:root {
  --color-surface: #fbfbfb;
  --color-surface-alt: #f1f1f1;
  --color-surface-deep: #e3e3e3;
  --color-ink: #303336;
  --color-ink-soft: #5c6066;
  --color-ink-muted: #787c82;
  --color-line: #d6d7d8;
  --color-primary: #0f72ea;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #dae8f9;
  --color-accent: #e20372;
  --color-accent-ink: #ffffff;
  --color-highlight: #f6cee2;
  --color-focus: #e00070;
  --color-contrast-surface: #141f2d;
  --color-contrast-ink: #e4e5e7;
  --color-contrast-line: #424b56;
  --color-contrast-accent: #fc1d8c;
  --overlay-scrim: linear-gradient(180deg, rgba(20, 31, 45, 0.35) 0%, rgba(20, 31, 45, 0.72) 55%, rgba(20, 31, 45, 0.92) 100%);
  --font-heading: "Source Han Sans SC", "Noto Sans SC", SimHei, "Microsoft YaHei", sans-serif;
  --font-body: "PingFang SC", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --font-mono: ui-monospace, Menlo, Consolas, monospace;
  --text-xs: 11.0px;
  --text-sm: 14.7px;
  --text-base: 17px;
  --text-lg: 22.7px;
  --text-xl: 30.2px;
  --text-2xl: 40.3px;
  --text-3xl: 53.7px;
  --text-4xl: 71.5px;
  --text-display: clamp(49px, 10.2vw, 130px);
  --text-figure: clamp(41px, 7.3vw, 94px);
  --weight-heading: 826;
  --weight-body: 400;
  --leading-body: 1.77;
  --leading-heading: 1.2;
  --tracking-heading: -0.019em;
  --radius-sm: 494px;
  --radius-md: 557px;
  --radius-lg: 620px;
  --radius-pill: 999px;
  --border-thin: 2px;
  --border-thick: 3px;
  --shadow-1: none;
  --shadow-2: none;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1120px;
  --measure: 69ch;
  --gutter: 24px;
  --section-y: 79px;
  --section-y-lg: 111px;
}

/* ------------------------------------------------------------
   0. Reset 与中文排版基线
   ------------------------------------------------------------ */
*,
*::before,
*::after { box-sizing: border-box; }

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

body {
  margin: 0;
  background-color: var(--color-surface);
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: var(--weight-body);
  line-height: var(--leading-body);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}

p { margin: 0; }

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

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

a {
  color: var(--color-primary);
  text-decoration: none;
}

a:hover { text-decoration: underline; text-underline-offset: 3px; }

button { font: inherit; color: inherit; }

:focus-visible {
  outline: var(--border-thick) solid var(--color-focus);
  outline-offset: 3px;
}

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

/* ------------------------------------------------------------
   1. 容器 / 栅格 / 区块
   ------------------------------------------------------------ */
.shell {
  width: 100%;
  max-width: calc(var(--container) + var(--gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section { padding-block: var(--section-y); }
.section--wide { padding-block: var(--section-y-lg); }
.section--soft { background-color: var(--color-surface-alt); }
.section--deep {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}
.section--deep h1,
.section--deep h2,
.section--deep h3 { color: var(--color-contrast-ink); }

.grid {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: var(--gutter);
}

.grid > * { grid-column: span 6; }

@media (min-width: 720px) {
  .col-1 { grid-column: span 1; }
  .col-2 { grid-column: span 2; }
  .col-3 { grid-column: span 3; }
  .col-4 { grid-column: span 4; }
  .col-5 { grid-column: span 5; }
  .col-6 { grid-column: span 6; }
}

/* ------------------------------------------------------------
   2. 正文容器与标尺式编号
   ------------------------------------------------------------ */
.prose { max-width: var(--measure); }
.prose p { margin-bottom: var(--space-3); }
.prose p:last-child { margin-bottom: 0; }
.prose h2 { font-size: var(--text-xl); margin: var(--space-6) 0 var(--space-2); }
.prose h3 { font-size: var(--text-lg); margin: var(--space-4) 0 var(--space-2); }
.prose ul, .prose ol { margin-bottom: var(--space-3); padding-left: var(--space-3); }
.prose li { margin-bottom: var(--space-1); position: relative; }
.prose ul li::before {
  content: "";
  position: absolute;
  left: calc(var(--space-2) * -1);
  top: 0.72em;
  width: var(--border-thick);
  height: 12px;
  background-color: var(--color-accent);
}
.prose ol { list-style: decimal; }

.scale-number {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-2xl);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
  color: var(--color-primary);
}

/* ------------------------------------------------------------
   3. 通用按钮
   ------------------------------------------------------------ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  min-height: 44px;
  padding: var(--space-2) var(--space-4);
  border: 0;
  border-radius: var(--radius-pill);
  font-family: var(--font-heading);
  font-size: var(--text-base);
  font-weight: var(--weight-heading);
  letter-spacing: var(--tracking-heading);
  text-decoration: none;
  cursor: pointer;
  transition: background-color 140ms ease, color 140ms ease;
}

.btn:hover { text-decoration: none; }

.btn--primary {
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
}
.btn--primary:hover {
  background-color: color-mix(in srgb, var(--color-primary) 84%, #000000);
}

.btn--accent {
  background-color: var(--color-accent);
  color: var(--color-accent-ink);
}
.btn--accent:hover {
  background-color: color-mix(in srgb, var(--color-accent) 84%, #000000);
}

.btn--ghost {
  background-color: transparent;
  color: var(--color-ink);
  border: var(--border-thin) solid var(--color-ink);
  padding: calc(var(--space-2) - var(--border-thin)) calc(var(--space-4) - var(--border-thin));
}
.btn--ghost:hover {
  background-color: var(--color-surface-deep);
}

/* ------------------------------------------------------------
   4. 面包屑
   ------------------------------------------------------------ */
.breadcrumb {
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}
.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-1);
}
.breadcrumb__list li {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
}
.breadcrumb__list li + li::before {
  content: "";
  width: var(--border-thin);
  height: 11px;
  background-color: var(--color-line);
}
.breadcrumb a { color: var(--color-ink-soft); }
.breadcrumb a:hover { color: var(--color-primary); text-decoration: none; }
.breadcrumb [aria-current="page"] {
  color: var(--color-ink);
  font-weight: 700;
}

/* ------------------------------------------------------------
   5. 图片容器（供页面阶段放置占位）
   ------------------------------------------------------------ */
.figure {
  display: grid;
  gap: var(--space-2);
  margin: 0;
}

.figure__frame {
  position: relative;
  overflow: hidden;
  border-radius: 0;
  background-color: var(--color-contrast-surface);
  aspect-ratio: 16 / 9;
}

.figure--square .figure__frame { aspect-ratio: 1 / 1; }

.figure__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.figure__frame::after {
  content: "";
  position: absolute;
  inset: 0;
  background-color: color-mix(in srgb, var(--color-primary) 44%, transparent);
  mix-blend-mode: multiply;
  pointer-events: none;
}

.figure--accent .figure__frame::after {
  background-color: color-mix(in srgb, var(--color-accent) 42%, transparent);
}

.figure--plain .figure__frame::after { content: none; }

.figure__caption {
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}

.figure__caption--overlay {
  position: absolute;
  inset-inline: 0;
  bottom: 0;
  z-index: 2;
  padding: var(--space-3);
  background-image: var(--overlay-scrim);
  color: var(--color-primary-ink);
  font-size: var(--text-sm);
}

/* ------------------------------------------------------------
   6. 头部：深色状态轨 + 浅色栏目条
   ------------------------------------------------------------ */
.skip-link {
  position: absolute;
  left: var(--space-2);
  top: -120px;
  z-index: 200;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-pill);
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  transition: top 140ms ease;
}

.skip-link:focus {
  top: var(--space-2);
  text-decoration: none;
}

.site-header {
  position: relative;
  z-index: 50;
  background-color: var(--color-surface);
}

.header-rail {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.header-rail__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2) var(--space-4);
  min-height: 46px;
  padding-block: var(--space-1);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  color: inherit;
  font-family: var(--font-heading);
}

.brand:hover { text-decoration: none; }

.brand__mark {
  flex: none;
  width: 26px;
  height: 26px;
  border-radius: var(--radius-lg);
  background-image: linear-gradient(180deg, var(--color-primary) 0 50%, var(--color-accent) 50% 100%);
}

.brand__name {
  font-size: var(--text-base);
  font-weight: var(--weight-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-contrast-ink);
}

.brand__abbr {
  display: none;
  font-size: var(--text-base);
  font-weight: var(--weight-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-contrast-ink);
}

.rail-notes {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-1) var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: var(--color-contrast-ink);
}

.rail-notes__item {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
}

.rail-notes__dot {
  width: 7px;
  height: 7px;
  border-radius: var(--radius-pill);
  background-color: var(--color-contrast-accent);
}

.rail-notes__link {
  color: var(--color-contrast-accent);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
}
.rail-notes__link:hover { color: var(--color-contrast-ink); }

.header-bar { background-color: var(--color-surface); }

.header-bar__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  border-bottom: var(--border-thin) solid var(--color-line);
}

.site-nav { order: 0; }

.site-nav__list {
  display: flex;
  align-items: stretch;
  gap: var(--space-6);
}

.site-nav a {
  position: relative;
  display: inline-flex;
  align-items: center;
  min-height: 58px;
  padding-inline: 2px;
  color: var(--color-ink);
  font-family: var(--font-heading);
  font-size: var(--text-base);
  font-weight: var(--weight-heading);
  letter-spacing: var(--tracking-heading);
}

.site-nav a:hover {
  text-decoration: none;
  color: var(--color-primary);
}

.site-nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 26px;
  height: var(--border-thick);
  background-color: var(--color-accent);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 180ms ease;
}

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

.site-nav a[aria-current="page"] { color: var(--color-accent); }
.site-nav a[aria-current="page"]::after { transform: scaleX(1); }

.nav-toggle {
  display: none;
  align-items: center;
  gap: var(--space-1);
  align-self: center;
  margin-block: var(--space-1);
  padding: calc(var(--space-1) * 1.25) var(--space-3);
  min-height: 44px;
  border: var(--border-thin) solid transparent;
  border-radius: var(--radius-pill);
  background-color: var(--color-surface-deep);
  color: var(--color-ink);
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: var(--weight-heading);
  cursor: pointer;
}

.nav-toggle__bars {
  display: grid;
  gap: 4px;
  width: 16px;
}

.nav-toggle__bars span {
  display: block;
  height: 2px;
  border-radius: var(--radius-pill);
  background-color: currentColor;
  transition: transform 160ms ease;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:first-child {
  transform: translateY(3px) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:last-child {
  transform: translateY(-3px) rotate(-45deg);
}

@keyframes nav-in {
  from { opacity: 0; transform: translateY(-5px); }
  to { opacity: 1; transform: none; }
}

@media (max-width: 899px) {
  .header-bar__inner { padding-top: var(--space-2); }
  .nav-toggle { order: 1; margin-left: auto; display: inline-flex; }
  .site-nav {
    order: 2;
    flex: 1 0 100%;
    display: none;
  }
  .site-nav[data-open="true"] {
    display: block;
    animation: nav-in 200ms ease both;
  }
  .site-nav__list {
    gap: var(--space-2);
    overflow-x: auto;
    padding-block: var(--space-2) var(--space-3);
    scrollbar-width: none;
  }
  .site-nav__list::-webkit-scrollbar { display: none; }
  .site-nav__list li { flex: none; }
  .site-nav a {
    flex-direction: column;
    justify-content: center;
    gap: 6px;
    width: 88px;
    min-height: 0;
    padding: var(--space-1) 0;
    font-size: var(--text-xs);
    text-align: center;
    color: var(--color-ink-soft);
  }
  .site-nav a::before {
    content: attr(data-index);
    display: grid;
    place-items: center;
    width: 46px;
    height: 46px;
    border-radius: var(--radius-lg);
    background-color: var(--color-primary-soft);
    color: var(--color-primary);
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    font-weight: 700;
  }
  .site-nav a::after { display: none; }
  .site-nav a[aria-current="page"] { color: var(--color-accent); }
  .site-nav a[aria-current="page"]::before {
    background-color: var(--color-accent);
    color: var(--color-accent-ink);
  }
}

@media (max-width: 639px) {
  .brand__name { display: none; }
  .brand__abbr { display: inline; }
  .rail-notes__item { display: none; }
}

/* ------------------------------------------------------------
   7. 页脚：卡片面板 + 深色几何
   ------------------------------------------------------------ */
.site-footer {
  position: relative;
  overflow: hidden;
  padding-block: var(--section-y-lg) var(--space-4);
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: -170px;
  right: -130px;
  width: 420px;
  height: 420px;
  border-radius: var(--radius-lg);
  border: var(--border-thick) solid color-mix(in srgb, var(--color-contrast-accent) 34%, transparent);
  pointer-events: none;
}

.site-footer::after {
  content: "";
  position: absolute;
  left: -70px;
  bottom: -110px;
  width: 240px;
  height: 240px;
  border-radius: var(--radius-lg);
  background-color: color-mix(in srgb, var(--color-primary) 26%, transparent);
  pointer-events: none;
}

.footer-grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--gutter);
}

.footer-card {
  grid-column: span 12;
  padding: var(--space-4);
  border: var(--border-thin) solid color-mix(in srgb, var(--color-contrast-ink) 13%, transparent);
  border-radius: 0;
  background-color: color-mix(in srgb, var(--color-contrast-ink) 7%, transparent);
}

@media (min-width: 900px) {
  .footer-card--venue { grid-column: span 7; }
  .footer-card--contact { grid-column: span 5; }
  .footer-card--rhythm { grid-column: span 4; }
  .footer-card--nav { grid-column: span 8; }
}

.footer-card__title {
  margin-bottom: var(--space-2);
  color: var(--color-contrast-ink);
  font-size: var(--text-lg);
}

.footer-card__title::before {
  content: "";
  display: block;
  width: 24px;
  height: var(--border-thick);
  margin-bottom: var(--space-2);
  background-color: var(--color-contrast-accent);
}

.footer-card__text {
  font-size: var(--text-sm);
  color: color-mix(in srgb, var(--color-contrast-ink) 78%, transparent);
}

.footer-marks {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2) var(--space-6);
  margin-top: var(--space-3);
}

.footer-marks li {
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: color-mix(in srgb, var(--color-contrast-ink) 70%, transparent);
}

.footer-marks__num {
  display: block;
  margin-bottom: 4px;
  font-family: var(--font-mono);
  font-size: var(--text-2xl);
  font-weight: 700;
  line-height: 1;
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.03em;
  color: var(--color-contrast-accent);
}

.contact-list {
  display: grid;
  gap: var(--space-2);
}

.contact-list__row {
  display: grid;
  gap: 6px;
  padding-top: var(--space-2);
  border-top: var(--border-thin) solid color-mix(in srgb, var(--color-contrast-ink) 14%, transparent);
}

.contact-list__row:first-child {
  padding-top: 0;
  border-top: 0;
}

.contact-list__key {
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent);
}

.contact-list__value {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-contrast-ink);
}

.copy-field {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  width: 100%;
  padding: var(--space-1) var(--space-2);
  border: 0;
  border-left: var(--border-thick) solid var(--color-contrast-accent);
  background-color: color-mix(in srgb, var(--color-contrast-accent) 13%, transparent);
  color: var(--color-contrast-ink);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  text-align: left;
  cursor: pointer;
  transition: background-color 140ms ease;
}

.copy-field:hover {
  background-color: color-mix(in srgb, var(--color-contrast-accent) 22%, transparent);
}

.copy-field__text {
  overflow-wrap: anywhere;
}

.copy-field__state {
  flex: none;
  font-family: var(--font-body);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: var(--color-contrast-accent);
}

.rhythm-figure {
  display: flex;
  align-items: baseline;
  gap: var(--space-2);
  margin-bottom: var(--space-2);
}

.rhythm-figure__num {
  font-family: var(--font-mono);
  font-size: var(--text-2xl);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
  color: var(--color-contrast-ink);
}

.rhythm-figure__unit {
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-contrast-accent);
}

.footer-nav {
  display: grid;
  gap: var(--space-3);
}

.footer-nav__list,
.footer-nav__legal {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1) var(--space-4);
}

.footer-nav a {
  position: relative;
  display: inline-block;
  padding-left: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-contrast-ink);
}

.footer-nav a::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: var(--border-thin);
  height: 12px;
  transform: translateY(-50%);
  background-color: var(--color-contrast-line);
}

.footer-nav a:hover { color: var(--color-contrast-accent); text-decoration: none; }

.footer-nav__legal {
  padding-top: var(--space-2);
  border-top: var(--border-thin) solid var(--color-contrast-line);
}

.footer-nav__legal a { color: var(--color-contrast-accent); }
.footer-nav__legal a::before { background-color: color-mix(in srgb, var(--color-contrast-accent) 55%, transparent); }

.footer-base {
  position: relative;
  z-index: 1;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-1) var(--space-3);
  margin-top: var(--space-6);
  padding-top: var(--space-3);
  border-top: var(--border-thin) solid var(--color-contrast-line);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: color-mix(in srgb, var(--color-contrast-ink) 68%, transparent);
}

/* ------------------------------------------------------------
   8. 显现动效
   ------------------------------------------------------------ */
.js-ready .reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 320ms ease, transform 320ms ease;
}

.js-ready .reveal.is-visible {
  opacity: 1;
  transform: none;
}

/* ------------------------------------------------------------
   9. 可访问性与降级
   ------------------------------------------------------------ */
@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;
  }
  .js-ready .reveal { opacity: 1 !important; transform: none !important; }
  .site-nav a::after { transition: none !important; }
}

@media (max-width: 479px) {
  :root { --gutter: 16px; }
  .rail-notes { font-size: var(--text-xs); }
  .footer-card { padding: var(--space-3); }
}