:root {
  --bg: oklch(96.6% 0.018 92);
  --surface: oklch(99.2% 0.01 92);
  --surface-2: oklch(92.5% 0.025 94);
  --ink: oklch(22% 0.032 248);
  --muted: oklch(47% 0.036 248);
  --soft: oklch(62% 0.035 248);
  --line: oklch(79% 0.031 90);
  --line-strong: oklch(64% 0.054 82);
  --accent: oklch(53% 0.145 36);
  --accent-dark: oklch(37% 0.112 35);
  --blue: oklch(47% 0.112 232);
  --green: oklch(48% 0.095 151);
  --shadow: 0 24px 70px oklch(25% 0.04 248 / 0.16);
  --maxw: 1160px;
}

* { box-sizing: border-box; }

html {
  min-height: 100%;
  scroll-behavior: smooth;
}

body {
  min-height: 100%;
  margin: 0;
  font-family: "Avenir Next", "Gill Sans", "Trebuchet MS", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  line-height: 1.75;
  background:
    linear-gradient(90deg, oklch(34% 0.045 248 / 0.08) 1px, transparent 1px) 0 0 / 88px 88px,
    linear-gradient(0deg, oklch(34% 0.045 248 / 0.07) 1px, transparent 1px) 0 0 / 88px 88px,
    radial-gradient(circle at 14% 10%, oklch(79% 0.125 62 / 0.62), transparent 32rem),
    radial-gradient(circle at 92% 6%, oklch(76% 0.11 217 / 0.45), transparent 30rem),
    var(--bg);
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image:
    linear-gradient(oklch(18% 0.02 248 / 0.03) 1px, transparent 1px),
    linear-gradient(90deg, oklch(18% 0.02 248 / 0.03) 1px, transparent 1px);
  background-size: 16px 16px;
  mask-image: linear-gradient(to bottom, black, transparent 68%);
}

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

a:focus-visible,
button:focus-visible {
  outline: 3px solid oklch(62% 0.17 55);
  outline-offset: 4px;
}

.header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: oklch(96.6% 0.018 92 / 0.86);
  border-bottom: 1px solid oklch(69% 0.035 85 / 0.55);
  backdrop-filter: blur(16px) saturate(1.2);
}

.nav {
  width: min(var(--maxw), calc(100% - 32px));
  min-height: 72px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.brand {
  display: inline-flex;
  align-items: center;
  min-width: 0;
  gap: 12px;
}

.logo {
  width: 38px;
  height: 38px;
  flex: 0 0 auto;
  border: 1px solid var(--ink);
  border-radius: 50%;
  background:
    radial-gradient(circle at 50% 50%, transparent 24%, var(--accent) 25% 31%, transparent 32%),
    linear-gradient(135deg, transparent 44%, var(--ink) 45% 55%, transparent 56%),
    var(--surface);
  box-shadow: 5px 5px 0 var(--ink);
}

.site-title,
.brand h1 {
  display: block;
  margin: 0;
  font-size: 15px;
  font-weight: 800;
  letter-spacing: 0;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.subtitle {
  display: block;
  margin-top: 1px;
  color: var(--muted);
  font-size: 11px;
  letter-spacing: 0.02em;
}

.links {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 6px;
  flex-wrap: wrap;
}

.links a {
  display: inline-flex;
  min-height: 38px;
  align-items: center;
  padding: 0 12px;
  border: 1px solid transparent;
  border-radius: 999px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 700;
  transition: background-color .18s ease, color .18s ease, transform .18s ease, border-color .18s ease;
}

.links a:hover,
.links a[aria-current="page"] {
  color: var(--ink);
  border-color: var(--ink);
  background: var(--surface);
  transform: translateY(-1px);
}

main {
  width: min(var(--maxw), calc(100% - 32px));
  margin: 0 auto;
  padding: clamp(28px, 5vw, 64px) 0 72px;
}

.home-hero {
  min-height: calc(100vh - 120px);
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(320px, .85fr);
  align-items: center;
  gap: clamp(28px, 5vw, 72px);
  padding-bottom: clamp(36px, 6vw, 78px);
}

.hero-copy {
  max-width: 760px;
}

.eyebrow {
  margin: 0 0 14px;
  color: var(--accent-dark);
  font-size: 13px;
  font-weight: 900;
  letter-spacing: .08em;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  margin: 0;
  line-height: 1.12;
  letter-spacing: 0;
}

.home-hero h1 {
  max-width: 12ch;
  font-size: clamp(48px, 8.8vw, 112px);
  font-weight: 900;
}

.hero-lead {
  max-width: 68ch;
  margin: 28px 0 0;
  color: var(--muted);
  font-size: clamp(17px, 1.7vw, 21px);
  line-height: 1.85;
}

.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 34px;
}

.button {
  min-height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 18px;
  border: 1.5px solid var(--ink);
  border-radius: 999px;
  background: var(--surface);
  color: var(--ink);
  font-size: 15px;
  font-weight: 900;
  box-shadow: 5px 5px 0 var(--ink);
  transition: transform .18s ease, box-shadow .18s ease, background-color .18s ease;
}

.button:hover {
  transform: translate(2px, 2px);
  box-shadow: 3px 3px 0 var(--ink);
}

.button.primary {
  background: var(--accent);
  color: oklch(98% 0.01 80);
}

.hero-visual {
  min-height: 520px;
  position: relative;
  border: 1.5px solid var(--ink);
  border-radius: 28px;
  overflow: hidden;
  background:
    radial-gradient(circle at 50% 50%, transparent 0 32%, oklch(51% 0.12 228 / .22) 33% 34%, transparent 35%),
    radial-gradient(circle at 50% 50%, transparent 0 54%, oklch(48% 0.11 36 / .24) 55% 56%, transparent 57%),
    linear-gradient(135deg, oklch(99% 0.01 93), oklch(87% 0.055 81));
  box-shadow: var(--shadow), 10px 10px 0 var(--ink);
}

.hero-visual::before,
.hero-visual::after {
  content: "";
  position: absolute;
  border: 1.5px solid var(--ink);
  border-radius: 50%;
  transform: translate(-50%, -50%) rotate(-16deg);
}

.hero-visual::before {
  width: 390px;
  height: 178px;
  top: 50%;
  left: 50%;
  background: oklch(99% 0.01 93 / 0.52);
}

.hero-visual::after {
  width: 220px;
  height: 96px;
  top: 50%;
  left: 50%;
  border-color: var(--accent-dark);
}

.lens-grid {
  position: absolute;
  inset: 26px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}

.lens-grid span {
  border: 1px solid oklch(28% 0.035 248 / 0.25);
  border-radius: 16px;
  background: oklch(98% 0.01 92 / 0.32);
}

.signal-card {
  position: absolute;
  display: grid;
  gap: 2px;
  width: min(58%, 240px);
  padding: 13px 14px;
  border: 1.5px solid var(--ink);
  border-radius: 16px;
  background: var(--surface);
  box-shadow: 6px 6px 0 var(--ink);
}

.signal-card strong {
  color: var(--ink);
  font-size: 18px;
  line-height: 1.2;
}

.signal-card span {
  color: var(--muted);
  font-size: 13px;
}

.signal-card-a {
  top: 42px;
  left: 36px;
}

.signal-card-b {
  right: 34px;
  top: 44%;
  transform: translateY(-50%);
}

.signal-card-c {
  left: 58px;
  bottom: 46px;
}

.section {
  padding: clamp(36px, 6vw, 70px) 0;
  border-top: 1.5px solid var(--line);
}

.section-heading {
  display: grid;
  grid-template-columns: minmax(170px, .32fr) minmax(0, 1fr);
  gap: 24px;
  align-items: baseline;
  margin-bottom: 24px;
}

.section-heading .eyebrow {
  margin: 0;
}

.section h2 {
  font-size: clamp(30px, 5vw, 64px);
  font-weight: 900;
}

.path-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.path-list a {
  min-height: 210px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 22px;
  border: 1.5px solid var(--ink);
  border-radius: 22px;
  background: var(--surface);
  box-shadow: 6px 6px 0 oklch(26% 0.03 248 / .88);
  transition: transform .18s ease, box-shadow .18s ease;
}

.path-list a:nth-child(2) {
  background: oklch(90% 0.06 88);
}

.path-list a:nth-child(3) {
  background: oklch(90% 0.045 205);
}

.path-list a:hover,
.topic-grid a:hover,
.article-row a:hover {
  transform: translate(2px, 2px);
  box-shadow: 3px 3px 0 oklch(26% 0.03 248 / .88);
}

.path-list span {
  color: var(--accent-dark);
  font-size: 14px;
  font-weight: 900;
}

.path-list strong {
  display: block;
  margin-top: 36px;
  font-size: clamp(22px, 2.4vw, 34px);
  line-height: 1.15;
}

.path-list em,
.article-row em {
  display: block;
  color: var(--muted);
  font-style: normal;
}

.path-list em {
  margin-top: 16px;
  font-size: 15px;
}

.topic-grid {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  border: 1.5px solid var(--ink);
  border-radius: 24px;
  overflow: hidden;
  background: var(--surface);
  box-shadow: 8px 8px 0 var(--ink);
}

.topic-grid a {
  min-height: 152px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 18px;
  padding: 18px;
  border-right: 1.5px solid var(--ink);
  background: var(--surface);
  transition: background-color .18s ease, transform .18s ease;
}

.topic-grid a:nth-child(2n) {
  background: oklch(94% 0.036 82);
}

.topic-grid a:nth-child(3n) {
  background: oklch(93% 0.032 196);
}

.topic-grid a:last-child {
  border-right: 0;
}

.topic-grid span {
  font-size: 20px;
  font-weight: 900;
  line-height: 1.2;
}

.topic-grid small {
  color: var(--muted);
  font-size: 12px;
  line-height: 1.4;
}

.article-index {
  display: grid;
  gap: 10px;
}

.article-row a {
  display: grid;
  grid-template-columns: 64px minmax(0, 1fr) 150px;
  align-items: center;
  gap: 18px;
  min-height: 94px;
  padding: 16px 18px;
  border: 1.5px solid var(--ink);
  border-radius: 18px;
  background: oklch(98.8% 0.011 92 / 0.86);
  box-shadow: 5px 5px 0 oklch(26% 0.03 248 / .88);
  transition: transform .18s ease, box-shadow .18s ease, background-color .18s ease;
}

.article-row.featured a {
  min-height: 124px;
  background: oklch(89% 0.075 60);
}

.article-no {
  display: grid;
  width: 48px;
  height: 48px;
  place-items: center;
  border: 1.5px solid var(--ink);
  border-radius: 50%;
  background: var(--surface);
  color: var(--accent-dark);
  font-weight: 900;
  line-height: 1;
}

.article-body strong {
  display: block;
  font-size: clamp(17px, 1.8vw, 22px);
  line-height: 1.35;
}

.article-body em {
  margin-top: 6px;
  font-size: 14px;
  line-height: 1.6;
}

.article-meta {
  justify-self: end;
  width: max-content;
  max-width: 100%;
  padding: 6px 10px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  color: var(--accent-dark);
  background: oklch(98% 0.01 92 / 0.7);
  font-size: 12px;
  font-weight: 900;
}

.main {
  width: min(880px, calc(100% - 32px));
  margin: 0 auto;
  padding: clamp(26px, 4vw, 48px) 0 64px;
}

.hero {
  padding: clamp(22px, 4vw, 36px);
  border: 1.5px solid var(--ink);
  border-radius: 24px;
  background: var(--surface);
  box-shadow: 8px 8px 0 var(--ink);
}

.hero h2 {
  margin: 0 0 12px;
  font-size: clamp(28px, 4.5vw, 52px);
  font-weight: 900;
}

.hero p {
  margin: 10px 0;
  color: var(--muted);
}

.grid {
  margin-top: 18px;
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 14px;
}

.card {
  grid-column: span 12;
  border: 1.5px solid var(--ink);
  border-radius: 18px;
  padding: 18px;
  background: var(--surface);
  box-shadow: 5px 5px 0 oklch(26% 0.03 248 / .88);
}

.card h3 {
  margin: 0 0 8px;
  font-size: 18px;
  line-height: 1.35;
}

.card p {
  margin: 0 0 12px;
  color: var(--muted);
}

.card a {
  color: var(--ink);
}

.card a:hover {
  color: var(--accent-dark);
}

.meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  color: var(--muted);
  font-size: 12px;
}

.kbd {
  display: inline-flex;
  align-items: center;
  min-height: 24px;
  padding: 0 7px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  background: oklch(94% 0.028 83);
  color: var(--accent-dark);
  font-size: 12px;
  font-weight: 800;
}

.article {
  padding: clamp(24px, 4vw, 44px);
  border: 1.5px solid var(--ink);
  border-radius: 24px;
  background: var(--surface);
  box-shadow: 8px 8px 0 var(--ink);
}

.article h2 {
  margin-top: 0;
  font-size: clamp(28px, 4.5vw, 52px);
  font-weight: 900;
}

.article h3 {
  margin-top: 34px;
  font-size: 25px;
}

.article h4 {
  margin-top: 24px;
  font-size: 19px;
}

.article p,
.article ul,
.article ol {
  color: var(--muted);
}

.article a {
  color: var(--accent-dark);
  font-weight: 800;
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

.article .note {
  padding: 14px 16px;
  border: 1.5px solid var(--ink);
  border-radius: 16px;
  background: oklch(92% 0.05 81);
  color: var(--muted);
}

.footer {
  width: min(var(--maxw), calc(100% - 32px));
  margin: 0 auto 28px;
  color: var(--muted);
  font-size: 13px;
}

.footer .line {
  border-top: 1.5px solid var(--line);
  padding-top: 18px;
}

@media (min-width: 860px) {
  .card {
    grid-column: span 6;
  }
}

@media (max-width: 980px) {
  .home-hero {
    min-height: auto;
    grid-template-columns: 1fr;
  }

  .home-hero h1 {
    max-width: 13ch;
  }

  .hero-visual {
    min-height: 430px;
  }

  .path-list {
    grid-template-columns: 1fr;
  }

  .topic-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .topic-grid a {
    border-right: 0;
    border-bottom: 1.5px solid var(--ink);
  }

  .topic-grid a:nth-last-child(-n + 2) {
    border-bottom: 0;
  }
}

@media (max-width: 720px) {
  .nav {
    min-height: auto;
    padding: 12px 0;
    align-items: flex-start;
    flex-direction: column;
  }

  .links {
    width: 100%;
    justify-content: flex-start;
  }

  .home-hero h1 {
    max-width: 10.8ch;
    font-size: clamp(42px, 14vw, 66px);
  }

  .hero-lead {
    font-size: 16px;
  }

  .hero-visual {
    min-height: 360px;
    border-radius: 22px;
    box-shadow: 6px 6px 0 var(--ink);
  }

  .signal-card {
    width: 210px;
  }

  .signal-card-a {
    top: 26px;
    left: 22px;
  }

  .signal-card-b {
    right: 20px;
  }

  .signal-card-c {
    left: 28px;
    bottom: 26px;
  }

  .section-heading {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .topic-grid {
    grid-template-columns: 1fr;
  }

  .topic-grid a,
  .topic-grid a:nth-last-child(-n + 2) {
    min-height: 118px;
    border-bottom: 1.5px solid var(--ink);
  }

  .topic-grid a:last-child {
    border-bottom: 0;
  }

  .article-row a {
    grid-template-columns: 44px minmax(0, 1fr);
    gap: 14px;
  }

  .article-no {
    width: 38px;
    height: 38px;
    font-size: 12px;
  }

  .article-meta {
    grid-column: 2;
    justify-self: start;
    margin-top: 2px;
  }
}

@media (max-width: 420px) {
  main,
  .main,
  .nav,
  .footer {
    width: min(100% - 24px, var(--maxw));
  }

  .hero-actions {
    flex-direction: column;
  }

  .button {
    width: 100%;
  }

  .home-hero h1 {
    max-width: none;
    font-size: 38px;
  }

  .hero-visual {
    min-height: 315px;
  }

  .signal-card {
    width: 190px;
    padding: 10px 12px;
  }

  .signal-card strong {
    font-size: 16px;
  }

  .signal-card span {
    font-size: 12px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}