/* ==========================================================================
   乐鱼官网入口登录网 — 共享样式 /assets/site.css
   方向：展览画册式分块 · 夜场灯光色场 · 玻璃层与实色层并置
   ========================================================================== */

/* ---------- reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

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

ul, ol { list-style: none; }

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

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

button { background: none; border: 0; }

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

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

hr { border: 0; border-top: 1px solid var(--paper-300); }

:target { scroll-margin-top: calc(var(--header-h) + 16px); }

/* ---------- tokens ---------- */
:root {
  --blue-900: #071A2F;
  --blue-700: #0E2E4F;
  --blue-500: #17527F;
  --coral-500: #FF6A3D;
  --coral-200: #FFC7B0;
  --mint-400: #38F2C8;
  --paper-100: #F6F1E7;
  --paper-300: #E6DCCB;
  --ink-900: #101820;
  --ink-600: #46565F;
  --mist-300: #A9BCC9;
  --amber-500: #FFB020;

  --font-body: "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Heiti SC", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-data: "JetBrains Mono", "IBM Plex Mono", "SFMono-Regular", Menlo, Consolas, "Courier New", monospace;

  --header-h: 84px;
  --gutter: 96px;
  --gap: 24px;
  --radius: 14px;
  --cut: 20px;

  --shadow-1: 0 6px 18px rgba(7, 26, 47, .10);
  --shadow-2: 0 20px 44px rgba(7, 26, 47, .22);
  --shadow-mint: 0 0 26px rgba(56, 242, 200, .26);
  --ease: cubic-bezier(.22, .61, .36, 1);
  --focus: #38F2C8;
}

@media (max-width: 1280px) { :root { --gutter: 64px; } }
@media (max-width: 1024px) { :root { --gutter: 40px; --header-h: 70px; } }
@media (max-width: 640px)  { :root { --gutter: 20px; --header-h: 64px; --gap: 18px; } }

/* ---------- base ---------- */
body {
  font-family: var(--font-body);
  font-size: 16.5px;
  line-height: 1.75;
  letter-spacing: .01em;
  color: var(--ink-900);
  background: var(--paper-100);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

main { padding-top: var(--header-h); }
.main--flush { padding-top: 0; }

h1, h2, h3, h4 { line-height: 1.2; font-weight: 900; color: var(--ink-900); }
h1 { font-size: clamp(32px, 4.4vw, 56px); }
h2 { font-size: clamp(24px, 2.6vw, 36px); }
h3 { font-size: clamp(20px, 1.8vw, 26px); }
h4 { font-size: 18px; }

p { text-wrap: pretty; }

::selection { background: var(--mint-400); color: var(--blue-900); }

:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ---------- layout ---------- */
.container {
  width: 100%;
  max-width: 1360px;
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section { padding: clamp(56px, 7vw, 104px) 0; position: relative; }
.section--dark { background: var(--blue-900); color: var(--paper-100); }
.section--dark h1, .section--dark h2, .section--dark h3, .section--dark h4 { color: var(--paper-100); }
.section--dark p { color: var(--mist-300); }
.section--paper { background: var(--paper-100); color: var(--ink-900); }
.section--mist { background: linear-gradient(180deg, var(--paper-100) 0%, #EFE8DB 100%); }
.section--tight { padding: clamp(32px, 4vw, 56px) 0; }

.grid { display: grid; gap: var(--gap); }
.grid--7-5 { grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); }
.grid--5-7 { grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); }
.grid--8-4 { grid-template-columns: minmax(0, 8fr) minmax(0, 4fr); }

@media (max-width: 900px) {
  .grid--7-5, .grid--5-7, .grid--8-4 { grid-template-columns: minmax(0, 1fr); }
}

.wedge { position: relative; }
.wedge::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: 100%;
  height: clamp(28px, 4vw, 72px);
  background: var(--wedge-color, var(--paper-100));
  clip-path: polygon(0 0, 100% 0, 0 100%);
  pointer-events: none;
  z-index: 3;
}

/* ---------- typography helpers ---------- */
.display {
  display: inline-block;
  font-weight: 900;
  transform: skewX(-8deg);
  transform-origin: left center;
  letter-spacing: .015em;
}

.data-num {
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  letter-spacing: -.015em;
}

.chapter-mark {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-data);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .34em;
  text-transform: uppercase;
  color: var(--coral-500);
}
.chapter-mark::after {
  content: "";
  width: 46px;
  height: 1px;
  background: currentColor;
  opacity: .65;
}
.chapter-mark--on-dark { color: var(--mint-400); }

.reading { max-width: 46em; }
.prose { max-width: 42em; font-size: 16.5px; color: var(--ink-900); }
.prose p + p { margin-top: 16px; }
.prose strong { font-weight: 900; }
.section--dark .prose, .section--dark .reading { color: var(--mist-300); }

/* ---------- breadcrumbs ---------- */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 20px 0 0;
  font-size: 13px;
  color: var(--ink-600);
}
.breadcrumbs__item { display: inline-flex; align-items: center; gap: 8px; }
.breadcrumbs__link { color: var(--blue-500); font-weight: 600; }
.breadcrumbs__link:hover { color: var(--coral-500); }
.breadcrumbs__sep { color: var(--mist-300); }
.breadcrumbs__current { color: var(--ink-600); }
.breadcrumbs--on-dark { color: var(--mist-300); }
.breadcrumbs--on-dark .breadcrumbs__link { color: var(--mint-400); }
.breadcrumbs--on-dark .breadcrumbs__current { color: var(--paper-100); }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 24px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-size: 15px;
  font-weight: 700;
  line-height: 1.2;
  text-align: center;
  cursor: pointer;
  transition: transform .18s var(--ease), box-shadow .18s var(--ease),
              background-color .18s var(--ease), color .18s var(--ease),
              border-color .18s var(--ease);
}
.btn--sm { padding: 9px 17px; font-size: 13.5px; }
.btn--primary {
  background: var(--coral-500);
  color: #1A0B05;
  box-shadow: 0 8px 22px rgba(255, 106, 61, .30);
}
.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 14px 30px rgba(255, 106, 61, .42); }
.btn--mint { background: var(--mint-400); color: var(--blue-900); }
.btn--mint:hover { transform: translateY(-2px); box-shadow: var(--shadow-mint); }
.btn--ghost {
  background: transparent;
  color: var(--paper-100);
  border-color: rgba(246, 241, 231, .38);
}
.btn--ghost:hover { border-color: var(--mint-400); color: var(--mint-400); transform: translateY(-2px); }
.btn--dark { background: var(--blue-700); color: var(--paper-100); }
.btn--dark:hover { background: var(--blue-900); transform: translateY(-2px); }

/* ---------- cards / data ---------- */
.glass-card {
  background: rgba(23, 82, 127, .26);
  border: 1px solid rgba(169, 188, 201, .34);
  border-radius: var(--radius);
  padding: 22px 24px;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  color: var(--paper-100);
  transition: transform .22s var(--ease), box-shadow .22s var(--ease), border-color .22s var(--ease);
}
.glass-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-2); border-color: rgba(56, 242, 200, .5); }

.data-card {
  background: var(--paper-100);
  border: 1px solid var(--paper-300);
  border-radius: var(--radius);
  padding: 22px 24px;
  box-shadow: var(--shadow-1);
  transition: transform .22s var(--ease), box-shadow .22s var(--ease);
}
.data-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-2); }

.cut-corner {
  clip-path: polygon(var(--cut) 0, 100% 0, 100% 100%, 0 100%, 0 var(--cut));
  border-radius: 0;
}

.stat { display: flex; flex-direction: column; gap: 6px; }
.stat__value {
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: clamp(40px, 5.4vw, 84px);
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--mint-400);
}
.section--paper .stat__value, .section--mist .stat__value { color: var(--blue-700); }
.stat__label {
  font-size: 13px;
  letter-spacing: .16em;
  color: var(--ink-600);
}
.section--dark .stat__label { color: var(--mist-300); }
.stat--accent .stat__value { color: var(--coral-500); }

/* ---------- tags ---------- */
.tag-group { display: flex; flex-wrap: wrap; gap: 10px; }
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 15px;
  border-radius: 999px;
  border: 1px solid rgba(169, 188, 201, .42);
  background: var(--blue-500);
  color: var(--paper-100);
  font-size: 13.5px;
  font-weight: 600;
  letter-spacing: .02em;
  cursor: pointer;
  transition: transform .2s var(--ease), background-color .2s var(--ease),
              color .2s var(--ease), border-color .2s var(--ease);
}
.tag:hover { transform: translateY(-2px); }
.tag.is-active,
.tag[aria-pressed="true"] {
  background: var(--coral-500);
  color: #1A0B05;
  border-color: transparent;
}

/* ---------- fold ---------- */
.fold {
  border-left: 3px solid var(--coral-500);
  background: rgba(230, 220, 203, .42);
  border-radius: 0 12px 12px 0;
  padding: 12px 18px;
}
.fold > summary {
  cursor: pointer;
  list-style: none;
  font-weight: 700;
  color: var(--blue-700);
}
.fold > summary::-webkit-details-marker { display: none; }
.fold > summary::after {
  content: "＋";
  float: right;
  font-weight: 900;
  color: var(--coral-500);
}
.fold[open] > summary::after { content: "－"; }
.fold__body { margin-top: 10px; font-size: 15.5px; color: var(--ink-600); }

/* ---------- media frame ---------- */
.media-frame {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius);
  background:
    radial-gradient(circle at 22% 18%, rgba(56, 242, 200, .22), transparent 58%),
    linear-gradient(135deg, var(--blue-700) 0%, var(--blue-900) 100%);
  border: 1px solid rgba(169, 188, 201, .30);
  clip-path: polygon(var(--cut) 0, 100% 0, 100% 100%, 0 100%, 0 var(--cut));
}
.media-frame > img,
.media-frame > picture,
.media-frame > picture > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.media-frame--21x9 { aspect-ratio: 21 / 9; }
.media-frame--16x9 { aspect-ratio: 16 / 9; }
.media-frame--4x3 { aspect-ratio: 4 / 3; }
.media-frame--1x1 { aspect-ratio: 1 / 1; }
.media-frame--portrait { aspect-ratio: 3 / 4; }
.media-frame__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 16px 20px 14px;
  font-size: 13px;
  color: var(--paper-100);
  background: linear-gradient(180deg, rgba(7, 26, 47, 0), rgba(7, 26, 47, .88));
}

/* ==========================================================================
   HEADER
   ========================================================================== */
.skip-link {
  position: fixed;
  top: -120px;
  left: 16px;
  z-index: 300;
  padding: 10px 20px;
  border-radius: 0 0 12px 12px;
  background: var(--mint-400);
  color: var(--blue-900);
  font-weight: 700;
  transition: top .18s var(--ease);
}
.skip-link:focus { top: 0; }

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  color: var(--paper-100);
}
.site-header::before {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(7, 26, 47, .80);
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  border-bottom: 1px solid rgba(246, 241, 231, .12);
  transition: background-color .25s var(--ease), border-color .25s var(--ease),
              box-shadow .25s var(--ease);
  pointer-events: none;
}
.site-header.is-solid::before {
  background: rgba(14, 46, 79, .97);
  border-bottom-color: rgba(56, 242, 200, .34);
  box-shadow: 0 16px 34px rgba(4, 15, 28, .42);
}

.reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 140;
  pointer-events: none;
}
.reading-progress__bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--mint-400) 0%, var(--coral-500) 100%);
  box-shadow: 0 0 12px rgba(56, 242, 200, .65);
}

.site-header__bar { position: relative; z-index: 2; }

.site-header__inner {
  display: flex;
  align-items: center;
  gap: clamp(14px, 2.4vw, 40px);
  min-height: var(--header-h);
}

/* brand */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
  color: var(--paper-100);
}
.brand__mark {
  position: relative;
  flex: 0 0 auto;
  width: 34px;
  height: 34px;
  border-radius: 10px 4px 10px 4px;
  background: linear-gradient(135deg, var(--mint-400) 0%, var(--blue-500) 46%, var(--coral-500) 100%);
  box-shadow: 0 0 0 1px rgba(56, 242, 200, .45), 0 6px 18px rgba(56, 242, 200, .22);
}
.brand__mark::after {
  content: "";
  position: absolute;
  inset: 10px 9px;
  border-radius: 2px;
  background: var(--blue-900);
  opacity: .55;
  transform: skewX(-8deg);
}
.brand__mark--lg { width: 44px; height: 44px; }
.brand__mark--lg::after { inset: 14px 12px; }
.brand__text { display: flex; flex-direction: column; line-height: 1.16; }
.brand__name {
  display: inline-block;
  font-size: 17px;
  font-weight: 900;
  letter-spacing: .02em;
  transform: skewX(-8deg);
  transform-origin: left center;
}
.brand__note {
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--mist-300);
}

/* nav */
.nav {
  flex: 1 1 auto;
  display: flex;
  justify-content: center;
  align-items: center;
}
.nav__list {
  display: flex;
  align-items: center;
  gap: clamp(8px, 1.5vw, 26px);
}
.nav__item { display: flex; }
.nav__link {
  position: relative;
  display: inline-block;
  padding: 9px 2px;
  font-size: 15px;
  font-weight: 600;
  color: var(--paper-100);
  transition: color .2s var(--ease);
}
.nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 3px;
  height: 2px;
  background: var(--mint-400);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .2s var(--ease), background-color .2s var(--ease);
}
.nav__link:hover { color: var(--mint-400); }
.nav__link:hover::after { transform: scaleX(1); }
.nav__link[aria-current="page"] { color: var(--mint-400); }
.nav__link[aria-current="page"]::after { transform: scaleX(1); background: var(--coral-500); }

.nav__extra { display: none; }

/* header tools */
.header-tools {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: 12px;
}
.header-tools__links { display: flex; align-items: center; gap: 10px; }

.utility-link {
  display: inline-block;
  padding: 6px 12px;
  border-radius: 999px;
  border: 1px solid rgba(169, 188, 201, .30);
  font-size: 13px;
  color: var(--mist-300);
  transition: color .2s var(--ease), border-color .2s var(--ease), background-color .2s var(--ease);
}
.utility-link:hover {
  color: var(--paper-100);
  border-color: var(--mint-400);
  background: rgba(56, 242, 200, .10);
}

@media (max-width: 1180px) {
  .utility-link { display: none; }
}

/* nav toggle */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 8px 15px;
  border-radius: 999px;
  border: 1px solid rgba(169, 188, 201, .38);
  background: rgba(246, 241, 231, .07);
  color: var(--paper-100);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: border-color .2s var(--ease), background-color .2s var(--ease);
}
.nav-toggle:hover { border-color: var(--mint-400); }
.nav-toggle__bars {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
  width: 16px;
}
.nav-toggle__bars span {
  display: block;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform .2s var(--ease), width .2s var(--ease);
}
.nav-toggle__bars span:last-child { width: 68%; }
.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 { width: 100%; transform: translateY(-3px) rotate(-45deg); }

/* mobile nav panel */
@media (max-width: 1024px) {
  .nav-toggle { display: inline-flex; }

  .nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    display: block;
    justify-content: flex-start;
    background: rgba(7, 26, 47, .98);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(56, 242, 200, .22);
    padding: 10px var(--gutter) 26px;
    max-height: 0;
    overflow: hidden;
    visibility: hidden;
    transition: max-height .3s var(--ease), visibility .3s var(--ease);
    z-index: 3;
  }
  .nav[data-open="true"] {
    max-height: 76vh;
    overflow-y: auto;
    visibility: visible;
  }

  .nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }
  .nav__item { display: block; }
  .nav__link {
    display: block;
    padding: 15px 4px;
    font-size: 17px;
    border-bottom: 1px solid rgba(169, 188, 201, .16);
  }
  .nav__link::after { display: none; }
  .nav__link[aria-current="page"] {
    padding-left: 16px;
    border-left: 3px solid var(--coral-500);
    border-radius: 0 10px 10px 0;
    background: rgba(56, 242, 200, .07);
  }

  .nav__extra {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 20px;
    align-items: center;
  }
  .nav__extra-link {
    display: inline-block;
    padding: 8px 15px;
    border-radius: 999px;
    border: 1px solid rgba(169, 188, 201, .34);
    font-size: 13.5px;
    color: var(--paper-100);
  }
  .nav__extra-link:hover { border-color: var(--mint-400); color: var(--mint-400); }
}

/* diagnostic bar */
.diagnostic-bar {
  position: fixed;
  top: calc(var(--header-h) + 14px);
  right: var(--gutter);
  z-index: 95;
  width: min(390px, calc(100vw - var(--gutter) * 2));
  border: 1px solid var(--amber-500);
  border-radius: 14px;
  background: rgba(7, 26, 47, .92);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow: 0 18px 40px rgba(4, 15, 28, .42);
  color: var(--paper-100);
  overflow: hidden;
  transition: opacity .2s var(--ease), transform .2s var(--ease);
}
.diagnostic-bar[hidden] { display: none; }

.diagnostic-bar__row {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px 10px 15px;
}
.diagnostic-bar__pulse {
  flex: 0 0 auto;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--amber-500);
  animation: diagPulse 2.6s ease-out infinite;
}
@keyframes diagPulse {
  0%   { box-shadow: 0 0 0 0 rgba(255, 176, 32, .55); }
  70%  { box-shadow: 0 0 0 10px rgba(255, 176, 32, 0); }
  100% { box-shadow: 0 0 0 0 rgba(255, 176, 32, 0); }
}
.diagnostic-bar__text {
  flex: 1 1 auto;
  font-size: 13px;
  line-height: 1.5;
  color: var(--paper-100);
}
.diagnostic-bar__toggle {
  flex: 0 0 auto;
  padding: 5px 11px;
  border-radius: 999px;
  border: 1px solid rgba(255, 176, 32, .55);
  color: var(--amber-500);
  font-size: 12px;
  font-weight: 700;
  cursor: pointer;
  transition: background-color .2s var(--ease), color .2s var(--ease);
}
.diagnostic-bar__toggle:hover { background: var(--amber-500); color: var(--blue-900); }
.diagnostic-bar__close {
  flex: 0 0 auto;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  color: var(--mist-300);
  font-size: 18px;
  line-height: 1;
  cursor: pointer;
  transition: background-color .2s var(--ease), color .2s var(--ease);
}
.diagnostic-bar__close:hover { background: rgba(169, 188, 201, .18); color: var(--paper-100); }

.diagnostic-bar__panel {
  max-height: 0;
  padding: 0 16px;
  overflow: hidden;
  transition: max-height .28s var(--ease), padding .28s var(--ease);
}
.diagnostic-bar[data-open="true"] .diagnostic-bar__panel {
  max-height: 360px;
  padding: 0 16px 16px;
}
.diagnostic-list {
  counter-reset: diag;
  display: grid;
  gap: 8px;
  padding-top: 4px;
  border-top: 1px solid rgba(255, 176, 32, .28);
}
.diagnostic-list li {
  counter-increment: diag;
  position: relative;
  padding-left: 26px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--mist-300);
}
.diagnostic-list li::before {
  content: counter(diag);
  position: absolute;
  left: 0;
  top: 2px;
  width: 17px;
  height: 17px;
  border-radius: 50%;
  background: rgba(255, 176, 32, .18);
  color: var(--amber-500);
  font-family: var(--font-data);
  font-size: 10px;
  font-weight: 700;
  line-height: 17px;
  text-align: center;
}
.diagnostic-bar__link {
  display: inline-block;
  margin-top: 12px;
  font-size: 13px;
  font-weight: 700;
  color: var(--mint-400);
  border-bottom: 1px solid rgba(56, 242, 200, .5);
}
.diagnostic-bar__link:hover { color: var(--paper-100); border-bottom-color: var(--paper-100); }

@media (max-width: 768px) {
  .diagnostic-bar {
    left: 16px;
    right: 16px;
    width: auto;
    top: calc(var(--header-h) + 10px);
  }
  .diagnostic-bar__text { font-size: 12.5px; }
}

/* to top */
.to-top {
  position: fixed;
  right: 26px;
  bottom: 26px;
  z-index: 96;
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--blue-700);
  color: var(--mint-400);
  border: 1px solid rgba(56, 242, 200, .45);
  box-shadow: var(--shadow-2);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity .22s var(--ease), transform .22s var(--ease),
              visibility .22s var(--ease), background-color .2s var(--ease),
              color .2s var(--ease);
}
.to-top.is-visible { opacity: 1; visibility: visible; transform: translateY(0); }
.to-top:hover { background: var(--blue-900); color: var(--paper-100); }
.to-top__icon { font-size: 19px; line-height: 1; }
@media (max-width: 640px) {
  .to-top { right: 16px; bottom: 16px; width: 44px; height: 44px; }
}

/* ==========================================================================
   FOOTER
   ========================================================================== */
.site-footer {
  position: relative;
  overflow: hidden;
  margin-top: clamp(48px, 6vw, 96px);
  padding: clamp(56px, 6vw, 84px) 0 32px;
  background: var(--blue-900);
  color: var(--paper-100);
}
.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(56, 242, 200, .5), transparent);
}
.site-footer__glow {
  position: absolute;
  border-radius: 50%;
  pointer-events: none;
  filter: blur(6px);
}
.site-footer__glow--mint {
  top: -170px;
  left: -12%;
  width: 62%;
  height: 360px;
  background: radial-gradient(circle, rgba(56, 242, 200, .17), transparent 66%);
}
.site-footer__glow--coral {
  right: -14%;
  bottom: -190px;
  width: 58%;
  height: 380px;
  background: radial-gradient(circle, rgba(255, 106, 61, .15), transparent 66%);
}

.site-footer__inner { position: relative; z-index: 2; }

.site-footer__top {
  display: grid;
  grid-template-columns: minmax(0, 1.45fr) repeat(3, minmax(0, .82fr));
  gap: 44px 36px;
  padding-bottom: 44px;
  border-bottom: 1px solid rgba(169, 188, 201, .18);
}

.footer-brand { display: flex; flex-direction: column; gap: 10px; }
.footer-brand__name {
  font-size: 18px;
  font-weight: 900;
  letter-spacing: .02em;
  color: var(--paper-100);
  transform: skewX(-8deg);
  transform-origin: left center;
}
.footer-brand__note {
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--mist-300);
}
.footer-brand__desc {
  max-width: 26em;
  margin-top: 4px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist-300);
}

.footer-col { display: flex; flex-direction: column; gap: 14px; }
.footer-col__title {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .22em;
  color: var(--coral-500);
}
.footer-col__list { display: flex; flex-direction: column; gap: 10px; }
.footer-col__link {
  display: inline-block;
  font-size: 14.5px;
  color: var(--paper-100);
  transition: color .2s var(--ease), transform .2s var(--ease);
}
.footer-col__link:hover { color: var(--mint-400); transform: translateX(3px); }

.site-footer__contact {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 22px 36px;
  padding: 28px 0;
  border-bottom: 1px solid rgba(169, 188, 201, .18);
}
.footer-contact__item { display: flex; flex-direction: column; gap: 5px; }
.footer-contact__label {
  font-size: 11px;
  letter-spacing: .22em;
  color: var(--mint-400);
}
.footer-contact__value {
  font-size: 15px;
  font-weight: 600;
  line-height: 1.6;
  color: var(--paper-100);
  word-break: break-word;
}
.footer-contact__value--data {
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  letter-spacing: .01em;
}
.footer-contact__hint {
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--mist-300);
}

.site-footer__bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: flex-start;
  gap: 14px 32px;
  padding-top: 22px;
}
.footer-legal {
  flex: 1 1 480px;
  max-width: 60em;
  font-size: 12.5px;
  line-height: 1.75;
  color: var(--mist-300);
}
.footer-copy {
  flex: 0 0 auto;
  font-family: var(--font-data);
  font-size: 12.5px;
  color: var(--mist-300);
}

@media (max-width: 1024px) {
  .site-footer__top { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-brand { grid-column: 1 / -1; }
}
@media (max-width: 640px) {
  .site-footer__top { grid-template-columns: minmax(0, 1fr); gap: 32px; }
  .site-footer__contact { grid-template-columns: minmax(0, 1fr); }
  .site-footer__bottom { flex-direction: column; }
}

/* ==========================================================================
   reduced motion
   ========================================================================== */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
}