/* Birthday in π — styles */
:root {
  --bg: #0d1117;
  --surface: #161b22;
  --border: #30363d;
  --text: #e6edf3;
  --muted: #8b949e;
  --accent: #58a6ff;
  --accent-dim: #388bfd;
  --success: #3fb950;
  --highlight: #ffd700;
  --radius: 12px;
  --font-sans: 'Source Sans 3', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, monospace;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
}

.page {
  max-width: 720px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

.header {
  text-align: center;
  margin-bottom: 2.5rem;
}

.home-link {
  display: inline-block;
  color: var(--muted);
  text-decoration: none;
  font-size: 0.9rem;
  margin-bottom: 1rem;
}
.home-link:hover {
  color: var(--accent);
}

.title {
  font-size: 2.25rem;
  font-weight: 700;
  margin: 0 0 0.5rem;
  letter-spacing: -0.02em;
}

.tagline {
  color: var(--muted);
  margin: 0;
  font-size: 1.1rem;
}

.main {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

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

.card h2 {
  margin: 0 0 0.5rem;
  font-size: 1.25rem;
}

.hint {
  color: var(--muted);
  font-size: 0.9rem;
  margin: 0 0 1rem;
}

.date-form {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.date-inputs {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.date-field {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.date-field label {
  font-size: 0.8rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.date-field select,
.date-field input {
  padding: 0.6rem 0.8rem;
  font-size: 1rem;
  font-family: inherit;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  min-width: 120px;
}

.date-field input[type="number"] {
  min-width: 90px;
}

.date-field select:focus,
.date-field input:focus {
  outline: none;
  border-color: var(--accent);
}

.name-input-wrap {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.name-input-wrap input {
  flex: 1;
  min-width: 160px;
  padding: 0.6rem 1rem;
  font-size: 1rem;
  font-family: inherit;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
}

.name-input-wrap input:focus {
  outline: none;
  border-color: var(--accent);
}

.btn {
  padding: 0.65rem 1.25rem;
  font-size: 1rem;
  font-family: inherit;
  font-weight: 600;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s;
}

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

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

.btn-primary:active {
  transform: scale(0.98);
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.loading {
  text-align: center;
  padding: 2rem;
  color: var(--muted);
}

.loading.hidden {
  display: none !important;
}

.spinner {
  width: 40px;
  height: 40px;
  margin: 0 auto 1rem;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

.result-section {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
}

.result-section.hidden {
  display: none !important;
}

.result-section.found .result-status {
  color: var(--success);
}

.result-section.not-found .result-status {
  color: #f85149;
}

.result-status {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

.result-detail {
  font-size: 0.9rem;
  color: var(--muted);
  margin-bottom: 1rem;
}

.digits-display {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem 1.25rem;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  line-height: 1.8;
  overflow-x: auto;
  margin: 1rem 0;
  position: relative;
}

.digits-display .before {
  color: var(--muted);
}

.digits-display .match {
  background: var(--highlight);
  color: var(--bg);
  padding: 0 2px;
  border-radius: 2px;
  font-weight: 600;
}

.digits-display .after {
  color: var(--muted);
}

.position-bar {
  height: 8px;
  background: var(--border);
  border-radius: 4px;
  overflow: hidden;
  margin: 1rem 0;
}

.position-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--success));
  border-radius: 4px;
  transition: width 0.5s ease-out;
}

.position-label {
  font-size: 0.85rem;
  color: var(--muted);
  margin-top: 0.5rem;
}

.permutations-tried {
  font-size: 0.85rem;
  color: var(--muted);
  margin-top: 0.75rem;
}

.trivia-section {
  margin-top: 2rem;
}

.trivia-section h2 {
  font-size: 1.5rem;
  margin-bottom: 1rem;
}

.trivia-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  margin-bottom: 1rem;
}

.trivia-card h3 {
  font-size: 1rem;
  margin: 0 0 0.5rem;
  color: var(--accent);
}

.trivia-card p,
.trivia-card ul {
  margin: 0;
  color: var(--text);
  font-size: 0.95rem;
}

.trivia-card ul {
  padding-left: 1.25rem;
}

.trivia-card li {
  margin-bottom: 0.25rem;
}

.footer {
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  text-align: center;
  font-size: 0.9rem;
  color: var(--muted);
}

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

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

/* Animation for digits scrolling into view */
@keyframes highlight-pulse {
  0%, 100% { background: var(--highlight); }
  50% { background: #ffec8b; }
}

.digits-display .match.animate {
  animation: highlight-pulse 1.5s ease-in-out 2;
}