/* ==========================================================================
   LeetPrep / PrepZone — Premium Vanilla CSS Design System
   Crafted for Engineering Education, Syllabus Directories & Academic Portals
   ========================================================================== */

/* --- Custom Design Tokens & Color Harmony --- */
:root {
  /* Brand Gradients & Accents */
  --lp-primary: #2563eb;
  --lp-primary-hover: #1d4ed8;
  --lp-primary-light: #eff6ff;
  --lp-primary-border: #bfdbfe;
  
  --lp-indigo: #4f46e5;
  --lp-purple: #7c3aed;
  --lp-cyan: #06b6d4;
  --lp-emerald: #10b981;
  --lp-amber: #f59e0b;
  --lp-rose: #f43f5e;
  
  --lp-gradient-brand: linear-gradient(135deg, #2563eb 0%, #4f46e5 60%, #7c3aed 100%);
  --lp-gradient-subtle: linear-gradient(180deg, rgba(37, 99, 235, 0.04) 0%, rgba(255, 255, 255, 0) 100%);
  --lp-gradient-card: linear-gradient(145deg, #ffffff 0%, #fbfcfe 100%);
  
  /* Slate & Neutral Palette */
  --lp-navy: #0f172a;
  --lp-slate-900: #0f172a;
  --lp-slate-800: #1e293b;
  --lp-slate-700: #334155;
  --lp-slate-600: #475569;
  --lp-slate-500: #64748b;
  --lp-slate-400: #94a3b8;
  --lp-slate-300: #cbd5e1;
  --lp-slate-200: #e2e8f0;
  --lp-slate-100: #f1f5f9;
  --lp-slate-50: #f8fafc;
  --lp-white: #ffffff;
  
  /* Typography */
  --lp-font-sans: 'Outfit', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --lp-font-display: 'Sora', 'Outfit', sans-serif;
  --lp-font-mono: 'JetBrains Mono', monospace;
  
  /* Elevation & Shadows */
  --lp-shadow-xs: 0 1px 2px 0 rgba(15, 23, 42, 0.04);
  --lp-shadow-sm: 0 1px 3px 0 rgba(15, 23, 42, 0.06), 0 1px 2px -1px rgba(15, 23, 42, 0.04);
  --lp-shadow-md: 0 4px 12px -2px rgba(15, 23, 42, 0.06), 0 2px 6px -2px rgba(15, 23, 42, 0.04);
  --lp-shadow-lg: 0 12px 24px -4px rgba(15, 23, 42, 0.08), 0 4px 8px -3px rgba(15, 23, 42, 0.03);
  --lp-shadow-xl: 0 20px 32px -6px rgba(15, 23, 42, 0.09), 0 8px 16px -4px rgba(15, 23, 42, 0.04);
  --lp-shadow-glow: 0 0 24px rgba(37, 99, 235, 0.22);
  
  /* Shapes & Borders */
  --lp-radius-sm: 6px;
  --lp-radius-md: 10px;
  --lp-radius-lg: 14px;
  --lp-radius-xl: 20px;
  --lp-radius-full: 9999px;
  
  /* Transitions */
  --lp-transition: all 0.24s cubic-bezier(0.16, 1, 0.3, 1);
}

/* --- Base & Reset Enhancements --- */
html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--lp-font-sans);
  background-color: #ffffff;
  color: var(--lp-slate-800);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

::selection {
  background: rgba(37, 99, 235, 0.18);
  color: var(--lp-primary);
}

/* --- Premium Brand Logo Styling --- */
.brand-logo {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none !important;
  transition: var(--lp-transition);
  user-select: none;
}

.brand-logo:hover {
  transform: translateY(-1px);
}

.brand-logo .logo-mark {
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  filter: drop-shadow(0 4px 10px rgba(37, 99, 235, 0.28));
  transition: var(--lp-transition);
}

.brand-logo:hover .logo-mark {
  transform: rotate(-3deg) scale(1.04);
}

.brand-logo .logo-text-group {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}

.brand-logo .logo-title {
  font-family: var(--lp-font-display);
  font-size: 21px;
  font-weight: 800;
  color: var(--lp-navy);
  letter-spacing: -0.03em;
  display: flex;
  align-items: center;
}

.brand-logo .logo-accent {
  background: var(--lp-gradient-brand);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
  padding-left: 1px;
}

.brand-logo .logo-sub {
  font-size: 9.5px;
  font-weight: 700;
  color: var(--lp-slate-400);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-top: 2px;
}

/* Footer Brand Logo */
.footer-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 14px;
}

.footer-logo-title {
  font-family: var(--lp-font-display);
  font-size: 20px;
  font-weight: 800;
  color: var(--lp-navy);
  letter-spacing: -0.02em;
}

.footer-tagline {
  font-size: 12px;
  color: var(--lp-slate-500);
  margin-top: 2px;
}

/* --- Glassmorphic Sticky Header --- */
.site-header {
  background: rgba(255, 255, 255, 0.92) !important;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(226, 232, 240, 0.85) !important;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 4px 20px -8px rgba(15, 23, 42, 0.05);
  transition: var(--lp-transition);
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 6px;
}

.main-nav a {
  color: var(--lp-slate-600);
  font-size: 14.5px;
  font-weight: 500;
  padding: 8px 14px;
  border-radius: var(--lp-radius-md);
  text-decoration: none !important;
  transition: var(--lp-transition);
  position: relative;
}

.main-nav a:hover {
  color: var(--lp-primary);
  background: rgba(37, 99, 235, 0.06);
}

.main-nav a.active {
  color: var(--lp-primary);
  font-weight: 700;
  background: rgba(37, 99, 235, 0.09);
}

/* --- Premium Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--lp-font-sans);
  font-size: 14px;
  font-weight: 600;
  padding: 10px 20px;
  border-radius: var(--lp-radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none !important;
  transition: var(--lp-transition);
  line-height: 1.4;
}

.btn-primary {
  background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%) !important;
  color: #ffffff !important;
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.28);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #1d4ed8 0%, #1e40af 100%) !important;
  box-shadow: 0 6px 18px rgba(37, 99, 235, 0.4);
  transform: translateY(-2px);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-outline {
  background: #ffffff !important;
  color: var(--lp-slate-700) !important;
  border-color: var(--lp-slate-200) !important;
  box-shadow: var(--lp-shadow-xs);
}

.btn-outline:hover {
  background: var(--lp-slate-50) !important;
  border-color: var(--lp-slate-300) !important;
  color: var(--lp-primary) !important;
  transform: translateY(-2px);
  box-shadow: var(--lp-shadow-sm);
}

/* --- Hero Section Refinement --- */
.hero-section {
  position: relative;
  overflow: hidden;
  background: radial-gradient(circle at 50% 0%, rgba(37, 99, 235, 0.06) 0%, transparent 65%), #ffffff;
  border-bottom: 1px solid var(--lp-slate-200);
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: #eff6ff !important;
  color: var(--lp-primary) !important;
  border: 1px solid rgba(37, 99, 235, 0.2) !important;
  padding: 6px 16px;
  border-radius: var(--lp-radius-full);
  font-size: 13px;
  font-weight: 600;
  box-shadow: 0 2px 6px rgba(37, 99, 235, 0.06);
}

.hero-tag::before {
  content: '';
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--lp-primary);
  display: inline-block;
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.2);
  animation: pulseDot 2s infinite ease-in-out;
}

@keyframes pulseDot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.6; transform: scale(1.3); }
}

/* --- Interactive Syllabus Finder --- */
.finder-card-wrapper {
  background: #ffffff;
  border: 1px solid rgba(203, 213, 225, 0.8);
  border-radius: var(--lp-radius-lg);
  padding: 30px;
  box-shadow: var(--lp-shadow-xl);
  transition: var(--lp-transition);
}

.finder-select-styled {
  width: 100%;
  padding: 12px 16px;
  border: 1.5px solid var(--lp-slate-200);
  border-radius: var(--lp-radius-md);
  font-size: 14.5px;
  font-family: var(--lp-font-sans);
  color: var(--lp-slate-800);
  background-color: #ffffff;
  outline: none;
  transition: var(--lp-transition);
  cursor: pointer;
}

.finder-select-styled:focus {
  border-color: var(--lp-primary);
  box-shadow: 0 0 0 3.5px rgba(37, 99, 235, 0.15);
}

/* --- Premium Cards & Hover Elevations --- */
.premium-card {
  background: #ffffff;
  border: 1px solid var(--lp-slate-200);
  border-radius: var(--lp-radius-lg);
  padding: 26px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--lp-transition);
  position: relative;
  overflow: hidden;
}

.premium-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--lp-gradient-brand);
  opacity: 0;
  transition: var(--lp-transition);
}

.premium-card:hover {
  transform: translateY(-5px);
  border-color: rgba(37, 99, 235, 0.35);
  box-shadow: var(--lp-shadow-xl);
}

.premium-card:hover::before {
  opacity: 1;
}

/* --- Syllabus Tables --- */
.table-container {
  border-radius: var(--lp-radius-md);
  border: 1px solid var(--lp-slate-200);
  overflow-x: auto;
  box-shadow: var(--lp-shadow-xs);
  background: #ffffff;
}

.table-container table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  text-align: left;
}

.table-container th {
  background: var(--lp-slate-50);
  color: var(--lp-slate-600);
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 14px 18px;
  border-bottom: 1.5px solid var(--lp-slate-200);
}

.table-container td {
  padding: 14px 18px;
  border-bottom: 1px solid var(--lp-slate-100);
  color: var(--lp-slate-700);
  vertical-align: middle;
}

.table-container tr:last-child td {
  border-bottom: none;
}

.table-container tr:hover td {
  background: rgba(248, 250, 252, 0.8);
}

/* --- Status Pills & Badges --- */
.badge-pill {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 11.5px;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: var(--lp-radius-full);
  letter-spacing: 0.02em;
}

.badge-blue { background: #eff6ff; color: #2563eb; border: 1px solid #bfdbfe; }
.badge-green { background: #f0fdf4; color: #16a34a; border: 1px solid #bbf7d0; }
.badge-purple { background: #faf5ff; color: #7e22ce; border: 1px solid #e9d5ff; }
.badge-orange { background: #fff7ed; color: #ea580c; border: 1px solid #fed7aa; }

/* --- Responsive Polish --- */
@media (max-width: 768px) {
  .site-header {
    padding: 4px 0;
  }
  .brand-logo .logo-title {
    font-size: 19px;
  }
  .brand-logo .logo-sub {
    display: none;
  }
}