:root {
  --paper: #f3ede1;
  --paper-2: #ebe3d2;
  --paper-3: #e2d8c2;
  --card: #fbf7ec;
  --ink: #1a1814;
  --ink-2: #3a352c;
  --muted: #6f6754;
  --line: #cfc4ac;
  --line-2: #b8ab8e;
  --accent: #6b4f1d;
  --accent-soft: #c9a566;
  --accent-wash: #efe3c7;
  --good: #2a5d57;
  --good-wash: #dde9e6;
  --warn: #8a3a1f;
  --warn-wash: #ecd6c8;
  --serif: "Source Serif 4", "Iowan Old Style", "Charter", Georgia, serif;
  --sans: "Manrope", ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 15px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: 0.32;
  mix-blend-mode: multiply;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='240' height='240'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 0.1  0 0 0 0 0.09  0 0 0 0 0.07  0 0 0 0.06 0'/></filter><rect width='100%' height='100%' filter='url(%23n)'/></svg>");
  z-index: 0;
}

button, input, select { font: inherit; color: inherit; }
button { cursor: pointer; }
button:disabled { cursor: not-allowed; opacity: 0.45; }
a { color: var(--accent); text-decoration: none; border-bottom: 1px solid currentColor; }

h1, h2, h3 { margin: 0; font-weight: 500; line-height: 1.15; letter-spacing: -0.01em; }
h1, h2 { font-family: var(--serif); font-weight: 400; }
h1 { max-width: 16ch; font-size: clamp(40px, 6vw, 68px); letter-spacing: -0.02em; }
h1 em { color: var(--accent); font-style: italic; }
h2 { font-size: clamp(26px, 2.6vw, 34px); }
h3 { font-family: var(--serif); font-size: 22px; }
p { margin: 0; }

.app {
  position: relative;
  z-index: 1;
  max-width: 1340px;
  margin: 0 auto;
  padding: 28px clamp(20px, 3vw, 40px) 80px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 42px;
}
.brand { display: flex; align-items: center; gap: 14px; color: inherit; border-bottom: 0; }
.brand-mark {
  display: inline-grid; place-items: center;
  width: 36px; height: 36px;
  border: 1.5px solid var(--ink); border-radius: 50%;
  background: var(--card);
  font-family: var(--serif); font-size: 18px; font-style: italic;
}
.brand-name { display: block; font-family: var(--serif); font-size: 19px; line-height: 1.1; }
.brand-meta { display: block; color: var(--muted); font-family: var(--mono); font-size: 12px; }
.topbar-right { display: flex; flex-wrap: wrap; gap: 18px; color: var(--muted); font-family: var(--mono); font-size: 12px; }
.topbar-right a { color: var(--muted); border-bottom-color: transparent; }
.topbar-right a:hover { color: var(--ink); border-bottom-color: var(--ink); }

.kicker {
  color: var(--accent);
  font-family: var(--mono); font-size: 11px; font-weight: 500;
  text-transform: uppercase; letter-spacing: 0.08em;
  margin-bottom: 16px;
}
.kicker .dot {
  display: inline-block; width: 6px; height: 6px; margin-right: 8px;
  background: currentColor; border-radius: 50%; transform: translateY(-1px);
}

.hero { margin-bottom: 56px; }
.hero-sub {
  max-width: 50ch; margin: 18px 0 0;
  color: var(--ink-2); font-family: var(--serif);
  font-size: clamp(18px, 1.8vw, 22px); font-style: italic; line-height: 1.45;
}

.tabs {
  display: flex; flex-wrap: wrap; gap: 0;
  padding: 0; margin: 0 0 28px;
  border-bottom: 1px solid var(--line);
}
.tab {
  background: transparent; border: 0;
  padding: 12px 18px;
  font-family: var(--mono); font-size: 12px;
  text-transform: uppercase; letter-spacing: 0.06em;
  color: var(--muted);
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
}
.tab:hover { color: var(--ink); }
.tab.is-active { color: var(--ink); border-bottom-color: var(--accent); }

.section-intro {
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(0, 1fr);
  gap: 36px;
  margin-bottom: 28px;
}
.section-intro p {
  max-width: 60ch;
  color: var(--ink-2); font-size: 16px; line-height: 1.65;
}
.section-intro .aside {
  padding: 16px 18px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  font-size: 13.5px; color: var(--ink-2);
}
.section-intro .aside strong { color: var(--ink); }
@media (max-width: 800px) {
  .section-intro { grid-template-columns: 1fr; gap: 18px; }
}

.conv-lesson {
  display: grid;
  gap: 18px;
  margin-bottom: 30px;
}
.lesson-check {
  padding: 14px 16px;
  background: var(--good-wash);
  border: 1px solid rgba(42, 93, 87, 0.35);
  border-left: 4px solid var(--good);
  border-radius: 10px;
  color: var(--ink-2);
}
.lesson-block {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 22px;
}
.lesson-block h3 { margin-bottom: 8px; }
.lesson-block h4 {
  margin: 0 0 8px;
  font-family: var(--mono);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent);
}
.lesson-block > p {
  max-width: 78ch;
  color: var(--ink-2);
  margin-bottom: 14px;
}
.edge-map-note {
  max-width: 84ch;
  margin: 10px 0 16px;
  padding: 12px 14px;
  background: var(--warn-wash);
  border: 1px solid rgba(138, 58, 31, 0.28);
  border-left: 4px solid var(--warn);
  border-radius: 8px;
  color: var(--ink-2);
  font-size: 14px;
}
.edge-map-note strong { color: var(--warn); }
.lesson-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: end;
  margin: 12px 0 16px;
}
.lesson-controls label {
  display: grid;
  gap: 4px;
  min-width: 160px;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.lesson-controls select {
  min-height: 34px;
  padding: 6px 8px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 13px;
  text-transform: none;
  letter-spacing: 0;
}
.matrix-demo-row {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  align-items: flex-start;
  margin-top: 16px;
}
.matrix-demo-row figure,
.conv-step-layout figure {
  margin: 0;
}
.matrix-demo-row figcaption,
.conv-step-layout figcaption {
  margin-top: 8px;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 11px;
  max-width: 300px;
}
.matrix-grid {
  display: grid;
  gap: 1px;
  width: max-content;
  padding: 2px;
  background: var(--ink);
  border: 1px solid var(--ink);
}
.matrix-grid span {
  display: grid;
  place-items: center;
  font-family: var(--mono);
  font-size: 10px;
  font-weight: 600;
  line-height: 1;
  outline-offset: -2px;
}
.matrix-grid.compact span {
  font-size: 0;
}
.matrix-grid span.is-active {
  outline: 3px solid #f0c542;
  z-index: 1;
}
.matrix-grid span.is-computed {
  box-shadow: inset 0 0 0 1px rgba(42, 93, 87, 0.35);
}
.kernel-readout {
  position: relative;
  display: grid;
  grid-template-columns: repeat(3, 50px);
  gap: 6px;
  width: max-content;
}
.kernel-readout span {
  display: grid;
  place-items: center;
  height: 38px;
  background: var(--accent-wash);
  border: 1px solid var(--accent-soft);
  border-radius: 6px;
  font-family: var(--mono);
  font-size: 13px;
}
.kernel-readout small {
  grid-column: 1 / -1;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 11px;
}
.conv-step-layout {
  display: grid;
  grid-template-columns: max-content max-content max-content;
  gap: 22px;
  align-items: start;
  overflow-x: auto;
  padding-bottom: 4px;
}
.calc-readout {
  margin-top: 14px;
  padding: 12px 14px;
  background: var(--paper-2);
  border: 1px dashed var(--line-2);
  border-radius: 8px;
  color: var(--ink-2);
  font-family: var(--mono);
  font-size: 12px;
  overflow-x: auto;
}
.why-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(235px, 1fr));
  gap: 14px;
  margin-top: 14px;
}
.why-grid article {
  padding: 14px;
  background: var(--paper-2);
  border: 1px solid var(--line);
  border-radius: 10px;
}
.why-grid article p {
  margin-top: 10px;
  color: var(--ink-2);
  font-size: 13px;
}
.mini-pair {
  display: grid;
  gap: 8px;
  justify-items: start;
}
.mini-pair > span {
  color: var(--accent);
  font-family: var(--mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.panel {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 22px;
  margin-bottom: 26px;
}
.panel-head {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  align-items: start;
  margin-bottom: 16px;
}
.panel-head p,
.panel-copy {
  max-width: 78ch;
  color: var(--ink-2);
  font-size: 13.5px;
  margin-top: 8px;
}
.segmented {
  display: inline-flex;
  border: 1px solid var(--line);
  border-radius: 9px;
  overflow: hidden;
  background: var(--paper);
  flex: 0 0 auto;
}
.segmented button {
  border: 0;
  background: transparent;
  padding: 8px 12px;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.segmented button + button { border-left: 1px solid var(--line); }
.segmented button.is-active { background: var(--ink); color: var(--card); }
.stage-label {
  display: block;
  color: var(--accent);
  font-family: var(--mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 7px;
}
.source-line {
  margin-top: 12px;
  color: var(--muted);
  font-size: 12px;
}
.train-use {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 42px minmax(0, 1fr);
  gap: 14px;
  align-items: stretch;
}
.train-use article,
.timeline-detail,
.prompt-pair article,
.injection-grid article {
  padding: 16px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 10px;
}
.train-use article strong {
  display: block;
  font-family: var(--serif);
  font-size: 34px;
  line-height: 1.05;
  color: var(--ink);
  margin-bottom: 8px;
}
.train-use article p,
.train-use article small,
.timeline-detail p,
.timeline-detail small,
.prompt-pair article p,
.injection-grid article p {
  color: var(--ink-2);
}
.train-use article small,
.timeline-detail small {
  display: block;
  margin-top: 10px;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 11px;
}
.arrow-flow {
  display: grid;
  place-items: center;
  color: var(--accent);
  font-family: var(--serif);
  font-size: 34px;
}
.timeline {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 8px;
  margin: 16px 0;
}
.timeline button {
  min-height: 76px;
  padding: 12px;
  text-align: left;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 9px;
  color: var(--ink);
  font-family: var(--serif);
  font-size: 17px;
}
.timeline button span {
  display: block;
  margin-bottom: 5px;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.timeline button.is-active {
  background: var(--good-wash);
  border-color: var(--good);
}
.timeline-detail h4 {
  margin: 0 0 8px;
  font-family: var(--serif);
  font-size: 24px;
  font-weight: 500;
}
.context-bar {
  position: relative;
  display: flex;
  height: 46px;
  overflow: hidden;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 10px;
  margin: 16px 0;
}
.context-bar span {
  display: grid;
  place-items: center;
  min-width: 32px;
  color: #fff;
  font-family: var(--mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  white-space: nowrap;
}
.context-bar .ctx-history { background: #6b4f1d; }
.context-bar .ctx-docs { background: #2a5d57; }
.context-bar .ctx-question { background: #8a3a1f; }
.context-bar i {
  position: absolute;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--ink);
  box-shadow: 0 0 0 999px rgba(251, 247, 236, 0.58);
}
.compact-controls { grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); }
.mini-control { min-width: 250px; }
.multimodal-layout {
  display: grid;
  grid-template-columns: minmax(220px, 0.75fr) minmax(0, 1.5fr);
  gap: 18px;
  align-items: stretch;
}
.modal-card {
  padding: 16px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 10px;
}
.modal-card strong {
  display: block;
  margin-top: 12px;
  font-family: var(--serif);
  font-size: 23px;
}
.modal-card span {
  display: block;
  color: var(--muted);
  font-size: 13px;
}
.fake-image {
  height: 150px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background:
    radial-gradient(circle at 52% 54%, #d4452d 0 30%, transparent 31%),
    radial-gradient(circle at 50% 42%, #2a5d57 0 8%, transparent 9%),
    linear-gradient(135deg, #f3ede1, #efe3c7);
}
.modal-card.rain .fake-image {
  background:
    repeating-linear-gradient(115deg, transparent 0 15px, rgba(42, 93, 87, 0.7) 16px 18px),
    linear-gradient(135deg, #b7cad0, #e5eced);
}
.modal-card.receipt .fake-image {
  background:
    linear-gradient(90deg, transparent 0 12%, rgba(26, 24, 20, 0.18) 12% 13%, transparent 13% 100%),
    repeating-linear-gradient(0deg, #fbf7ec 0 14px, #d9cfba 15px 16px);
}
.embedding-space {
  position: relative;
  min-height: 230px;
  background:
    linear-gradient(90deg, rgba(207,196,172,0.45) 1px, transparent 1px),
    linear-gradient(0deg, rgba(207,196,172,0.45) 1px, transparent 1px),
    var(--paper);
  background-size: 42px 42px;
  border: 1px solid var(--line);
  border-radius: 10px;
  overflow: hidden;
}
.embedding-space b {
  position: absolute;
  transform: translate(-50%, -50%);
  display: grid;
  place-items: center;
  width: 72px;
  height: 72px;
  border-radius: 50%;
  border: 2px solid currentColor;
  background: var(--card);
  font-family: var(--mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.embedding-space .m-text { color: var(--accent); }
.embedding-space .m-image { color: var(--good); }
.embedding-space .m-audio { color: var(--warn); }
.embedding-space .axis {
  position: absolute;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.embedding-space .axis.x { right: 12px; bottom: 8px; }
.embedding-space .axis.y { left: 10px; top: 10px; }
.prompt-pair {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}
.prompt-pair article:first-child {
  border-color: rgba(138, 58, 31, 0.45);
  background: var(--warn-wash);
}
.prompt-pair article:last-child {
  border-color: rgba(42, 93, 87, 0.4);
  background: var(--good-wash);
}
.injection-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr 1fr;
  gap: 14px;
}
.injection-grid mark {
  background: rgba(138, 58, 31, 0.18);
  color: var(--warn);
  padding: 1px 3px;
}
.unsafe-output {
  border-color: var(--warn);
  background: var(--warn-wash);
}
.safe-output {
  border-color: var(--good);
  background: var(--good-wash);
}
.switch {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  white-space: nowrap;
}
.switch input { position: absolute; opacity: 0; pointer-events: none; }
.switch span {
  position: relative;
  width: 46px;
  height: 24px;
  border-radius: 999px;
  background: var(--line-2);
  border: 1px solid var(--line);
}
.switch span::after {
  content: "";
  position: absolute;
  width: 18px;
  height: 18px;
  left: 2px;
  top: 2px;
  border-radius: 50%;
  background: var(--card);
  transition: transform 0.15s ease;
}
.switch input:checked + span { background: var(--good); }
.switch input:checked + span::after { transform: translateX(22px); }
@media (max-width: 860px) {
  .panel-head,
  .multimodal-layout { grid-template-columns: 1fr; display: grid; }
  .train-use,
  .prompt-pair,
  .injection-grid { grid-template-columns: 1fr; }
  .arrow-flow { transform: rotate(90deg); }
  .timeline { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 560px) {
  .timeline { grid-template-columns: 1fr; }
  .context-bar span { font-size: 0; }
}

.canvas-wrap {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 12px;
  display: flex; justify-content: center;
}
canvas { display: block; max-width: 100%; height: auto; image-rendering: -moz-crisp-edges; image-rendering: pixelated; }
.canvas-wrap.smooth canvas { image-rendering: auto; }

.controls {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px 22px;
  margin-top: 16px;
}
.control { display: flex; flex-direction: column; gap: 4px; font-size: 13px; }
.control-label {
  display: flex; justify-content: space-between; align-items: baseline;
  color: var(--muted); font-family: var(--mono); font-size: 11px;
  text-transform: uppercase; letter-spacing: 0.06em;
}
.control-label .val { color: var(--ink); font-family: var(--mono); font-size: 12px; }
.control input[type="range"] { width: 100%; }
.control select, .control input[type="text"] {
  padding: 6px 8px;
  border: 1px solid var(--line); border-radius: 6px;
  background: var(--paper); color: var(--ink);
}

.actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 14px; }
.btn {
  padding: 8px 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--mono); font-size: 12px;
  text-transform: uppercase; letter-spacing: 0.05em;
  transition: background 0.12s ease, border-color 0.12s ease;
}
.btn:hover:not(:disabled) { background: var(--accent-wash); border-color: var(--accent-soft); }
.btn.primary { background: var(--ink); color: var(--card); border-color: var(--ink); }
.btn.primary:hover:not(:disabled) { background: var(--accent); border-color: var(--accent); }
.btn.warn { background: var(--warn-wash); border-color: var(--warn); color: var(--warn); }

.metrics {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 18px;
  margin-top: 16px;
  padding: 14px 16px;
  background: var(--paper-2);
  border: 1px solid var(--line);
  border-radius: 10px;
}
.metric .lbl { display: block; color: var(--muted); font-family: var(--mono); font-size: 10.5px; text-transform: uppercase; letter-spacing: 0.06em; margin-bottom: 2px; }
.metric .num { display: block; font-family: var(--serif); font-size: 28px; line-height: 1.05; color: var(--ink); }
.metric .unit { color: var(--muted); font-family: var(--mono); font-size: 11px; margin-left: 4px; }

.kernel-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 56px));
  gap: 6px;
  width: max-content;
}
.kernel-grid input {
  width: 56px; height: 38px;
  text-align: center;
  border: 1px solid var(--line); border-radius: 6px;
  background: var(--paper);
  font-family: var(--mono); font-size: 13px;
}

.kv {
  display: grid;
  grid-template-columns: minmax(140px, auto) 1fr;
  gap: 6px 14px;
  font-size: 13px;
}
.kv dt { color: var(--muted); font-family: var(--mono); font-size: 11px; text-transform: uppercase; letter-spacing: 0.06em; align-self: center; }
.kv dd { margin: 0; color: var(--ink-2); }

.bars { display: flex; flex-direction: column; gap: 6px; margin-top: 14px; }
.bar-row {
  display: grid;
  grid-template-columns: 110px 1fr 56px;
  align-items: center;
  gap: 12px;
  font-family: var(--mono); font-size: 12.5px;
}
.bar-row .lbl { color: var(--ink); }
.bar-row .pct { color: var(--muted); text-align: right; }
.bar-track {
  position: relative;
  height: 14px;
  background: var(--paper-2);
  border: 1px solid var(--line);
  border-radius: 4px;
  overflow: hidden;
}
.bar-fill {
  position: absolute; left: 0; top: 0; bottom: 0;
  background: linear-gradient(90deg, var(--accent-soft), var(--accent));
  transition: width 0.4s ease;
}
.bar-row.is-pick .bar-fill { background: linear-gradient(90deg, var(--good), #1d4a44); }

.callout {
  margin-top: 18px;
  padding: 14px 16px;
  background: var(--accent-wash);
  border: 1px solid var(--accent-soft);
  border-radius: 10px;
  font-size: 14px; color: var(--ink-2);
}
.callout strong { color: var(--ink); }
.callout.warn { background: var(--warn-wash); border-color: var(--warn); }

.image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(110px, 1fr));
  gap: 8px;
}
.image-grid button {
  padding: 0;
  background: transparent;
  border: 2px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
  aspect-ratio: 1;
}
.image-grid button.is-active { border-color: var(--accent); }
.image-grid button canvas { width: 100%; height: 100%; }

.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}
.split .canvas-wrap { padding: 0; border-radius: 10px; }
.split figcaption {
  margin-top: 8px;
  font-family: var(--mono); font-size: 11px; color: var(--muted);
  text-transform: uppercase; letter-spacing: 0.06em;
}
@media (max-width: 760px) { .split { grid-template-columns: 1fr; } }

.colophon {
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px;
  margin-top: 60px; padding-top: 24px;
  border-top: 1px solid var(--line);
  color: var(--muted); font-family: var(--mono);
  font-size: 11px; text-transform: uppercase; letter-spacing: 0.06em;
}
.colophon a { color: var(--muted); border-bottom-color: transparent; }
.colophon a:hover { color: var(--ink); border-bottom-color: var(--ink); }

@media (max-width: 720px) {
  .topbar { flex-direction: column; align-items: flex-start; }
  h1 { font-size: 40px; }
}