:root {
  --bg: #f4f6f8;
  --paper: #ffffff;
  --ink: #17202a;
  --muted: #5d6876;
  --line: #d3d9e1;
  --line-strong: #9aa6b4;
  --accent: #9b1c1f;
  --accent-soft: #fff4f2;
  --blue: #225c86;
  --code-bg: #eef2f5;
  --code-ink: #18212b;
  --mono: "Cascadia Code", "JetBrains Mono", Consolas, monospace;
  --serif: "Source Serif 4", "Iowan Old Style", "Palatino Linotype", Georgia, serif;
  --ui: "Aptos", "Segoe UI Variable Text", "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 17px;
  line-height: 1.64;
}

body,
button,
input {
  letter-spacing: 0;
}

a {
  color: var(--blue);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

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

.page {
  width: min(1080px, calc(100% - 34px));
  margin: 0 auto;
  padding: 34px 0 72px;
}

.hero {
  border-top: 4px solid var(--ink);
  border-bottom: 1px solid var(--line-strong);
  padding: 28px 0 24px;
}

.hero-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(300px, 0.72fr);
  gap: 28px;
  align-items: start;
}

.hero-copy {
  min-width: 0;
}

.hero-visual {
  margin: 0;
}

.hero-visual img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line-strong);
  border-radius: 8px;
  background: var(--paper);
}

.eyebrow,
.card-kicker,
.algo-label {
  display: inline-block;
  color: var(--accent);
  font-family: var(--mono);
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  margin: 0;
  color: var(--ink);
  font-family: var(--ui);
  font-weight: 720;
  line-height: 1.12;
  letter-spacing: 0;
}

h1 {
  max-width: 860px;
  margin-top: 12px;
  font-size: 3.05rem;
}

h2 {
  font-size: 1.72rem;
}

h3 {
  margin: 22px 0 8px;
  font-size: 1.13rem;
}

p {
  margin: 12px 0 0;
}

.dek {
  max-width: 880px;
  color: #2e3946;
  font-size: 1.08rem;
}

.byline,
.hero-meta,
.profile-links {
  font-family: var(--ui);
}

.byline {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  margin-top: 18px;
  color: var(--muted);
  font-size: 0.95rem;
}

.profile-links {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
  margin-top: 20px;
}

.profile-links a {
  min-height: 70px;
  padding: 12px 13px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
  color: var(--ink);
  font-weight: 700;
  text-decoration: none;
}

.profile-links span {
  display: block;
  margin-top: 4px;
  color: var(--muted);
  font-size: 0.85rem;
  font-weight: 500;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 10px;
  margin-top: 20px;
  color: #3e4a58;
  font-size: 0.9rem;
}

.hero-meta span {
  padding: 5px 8px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--paper);
}

.grid {
  display: grid;
  gap: 22px;
  margin-top: 26px;
}

.grid > * {
  min-width: 0;
}

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

.grid-3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.panel,
.stat {
  border-bottom: 1px solid var(--line);
  background: transparent;
}

.panel {
  padding: 28px 0;
}

.grid > .panel,
.stat {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
  padding: 20px;
}

.stat strong {
  display: block;
  margin-top: 8px;
  font-family: var(--ui);
  font-size: 1.08rem;
  line-height: 1.25;
}

.stat p {
  color: var(--muted);
  font-size: 0.96rem;
}

.stat-head,
.section-head {
  display: flex;
  align-items: baseline;
  gap: 10px;
}

.section-head {
  margin-top: 8px;
}

.icon-badge {
  display: none;
}

ul,
ol {
  margin: 12px 0 0;
  padding-left: 1.3rem;
}

li + li {
  margin-top: 7px;
}

code,
pre {
  font-family: var(--mono);
}

code {
  padding: 0.08rem 0.25rem;
  border-radius: 4px;
  background: var(--code-bg);
  color: var(--code-ink);
  font-size: 0.9em;
  overflow-wrap: anywhere;
}

pre {
  margin: 16px 0 0;
  padding: 15px 16px;
  overflow-x: auto;
  border: 1px solid #c7d0da;
  border-radius: 8px;
  background: #f8fafc;
  color: var(--code-ink);
  font-size: 0.84rem;
  line-height: 1.55;
}

pre code {
  padding: 0;
  background: transparent;
}

.tok-key {
  color: #8a2b2f;
}

.tok-fn {
  color: #0f5b78;
}

.tok-str {
  color: #6b4a00;
}

.note {
  margin-top: 16px;
  padding: 12px 14px;
  border-left: 4px solid var(--accent);
  border-radius: 0 6px 6px 0;
  background: var(--accent-soft);
  color: #34251f;
}

.inline-proof {
  margin: 18px 0 0;
}

.inline-proof img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line-strong);
  border-radius: 6px;
  background: var(--paper);
}

figcaption {
  margin-top: 8px;
  color: var(--muted);
  font-family: var(--ui);
  font-size: 0.88rem;
}

.timeline {
  margin-top: 12px;
  border-top: 1px solid var(--line);
}

.timeline-item {
  padding: 13px 0;
  border-bottom: 1px solid var(--line);
}

.timeline-item strong {
  display: block;
  margin-bottom: 3px;
  font-family: var(--ui);
}

.lab-steps {
  padding-left: 1.45rem;
}

.algo-demo {
  margin-top: 24px;
  padding: 20px;
  border: 1px solid var(--line-strong);
  border-radius: 8px;
  background: #fbfcfd;
}

.algo-demo-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 18px;
}

.algo-demo-head h3 {
  margin-top: 6px;
}

.algo-demo-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.algo-demo-button {
  min-height: 38px;
  padding: 8px 12px;
  border: 1px solid #8290a0;
  border-radius: 6px;
  background: var(--paper);
  color: var(--ink);
  cursor: pointer;
  font-family: var(--ui);
  font-weight: 700;
}

.algo-demo-button:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.algo-demo-copy,
.algo-form-copy,
.algo-foot {
  color: var(--muted);
  font-family: var(--ui);
  font-size: 0.93rem;
}

.algo-form {
  margin-top: 18px;
}

.algo-field {
  display: grid;
  gap: 6px;
}

.algo-input {
  width: 100%;
  max-width: 360px;
  min-height: 42px;
  padding: 8px 10px;
  border: 1px solid var(--line-strong);
  border-radius: 6px;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--mono);
  font-size: 1rem;
}

.algo-input:focus {
  border-color: var(--blue);
  outline: 2px solid rgba(34, 92, 134, 0.18);
}

.algo-stage-strip {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 8px;
  margin-top: 18px;
}

.algo-stage {
  padding: 8px 9px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--paper);
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.75rem;
  text-align: center;
}

.algo-stage.is-hot {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent);
}

.algo-stage.is-done {
  border-color: #a9c0d3;
  background: #eff5f9;
  color: var(--blue);
}

.algo-demo-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: 16px;
}

.algo-card {
  min-width: 0;
  padding: 15px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
}

.algo-card-output {
  border-color: #b8c5d2;
}

.algo-rows {
  display: grid;
  gap: 8px;
  margin-top: 12px;
}

.algo-row {
  display: grid;
  gap: 5px;
  padding: 9px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #f7f9fb;
  font-family: var(--ui);
  font-size: 0.88rem;
}

.algo-row code {
  overflow-wrap: anywhere;
  font-size: 0.8rem;
}

.algo-row.is-hot,
.algo-index-item.is-hot,
.algo-password-char.is-hot {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent);
}

.algo-index-list,
.chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  margin-top: 12px;
}

.algo-index-item,
.chip,
.algo-password-char {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 34px;
  min-height: 34px;
  padding: 5px 7px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #f7f9fb;
  font-family: var(--mono);
  font-size: 0.84rem;
}

.algo-result-stack {
  display: grid;
  gap: 10px;
  margin-top: 12px;
}

.algo-result {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #f7f9fb;
  font-family: var(--ui);
}

.algo-result strong {
  font-family: var(--mono);
  font-size: 1rem;
}

.algo-status {
  min-height: 1.4em;
}

@media (max-width: 900px) {
  body {
    font-size: 16px;
  }

  .page {
    width: min(100% - 24px, 680px);
    padding-top: 22px;
  }

  h1 {
    font-size: 2.2rem;
  }

  h2 {
    font-size: 1.45rem;
  }

  .grid-2,
  .grid-3,
  .hero-layout,
  .profile-links,
  .algo-demo-grid {
    grid-template-columns: 1fr;
  }

  .algo-demo-head {
    display: grid;
  }

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

  .algo-result {
    display: grid;
  }
}

@media (max-width: 520px) {
  .page {
    width: min(100% - 18px, 460px);
  }

  h1 {
    font-size: 1.9rem;
  }

  .grid > .panel,
  .stat,
  .algo-demo {
    padding: 15px;
  }

  .algo-stage-strip {
    grid-template-columns: 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition: none !important;
    animation: none !important;
  }
}