/* ============================================================
   四季指南 · 共享站级样式 /assets/site.css
   纸面暖灰 + 四季四色 + 对照标记；等宽索引配宋体正文
   ============================================================ */

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

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

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

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

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

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

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

table { border-collapse: collapse; width: 100%; }

/* ---------- 2. Tokens ---------- */
:root {
  --canvas: #F4F1EC;
  --paper: #FAF8F4;
  --ink: #1F2421;
  --ink-2: #4A514C;
  --line: #D9D3C9;
  --line-soft: #E7E2D9;

  --spring: #D98C9A;
  --summer: #5B8FA8;
  --autumn: #D08A4E;
  --winter: #7FA6A0;
  --mark: #B4552F;

  --spring-ink: #8E4B57;
  --summer-ink: #3D6B82;
  --autumn-ink: #8E5722;
  --winter-ink: #456E68;

  --font-display: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-body: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "SimSun", Georgia, serif;
  --font-mono: "IBM Plex Mono", "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --shell-max: 1240px;
  --gutter: clamp(20px, 4vw, 56px);

  --header-h: 94px;

  --ease: cubic-bezier(.22, .61, .36, 1);
  --shadow-soft: 0 18px 40px -32px rgba(31, 36, 33, .55);
}

@media (max-width: 980px) {
  :root { --header-h: 64px; }
}

/* ---------- 3. Base typography ---------- */
body {
  background-color: var(--canvas);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.85;
  letter-spacing: .01em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -.012em;
  color: var(--ink);
}

h1 { font-size: clamp(2.25rem, 5.2vw, 3.6rem); }
h2 { font-size: clamp(1.6rem, 2.9vw, 2.35rem); }
h3 { font-size: clamp(1.2rem, 1.9vw, 1.5rem); }
h4 { font-size: 1.08rem; }

strong, b { font-weight: 700; }

::selection {
  background-color: rgba(217, 140, 154, .34);
  color: var(--ink);
}

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

.site-footer :focus-visible {
  outline-color: var(--autumn);
}

@media (prefers-reduced-motion: no-preference) {
  html { scroll-behavior: smooth; }
}

/* ---------- 4. Utilities ---------- */
.shell {
  width: min(100% - (var(--gutter) * 2), var(--shell-max));
  margin-inline: auto;
}

.mono {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  font-weight: 400;
}

.section-num {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--ink-2);
  text-transform: uppercase;
}

.season-rule {
  height: 2px;
  border: 0;
  margin: 0;
  background: linear-gradient(
    90deg,
    var(--spring) 0 25%,
    var(--summer) 25% 50%,
    var(--autumn) 50% 75%,
    var(--winter) 75% 100%
  );
  opacity: .9;
}

.site-main { display: block; }

.site-main--offset {
  padding-top: calc(var(--header-h) + 16px);
}

/* ---------- 5. Skip link ---------- */
.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 200;
  transform: translateY(-180%);
  padding: 11px 18px;
  background-color: var(--ink);
  color: var(--paper);
  border-radius: 2px;
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 700;
  transition: transform .18s var(--ease);
}

.skip-link:focus,
.skip-link:focus-visible {
  transform: translateY(0);
  outline-color: var(--autumn);
}

/* ---------- 6. Buttons ---------- */
.btn {
  --btn-bg: var(--ink);
  --btn-fg: var(--paper);
  --btn-bd: var(--ink);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5em;
  min-height: 44px;
  padding: 0 22px;
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: .03em;
  line-height: 1;
  white-space: nowrap;
  color: var(--btn-fg);
  background-color: var(--btn-bg);
  border: 1px solid var(--btn-bd);
  border-radius: 2px;
  transition:
    background-color .16s var(--ease),
    border-color .16s var(--ease),
    color .16s var(--ease),
    transform .16s var(--ease);
}

.btn:hover { transform: translateY(-1px); }
.btn:active { transform: translateY(0); }

.btn--solid {
  --btn-bg: var(--ink);
  --btn-fg: var(--paper);
  --btn-bd: var(--ink);
}

.btn--solid:hover {
  --btn-bg: var(--mark);
  --btn-bd: var(--mark);
}

.btn--ghost {
  --btn-bg: transparent;
  --btn-fg: var(--ink);
  --btn-bd: var(--line);
}

.btn--ghost:hover {
  --btn-bg: rgba(31, 36, 33, .05);
  --btn-bd: var(--ink);
}

.btn--on-dark {
  --btn-bg: var(--paper);
  --btn-fg: var(--ink);
  --btn-bd: var(--paper);
}

.btn--on-dark:hover {
  --btn-bg: var(--spring);
  --btn-bd: var(--spring);
}

.btn--ghost-dark {
  --btn-bg: transparent;
  --btn-fg: var(--paper);
  --btn-bd: rgba(250, 248, 244, .32);
}

.btn--ghost-dark:hover {
  --btn-bd: var(--paper);
  --btn-bg: rgba(250, 248, 244, .08);
}

.btn--sm {
  min-height: 36px;
  padding: 0 14px;
  font-size: 13px;
}

/* ---------- 7. Season tags ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: .5em;
  padding: 3px 11px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background-color: transparent;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  line-height: 1.7;
  white-space: nowrap;
  color: var(--ink-2);
}

.tag::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--line);
  flex: none;
}

.tag--spring {
  color: var(--spring-ink);
  border-color: rgba(217, 140, 154, .55);
  background-color: rgba(217, 140, 154, .14);
}
.tag--spring::before { background-color: var(--spring); }

.tag--summer {
  color: var(--summer-ink);
  border-color: rgba(91, 143, 168, .5);
  background-color: rgba(91, 143, 168, .12);
}
.tag--summer::before { background-color: var(--summer); }

.tag--autumn {
  color: var(--autumn-ink);
  border-color: rgba(208, 138, 78, .55);
  background-color: rgba(208, 138, 78, .14);
}
.tag--autumn::before { background-color: var(--autumn); }

.tag--winter {
  color: var(--winter-ink);
  border-color: rgba(127, 166, 160, .55);
  background-color: rgba(127, 166, 160, .16);
}
.tag--winter::before { background-color: var(--winter); }

/* ---------- 8. Breadcrumb ---------- */
.breadcrumb {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--ink-2);
}

.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .25em;
}

.breadcrumb li {
  display: inline-flex;
  align-items: center;
}

.breadcrumb li:not(:last-child)::after {
  content: "/";
  margin-inline: .55em;
  color: var(--line);
}

.breadcrumb a {
  border-bottom: 1px solid transparent;
  transition: color .16s var(--ease), border-color .16s var(--ease);
}

.breadcrumb a:hover {
  color: var(--ink);
  border-bottom-color: var(--line);
}

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

/* ---------- 9. Layout helpers ---------- */
.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: 24px;
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 220px) minmax(0, 1fr);
  gap: 48px;
  align-items: start;
}

.index-col {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  line-height: 2;
  color: var(--ink-2);
  border-top: 1px solid var(--line);
  padding-top: 14px;
}

.prose {
  max-width: 66ch;
  font-size: 17px;
  line-height: 1.9;
  color: var(--ink);
}

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

.prose h2,
.prose h3 { margin-top: 1.8em; margin-bottom: .6em; }

.prose ul,
.prose ol {
  margin-top: .8em;
  padding-left: 1.2em;
  list-style: disc;
}

.prose li + li { margin-top: .4em; }

.prose a {
  color: var(--ink);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: .22em;
  text-decoration-color: var(--autumn);
  transition: text-decoration-color .16s var(--ease);
}

.prose a:hover { text-decoration-color: var(--mark); }

@media (max-width: 900px) {
  .grid-12 { grid-template-columns: repeat(6, minmax(0, 1fr)); }
}

@media (max-width: 860px) {
  .split { grid-template-columns: 1fr; gap: 20px; }
}

@media (max-width: 600px) {
  .grid-12 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .prose { font-size: 16.5px; }
}

/* ---------- 10. Media frame (页面阶段放图用) ---------- */
.media-frame {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  aspect-ratio: 4 / 3;
  background-color: var(--paper);
  border: 1px solid var(--line);
}

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

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 2;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(31, 36, 33, .07) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(31, 36, 33, .07) 1px, transparent 1px);
  background-size: 32px 32px;
  mix-blend-mode: multiply;
}

.media-frame--wide { aspect-ratio: 16 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--square { aspect-ratio: 1 / 1; }

.media-frame--overlay::before {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  z-index: 1;
  height: 58%;
  background: linear-gradient(180deg, rgba(31, 36, 33, 0), rgba(31, 36, 33, .46));
  pointer-events: none;
}

.media-caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--ink-2);
}

@media (max-width: 600px) {
  .media-frame { aspect-ratio: 3 / 2; }
}

/* ---------- 11. Disclosure ---------- */
.disclosure { border-top: 1px solid var(--line); }

.disclosure summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 18px 0;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--ink);
  transition: color .16s var(--ease);
}

.disclosure summary::-webkit-details-marker { display: none; }
.disclosure summary:hover { color: var(--mark); }

.disclosure summary::after {
  content: "";
  flex: none;
  width: 9px;
  height: 9px;
  border-right: 1.5px solid var(--ink-2);
  border-bottom: 1.5px solid var(--ink-2);
  transform: rotate(45deg) translateY(-2px);
  transition: transform .2s var(--ease);
}

.disclosure[open] summary::after {
  transform: rotate(-135deg) translateY(-2px);
}

.disclosure .disclosure-body {
  padding: 0 0 22px;
  max-width: 68ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink-2);
}

.disclosure .disclosure-body p + p { margin-top: .8em; }

/* ---------- 12. Rail ---------- */
.rail {
  display: flex;
  gap: 16px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  padding-bottom: 10px;
  scrollbar-width: thin;
  scrollbar-color: var(--line) transparent;
}

.rail > * {
  flex: 0 0 auto;
  scroll-snap-align: start;
}

.rail::-webkit-scrollbar { height: 6px; }
.rail::-webkit-scrollbar-track { background-color: transparent; }
.rail::-webkit-scrollbar-thumb {
  background-color: var(--line);
  border-radius: 99px;
}

/* ---------- 13. Reveal ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity .34s var(--ease), transform .34s var(--ease);
}

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

/* ============================================================
   14. HEADER
   ============================================================ */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 90;
  isolation: isolate;
  color: var(--ink);
  transition: background-color .3s var(--ease), box-shadow .3s var(--ease);
}

.site-header::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background: linear-gradient(
    180deg,
    rgba(244, 241, 236, .97) 0%,
    rgba(244, 241, 236, .84) 62%,
    rgba(244, 241, 236, 0) 100%
  );
  transition: opacity .3s var(--ease);
}

.site-header[data-stuck] {
  background-color: var(--canvas);
  box-shadow: 0 1px 0 var(--line), var(--shadow-soft);
}

.site-header[data-stuck]::after { opacity: 0; }

/* --- 14.1 元信息条 --- */
.header-strip {
  height: 33px;
  overflow: hidden;
  border-bottom: 1px solid var(--line);
  transition: height .28s var(--ease), border-color .28s var(--ease);
}

.site-header[data-stuck] .header-strip {
  height: 0;
  border-bottom-color: transparent;
}

.strip-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  height: 32px;
}

.strip-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--ink-2);
  white-space: nowrap;
}

.season-dots {
  display: inline-grid;
  grid-auto-flow: column;
  gap: 3px;
  flex: none;
}

.season-dots i {
  display: block;
  width: 5px;
  height: 5px;
  border-radius: 50%;
}

.season-dots i:nth-child(1) { background-color: var(--spring); }
.season-dots i:nth-child(2) { background-color: var(--summer); }
.season-dots i:nth-child(3) { background-color: var(--autumn); }
.season-dots i:nth-child(4) { background-color: var(--winter); }

.strip-meta {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: .14em;
  color: var(--ink-2);
  white-space: nowrap;
}

.strip-link {
  color: var(--ink-2);
  border-bottom: 1px solid var(--line);
  padding-bottom: 1px;
  transition: color .16s var(--ease), border-color .16s var(--ease);
}

.strip-link:hover {
  color: var(--ink);
  border-bottom-color: var(--mark);
}

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

.strip-call { white-space: nowrap; }

/* --- 14.2 主栏 --- */
.header-bar { position: relative; }

.header-inner {
  display: flex;
  align-items: center;
  gap: clamp(16px, 3vw, 40px);
  padding-block: 14px;
  transition: padding .28s var(--ease);
}

.site-header[data-stuck] .header-inner { padding-block: 10px; }

/* 品牌 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex: none;
  padding-block: 2px;
}

.brand-mark {
  display: inline-grid;
  grid-auto-flow: column;
  gap: 3px;
  align-items: end;
  height: 26px;
}

.brand-mark i {
  display: block;
  width: 4px;
  border-radius: 1px;
}

.brand-mark i:nth-child(1) { height: 14px; background-color: var(--spring); }
.brand-mark i:nth-child(2) { height: 20px; background-color: var(--summer); }
.brand-mark i:nth-child(3) { height: 26px; background-color: var(--autumn); }
.brand-mark i:nth-child(4) { height: 17px; background-color: var(--winter); }

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 3px;
  line-height: 1;
}

.brand-name {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 800;
  letter-spacing: .08em;
  color: var(--ink);
}

.brand-sub {
  font-size: 10px;
  letter-spacing: .2em;
  color: var(--ink-2);
}

/* 导航 */
.nav {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 28px);
  margin-left: auto;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.6vw, 24px);
}

.nav-item { position: relative; }

.nav-link {
  position: relative;
  display: inline-block;
  padding: 6px 2px;
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: .02em;
  color: var(--ink-2);
  transition: color .16s var(--ease);
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background-color: var(--ink);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .2s var(--ease), background-color .2s var(--ease);
}

.nav-link:hover { color: var(--ink); }
.nav-link:hover::after { transform: scaleX(1); }

.nav-link[aria-current="page"] {
  color: var(--ink);
  font-weight: 700;
}

.nav-link[aria-current="page"]::after {
  height: 3px;
  transform: scaleX(1);
  background-image: linear-gradient(
    90deg,
    var(--spring) 0 25%,
    var(--summer) 25% 50%,
    var(--autumn) 50% 75%,
    var(--winter) 75% 100%
  );
}

.nav-foot { display: none; }

.nav-note {
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--ink-2);
}

/* 右侧动作 */
.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: none;
}

.header-cta-primary,
.header-cta-secondary {
  min-height: 40px;
  padding-inline: 18px;
  font-size: 13px;
}

/* 移动索引按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  min-height: 40px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: 2px;
  background-color: var(--paper);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--ink);
  transition: border-color .16s var(--ease), background-color .16s var(--ease);
}

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

.nav-toggle-icon {
  position: relative;
  display: inline-block;
  width: 16px;
  height: 10px;
  flex: none;
}

.nav-toggle-icon span {
  position: absolute;
  left: 0;
  width: 100%;
  height: 1.5px;
  background-color: var(--ink);
  transition: transform .2s var(--ease), opacity .16s var(--ease);
}

.nav-toggle-icon span:nth-child(1) { top: 0; }
.nav-toggle-icon span:nth-child(2) { bottom: 0; }

.site-header[data-open] .nav-toggle-icon span:nth-child(1) {
  transform: translateY(4.25px) rotate(45deg);
}

.site-header[data-open] .nav-toggle-icon span:nth-child(2) {
  transform: translateY(-4.25px) rotate(-45deg);
}

.nav-toggle-label { white-space: nowrap; }

/* 阅读进度 */
.scroll-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  pointer-events: none;
  background-color: transparent;
  transition: background-color .3s var(--ease);
}

.site-header[data-stuck] .scroll-progress { background-color: var(--line-soft); }

.scroll-progress-bar {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(0);
  transform-origin: left center;
  background-image: linear-gradient(
    90deg,
    var(--spring) 0 25%,
    var(--summer) 25% 50%,
    var(--autumn) 50% 75%,
    var(--winter) 75% 100%
  );
}

/* --- 14.3 头部响应式 --- */
@media (max-width: 1180px) {
  .header-cta-secondary { display: none; }
}

@media (max-width: 980px) {
  .header-strip { display: none; }

  .header-inner { padding-block: 12px; }
  .site-header[data-stuck] .header-inner { padding-block: 12px; }

  .header-cta-primary,
  .header-cta-secondary { display: none; }

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

  .nav {
    position: fixed;
    left: 0;
    right: 0;
    top: var(--header-h);
    display: block;
    margin: 0;
    padding: 18px var(--gutter) 30px;
    max-height: calc(100dvh - var(--header-h));
    overflow-y: auto;
    background-color: var(--paper);
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
    box-shadow: 0 30px 50px -34px rgba(31, 36, 33, .5);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    pointer-events: none;
    transition:
      opacity .2s var(--ease),
      transform .24s var(--ease),
      visibility .24s var(--ease);
  }

  .site-header[data-open] .nav {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
    pointer-events: auto;
  }

  .nav-list {
    display: grid;
    gap: 0;
    align-items: stretch;
  }

  .nav-item { border-bottom: 1px solid var(--line); }

  .nav-link {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 15px 0;
    font-size: 17px;
    font-weight: 600;
  }

  .nav-link::after { display: none; }

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

  .nav-link[aria-current="page"]::before {
    content: "当前";
    order: 2;
    font-family: var(--font-mono);
    font-size: 10px;
    font-weight: 400;
    letter-spacing: .16em;
    color: var(--mark);
  }

  .nav-foot {
    display: grid;
    gap: 10px;
    margin-top: 22px;
  }

  .nav-foot .btn { width: 100%; }

  .nav-note {
    margin-top: 6px;
    text-align: center;
  }
}

@media (max-width: 420px) {
  .brand-name { font-size: 17px; }
  .brand-sub { font-size: 9px; letter-spacing: .16em; }
  .nav-toggle-label { display: none; }
}

/* ============================================================
   15. FOOTER
   ============================================================ */
.site-footer {
  position: relative;
  margin-top: clamp(64px, 9vw, 112px);
  background-color: var(--ink);
  color: rgba(250, 248, 244, .74);
  font-family: var(--font-display);
}

.footer-seasons {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  height: 4px;
}

.footer-seasons i { display: block; }
.footer-seasons i:nth-child(1) { background-color: var(--spring); }
.footer-seasons i:nth-child(2) { background-color: var(--summer); }
.footer-seasons i:nth-child(3) { background-color: var(--autumn); }
.footer-seasons i:nth-child(4) { background-color: var(--winter); }

.footer-main {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(0, 1.5fr) minmax(0, .95fr);
  gap: clamp(28px, 4vw, 64px);
  padding-block: clamp(44px, 6vw, 76px);
}

/* 品牌区 */
.footer-brand { min-width: 0; }

.footer-logo {
  display: inline-flex;
  flex-direction: column;
  gap: 7px;
}

.footer-logo-cn {
  font-family: var(--font-display);
  font-size: 28px;
  font-weight: 800;
  letter-spacing: .1em;
  line-height: 1;
  color: var(--paper);
}

.footer-logo-en {
  font-size: 10px;
  letter-spacing: .24em;
  color: rgba(250, 248, 244, .45);
}

.footer-line {
  margin-top: 16px;
  max-width: 30ch;
  font-size: 14px;
  line-height: 1.8;
  letter-spacing: .02em;
  color: rgba(250, 248, 244, .62);
}

.footer-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

/* 索引列 */
.footer-nav {
  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: 16px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: .2em;
  line-height: 1.6;
  text-transform: uppercase;
  color: rgba(250, 248, 244, .48);
}

.footer-links li + li { margin-top: 11px; }

.footer-links a {
  position: relative;
  display: inline-block;
  padding-bottom: 2px;
  font-size: 14px;
  letter-spacing: .02em;
  color: rgba(250, 248, 244, .8);
  transition: color .16s var(--ease);
}

.footer-links a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 1px;
  background-color: var(--autumn);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .2s var(--ease);
}

.footer-links a:hover { color: var(--paper); }
.footer-links a:hover::after { transform: scaleX(1); }

/* 联系 */
.footer-contact { min-width: 0; }

.footer-contact-list li {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 10px;
  padding-block: 6px;
  font-size: 13.5px;
  line-height: 1.7;
  color: rgba(250, 248, 244, .8);
  word-break: break-word;
}

.contact-key {
  padding-top: 3px;
  font-size: 10px;
  letter-spacing: .14em;
  color: rgba(250, 248, 244, .42);
}

.footer-note {
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px solid rgba(250, 248, 244, .14);
  font-size: 12.5px;
  line-height: 1.85;
  color: rgba(250, 248, 244, .5);
}

/* 底部法律条 */
.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 24px;
  padding-block: 20px 26px;
  border-top: 1px solid rgba(250, 248, 244, .14);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .08em;
  color: rgba(250, 248, 244, .48);
}

.footer-copy { white-space: nowrap; }
.footer-icp { white-space: nowrap; }

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  margin-left: auto;
}

.footer-legal a {
  transition: color .16s var(--ease);
}

.footer-legal a:hover { color: var(--paper); }

@media (max-width: 1024px) {
  .footer-main {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.2fr);
  }
  .footer-brand { grid-column: 1 / -1; }
  .footer-contact { grid-column: 1 / -1; }
  .footer-note { max-width: 62ch; }
}

@media (max-width: 720px) {
  .footer-main { grid-template-columns: 1fr; }
  .footer-nav { grid-template-columns: 1fr 1fr; gap: 24px; }
  .footer-contact { grid-column: auto; }
  .footer-legal { margin-left: 0; }
}

@media (max-width: 420px) {
  .footer-logo-cn { font-size: 24px; }
  .footer-nav { grid-template-columns: 1fr; }
}

/* ---------- 16. Reduced motion ---------- */
@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;
  }

  .btn:hover { transform: none; }
  .site-header[data-open] .nav { transform: none; }
}