:root {
  --bg: #071018;
  --bg-soft: #0c1722;
  --panel: #101f2c;
  --panel-2: #142636;
  --line: #284052;
  --text: #eaf2f7;
  --muted: #9cb0bd;
  --accent: #53d3a7;
  --accent-2: #6ca8ff;
  --accent-3: #e9b75b;
  --danger: #f27f7f;
  --success: #68d391;
  --shadow: 0 20px 70px rgba(0, 0, 0, 0.3);
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background:
    radial-gradient(circle at 15% 0%, rgba(83, 211, 167, 0.12), transparent 32rem),
    radial-gradient(circle at 90% 15%, rgba(108, 168, 255, 0.10), transparent 30rem),
    var(--bg);
  color: var(--text);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.6;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
button, select, input { font: inherit; }
button { cursor: pointer; }
code {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  color: #b8e8d7;
}

.skip-link {
  position: fixed;
  top: -5rem;
  left: 1rem;
  z-index: 1000;
  background: white;
  color: #111;
  padding: 0.75rem 1rem;
  border-radius: 0.4rem;
}
.skip-link:focus { top: 1rem; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 1px solid rgba(156, 176, 189, 0.18);
  background: rgba(7, 16, 24, 0.86);
  backdrop-filter: blur(18px);
}
.header-inner {
  width: min(1180px, calc(100% - 2rem));
  margin: 0 auto;
  min-height: 4.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}
.brand { color: var(--text); font-weight: 750; letter-spacing: -0.02em; }
nav { display: flex; gap: 1rem; font-size: 0.92rem; }
nav a { color: var(--muted); }

.section-shell {
  width: min(1180px, calc(100% - 2rem));
  margin: 0 auto;
  padding: 5rem 0;
}
.compact-section { padding-top: 1rem; }
.hero { padding-top: 6.5rem; }
.eyebrow-row { display: flex; flex-wrap: wrap; gap: 0.6rem; align-items: center; margin-bottom: 1.5rem; }
.eyebrow, .status-chip, .label {
  display: inline-flex;
  align-items: center;
  width: fit-content;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-size: 0.72rem;
  font-weight: 750;
}
.eyebrow { color: var(--accent); }
.status-chip {
  color: #c8d8e1;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.32rem 0.65rem;
}
.label { color: var(--accent-2); }

.hero-grid { display: grid; grid-template-columns: minmax(0, 1.45fr) minmax(18rem, 0.75fr); gap: 3rem; align-items: start; }
h1 { font-size: clamp(4rem, 11vw, 8rem); line-height: 0.9; margin: 0; letter-spacing: -0.07em; }
.subtitle { font-size: clamp(1.35rem, 3vw, 2.2rem); color: #c9d8e1; max-width: 48rem; margin: 1.4rem 0 0; line-height: 1.2; letter-spacing: -0.03em; }
.lede { color: var(--muted); font-size: 1.08rem; max-width: 50rem; margin-top: 1.5rem; }
.hero-actions { display: flex; gap: 0.8rem; flex-wrap: wrap; margin-top: 2rem; }

.primary-button, .secondary-button, .ghost-button, .profile-button, .graph-filter {
  border-radius: 0.65rem;
  padding: 0.7rem 1rem;
  border: 1px solid transparent;
  transition: transform 120ms ease, background 120ms ease, border-color 120ms ease;
}
.primary-button { background: var(--accent); color: #042016; font-weight: 750; }
.secondary-button { background: transparent; color: var(--text); border-color: var(--line); }
.ghost-button, .profile-button, .graph-filter { background: rgba(255,255,255,0.02); color: var(--muted); border-color: var(--line); }
.primary-button:hover, .secondary-button:hover, .ghost-button:hover, .profile-button:hover, .graph-filter:hover { transform: translateY(-1px); text-decoration: none; }
.profile-button.active, .graph-filter.active { background: rgba(83, 211, 167, 0.14); color: var(--accent); border-color: rgba(83, 211, 167, 0.5); }

.source-card, .classification-card, .canvas-panel, .detail-panel, .sandbox-controls, .sandbox-result, .chart-card, .analysis-grid article, .limits-panel, .connections-grid a, .source-list {
  border: 1px solid rgba(156, 176, 189, 0.18);
  background: linear-gradient(150deg, rgba(20, 38, 54, 0.92), rgba(12, 23, 34, 0.94));
  border-radius: 1rem;
  box-shadow: var(--shadow);
}
.source-card { padding: 1.5rem; }
.source-card h2 { margin-top: 0; font-size: 1rem; }
.source-card dl div { display: grid; grid-template-columns: 1fr auto; gap: 1rem; border-top: 1px solid rgba(156,176,189,0.12); padding: 0.65rem 0; }
dt { color: var(--muted); }
dd { margin: 0; text-align: right; }
.small-note { font-size: 0.82rem; color: var(--muted); }

.section-heading { display: grid; grid-template-columns: 3.4rem 1fr; gap: 1rem; align-items: start; margin-bottom: 2rem; }
.section-number { color: var(--accent); font-family: monospace; font-size: 0.9rem; padding-top: 0.45rem; }
.section-heading h2 { margin: 0; font-size: clamp(1.8rem, 4vw, 3rem); letter-spacing: -0.04em; line-height: 1.08; }
.section-heading p { margin: 0.5rem 0 0; color: var(--muted); max-width: 48rem; }

.classification-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; }
.classification-card { padding: 1.5rem; box-shadow: none; }
.classification-card h3 { margin: 0.6rem 0; font-size: 1.35rem; }
.classification-card p { color: var(--muted); margin-bottom: 0; }

.control-bar { display: flex; flex-wrap: wrap; align-items: center; gap: 0.6rem; margin-bottom: 1rem; }
.control-label { font-size: 0.8rem; color: var(--muted); margin-right: 0.3rem; text-transform: uppercase; letter-spacing: 0.12em; }
.visual-grid { display: grid; gap: 1rem; }
.wide-left { grid-template-columns: minmax(0, 2fr) minmax(17rem, 0.8fr); }
.canvas-panel { position: relative; min-height: 31rem; overflow: hidden; }
.canvas-panel.tall { min-height: 37rem; }
.canvas-panel canvas { width: 100%; height: 100%; min-height: inherit; display: block; touch-action: none; }
.canvas-legend {
  position: absolute;
  left: 1rem;
  bottom: 1rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  background: rgba(7,16,24,0.78);
  border: 1px solid rgba(156,176,189,0.2);
  border-radius: 0.65rem;
  padding: 0.55rem 0.7rem;
  font-size: 0.74rem;
  color: var(--muted);
  pointer-events: none;
}
.canvas-legend span { display: flex; gap: 0.35rem; align-items: center; }
.canvas-legend i { width: 0.65rem; height: 0.65rem; border-radius: 50%; display: inline-block; }
.required-dot { background: var(--accent); }
.enhanced-dot { background: var(--accent-3); }
.internal-dot { background: #597080; }
.detail-panel { padding: 1.5rem; box-shadow: none; }
.detail-panel h3 { font-size: 1.5rem; margin: 0.6rem 0; }
.detail-panel h4 { margin: 1.4rem 0 0.45rem; font-size: 0.86rem; text-transform: uppercase; letter-spacing: 0.08em; color: #c5d6df; }
.detail-panel p, .detail-panel li { color: var(--muted); }
.detail-panel ul { padding-left: 1.2rem; }
.node-metadata div { border-top: 1px solid rgba(156,176,189,0.12); padding: 0.65rem 0; }
.node-metadata dt { font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.08em; }
.node-metadata dd { text-align: left; margin-top: 0.15rem; color: var(--text); }

.sandbox-grid { display: grid; grid-template-columns: minmax(18rem, 0.9fr) minmax(18rem, 1.1fr); gap: 1rem; }
.sandbox-controls, .sandbox-result { padding: 1.5rem; box-shadow: none; }
.sandbox-controls { display: grid; gap: 1rem; }
.sandbox-controls label { display: grid; gap: 0.35rem; color: #d8e3e9; }
.sandbox-controls select {
  width: 100%;
  background: #09141d;
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 0.55rem;
  padding: 0.65rem;
}
fieldset { border: 1px solid var(--line); border-radius: 0.7rem; padding: 1rem; display: grid; gap: 0.65rem; }
legend { padding: 0 0.4rem; color: var(--muted); font-size: 0.82rem; }
fieldset label { display: flex !important; align-items: flex-start; gap: 0.55rem !important; color: var(--muted) !important; font-size: 0.9rem; }
input[type="checkbox"] { accent-color: var(--accent); margin-top: 0.25rem; }
.result-badge { width: fit-content; border-radius: 999px; padding: 0.35rem 0.7rem; text-transform: uppercase; letter-spacing: 0.08em; font-size: 0.72rem; font-weight: 800; }
.result-badge.pending { background: rgba(108,168,255,0.15); color: var(--accent-2); }
.result-badge.pass { background: rgba(104,211,145,0.15); color: var(--success); }
.result-badge.fail { background: rgba(242,127,127,0.15); color: var(--danger); }
.sandbox-result h3 { font-size: 1.7rem; margin-bottom: 0.2rem; }
.sandbox-result p, .sandbox-result li { color: var(--muted); }
.sandbox-result ul { padding-left: 1.2rem; }
.receipt-box { margin-top: 1.5rem; display: grid; grid-template-columns: 1fr auto; gap: 0.65rem 1rem; border-top: 1px solid var(--line); padding-top: 1rem; }
.receipt-box span { color: var(--muted); }

.chart-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.chart-card { padding: 1.25rem; box-shadow: none; }
.chart-heading { display: flex; justify-content: space-between; align-items: flex-start; gap: 1rem; }
.chart-heading h3 { margin: 0.35rem 0 0; }
.chart-wrap { height: 23rem; margin-top: 1rem; }
.chart-wrap canvas { width: 100% !important; height: 100% !important; }
.receipt-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; margin-top: 1rem; }
.receipt-grid article { border: 1px solid rgba(156,176,189,0.18); border-radius: 0.8rem; padding: 1.2rem; background: rgba(16,31,44,0.75); }
.metric { display: block; font-size: 2.4rem; font-weight: 800; letter-spacing: -0.05em; color: var(--accent); }
.receipt-grid h3 { font-size: 1rem; margin: 0.1rem 0; }
.receipt-grid p { color: var(--muted); margin-bottom: 0; font-size: 0.85rem; }

.analysis-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1rem; }
.analysis-grid article { padding: 1.5rem; box-shadow: none; }
.analysis-grid h3 { margin-top: 0; }
.analysis-grid p { color: var(--muted); }
.limits-panel { padding: 1.5rem; margin-top: 1rem; box-shadow: none; border-color: rgba(233,183,91,0.35); }
.limits-panel h3 { margin-top: 0; color: var(--accent-3); }
.limits-panel li { color: var(--muted); margin: 0.45rem 0; }

.connections-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; }
.connections-grid a { padding: 1.3rem; box-shadow: none; display: grid; gap: 0.5rem; color: var(--text); }
.connections-grid a:hover { border-color: rgba(83,211,167,0.55); text-decoration: none; transform: translateY(-2px); }
.connections-grid span { color: var(--muted); font-size: 0.88rem; }
.source-list { padding: 1rem 1.4rem; box-shadow: none; }
.source-list div { display: grid; grid-template-columns: minmax(12rem, 0.55fr) 1fr; gap: 1rem; padding: 0.75rem 0; border-bottom: 1px solid rgba(156,176,189,0.12); }
.source-list div:last-child { border-bottom: 0; }
.source-list span { color: var(--muted); }
.source-list code { overflow-wrap: anywhere; }

.site-footer {
  width: min(1180px, calc(100% - 2rem));
  margin: 0 auto;
  padding: 2rem 0 4rem;
  border-top: 1px solid rgba(156,176,189,0.18);
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  color: var(--muted);
}
.site-footer div { display: grid; }
.site-footer strong { color: var(--text); }

@media (max-width: 900px) {
  .hero-grid, .wide-left, .sandbox-grid, .chart-grid { grid-template-columns: 1fr; }
  .classification-grid, .connections-grid { grid-template-columns: 1fr 1fr; }
  .receipt-grid { grid-template-columns: 1fr 1fr; }
  .detail-panel { min-height: auto; }
}

@media (max-width: 620px) {
  .header-inner { align-items: flex-start; padding: 0.8rem 0; }
  nav { display: none; }
  .section-shell { padding: 3.8rem 0; }
  .hero { padding-top: 4.5rem; }
  .section-heading { grid-template-columns: 1fr; gap: 0.2rem; }
  .classification-grid, .connections-grid, .receipt-grid, .analysis-grid { grid-template-columns: 1fr; }
  .source-list div { grid-template-columns: 1fr; gap: 0.2rem; }
  .canvas-panel { min-height: 27rem; }
  .canvas-panel.tall { min-height: 32rem; }
  .canvas-legend { right: 1rem; }
  .site-footer { flex-direction: column; }
}

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