.site-header[data-open] .nav-toggle-bars::before {
  top: 5px;
  transform: rotate(45deg);
}
.site-header[data-open] .nav-toggle-bars::after {
  bottom: 6px;
  transform: rotate(-45deg);
}
.nav-toggle-text { line-height: 1; }

.scroll-progress {
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg,
    var(--spring) 0 25%,
    var(--summer) 25% 50%,
    var(--autumn) 50% 75%,
    var(--winter) 75% 100%);
  transform: scaleX(0);
  transform-origin: left center;
  pointer-events: none;
}

/* --- 导航（移动优先：下拉面板） --- */
.site-nav {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  z-index: 95;
  max-height: calc(100vh - var(--header-h));
  overflow-y: auto;
  padding: 14px 0 22px;
  background: var(--ink);
  color: var(--card);
  border-bottom: var(--hair) solid var(--ink);
  box-shadow: 0 20px 34px rgba(22, 59, 50, 0.24);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s linear;
}
.site-header[data-open] .site-nav {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.nav-caption {
  padding: 0 16px 12px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.16em;
  color: rgba(251, 247, 238, 0.5);
}

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

.nav-link {
  display: flex;
  flex-direction: row;
  align-items: baseline;
  gap: 12px;
  padding: 11px 16px;
  color: rgba(251, 247, 238, 0.82);
  border-left: 4px solid transparent;
  transition: background 0.16s ease, color 0.16s ease, border-color 0.16s ease;
}
.nav-index {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--spring);
}
.nav-label {
  font-size: 15px;
  font-weight: 600;
  line-height: 1.4;
  letter-spacing: 0.01em;
}
.nav-link:hover {
  background: rgba(255, 253, 247, 0.10);
  color: var(--card);
  border-left-color: rgba(255, 253, 247, 0.45);
}
.nav-link[aria-current="page"] {
  background: rgba(217, 139, 22, 0.22);
  color: var(--card);
  border-left-color: var(--amber);
}
.nav-link[aria-current="page"] .nav-index { color: var(--amber); }

.nav-foot {
  margin-top: 18px;
  padding: 12px 16px 0;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.1em;
  color: rgba(251, 247, 238, 0.42);
  border-top: 2px solid rgba(251, 247, 238, 0.16);
}

@media (max-width: 860px) {
  .brand-descriptor { display: none; }
}
@media (max-width: 760px) {
  .header-tools { display: none; }
  .nav-toggle { margin-left: auto; }
}
@media (max-width: 400px) {
  .nav-toggle-text { display: none; }
}

/* --- 桌面端：坐标轴导航脊 --- */
@media (min-width: 960px) {
  body { padding-left: var(--rail-w); }

  .nav-toggle { display: none; }

  .site-nav {
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    right: auto;
    width: var(--rail-w);
    max-height: none;
    display: flex;
    flex-direction: column;
    padding: 18px 0 18px;
    overflow-y: auto;
    border-bottom: 0;
    border-right: var(--hair) solid var(--ink);
    box-shadow: 6px 0 0 rgba(22, 59, 50, 0.06);
    opacity: 1;
    visibility: visible;
    transform: none;
  }
  .nav-caption { padding: 0 14px 12px; }
  .nav-list { flex: 0 0 auto; }
  .nav-link {
    flex-direction: column;
    align-items: flex-start;
    gap: 3px;
    padding: 10px 12px 10px 14px;
  }
  .nav-index { font-size: 10px; }
  .nav-label { font-size: 13px; line-height: 1.35; }
  .nav-foot { margin-top: auto; padding: 12px 14px 0; }
}

/* ========== 4. 页脚 ========== */
.site-footer {
  position: relative;
  margin-top: clamp(56px, 9vw, 110px);
  background: var(--ink);
  color: rgba(251, 247, 238, 0.78);
  border-top: var(--hair) solid var(--ink);
}
.site-footer::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 7px;
  background: linear-gradient(90deg,
    var(--spring) 0 25%,
    var(--summer) 25% 50%,
    var(--autumn) 50% 75%,
    var(--winter) 75% 100%);
}
.site-footer::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(90deg,
    rgba(251, 247, 238, 0.055) 0 1px,
    transparent 1px 96px);
  opacity: 0.6;
}

.footer-inner {
  position: relative;
  z-index: 1;
  width: min(1180px, 100%);
  margin-inline: auto;
  padding: clamp(34px, 5vw, 62px) clamp(18px, 4vw, 44px) 26px;
}

.footer-top {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px 26px;
  padding-bottom: 22px;
  border-bottom: 2px solid rgba(251, 247, 238, 0.18);
}
.footer-brand {
  font-family: var(--font-display);
  font-size: clamp(19px, 2.4vw, 25px);
  font-weight: 800;
  letter-spacing: 0.01em;
  color: var(--card);
}
.footer-seasons {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.season-chip {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 4px 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.05em;
  color: rgba(251, 247, 238, 0.88);
  border: 2px solid rgba(251, 247, 238, 0.2);
  border-radius: 2px;
}
.season-chip::before {
  content: "";
  width: 9px;
  height: 9px;
  background: var(--chip, var(--mist));
}
.season-chip--spring { --chip: var(--spring); }
.season-chip--summer { --chip: var(--summer); }
.season-chip--autumn { --chip: var(--autumn); }
.season-chip--winter { --chip: var(--winter); }

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
  gap: clamp(24px, 3.6vw, 44px);
  padding: clamp(24px, 3.4vw, 38px) 0;
}
.footer-col-title {
  margin-bottom: 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.18em;
  color: var(--spring);
}
.footer-links {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.footer-links a {
  display: inline-block;
  padding: 4px 0;
  font-size: 14px;
  color: rgba(251, 247, 238, 0.8);
  border-bottom: 1px solid transparent;
  transition: color 0.16s ease, border-color 0.16s ease;
}
.footer-links a:hover {
  color: var(--card);
  border-bottom-color: var(--amber);
}
.footer-meta p {
  font-size: 13.5px;
  line-height: 1.75;
  color: rgba(251, 247, 238, 0.74);
}
.footer-meta p + p { margin-top: 7px; }

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 24px;
  padding-top: 20px;
  border-top: 2px solid rgba(251, 247, 238, 0.18);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: rgba(251, 247, 238, 0.6);
}
.footer-note a {
  color: rgba(251, 247, 238, 0.86);
  border-bottom: 1px solid rgba(251, 247, 238, 0.3);
}
.footer-note a:hover {
  color: var(--card);
  border-bottom-color: var(--amber);
}

/* ========== 5. 通用布局 ========== */
.container {
  width: min(1120px, calc(100% - 2 * clamp(18px, 4vw, 44px)));
  margin-inline: auto;
}
.section { padding-block: clamp(38px, 6vw, 76px); }
.section--tight { padding-block: clamp(24px, 3.6vw, 44px); }

.grid {
  display: grid;
  gap: clamp(16px, 2.4vw, 28px);
}
.grid--cards { grid-template-columns: repeat(auto-fit, minmax(min(100%, 260px), 1fr)); }
.grid--split { grid-template-columns: 1fr; }
@media (min-width: 900px) {
  .grid--split {
    grid-template-columns: 0.92fr 1.08fr;
    align-items: start;
  }
}
.stack > * + * { margin-top: 14px; }

/* ========== 6. 文字工具 ========== */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-btn);
}
.eyebrow::before {
  content: "";
  width: 22px;
  height: 3px;
  background: var(--amber);
}
.section-title { margin-bottom: 10px; }
.lede {
  max-width: 34em;
  font-size: clamp(15.5px, 1.6vw, 17.5px);
  line-height: 1.85;
  color: rgba(22, 59, 50, 0.78);
}

/* ========== 7. 按钮 ========== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 12px 22px;
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--ink);
  background: var(--card);
  border: var(--hair) solid var(--ink);
  box-shadow: var(--shadow-hard);
  transition: transform 0.16s ease, box-shadow 0.16s ease, background 0.16s ease, color 0.16s ease;
}
.btn:hover {
  transform: translate(-2px, -2px);
  box-shadow: 7px 7px 0 var(--ink);
}
.btn:active {
  transform: translate(2px, 2px);
  box-shadow: 2px 2px 0 var(--ink);
}
.btn--primary {
  color: var(--card);
  background: var(--ink-btn);
}
.btn--primary:hover { background: #17493A; }
.btn--accent {
  color: var(--ink);
  background: var(--amber);
}
.btn--ghost {
  background: transparent;
  box-shadow: none;
}
.btn--ghost:hover {
  background: rgba(47, 158, 110, 0.12);
  box-shadow: none;
}

/* ========== 8. 卡片 / 面板 / 标签 ========== */
.card {
  position: relative;
  padding: clamp(18px, 2.4vw, 26px);
  background: var(--card);
  border: var(--hair) solid var(--ink);
  box-shadow: var(--shadow-soft);
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}
.card:hover {
  transform: translate(-2px, -2px);
  box-shadow: 9px 9px 0 rgba(22, 59, 50, 0.16);
}
.card--spring { border-top: 9px solid var(--spring); }
.card--summer { border-top: 9px solid var(--summer); }
.card--autumn { border-top: 9px solid var(--autumn); }
.card--winter { border-top: 9px solid var(--winter); }

.panel {
  padding: clamp(18px, 2.6vw, 30px);
  background: var(--card);
  border: var(--hair) solid var(--ink);
  box-shadow: var(--shadow-soft);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--ink);
  background: var(--card);
  border: 2px solid var(--ink);
  border-radius: 2px;
}
.tag--spring { background: rgba(123, 201, 111, 0.28); }
.tag--summer { background: rgba(47, 158, 110, 0.20); }
.tag--autumn { background: rgba(224, 138, 60, 0.24); }
.tag--winter { background: rgba(108, 143, 184, 0.24); }
.tag--amber { background: rgba(217, 139, 22, 0.30); }

/* ========== 9. 列表 / 分隔 / 面包屑 ========== */
.index-list { display: grid; gap: 10px; }
.index-list li {
  display: flex;
  gap: 12px;
  align-items: baseline;
  padding-bottom: 10px;
  border-bottom: 1px dashed var(--mist);
}
.index-list li:last-child { border-bottom: 0; padding-bottom: 0; }

.rule {
  height: 3px;
  background: var(--ink);
  border: 0;
}
.rule--soft {
  height: 2px;
  background: var(--mist);
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  margin-bottom: 18px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: rgba(22, 59, 50, 0.6);
}
.breadcrumb li + li::before {
  content: "›";
  margin-right: 6px;
  color: rgba(22, 59, 50, 0.35);
}
.breadcrumb a { transition: color 0.16s ease; }
.breadcrumb a:hover { color: var(--ink-btn); }

/* ========== 10. 图片容器基础 ========== */
.img-frame {
  position: relative;
  display: block;
  overflow: hidden;
  width: 100%;
  aspect-ratio: 4 / 3;
  background: var(--card);
  border: var(--hair) solid var(--ink);
  box-shadow: var(--shadow-soft);
}
.img-frame > img,
.img-frame > picture,
.img-frame > svg {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.img-frame--wide { aspect-ratio: 16 / 9; }
.img-frame--tall { aspect-ratio: 3 / 4; }
.img-frame--spring { background: linear-gradient(150deg, #EAF6E3, #CBEAC0); }
.img-frame--summer { background: linear-gradient(150deg, #E4F3EA, #B6DFC9); }
.img-frame--autumn { background: linear-gradient(150deg, #FBEDDD, #F2CFA6); }
.img-frame--winter { background: linear-gradient(150deg, #E9EFF6, #C3D4E6); }

/* ========== 11. 滚动显现 ========== */
html.js-motion [data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.4s ease, transform 0.4s cubic-bezier(0.22, 0.7, 0.3, 1);
  transition-delay: var(--reveal-delay, 0ms);
}
html.js-motion [data-reveal].is-revealed {
  opacity: 1;
  transform: none;
}

/* ========== 12. 降低动效 ========== */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  html.js-motion [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}