* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg: #0d0d0f;
  --surface: #16161a;
  --border: #2a2a35;
  --accent: #7f5af0;
  --accent-dim: #5c3fb0;
  --text: #fffffe;
  --muted: #94a1b2;
  --red: #ef4444;
  --gold: #f59e0b;
  --pi: #06b6d4;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* NAV */
nav {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 0 2rem;
  display: flex;
  align-items: center;
  gap: 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-brand {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--accent);
  text-decoration: none;
  padding: 1rem 1.5rem 1rem 0;
  margin-right: 1rem;
  border-right: 1px solid var(--border);
  letter-spacing: 0.02em;
}

.nav-brand span {
  color: var(--muted);
}

nav a.nav-link {
  color: var(--muted);
  text-decoration: none;
  padding: 1rem 1.2rem;
  font-size: 0.9rem;
  transition: color 0.2s, border-bottom 0.2s;
  border-bottom: 2px solid transparent;
  display: inline-block;
}

nav a.nav-link:hover {
  color: var(--text);
}

nav a.nav-link.active {
  color: var(--accent);
  border-bottom: 2px solid var(--accent);
}

/* MAIN */
main {
  flex: 1;
  padding: 3rem 2rem;
  max-width: 900px;
  margin: 0 auto;
  width: 100%;
}

/* HERO */
.hero {
  text-align: center;
  padding: 4rem 0 3rem;
}

.hero-tag {
  display: inline-block;
  background: rgba(127, 90, 240, 0.15);
  border: 1px solid var(--accent-dim);
  color: var(--accent);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.3rem 0.8rem;
  border-radius: 4px;
  margin-bottom: 1.5rem;
}

.hero h1 {
  font-size: 3rem;
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 1rem;
  letter-spacing: -0.02em;
}

.hero h1 .highlight {
  color: var(--accent);
}

.hero p {
  color: var(--muted);
  font-size: 1.1rem;
  max-width: 540px;
  margin: 0 auto 2rem;
  line-height: 1.7;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.7rem 1.5rem;
  border-radius: 6px;
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.2s;
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
}

.btn-primary:hover {
  background: var(--accent-dim);
}

.btn-outline {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}

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

.btn-group {
  display: flex;
  gap: 0.75rem;
  justify-content: center;
  flex-wrap: wrap;
}

/* CARDS */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.25rem;
  margin-top: 2.5rem;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.5rem;
  transition: border-color 0.2s;
}

.card:hover {
  border-color: var(--accent-dim);
}

.card-icon {
  font-size: 1.8rem;
  margin-bottom: 0.75rem;
}

.card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.4rem;
}

.card p {
  color: var(--muted);
  font-size: 0.875rem;
  line-height: 1.6;
}

/* SECTION */
.section-label {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 1.5rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
}

/* BOARD OF SINS */
.sins-header {
  text-align: center;
  padding: 3rem 0 2rem;
}

.sins-header h1 {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--red);
  margin-bottom: 0.75rem;
}

.sins-header p {
  color: var(--muted);
  max-width: 500px;
  margin: 0 auto;
  line-height: 1.7;
}

.sin-list {
  list-style: none;
  margin-top: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.sin-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--red);
  border-radius: 8px;
  padding: 1.25rem 1.5rem;
  display: flex;
  align-items: flex-start;
  gap: 1rem;
}

.sin-number {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--red);
  opacity: 0.5;
  min-width: 2rem;
  line-height: 1;
}

.sin-content h3 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 0.3rem;
}

.sin-content p {
  color: var(--muted);
  font-size: 0.85rem;
  line-height: 1.6;
}

.severity {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.2rem 0.5rem;
  border-radius: 3px;
  margin-top: 0.4rem;
}

.severity-venial { background: rgba(245, 158, 11, 0.15); color: var(--gold); }
.severity-mortal { background: rgba(239, 68, 68, 0.15); color: var(--red); }

/* PI DAY */
.pi-header {
  text-align: center;
  padding: 3rem 0 2rem;
}

.pi-symbol {
  font-size: 5rem;
  line-height: 1;
  color: var(--pi);
  margin-bottom: 0.5rem;
}

.pi-header h1 {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--pi);
  margin-bottom: 0.75rem;
}

.pi-header .date-badge {
  display: inline-block;
  background: rgba(6, 182, 212, 0.12);
  border: 1px solid rgba(6, 182, 212, 0.3);
  color: var(--pi);
  padding: 0.3rem 0.9rem;
  border-radius: 4px;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  margin-bottom: 1rem;
}

.pi-header p {
  color: var(--muted);
  max-width: 520px;
  margin: 0 auto;
  line-height: 1.7;
}

.pi-digits {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.5rem;
  margin: 2rem 0;
  font-family: 'Courier New', monospace;
  font-size: 1rem;
  color: var(--pi);
  word-break: break-all;
  line-height: 1.8;
  letter-spacing: 0.05em;
}

.pi-digits .pi-label {
  color: var(--muted);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  display: block;
  margin-bottom: 0.75rem;
}

.fun-facts {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
  margin-top: 1.5rem;
}

.fact-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-top: 2px solid var(--pi);
  border-radius: 8px;
  padding: 1.25rem;
}

.fact-card h3 {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--pi);
  margin-bottom: 0.4rem;
}

.fact-card p {
  color: var(--muted);
  font-size: 0.85rem;
  line-height: 1.6;
}

/* FULLSCREEN OVERLAY */
.site-overlay {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 1000;
  background: var(--bg);
  flex-direction: column;
}

.site-overlay.open {
  display: flex;
}

.site-overlay iframe {
  flex: 1;
  width: 100%;
  border: none;
}

.overlay-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  z-index: 1001;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  font-size: 1.4rem;
  line-height: 1;
  width: 2.2rem;
  height: 2.2rem;
  border-radius: 6px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: border-color 0.2s, color 0.2s;
}

.overlay-close:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* CARD LINK */
.card-link {
  display: inline-block;
  margin-top: 0.75rem;
  font-size: 0.8rem;
  color: var(--accent);
  text-decoration: none;
}

.card-link:hover {
  text-decoration: underline;
}

/* STACK PILLS */
.stack-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1rem;
}

.pill {
  background: rgba(127, 90, 240, 0.1);
  border: 1px solid var(--accent-dim);
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 600;
  padding: 0.25rem 0.7rem;
  border-radius: 20px;
}

/* WIP BOX */
.wip-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 3rem 2rem;
  text-align: center;
  margin-top: 2rem;
}

.wip-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
  animation: spin 4s linear infinite;
  display: inline-block;
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

.wip-box h2 {
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.wip-box p {
  color: var(--muted);
  font-size: 0.9rem;
  max-width: 420px;
  margin: 0 auto;
  line-height: 1.7;
}

.wip-box a {
  color: var(--accent);
  text-decoration: none;
}

.wip-box a:hover {
  text-decoration: underline;
}

/* TABS */
.tab-bar {
  display: flex;
  gap: 0.25rem;
  justify-content: center;
  margin-top: 1.75rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.25rem;
  width: fit-content;
  margin-left: auto;
  margin-right: auto;
}

.tab-btn {
  background: transparent;
  border: none;
  color: var(--muted);
  font-size: 0.875rem;
  font-weight: 600;
  padding: 0.5rem 1.25rem;
  border-radius: 6px;
  cursor: pointer;
  transition: color 0.2s, background 0.2s;
}

.tab-btn:hover {
  color: var(--text);
}

.tab-btn.active {
  background: var(--accent);
  color: #fff;
}

/* ROADMAP */
.roadmap {
  display: flex;
  flex-direction: column;
  gap: 0;
  margin-top: 1rem;
  position: relative;
}

.roadmap::before {
  content: '';
  position: absolute;
  left: 1.1rem;
  top: 2.2rem;
  bottom: 2.2rem;
  width: 2px;
  background: var(--border);
}

.roadmap-phase {
  display: flex;
  gap: 1.25rem;
  padding: 0 0 1.5rem;
  position: relative;
}

.phase-marker {
  width: 2.2rem;
  height: 2.2rem;
  min-width: 2.2rem;
  border-radius: 50%;
  background: var(--surface);
  border: 2px solid var(--border);
  color: var(--muted);
  font-size: 0.85rem;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  z-index: 1;
}

.phase-marker.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.phase-body {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.1rem 1.25rem;
  flex: 1;
}

.phase-body h3 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.phase-items {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.phase-items li {
  color: var(--muted);
  font-size: 0.85rem;
  line-height: 1.5;
  padding-left: 1rem;
  position: relative;
}

.phase-items li::before {
  content: '—';
  position: absolute;
  left: 0;
  color: var(--border);
}

/* SPEC TABLES */
.spec-table-wrap,
.model-table-wrap {
  overflow-x: auto;
  margin-top: 1rem;
  border-radius: 8px;
  border: 1px solid var(--border);
}

.spec-table,
.model-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
}

.spec-table th,
.model-table th {
  background: rgba(127, 90, 240, 0.1);
  color: var(--accent);
  font-weight: 700;
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 0.7rem 1rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

.spec-table td,
.model-table td {
  padding: 0.65rem 1rem;
  border-bottom: 1px solid var(--border);
  color: var(--muted);
  vertical-align: top;
}

.spec-table td:first-child,
.model-table td:first-child {
  color: var(--text);
  font-weight: 600;
  white-space: nowrap;
  width: 35%;
}

.spec-table tr:last-child td,
.model-table tr:last-child td {
  border-bottom: none;
}

.spec-table.comparison td:first-child {
  width: 25%;
}

.highlight-cell {
  color: var(--accent) !important;
}

/* DOC HEADER */
.doc-header {
  margin-bottom: 1.5rem;
}

.doc-version {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--muted);
  letter-spacing: 0.05em;
}

/* FOOTER */
footer {
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding: 1.5rem 2rem;
  text-align: center;
  color: var(--muted);
  font-size: 0.8rem;
}

footer a {
  color: var(--accent);
  text-decoration: none;
}

footer a:hover {
  text-decoration: underline;
}