@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@300;400;600;700&family=Space+Mono:wght@400;700&display=swap');

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

:root {
  --bg-primary: #0a0a0a;
  --bg-secondary: #111111;
  --bg-card: #161616;
  --accent: #00ff88;
  --accent-warn: #ff6b35;
  --text-primary: #e8e8e8;
  --text-secondary: #888888;
  --border: #2a2a2a;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --font-display: 'Space Mono', monospace;
}

html, body {
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.6;
  min-height: 100vh;
}

/* ── HEADER ── */
header {
  border-bottom: 1px solid var(--border);
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--bg-secondary);
}
.header-left { display: flex; align-items: center; gap: 12px; }
.header-logo {
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 0.08em;
}
.header-sep { color: var(--border); }
.header-title {
  font-size: 12px;
  color: var(--text-secondary);
  letter-spacing: 0.04em;
}
.header-brand {
  font-size: 11px;
  color: var(--text-secondary);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

/* ── LAYOUT ── */
main {
  max-width: 780px;
  margin: 0 auto;
  padding: 28px 20px 60px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

/* ── CARDS ── */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 4px;
  overflow: hidden;
}
.card-header {
  padding: 10px 16px;
  border-bottom: 1px solid var(--border);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 8px;
}
.card-header::before {
  content: '';
  display: inline-block;
  width: 6px;
  height: 6px;
  background: var(--border);
  border-radius: 50%;
}
.card-body { padding: 16px; }

/* ── SIGNAL METRICS ── */
.metrics-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}
.metric-item { display: flex; flex-direction: column; gap: 3px; }
.metric-value {
  font-size: 18px;
  font-weight: 700;
  color: var(--accent);
  font-family: var(--font-display);
}
.metric-label {
  font-size: 10px;
  color: var(--text-secondary);
  letter-spacing: 0.06em;
}
.metrics-divider {
  grid-column: 1 / -1;
  border: none;
  border-top: 1px solid var(--border);
  margin: 4px 0;
}
.metric-row {
  grid-column: 1 / -1;
  display: flex;
  gap: 24px;
}
.metric-tag {
  font-size: 11px;
  color: var(--text-secondary);
}
.metric-tag span { color: var(--text-primary); }

/* ── AUTH ── */
.auth-row {
  display: flex;
  gap: 8px;
  align-items: center;
}
.token-input {
  flex: 1;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 3px;
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: 13px;
  padding: 9px 12px;
  outline: none;
  letter-spacing: 0.04em;
  transition: border-color 0.15s;
}
.token-input:focus { border-color: var(--accent); }
.token-input::placeholder { color: #444; }
.btn {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 3px;
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  padding: 9px 16px;
  cursor: pointer;
  letter-spacing: 0.06em;
  transition: border-color 0.15s, color 0.15s;
  white-space: nowrap;
}
.btn:hover { border-color: var(--accent); color: var(--accent); }
.btn:disabled { opacity: 0.35; cursor: not-allowed; }
.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #000;
  font-weight: 700;
}
.btn-primary:hover { background: #00cc6e; border-color: #00cc6e; color: #000; }
.btn-primary:disabled { background: #1a3d2b; border-color: #1a3d2b; color: #444; }

.status-row {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 10px;
  font-size: 12px;
  color: var(--text-secondary);
}
.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #333;
  flex-shrink: 0;
}
.status-dot.connected { background: var(--accent); box-shadow: 0 0 6px var(--accent); }
.status-dot.error { background: #ff4444; }

/* ── SUBMIT ── */
.drop-zone {
  border: 1px dashed var(--border);
  border-radius: 3px;
  padding: 20px;
  text-align: center;
  cursor: pointer;
  color: var(--text-secondary);
  font-size: 12px;
  transition: border-color 0.15s, color 0.15s;
  letter-spacing: 0.04em;
}
.drop-zone:hover, .drop-zone.drag-over {
  border-color: var(--accent);
  color: var(--accent);
}
.drop-zone input[type=file] { display: none; }

.or-divider {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 14px 0;
  color: var(--border);
  font-size: 11px;
  letter-spacing: 0.08em;
}
.or-divider::before, .or-divider::after {
  content: '';
  flex: 1;
  border-top: 1px solid var(--border);
}

.dimacs-label {
  font-size: 11px;
  color: var(--text-secondary);
  margin-bottom: 8px;
  letter-spacing: 0.06em;
}
.dimacs-textarea {
  width: 100%;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 3px;
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: 12px;
  padding: 10px 12px;
  resize: vertical;
  min-height: 100px;
  outline: none;
  line-height: 1.5;
  transition: border-color 0.15s;
}
.dimacs-textarea:focus { border-color: var(--accent); }
.dimacs-textarea::placeholder { color: #333; }

.submit-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 12px;
}
.instance-info { font-size: 11px; color: var(--text-secondary); }

/* ── RESULT ── */
.result-panel { display: none; }
.result-panel.visible { display: block; }

.result-grid {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 6px 12px;
  align-items: center;
}
.result-key {
  font-size: 11px;
  color: var(--text-secondary);
  letter-spacing: 0.06em;
}
.result-val {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-primary);
  font-family: var(--font-display);
}
.result-sat {
  color: var(--accent);
  display: flex;
  align-items: center;
  gap: 8px;
}
.result-unsat { color: var(--accent-warn); }
.result-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
  animation: pulse 1.4s ease-in-out infinite;
}
.result-dot.warn { background: var(--accent-warn); animation: pulse-warn 1.4s ease-in-out infinite; }

@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(0,255,136,0.6); }
  50% { box-shadow: 0 0 0 6px rgba(0,255,136,0); }
}
@keyframes pulse-warn {
  0%, 100% { box-shadow: 0 0 0 0 rgba(255,107,53,0.6); }
  50% { box-shadow: 0 0 0 6px rgba(255,107,53,0); }
}

.result-divider {
  grid-column: 1 / -1;
  border: none;
  border-top: 1px solid var(--border);
  margin: 6px 0;
}

/* loading state */
.loading-row {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 12px;
  color: var(--text-secondary);
  padding: 10px 0;
}
.spinner {
  width: 12px;
  height: 12px;
  border: 2px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ── HISTORY ── */
.history-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 12px;
}
.history-table th {
  text-align: left;
  padding: 6px 10px;
  font-size: 10px;
  color: var(--text-secondary);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  border-bottom: 1px solid var(--border);
  font-weight: 400;
}
.history-table td {
  padding: 7px 10px;
  border-bottom: 1px solid #1a1a1a;
  font-family: var(--font-mono);
  color: var(--text-secondary);
}
.history-table td:first-child { color: #444; font-size: 11px; }
.history-table .sat-cell { color: var(--accent); font-weight: 600; }
.history-table .unsat-cell { color: var(--accent-warn); font-weight: 600; }
.history-empty {
  text-align: center;
  padding: 20px;
  color: #333;
  font-size: 11px;
  letter-spacing: 0.06em;
}

/* ── SESSION BANNER ── */
.session-banner {
  display: none;
  background: #0d1f15;
  border: 1px solid #1a3d2b;
  border-radius: 3px;
  padding: 10px 16px;
  font-size: 12px;
  color: var(--text-secondary);
  gap: 16px;
  align-items: center;
}
.session-banner.visible { display: flex; }
.session-stat { display: flex; gap: 6px; align-items: baseline; }
.session-num { color: var(--accent); font-weight: 700; font-size: 14px; font-family: var(--font-display); }

/* ── SCROLLBAR ── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg-primary); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }