/* css/base.css — Design tokens, reset, utilities, scrollbar, body */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&display=swap');

:root {
  /* Core palette */
  --bg:         #0c0e14;
  --bg-card:    #13151d;
  --bg-card-2:  #181b25;
  --bg-hover:   #1d2030;
  --bg-surface: #222639;
  --border:     #252a3a;
  --border-glow:#3a3f55;

  /* Text */
  --text:       #e8eaf0;
  --text-sec:   #a0a5b8;
  --text-muted: #6b7089;

  /* Accents */
  --ras:     #6366f1;
  --ras-glow:#6366f140;
  --gk:      #10b981;
  --gk-glow: #10b98140;
  --sci:     #f59e0b;
  --sci-glow:#f59e0b40;
  --danger:  #ef4444;
  --purple:  #a855f7;

  /* Gradients */
  --grad-ras: linear-gradient(135deg, #6366f1, #818cf8);
  --grad-gk:  linear-gradient(135deg, #10b981, #34d399);
  --grad-sci: linear-gradient(135deg, #f59e0b, #fcd34d);
  --grad-hero:linear-gradient(135deg, #1e1b4b 0%, #0c0e14 100%);

  /* Radii / shadows */
  --radius:    12px;
  --radius-sm: 8px;
  --radius-xs: 6px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,.3);
  --shadow-md: 0 4px 16px rgba(0,0,0,.4);
  --shadow-lg: 0 8px 32px rgba(0,0,0,.5);
  --shadow-glow-ras: 0 0 20px var(--ras-glow);
  --shadow-glow-gk:  0 0 20px var(--gk-glow);
  --shadow-glow-sci: 0 0 20px var(--sci-glow);

  /* Subject accent palette */
  --subj-0: #6366f1; --subj-1: #10b981; --subj-2: #f59e0b;
  --subj-3: #ec4899; --subj-4: #06b6d4; --subj-5: #8b5cf6;
  --subj-6: #f43f5e; --subj-7: #14b8a6; --subj-8: #f97316;
  --subj-9: #3b82f6; --subj-10:#a3e635; --subj-11:#e879f9;

  /* Transitions */
  --ease: cubic-bezier(.4,0,.2,1);
  --dur:  .25s;
}

/* ---- Light Theme ---- */
[data-theme="light"] {
  --bg:         #f5f6fa;
  --bg-card:    #ffffff;
  --bg-card-2:  #f0f1f5;
  --bg-hover:   #e8e9ef;
  --bg-surface: #e2e4eb;
  --border:     #d4d6de;
  --border-glow:#bfc2cc;
  --text:       #1a1c24;
  --text-sec:   #4a4e5c;
  --text-muted: #7b7f90;
  --shadow-sm:  0 1px 3px rgba(0,0,0,.08);
  --shadow-md:  0 4px 16px rgba(0,0,0,.1);
  --shadow-lg:  0 8px 32px rgba(0,0,0,.12);
  --grad-hero:  linear-gradient(135deg, #eef2ff 0%, #f5f6fa 100%);
}
[data-theme="light"] .app-header { background: rgba(255,255,255,.9); }
[data-theme="light"] .auth-overlay { background: #f5f6fa; }

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  transition: background .3s var(--ease), color .3s var(--ease);
}

/* Custom scrollbar */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border-glow); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* Utility */
.hidden { display: none !important; }

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

/* Icon button (header) */
.icon-btn {
  width: 32px; height: 32px;
  display: flex; align-items: center; justify-content: center;
  border: 1px solid var(--border); border-radius: var(--radius-xs);
  background: transparent; color: var(--text-sec);
  cursor: pointer; transition: all var(--dur) var(--ease);
}
.icon-btn:hover { border-color: var(--ras); color: var(--ras); background: #6366f10d; }

/* Staggered card entrance */
@keyframes fadeSlideUp {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

.subject-card, .overlap-card, .hero-metric-card, .exam-arc-card,
.rev-dist-card, .velocity-card, .bm-card, .subject-breakdown-row {
  animation: fadeSlideUp .4s var(--ease) both;
  animation-delay: calc(var(--i, 0) * 60ms);
}

/* ---- Print styles ---- */
@media print {
  body { background: white !important; color: black !important; }
  .app-header, .context-bar, .tab-nav, .header-right,
  .exam-selector, .filter-bar, .toast-container,
  .notes-modal, .auth-overlay { display: none !important; }
  .subject-card { break-inside: avoid; border: 1px solid #ddd !important; background: white !important; }
  .topic-actions { display: none !important; }
  .topics-body { max-height: none !important; }
  .subject-card .topics-body { display: block !important; }
}