/* ==========================================================================
   TOEIC MASTER DESIGN SYSTEM — base.css
   Modern, Premium Dark & Light Glassmorphism UI
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=Outfit:wght@500;600;700;800&family=JetBrains+Mono:wght@400;500;600&display=swap');

:root {
  /* Color Palette - Cyber Indigo & Deep Glass */
  --bg-primary: #0a0d14;
  --bg-secondary: #111622;
  --bg-tertiary: #192032;
  --bg-elevated: rgba(25, 32, 50, 0.7);
  --bg-glass: rgba(17, 22, 34, 0.75);
  --bg-glass-card: rgba(25, 32, 50, 0.6);
  --bg-glass-hover: rgba(35, 45, 70, 0.75);

  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-focus: rgba(99, 102, 241, 0.5);
  --border-glass: rgba(255, 255, 255, 0.12);

  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --text-white: #ffffff;

  --accent-primary: #6366f1;
  --accent-primary-hover: #4f46e5;
  --accent-primary-glow: rgba(99, 102, 241, 0.35);
  --accent-secondary: #06b6d4;
  --accent-purple: #a855f7;

  --success: #10b981;
  --success-bg: rgba(16, 185, 129, 0.15);
  --success-border: rgba(16, 185, 129, 0.35);
  --warning: #f59e0b;
  --warning-bg: rgba(245, 158, 11, 0.15);
  --danger: #ef4444;
  --danger-bg: rgba(239, 68, 68, 0.15);
  --danger-border: rgba(239, 68, 68, 0.35);

  --font-main: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-heading: 'Outfit', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 24px rgba(99, 102, 241, 0.25);

  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Light Mode Overrides */
[data-theme="light"] {
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --bg-tertiary: #f1f5f9;
  --bg-elevated: rgba(255, 255, 255, 0.85);
  --bg-glass: rgba(255, 255, 255, 0.8);
  --bg-glass-card: rgba(255, 255, 255, 0.9);
  --bg-glass-hover: #e2e8f0;

  --border-subtle: rgba(0, 0, 0, 0.08);
  --border-focus: rgba(99, 102, 241, 0.6);
  --border-glass: rgba(0, 0, 0, 0.1);

  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --text-white: #ffffff;

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.12);
  --shadow-glow: 0 0 20px rgba(99, 102, 241, 0.15);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-main);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  position: relative;
  background-image: 
    radial-gradient(circle at 15% 15%, rgba(99, 102, 241, 0.08) 0%, transparent 40%),
    radial-gradient(circle at 85% 85%, rgba(6, 182, 212, 0.06) 0%, transparent 40%);
  background-attachment: fixed;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.25;
  color: var(--text-primary);
}

a {
  color: var(--accent-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--accent-secondary);
}

button {
  font-family: var(--font-main);
  cursor: pointer;
  border: none;
  outline: none;
  background: none;
  transition: all var(--transition-fast);
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
  background: var(--bg-tertiary);
  border-radius: var(--radius-full);
  border: 2px solid var(--bg-primary);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent-primary);
}

/* Utility Animations */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes pulseGlow {
  0%, 100% { box-shadow: 0 0 15px var(--accent-primary-glow); }
  50% { box-shadow: 0 0 28px var(--accent-primary-glow); }
}

@keyframes scaleIn {
  from { opacity: 0; transform: scale(0.95); }
  to { opacity: 1; transform: scale(1); }
}

.animate-fade-in {
  animation: fadeIn var(--transition-normal) forwards;
}

.glass-panel {
  background: var(--bg-glass-card);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}