/* ============================================================
   乐鱼体育主站 · 共享样式表 /assets/site.css
   深海夜港蓝图体系：reset、变量、中文排版、页头、页脚、
   通用按钮、面包屑、正文容器、网格与基础组件
   ============================================================ */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: 140px;
}

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

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

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

a { color: inherit; }

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

button {
  background: none;
  border: 0;
  cursor: pointer;
}

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

:focus-visible {
  outline: 3px solid var(--neon-400);
  outline-offset: 3px;
}

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

/* ---------- 2. Tokens ---------- */
:root {
  --abyss-950: #031625;
  --abyss-800: #0A2C4A;
  --harbor-600: #125A8A;
  --tide-300: #7FC4E8;
  --coral-500: #FF6B45;
  --coral-200: #FFC9B8;
  --neon-400: #2EE6C0;
  --gold-400: #F0C24B;
  --sand-050: #F6F2EA;
  --ink-900: #0C1116;
  --paper-000: #FFFFFF;
  --muted-500: #5A6B7A;

  --sans: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --cond: "Noto Sans SC Condensed", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --mono: "JetBrains Mono", "Roboto Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --shell-max: 1320px;
  --gutter: clamp(18px, 4vw, 48px);
  --hair: 1px solid rgba(127, 196, 232, 0.26);
  --hair-ink: 1px solid rgba(12, 17, 22, 0.14);
  --grid-cell: 64px;
}

/* ---------- 3. Base typography ---------- */
body {
  background-color: var(--sand-050);
  background-image:
    linear-gradient(90deg, rgba(12, 17, 22, 0.05) 1px, transparent 1px),
    linear-gradient(0deg, rgba(12, 17, 22, 0.05) 1px, transparent 1px);
  background-size: var(--grid-cell) var(--grid-cell);
  color: var(--ink-900);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.8;
  letter-spacing: 0.004em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-family: var(--cond);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.08;
  text-wrap: balance;
}

h1 { font-size: clamp(40px, 7vw, 84px); }
h2 { font-size: clamp(30px, 4.4vw, 52px); }
h3 { font-size: clamp(22px, 2.6vw, 30px); }

p + p { margin-top: 1.2em; }

strong { font-weight: 700; }

::selection {
  background: var(--coral-500);
  color: var(--abyss-950);
}

.mono {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
  letter-spacing: 0.02em;
}

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

.blueprint {
  background-image:
    linear-gradient(90deg, rgba(127, 196, 232, 0.13) 1px, transparent 1px),
    linear-gradient(0deg, rgba(127, 196, 232, 0.13) 1px, transparent 1px);
  background-size: var(--grid-cell) var(--grid-cell);
}

.blueprint--paper {
  background-image:
    linear-gradient(90deg, rgba(12, 17, 22, 0.07) 1px, transparent 1px),
    linear-gradient(0deg, rgba(12, 17, 22, 0.07) 1px, transparent 1px);
  background-size: var(--grid-cell) var(--grid-cell);
}

.rule {
  height: 3px;
  border: 0;
  margin: 0;
  background: var(--ink-900);
}

/* ---------- 5. Skip link ---------- */
.skip-link {
  position: fixed;
  top: -80px;
  left: 16px;
  z-index: 200;
  padding: 12px 20px;
  background: var(--coral-500);
  color: var(--abyss-950);
  font: 700 15px/1 var(--sans);
  letter-spacing: 0.04em;
  text-decoration: none;
  border: 2px solid var(--abyss-950);
  transition: top 0.2s ease;
}

.skip-link:focus { top: 16px; }

/* ---------- 6. Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background-color: var(--abyss-950);
  color: var(--sand-050);
  border-bottom: 2px solid var(--abyss-800);
}

.scroll-progress {
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 3px;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--neon-400), var(--coral-500));
  z-index: 3;
  pointer-events: none;
}

.header-top {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  min-height: 84px;
  padding-block: 14px;
}

.brand-block {
  display: flex;
  align-items: center;
  gap: 20px;
  min-width: 0;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 13px;
  text-decoration: none;
  color: var(--sand-050);
  flex: none;
}

.brand__mark {
  position: relative;
  width: 34px;
  height: 34px;
  flex: none;
  background: var(--coral-500);
  clip-path: polygon(0 0, 100% 0, 100% 62%, 50% 100%, 0 62%);
}

.brand__mark::after {
  content: "";
  position: absolute;
  inset: 8px 8px 13px;
  background: var(--abyss-950);
  clip-path: polygon(0 0, 100% 0, 100% 58%, 50% 100%, 0 58%);
}

.brand__text {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 0;
}

.brand__word {
  font-family: var(--cond);
  font-weight: 900;
  font-size: 22px;
  line-height: 1;
  letter-spacing: -0.01em;
  white-space: nowrap;
}

.brand__sub {
  font-family: var(--mono);
  font-weight: 500;
  font-size: 10px;
  line-height: 1;
  letter-spacing: 0.22em;
  color: var(--tide-300);
  white-space: nowrap;
}

.brand__note {
  padding-left: 20px;
  border-left: var(--hair);
  font-family: var(--mono);
  font-size: 11px;
  line-height: 1.6;
  letter-spacing: 0.16em;
  color: rgba(127, 196, 232, 0.78);
}

.header-nav-wrap {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-left: auto;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  border: 2px solid rgba(127, 196, 232, 0.55);
  color: var(--tide-300);
  font: 700 14px/1 var(--sans);
  letter-spacing: 0.08em;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
}

.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: currentColor;
}

.nav-toggle__bars::before { top: -6px; }
.nav-toggle__bars::after { top: 6px; }

.nav-toggle[aria-expanded="true"] {
  background: var(--coral-500);
  border-color: var(--coral-500);
  color: var(--abyss-950);
}

.nav-toggle__label { white-space: nowrap; }

.nav-dock { display: block; }

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

.nav-link {
  display: block;
  padding: 10px 13px;
  font-family: var(--sans);
  font-weight: 600;
  font-size: 16px;
  line-height: 1.2;
  color: #CDE4F1;
  text-decoration: none;
  border-bottom: 3px solid transparent;
  transition: color 0.2s ease, background 0.2s ease, border-color 0.2s ease;
}

.nav-link:hover {
  color: #FFFFFF;
  background: rgba(18, 90, 138, 0.6);
  border-bottom-color: var(--neon-400);
}

.nav-link[aria-current="page"] {
  color: #FFFFFF;
  background: var(--harbor-600);
  border-bottom-color: var(--coral-500);
}

/* 直达窄带 */
.direct-rail {
  position: relative;
  background: var(--abyss-800);
  border-top: var(--hair);
  border-bottom: 2px solid var(--abyss-950);
}

.direct-rail::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 6px;
  background-image: repeating-linear-gradient(90deg, rgba(127, 196, 232, 0.45) 0 1px, transparent 1px 16px);
  pointer-events: none;
}

.direct-rail__inner {
  display: flex;
  align-items: center;
  gap: 12px;
  padding-block: 9px;
}

.direct-rail__label {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 11px;
  line-height: 1;
  letter-spacing: 0.24em;
  color: var(--tide-300);
}

.direct-rail__meta {
  margin-left: auto;
  font-family: var(--mono);
  font-size: 12px;
  line-height: 1.5;
  letter-spacing: 0.12em;
  color: rgba(127, 196, 232, 0.8);
}

.rail-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 8px 14px;
  border: 2px solid rgba(46, 230, 192, 0.55);
  color: var(--neon-400);
  font-family: var(--sans);
  font-weight: 700;
  font-size: 14px;
  line-height: 1;
  letter-spacing: 0.04em;
  text-decoration: none;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.rail-btn:hover {
  background: var(--neon-400);
  border-color: var(--neon-400);
  color: var(--abyss-950);
}

.rail-btn--alt {
  border-color: rgba(255, 107, 69, 0.6);
  color: var(--coral-200);
}

.rail-btn--alt:hover {
  background: var(--coral-500);
  border-color: var(--coral-500);
  color: var(--abyss-950);
}

.rail-btn__idx {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 11px;
  letter-spacing: 0.1em;
  opacity: 0.8;
}

/* 滚动收窄状态 */
.site-header[data-condensed] .header-top {
  min-height: 56px;
  padding-block: 3px;
}

.site-header[data-condensed] .brand__mark { width: 22px; height: 22px; }
.site-header[data-condensed] .brand__word { font-size: 17px; }
.site-header[data-condensed] .brand__sub,
.site-header[data-condensed] .brand__note { display: none; }
.site-header[data-condensed] .nav-link { font-size: 13px; padding: 6px 10px; }
.site-header[data-condensed] .direct-rail__inner { padding-block: 5px; }
.site-header[data-condensed] .rail-btn { padding: 5px 10px; font-size: 12px; }
.site-header[data-condensed] .direct-rail__meta { display: none; }
.site-header[data-condensed] .direct-rail::after { height: 0; }

/* ---------- 7. Footer ---------- */
.site-footer {
  position: relative;
  margin-top: 0;
  background-color: var(--abyss-950);
  color: var(--sand-050);
  border-top: 3px solid var(--coral-500);
}

.footer-grid {
  display: grid;
  gap: 44px;
  padding-block: 60px 36px;
}

.footer-brand__line {
  margin-top: 20px;
  max-width: 34ch;
  font-size: 16px;
  line-height: 1.85;
  color: #B9CFDC;
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 32px;
}

.footer-col__title {
  margin-bottom: 16px;
  font-family: var(--mono);
  font-weight: 700;
  font-size: 12px;
  line-height: 1;
  letter-spacing: 0.2em;
  color: var(--tide-300);
}

.footer-list {
  display: flex;
  flex-direction: column;
  gap: 11px;
}

.footer-link {
  display: inline-block;
  font-family: var(--sans);
  font-weight: 500;
  font-size: 16px;
  line-height: 1.5;
  color: var(--sand-050);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.footer-link:hover {
  color: var(--coral-500);
  border-bottom-color: var(--coral-500);
}

.footer-link[aria-current="page"] {
  color: var(--coral-200);
  border-bottom-color: var(--coral-200);
}

.footer-contact {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 40px;
  padding-block: 24px;
  border-top: var(--hair);
  font-family: var(--mono);
  font-size: 14px;
  line-height: 1.7;
  letter-spacing: 0.02em;
}

.footer-contact__item {
  display: inline-flex;
  align-items: baseline;
  gap: 10px;
}

.footer-contact__key {
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--tide-300);
}

.footer-contact__val { color: var(--paper-000); }

.footer-base {
  background: rgba(10, 44, 74, 0.62);
  border-top: var(--hair);
}

.footer-base__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 30px;
  padding-block: 16px;
  font-family: var(--mono);
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: 0.12em;
  color: var(--tide-300);
}

.footer-base__place { color: var(--neon-400); }
.footer-base__copy { margin-left: auto; }

/* ---------- 8. Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 15px 24px;
  border: 2px solid transparent;
  font-family: var(--sans);
  font-weight: 700;
  font-size: 16px;
  line-height: 1;
  letter-spacing: 0.03em;
  text-decoration: none;
  transition: transform 0.18s ease, background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.btn:hover { transform: translate(-2px, -2px); }

.btn--coral {
  background: var(--coral-500);
  border-color: var(--coral-500);
  color: var(--abyss-950);
  box-shadow: 5px 5px 0 rgba(46, 230, 192, 0.4);
}

.btn--coral:hover {
  background: var(--coral-200);
  border-color: var(--coral-200);
}

.btn--ghost {
  background: transparent;
  border-color: rgba(127, 196, 232, 0.6);
  color: var(--tide-300);
}

.btn--ghost:hover {
  background: var(--neon-400);
  border-color: var(--neon-400);
  color: var(--abyss-950);
}

.btn--dark {
  background: var(--abyss-950);
  border-color: var(--abyss-950);
  color: var(--sand-050);
  box-shadow: 5px 5px 0 rgba(255, 107, 69, 0.45);
}

.btn--dark:hover {
  background: var(--abyss-800);
  border-color: var(--abyss-800);
}

/* ---------- 9. Breadcrumb & prose ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.5;
  letter-spacing: 0.08em;
  color: var(--muted-500);
}

.breadcrumb__item { display: inline-flex; align-items: center; gap: 10px; }

.breadcrumb a {
  color: var(--harbor-600);
  text-decoration: none;
  border-bottom: 1px solid rgba(18, 90, 138, 0.4);
}

.breadcrumb a:hover {
  color: var(--coral-500);
  border-bottom-color: var(--coral-500);
}

.breadcrumb__sep { color: var(--tide-300); }

.prose { max-width: 72ch; }
.prose h2 { margin-top: 1.6em; margin-bottom: 0.5em; font-size: clamp(26px, 3vw, 38px); }
.prose h3 { margin-top: 1.4em; margin-bottom: 0.4em; }
.prose ul, .prose ol { margin: 1em 0; padding-left: 1.4em; }
.prose ul li { list-style: none; position: relative; padding-left: 1.1em; }
.prose ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 8px;
  height: 2px;
  background: var(--coral-500);
}
.prose ol { list-style: decimal; }
.prose ol li { padding-left: 0.3em; margin-bottom: 0.4em; }
.prose a {
  color: var(--harbor-600);
  text-decoration: none;
  border-bottom: 2px solid rgba(18, 90, 138, 0.35);
}
.prose a:hover { color: var(--coral-500); border-bottom-color: var(--coral-500); }

/* ---------- 10. Page grid & rails ---------- */
.page-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 36px;
  align-items: start;
}

.canvas { min-width: 0; }

.rail-index {
  position: relative;
  align-self: start;
  padding-left: 16px;
  border-left: var(--hair-ink);
}

.rail-data {
  align-self: start;
  padding-left: 14px;
  border-left: var(--hair-ink);
  font-family: var(--mono);
  font-size: 12px;
  line-height: 1.8;
  letter-spacing: 0.1em;
  color: var(--muted-500);
}

@media (min-width: 1080px) {
  .page-grid--railed {
    grid-template-columns: 200px minmax(0, 1fr) 188px;
    gap: 44px;
  }

  .rail-index,
  .rail-data {
    position: sticky;
    top: 132px;
  }
}

/* ---------- 11. TOC ---------- */
.toc {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.toc__title {
  margin-bottom: 12px;
  font-family: var(--mono);
  font-weight: 700;
  font-size: 11px;
  line-height: 1;
  letter-spacing: 0.22em;
  color: var(--muted-500);
}

.toc__link {
  display: block;
  margin-left: -17px;
  padding: 7px 0 7px 16px;
  border-left: 3px solid transparent;
  font-family: var(--sans);
  font-weight: 600;
  font-size: 14px;
  line-height: 1.5;
  color: var(--muted-500);
  text-decoration: none;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.toc__link:hover { color: var(--harbor-600); }

.toc__link.is-active,
.toc__link[aria-current="true"] {
  color: var(--ink-900);
  border-left-color: var(--coral-500);
}

/* ---------- 12. Panels, stats, tracks ---------- */
.panel {
  border: 3px solid var(--abyss-950);
  background: var(--paper-000);
  box-shadow: 10px 10px 0 rgba(18, 90, 138, 0.22);
  padding: 26px;
}

.panel--dark {
  background: var(--abyss-800);
  color: var(--sand-050);
  border-color: var(--abyss-950);
  box-shadow: 10px 10px 0 rgba(255, 107, 69, 0.38);
}

.panel__label {
  display: inline-block;
  margin-bottom: 14px;
  font-family: var(--mono);
  font-weight: 700;
  font-size: 12px;
  line-height: 1;
  letter-spacing: 0.18em;
  color: var(--coral-500);
}

.stat {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.stat__value {
  font-family: var(--mono);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  font-size: clamp(40px, 6vw, 72px);
  line-height: 0.95;
  letter-spacing: -0.02em;
  color: var(--gold-400);
}

.stat__label {
  font-family: var(--sans);
  font-weight: 500;
  font-size: 13px;
  line-height: 1.6;
  letter-spacing: 0.06em;
  color: var(--tide-300);
}

.track {
  display: flex;
  gap: 16px;
  overflow-x: auto;
  padding-bottom: 14px;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
  scrollbar-color: var(--coral-500) rgba(127, 196, 232, 0.25);
  scrollbar-width: thin;
}

.track:focus-visible { outline: 3px solid var(--neon-400); outline-offset: 4px; }

.track__card {
  flex: 0 0 min(320px, 78vw);
  scroll-snap-align: start;
  padding: 20px;
  background: var(--paper-000);
  border: 2px solid var(--abyss-950);
  border-top: 6px solid var(--harbor-600);
  box-shadow: 7px 7px 0 rgba(12, 17, 22, 0.14);
}

/* ---------- 13. Section heads & annotations ---------- */
.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px;
  padding-bottom: 14px;
  margin-bottom: 26px;
  border-bottom: 3px solid var(--abyss-950);
}

.section-head__title {
  font-family: var(--cond);
  font-weight: 900;
  font-size: clamp(26px, 3.4vw, 42px);
  line-height: 1.05;
  letter-spacing: -0.02em;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--mono);
  font-weight: 700;
  font-size: 12px;
  line-height: 1;
  letter-spacing: 0.2em;
  color: var(--coral-500);
}

.eyebrow::before {
  content: "";
  width: 28px;
  height: 2px;
  background: currentColor;
}

.annotation {
  font-family: var(--mono);
  font-size: 12px;
  line-height: 1.75;
  letter-spacing: 0.1em;
  color: var(--muted-500);
}

.annotation--invert { color: var(--tide-300); }

.tag {
  display: inline-block;
  padding: 5px 10px;
  font-family: var(--mono);
  font-weight: 600;
  font-size: 12px;
  line-height: 1.4;
  letter-spacing: 0.08em;
  color: var(--abyss-950);
  background: var(--coral-200);
  border: 1px solid var(--coral-500);
}

.tag--neon {
  background: rgba(46, 230, 192, 0.2);
  border-color: var(--neon-400);
  color: #0A5A4B;
}

/* ---------- 14. Media frames (页面阶段放置图片) ---------- */
.media-frame {
  position: relative;
  width: 100%;
  overflow: hidden;
  background-color: var(--abyss-800);
  background-image:
    linear-gradient(135deg, rgba(18, 90, 138, 0.85), rgba(3, 22, 37, 0.95)),
    linear-gradient(90deg, rgba(127, 196, 232, 0.16) 1px, transparent 1px),
    linear-gradient(0deg, rgba(127, 196, 232, 0.16) 1px, transparent 1px);
  background-size: auto, 48px 48px, 48px 48px;
  border: 2px solid rgba(127, 196, 232, 0.35);
}

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

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

.media-frame__caption {
  position: absolute;
  left: 0;
  bottom: 0;
  max-width: 100%;
  padding: 7px 12px;
  background: rgba(3, 22, 37, 0.88);
  color: var(--tide-300);
  font-family: var(--mono);
  font-size: 12px;
  line-height: 1.5;
  letter-spacing: 0.1em;
}

.media-frame__tag {
  position: absolute;
  top: 0;
  right: 0;
  padding: 6px 11px;
  background: var(--neon-400);
  color: var(--abyss-950);
  font-family: var(--mono);
  font-weight: 700;
  font-size: 11px;
  line-height: 1.4;
  letter-spacing: 0.12em;
}

/* ---------- 15. Reveal & back-to-top ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.55s ease, transform 0.55s ease;
}

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

.to-top {
  position: fixed;
  right: 20px;
  bottom: 26px;
  z-index: 80;
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 11px 14px;
  background: var(--abyss-950);
  color: var(--coral-200);
  border: 2px solid var(--coral-500);
  box-shadow: 6px 6px 0 rgba(3, 22, 37, 0.5);
  font-family: var(--mono);
  font-weight: 600;
  font-size: 13px;
  line-height: 1;
  letter-spacing: 0.1em;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity 0.24s ease, transform 0.24s ease, visibility 0.24s ease, background 0.2s ease, color 0.2s ease;
}

.to-top[data-visible] {
  opacity: 1;
  visibility: visible;
  transform: none;
}

.to-top:hover {
  background: var(--coral-500);
  color: var(--abyss-950);
}

.to-top__arrow {
  width: 0;
  height: 0;
  border-left: 5px solid transparent;
  border-right: 5px solid transparent;
  border-bottom: 7px solid currentColor;
}

.to-top__text { white-space: nowrap; }

/* ---------- 16. Responsive ---------- */
@media (max-width: 1180px) {
  .brand__note { display: none; }
}

@media (max-width: 900px) {
  body { padding-bottom: 66px; }

  .header-top {
    min-height: 68px;
    gap: 14px;
    padding-block: 10px;
  }

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

  .nav-dock {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    z-index: 5;
    max-height: 72vh;
    overflow-y: auto;
    padding: 10px var(--gutter) 20px;
    background-color: var(--abyss-800);
    border-top: var(--hair);
    border-bottom: 3px solid var(--abyss-950);
  }

  .nav-dock[data-open] { display: block; }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .nav-link {
    padding: 15px 12px;
    border-bottom: 1px solid rgba(127, 196, 232, 0.16);
    border-left: 3px solid transparent;
  }

  .nav-link:hover { border-bottom-color: rgba(127, 196, 232, 0.16); }
  .nav-link[aria-current="page"] { border-left-color: var(--coral-500); }

  .site-header[data-condensed] .nav-link {
    font-size: 15px;
    padding: 15px 12px;
  }

  .direct-rail {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 70;
    border-top: 3px solid var(--coral-500);
    border-bottom: 0;
  }

  .direct-rail::after { display: none; }

  .direct-rail__inner {
    gap: 10px;
    padding-block: 10px;
  }

  .direct-rail__label,
  .direct-rail__meta { display: none; }

  .rail-btn {
    flex: 1 1 0;
    justify-content: center;
    padding: 10px 12px;
    font-size: 15px;
  }

  .site-header[data-condensed] .direct-rail__inner { padding-block: 10px; }
  .site-header[data-condensed] .rail-btn { padding: 10px 12px; font-size: 15px; }

  .footer-grid { padding-block: 44px 30px; gap: 34px; }
  .footer-base__copy { margin-left: 0; }

  .to-top { right: 14px; bottom: 82px; }
}

@media (max-width: 620px) {
  body { font-size: 16px; }

  .brand__word { font-size: 19px; }
  .brand__sub { font-size: 9px; letter-spacing: 0.18em; }

  .footer-links { grid-template-columns: minmax(0, 1fr); }
  .footer-contact { flex-direction: column; gap: 10px; }
  .footer-base__inner { font-size: 11px; letter-spacing: 0.08em; }

  .panel { padding: 20px; box-shadow: 7px 7px 0 rgba(18, 90, 138, 0.22); }
  .panel--dark { box-shadow: 7px 7px 0 rgba(255, 107, 69, 0.38); }
  .track__card { flex-basis: 84vw; }
}

/* ---------- 17. Reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }

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

  .scroll-progress { transition: none; }
}