:root {
  --ink-900: #071528;
  --ink-700: #0F2540;
  --ink-500: #1B3A5C;
  --cyan-400: #2ED3E0;
  --cyan-200: #A8EEF5;
  --amber-500: #E8A33D;
  --amber-200: #F7DFAE;
  --mist-50: #F4F7FA;
  --slate-400: #7C8FA3;
  --slate-700: #33465C;
  --teal-500: #3FB89A;
  --clay-500: #D8624F;

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

  --radius-lg: 22px;
  --radius-md: 16px;
  --radius-pill: 999px;

  --wrap: 1240px;
  --wrap-wide: 1440px;

  --shadow-soft: 0 18px 40px -28px rgba(7, 21, 40, 0.75);
  --shadow-card: 0 10px 26px -18px rgba(7, 21, 40, 0.55);
  --focus: 0 0 0 3px rgba(46, 211, 224, 0.55);

  --ease-out: cubic-bezier(0.22, 0.61, 0.36, 1);
  --dur: 260ms;
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 96px;
}

body {
  margin: 0;
  background: var(--mist-50);
  color: var(--slate-700);
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.85;
  font-weight: 400;
  letter-spacing: 0.005em;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0 0 0.6em;
  color: var(--ink-900);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.25;
}
h1 { font-size: 56px; }
h2 { font-size: 32px; }
h3 { font-size: 22px; }
p { margin: 0 0 1em; }
p:last-child { margin-bottom: 0; }

a { color: var(--ink-700); text-decoration: none; transition: color var(--dur) var(--ease-out); }
a:hover { color: var(--cyan-400); }

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

button { font: inherit; color: inherit; }

:focus-visible {
  outline: none;
  box-shadow: var(--focus);
  border-radius: 6px;
}

.mono,
.anchor-figure { font-family: var(--font-mono); font-weight: 600; letter-spacing: -0.01em; }

.skip-link {
  position: absolute;
  left: 16px;
  top: -80px;
  z-index: 200;
  padding: 10px 18px;
  background: var(--cyan-400);
  color: var(--ink-900);
  border-radius: var(--radius-pill);
  font-size: 14px;
  font-weight: 700;
  transition: top var(--dur) var(--ease-out);
}
.skip-link:focus { top: 16px; color: var(--ink-900); }

/* ---------- layout ---------- */
.container {
  width: 100%;
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 24px;
}
.container--wide { max-width: var(--wrap-wide); }

.section { padding: 88px 0; }
.section--dark { background: var(--ink-900); color: var(--cyan-200); }
.section--dark h1, .section--dark h2, .section--dark h3 { color: #fff; }
.section--ink { background: var(--ink-700); color: #DCE7F2; }
.section--mist { background: var(--mist-50); }
.section--tight { padding: 48px 0; }

.grid { display: grid; gap: 24px; }
.grid--12 { grid-template-columns: repeat(12, minmax(0, 1fr)); }
.col { min-width: 0; }
.col--3 { grid-column: span 3; }
.col--4 { grid-column: span 4; }
.col--5 { grid-column: span 5; }
.col--7 { grid-column: span 7; }
.col--8 { grid-column: span 8; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 14px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--slate-400);
}
.eyebrow::before {
  content: "";
  width: 26px;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--cyan-400), var(--amber-500));
}
.section--dark .eyebrow { color: var(--cyan-200); }

.anchor-figure {
  display: block;
  font-size: 44px;
  line-height: 1.1;
  color: var(--amber-500);
}

/* ---------- note rail ---------- */
.note-rail {
  border-left: 1px solid rgba(124, 143, 163, 0.35);
  padding-left: 18px;
}
.note-rail__label {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.18em;
  color: var(--slate-400);
}
.note-rail__index {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  letter-spacing: 0.18em;
  font-size: 12px;
  color: var(--slate-400);
  margin-top: 12px;
}
.section--dark .note-rail { border-left-color: rgba(168, 238, 245, 0.3); }
.section--dark .note-rail__label,
.section--dark .note-rail__index { color: var(--cyan-200); }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 26px;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  font-size: 15px;
  font-weight: 600;
  line-height: 1.2;
  cursor: pointer;
  background: transparent;
  color: var(--ink-900);
  transition: transform var(--dur) var(--ease-out), background-color var(--dur) var(--ease-out), color var(--dur) var(--ease-out), border-color var(--dur) var(--ease-out), box-shadow var(--dur) var(--ease-out);
}
.btn:hover { transform: translateY(-2px); }
.btn--sm { padding: 10px 20px; font-size: 14px; }
.btn--primary {
  background: var(--cyan-400);
  color: var(--ink-900);
  border-color: var(--cyan-400);
}
.btn--primary:hover { background: var(--cyan-200); border-color: var(--cyan-200); color: var(--ink-900); }
.btn--gold {
  background: linear-gradient(120deg, rgba(232, 163, 61, 0.16), rgba(46, 211, 224, 0.14));
  border-color: var(--amber-500);
  color: var(--amber-500);
}
.btn--gold:hover { background: var(--amber-500); color: var(--ink-900); border-color: var(--amber-500); }
.btn--ghost {
  border-color: rgba(124, 143, 163, 0.5);
  color: var(--ink-700);
}
.btn--ghost:hover { border-color: var(--cyan-400); color: var(--cyan-400); }
.section--dark .btn--ghost { border-color: rgba(168, 238, 245, 0.4); color: var(--cyan-200); }
.section--dark .btn--ghost:hover { border-color: var(--cyan-400); color: var(--cyan-400); }

/* ---------- breadcrumb ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 18px 0 0;
  font-size: 13px;
  color: var(--slate-400);
}
.breadcrumb__item { color: var(--slate-400); }
.breadcrumb__item a { color: var(--slate-400); }
.breadcrumb__item a:hover { color: var(--cyan-400); }
.breadcrumb__item[aria-current="page"] { color: var(--ink-700); font-weight: 600; }
.breadcrumb__sep { color: rgba(124, 143, 163, 0.6); }

/* ---------- card / tag ---------- */
.card {
  background: #fff;
  border: 1px solid rgba(124, 143, 163, 0.22);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  padding: 26px;
  transition: transform var(--dur) var(--ease-out), box-shadow var(--dur) var(--ease-out), border-color var(--dur) var(--ease-out);
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-soft); border-color: rgba(46, 211, 224, 0.5); }
.card__body { color: var(--slate-700); }
.card__title { font-size: 22px; margin-bottom: 8px; }
.card__meta { font-size: 13px; color: var(--slate-400); letter-spacing: 0.06em; }
.section--dark .card,
.section--ink .card {
  background: rgba(27, 58, 92, 0.55);
  border-color: rgba(168, 238, 245, 0.18);
  color: #DCE7F2;
}
.section--dark .card__title,
.section--ink .card__title { color: #fff; }

.tag {
  display: inline-flex;
  align-items: center;
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  background: rgba(46, 211, 224, 0.14);
  color: var(--ink-700);
}
.tag--cyan { background: rgba(46, 211, 224, 0.18); color: #0E6E77; }
.tag--teal { background: rgba(63, 184, 154, 0.18); color: #22795F; }
.tag--clay { background: rgba(216, 98, 79, 0.16); color: #9E3B2C; }
.section--dark .tag--cyan { background: rgba(46, 211, 224, 0.22); color: var(--cyan-200); }

/* ---------- media placeholders ---------- */
.media {
  position: relative;
  display: block;
  width: 100%;
  overflow: hidden;
  border-radius: var(--radius-lg);
  background:
    linear-gradient(135deg, rgba(46, 211, 224, 0.14), rgba(232, 163, 61, 0.12)),
    var(--ink-700);
  aspect-ratio: 16 / 9;
}
.media--frame { border: 1px solid rgba(168, 238, 245, 0.25); }
.media--plan { aspect-ratio: 4 / 3; }
.media--grid {
  background-image:
    linear-gradient(rgba(168, 238, 245, 0.16) 1px, transparent 1px),
    linear-gradient(90deg, rgba(168, 238, 245, 0.16) 1px, transparent 1px);
  background-size: 32px 32px, 32px 32px;
  background-color: var(--ink-900);
}
.media > img { width: 100%; height: 100%; object-fit: cover; display: block; }
.media--tall { aspect-ratio: 3 / 4; }
.media--square { aspect-ratio: 1 / 1; }

/* ---------- reveal / to-top ---------- */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity 320ms var(--ease-out), transform 320ms var(--ease-out); }
.reveal.is-visible { opacity: 1; transform: none; }

.to-top {
  position: fixed;
  right: 22px;
  bottom: 24px;
  z-index: 90;
  width: 46px;
  height: 46px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(46, 211, 224, 0.5);
  border-radius: var(--radius-pill);
  background: rgba(7, 21, 40, 0.9);
  cursor: pointer;
  transition: transform var(--dur) var(--ease-out), background-color var(--dur) var(--ease-out);
}
.to-top[hidden] { display: none; }
.to-top:hover { transform: translateY(-4px); background: var(--ink-700); }
.to-top__arrow {
  width: 10px;
  height: 10px;
  border-left: 2px solid var(--cyan-400);
  border-top: 2px solid var(--cyan-400);
  transform: rotate(45deg) translate(1px, 1px);
}

/* ---------- header ---------- */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: background-color 320ms var(--ease-out), border-color 320ms var(--ease-out), box-shadow 320ms var(--ease-out);
}
.site-header .header__inner { color: var(--mist-50); }
.site-header .brand__name,
.site-header .link-reset { color: #fff; }
.site-header .nav__link { color: rgba(244, 247, 250, 0.82); }
.site-header .nav__link:hover { color: var(--cyan-400); }
.site-header .nav__link[aria-current="page"],
.site-header .nav__link.is-current { color: var(--cyan-400); }
.site-header .nav__link[aria-current="page"]::after,
.site-header .nav__link.is-current::after { transform: scaleX(1); }
.site-header .brand__suffix { color: var(--cyan-200); }
.site-header .nav-toggle__bar { background: #fff; }
.site-header .nav-toggle__label { color: rgba(244, 247, 250, 0.9); }

.site-header[data-state="solid"] {
  background: rgba(7, 21, 40, 0.96);
  border-bottom-color: rgba(46, 211, 224, 0.24);
  box-shadow: 0 16px 34px -30px rgba(0, 0, 0, 0.9);
}

.header__progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background: rgba(124, 143, 163, 0.25);
  overflow: hidden;
}
.progress__bar {
  display: block;
  height: 100%;
  width: 100%;
  transform-origin: 0 50%;
  transform: scaleX(var(--progress, 0));
  background: linear-gradient(90deg, var(--cyan-400), var(--amber-500));
  transition: transform 120ms linear;
}

.header__inner {
  position: relative;
  display: flex;
  align-items: center;
  gap: 22px;
  min-height: 78px;
}

.header__brand { display: inline-flex; align-items: center; gap: 12px; color: #fff; }
.header__brand:hover { color: var(--cyan-400); }
.brand__mark {
  width: 34px;
  height: 34px;
  flex: 0 0 auto;
  border-radius: 10px 18px 10px 18px;
  background: linear-gradient(135deg, var(--cyan-400), var(--ink-500));
  box-shadow: inset 0 0 0 1px rgba(168, 238, 245, 0.4);
  position: relative;
}
.brand__mark::after {
  content: "";
  position: absolute;
  inset: 9px;
  border-radius: var(--radius-pill);
  border: 2px solid rgba(7, 21, 40, 0.6);
}
.brand__mark--footer { background: linear-gradient(135deg, var(--amber-500), var(--ink-500)); }
.brand__text { display: flex; flex-direction: column; line-height: 1.15; }
.brand__name { font-size: 18px; font-weight: 800; letter-spacing: -0.01em; }
.brand__suffix { font-size: 11px; font-weight: 600; letter-spacing: 0.22em; }

.header__tagline {
  margin: 0;
  padding-left: 18px;
  border-left: 1px solid rgba(168, 238, 245, 0.28);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--cyan-200);
}

.nav { margin-left: auto; display: flex; align-items: center; gap: 18px; }
.nav__list { display: flex; align-items: center; gap: 6px; }
.nav__link {
  position: relative;
  display: inline-block;
  padding: 8px 12px;
  font-size: 15px;
  font-weight: 500;
  border-radius: var(--radius-pill);
  transition: color var(--dur) var(--ease-out), background-color var(--dur) var(--ease-out);
}
.nav__link::after {
  content: "";
  position: absolute;
  left: 12px;
  right: 12px;
  bottom: 2px;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--cyan-400), var(--amber-500));
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform var(--dur) var(--ease-out);
}
.nav__link:hover { background: rgba(46, 211, 224, 0.1); }

.nav__cta { display: none; }
.header__cta { flex: 0 0 auto; }

.nav-toggle {
  display: none;
  align-items: center;
  gap: 6px;
  padding: 10px 14px;
  border: 1px solid rgba(168, 238, 245, 0.35);
  border-radius: var(--radius-pill);
  background: rgba(7, 21, 40, 0.4);
  cursor: pointer;
}
.nav-toggle__bar {
  display: block;
  width: 16px;
  height: 2px;
  border-radius: 2px;
  background: #fff;
  transition: transform 220ms var(--ease-out), opacity 220ms var(--ease-out);
}
.nav-toggle__bar + .nav-toggle__bar { margin-left: -16px; }
.nav-toggle__bar:nth-child(2) { transform: translateY(5px); }
.nav-toggle__label { font-size: 12px; letter-spacing: 0.14em; margin-left: 6px; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:first-child { transform: translateY(2px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2) { transform: translateY(-3px) rotate(-45deg); }

/* ---------- footer ---------- */
.site-footer {
  background:
    radial-gradient(120% 90% at 12% 0%, rgba(27, 58, 92, 0.85), transparent 60%),
    var(--ink-900);
  color: rgba(220, 231, 242, 0.82);
  padding: 72px 0 26px;
  margin-top: 0;
  border-top: 1px solid rgba(46, 211, 224, 0.18);
}
.footer__top {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 2.4fr);
  gap: 44px;
  padding-bottom: 40px;
}
.footer__brand { display: flex; flex-direction: column; gap: 14px; }
.footer__brandline {
  margin: 0;
  font-size: 16px;
  font-weight: 600;
  color: #fff;
  max-width: 22ch;
}
.footer__status {
  margin: 0;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  align-self: flex-start;
  padding: 5px 14px;
  border-radius: var(--radius-pill);
  border: 1px solid rgba(63, 184, 154, 0.5);
  background: rgba(63, 184, 154, 0.12);
  color: #93E3CC;
  font-size: 12px;
  letter-spacing: 0.08em;
}
.footer__columns {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr)) minmax(0, 1.5fr);
  gap: 28px;
}
.footer__coltitle {
  margin: 0 0 14px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.18em;
  color: var(--cyan-200);
  text-transform: uppercase;
}
.footer__list { display: flex; flex-direction: column; gap: 10px; }
.footer__list a {
  font-size: 15px;
  color: rgba(220, 231, 242, 0.82);
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease-out), border-color var(--dur) var(--ease-out);
}
.footer__list a:hover { color: var(--cyan-400); border-bottom-color: var(--cyan-400); }
.footer__address { font-size: 14px; line-height: 1.7; color: rgba(220, 231, 242, 0.7); }

.copy-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 0;
  border: 0;
  background: none;
  cursor: pointer;
  font-size: 15px;
  color: rgba(220, 231, 242, 0.82);
  border-bottom: 1px dashed rgba(46, 211, 224, 0.6);
  transition: color var(--dur) var(--ease-out);
}
.copy-btn:hover { color: var(--cyan-400); }
.copy-btn.is-copied { color: var(--teal-500); border-bottom-color: var(--teal-500); }

.footer__note {
  padding: 20px 24px;
  border-radius: var(--radius-md);
  background: rgba(27, 58, 92, 0.45);
  border: 1px solid rgba(168, 238, 245, 0.14);
  font-size: 13px;
  line-height: 1.8;
  color: rgba(220, 231, 242, 0.78);
}
.footer__note p { margin: 0; }

.footer__legal {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 26px;
  margin-top: 26px;
  padding-top: 20px;
  border-top: 1px solid rgba(124, 143, 163, 0.25);
  font-size: 13px;
  color: rgba(220, 231, 242, 0.65);
}
.footer__legalitem { margin: 0; display: inline-flex; align-items: center; gap: 8px; }
.footer__legalitem a { color: rgba(220, 231, 242, 0.75); }
.footer__legalitem a:hover { color: var(--cyan-400); }
.footer__dot {
  width: 8px;
  height: 8px;
  border-radius: var(--radius-pill);
  background: var(--cyan-400);
}
.footer__sep { color: rgba(124, 143, 163, 0.7); }

/* ---------- responsive ---------- */
@media (max-width: 1080px) {
  .header__tagline { display: none; }
  .nav__link { padding: 8px 9px; font-size: 14px; }
  .footer__top { grid-template-columns: 1fr; gap: 34px; }
  .footer__columns { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 880px) {
  h1 { font-size: 44px; }
  h2 { font-size: 28px; }
  .section { padding: 64px 0; }
  .col--3, .col--4, .col--5, .col--7, .col--8 { grid-column: span 12; }
  .note-rail__index { writing-mode: horizontal-tb; }
}

@media (max-width: 760px) {
  body { font-size: 16px; }
  h1 { font-size: 36px; }

  .header__inner { min-height: 68px; gap: 12px; }
  .header__cta { display: none; }
  .nav-toggle { display: inline-flex; margin-left: auto; }

  .nav {
    position: fixed;
    inset: 68px 0 0 0;
    z-index: 95;
    margin: 0;
    padding: 26px 24px 40px;
    flex-direction: column;
    align-items: stretch;
    gap: 20px;
    overflow-y: auto;
    background: rgba(7, 21, 40, 0.985);
    border-top: 1px solid rgba(46, 211, 224, 0.3);
    transform: translateY(-12px);
    opacity: 0;
    visibility: hidden;
    transition: opacity 240ms var(--ease-out), transform 240ms var(--ease-out), visibility 240ms var(--ease-out);
  }
  .nav[data-open="true"] {
    transform: none;
    opacity: 1;
    visibility: visible;
  }
  .nav__list { flex-direction: column; align-items: stretch; gap: 4px; }
  .nav__link {
    display: block;
    padding: 14px 16px;
    font-size: 17px;
    border-radius: var(--radius-md);
    border-bottom: 1px solid rgba(124, 143, 163, 0.2);
  }
  .nav__link::after { display: none; }
  .nav__link[aria-current="page"],
  .nav__link.is-current { background: rgba(46, 211, 224, 0.14); }
  .nav__cta { display: inline-flex; width: 100%; }

  .footer__columns { grid-template-columns: 1fr; gap: 26px; }
  .footer__legal { flex-direction: column; align-items: flex-start; }
  .to-top { right: 14px; bottom: 16px; }
}

@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;
  }
  .reveal { opacity: 1; transform: none; }
  .progress__bar { transition: none; }
  .btn:hover, .card:hover, .to-top:hover { transform: none; }
}