:root {
  --bg: #f4f7f8;
  --panel: #ffffff;
  --ink: #13272f;
  --muted: #597179;
  --accent: #0a8f7b;
  --accent-2: #f2b84b;
  --danger: #d8534f;
  --line: #e1ebee;
}

* {
  box-sizing: border-box;
}

html,
body {
  height: auto;
  min-height: 100%;
  overflow-y: scroll !important;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
  scrollbar-gutter: stable both-edges;
}

body {
  margin: 0;
  font-family: "Avenir Next", "Segoe UI", sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at 20% 10%, #d8f4ef 0%, transparent 35%),
    radial-gradient(circle at 90% 90%, #fff4da 0%, transparent 30%),
    var(--bg);
}

.site-header {
  padding: 1.2rem 1.6rem;
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(4px);
  display: flex;
  gap: 1rem;
  justify-content: space-between;
  align-items: end;
  flex-wrap: wrap;
}

.kicker {
  margin: 0;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-size: 0.72rem;
  color: var(--muted);
}

h1 {
  margin: 0.1rem 0;
  font-size: 1.4rem;
}

h2 {
  margin-top: 0;
  font-size: 1.1rem;
}

nav {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

nav a {
  text-decoration: none;
  color: var(--ink);
  border: 1px solid var(--line);
  padding: 0.45rem 0.7rem;
  border-radius: 999px;
  font-size: 0.9rem;
  background: #fff;
}

nav a.active {
  border-color: var(--accent);
  color: var(--accent);
  font-weight: 600;
}

.layout {
  display: grid;
  grid-template-columns: minmax(260px, 340px) 1fr;
  gap: 1rem;
  padding: 1rem;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 1rem;
  box-shadow: 0 12px 20px rgba(14, 33, 41, 0.06);
}

.controls label,
.controls select,
.controls input,
.controls button {
  display: block;
  width: 100%;
}

.controls label {
  margin-top: 0.7rem;
  margin-bottom: 0.25rem;
  font-size: 0.9rem;
}

.controls input[type="range"] {
  accent-color: var(--accent);
}

.button-row {
  margin-top: 0.8rem;
  display: flex;
  gap: 0.6rem;
}

button {
  border: 1px solid var(--line);
  background: #fff;
  color: var(--ink);
  border-radius: 9px;
  padding: 0.5rem;
  font-weight: 600;
  cursor: pointer;
}

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

select {
  padding: 0.45rem;
  border-radius: 8px;
  border: 1px solid var(--line);
}

.checkboxes {
  margin-top: 0.8rem;
  display: grid;
  gap: 0.3rem;
}

.checkboxes label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin: 0;
}

.model-definition {
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0.7rem 0.8rem;
  background: #fcfeff;
  font-size: 0.9rem;
  color: #23343b;
}

.model-definition p {
  margin: 0.18rem 0;
}

.landscape-summary {
  margin: 0.7rem 0 0.8rem;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
  gap: 0.5rem;
}

.landscape-pill {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0.42rem 0.55rem;
  background: #fcfeff;
  font-size: 0.88rem;
}

.landscape-controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.7rem;
}

.landscape-controls label {
  min-width: 0;
  margin: 0;
  width: auto;
  font-weight: 700;
}

.landscape-controls select {
  min-width: 220px;
  width: auto;
}

.viz-btn {
  border: 1px solid var(--line);
  background: #fff;
  color: var(--ink);
  border-radius: 9px;
  padding: 0.45rem 0.7rem;
  font-weight: 600;
  width: auto;
}

.viz-btn:hover {
  border-color: var(--accent);
}

.landscape-controls.toggles {
  margin-bottom: 0.8rem;
}

.viz-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #fff;
  padding: 0.36rem 0.62rem;
  font-size: 0.88rem;
  font-weight: 600;
}

.viz-toggle input {
  margin: 0;
}

.landscape-plot-wrap {
  width: min(100%, 980px);
  height: 620px;
  min-width: 320px;
  min-height: 320px;
  max-width: 1400px;
  max-height: 900px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  contain: layout size paint;
  min-inline-size: 0;
  min-block-size: 0;
}

.landscape-plot {
  width: 100%;
  height: 100%;
  display: block;
  overflow: hidden;
  min-width: 0;
  min-height: 0;
}

.landscape-plot-wrap:fullscreen {
  width: 100vw !important;
  height: 100vh !important;
  max-width: none;
  max-height: none;
  border-radius: 0;
  border-width: 0;
}

.plot-fallback {
  height: 100%;
  min-height: 240px;
  display: grid;
  place-items: center;
  text-align: center;
  color: #2a3c45;
  padding: 1rem;
  font-size: 0.92rem;
}

.viz-info-row {
  margin: 0.6rem 0 0.8rem;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 0.55rem;
}

.viz-chip {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0.45rem 0.6rem;
  background: #fcfeff;
  font-size: 0.88rem;
}

.viz-chip.warning {
  border-color: #f2b84b;
}

.stats {
  margin-top: 0.8rem;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 0.55rem;
  font-size: 0.9rem;
}

.stats span {
  display: block;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0.45rem 0.6rem;
  background: #fcfeff;
}

.hint {
  margin: 0.8rem 0 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.slice-label {
  margin: 0.65rem 0 0;
  color: var(--muted);
  font-size: 0.85rem;
}

.iteration-block {
  margin-top: 0.9rem;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 0.55rem;
}

.iteration-block label {
  margin: 0;
  min-width: 0;
  font-size: 0.9rem;
}

.iteration-block input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
}

.iteration-block span {
  font-size: 0.86rem;
  color: #324b55;
  font-weight: 600;
}

.classifier-panel {
  margin-top: 0.9rem;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0.65rem;
  background: #fff;
}

.classifier-panel h3 {
  margin: 0 0 0.5rem;
  font-size: 0.98rem;
}

#classifierCanvas {
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
}

.page-copy {
  max-width: 760px;
  margin: 1.2rem auto;
  line-height: 1.6;
}

@media (max-width: 980px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .landscape-plot-wrap {
    width: 100%;
    height: 420px;
    min-height: 280px;
  }
}

.home-page {
  margin-top: 1rem;
}

.home-grid {
  margin-top: 1rem;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
  gap: 0.9rem;
}

.home-card {
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.9rem;
  background: #fcfeff;
}

.home-card h3 {
  margin: 0;
  font-size: 1.05rem;
}

.home-card p {
  margin: 0.45rem 0 0.9rem;
  color: var(--muted);
}

.cta-button {
  display: inline-block;
  text-decoration: none;
  border: 1px solid var(--accent);
  color: #fff;
  background: var(--accent);
  border-radius: 9px;
  padding: 0.5rem 0.7rem;
  font-weight: 600;
}

.cta-button.secondary {
  background: #fff;
  color: var(--ink);
  border-color: var(--line);
}

.home-card.muted {
  background: #f8fafb;
}

.coming-soon {
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 600;
}

.confusion-panel h3 {
  margin: 1rem 0 0.45rem;
  font-size: 1rem;
}

.exercise-table {
  width: 100%;
  border-collapse: collapse;
  margin: 0.45rem 0 1rem;
  font-size: 0.9rem;
}

.exercise-table th,
.exercise-table td {
  border: 1px solid var(--line);
  padding: 0.45rem 0.5rem;
  text-align: left;
  vertical-align: middle;
  background: #fff;
}

.exercise-table th {
  background: #f6fbfc;
}

.exercise-table input,
.exercise-table select {
  width: 100%;
  padding: 0.4rem;
  border: 1px solid var(--line);
  border-radius: 6px;
}

.worked-tag {
  color: var(--muted);
  font-size: 0.82rem;
}

.solution-block {
  margin-top: 1rem;
  border-top: 1px dashed var(--line);
  padding-top: 0.8rem;
}

.solution-block h4 {
  margin: 0.8rem 0 0.35rem;
}