/* ==========================================================================
   LevelUp CGPA - Core Design System & Tokens
   Theme: Midnight Indigo & Modern Glassmorphism
   Typography: Plus Jakarta Sans & Inter
   ========================================================================== */

:root {
  /* Surface & Background Colors */
  --bg-base: #0a0d14;
  --bg-surface: #101623;
  --bg-card: rgba(22, 30, 46, 0.75);
  --bg-card-hover: rgba(30, 41, 64, 0.85);
  --bg-glass: rgba(18, 25, 39, 0.65);
  --bg-subtle: #151d2c;

  /* Borders & Dividers */
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-card: rgba(255, 255, 255, 0.12);
  --border-focus: rgba(99, 102, 241, 0.5);

  /* Primary Brand Accents */
  --primary: #6366f1;
  --primary-light: #818cf8;
  --primary-dark: #4f46e5;
  --primary-glow: rgba(99, 102, 241, 0.25);

  --secondary: #8b5cf6;
  --secondary-glow: rgba(139, 92, 246, 0.25);

  /* Semantic Highlights (No harsh reds, all growth-oriented) */
  --emerald: #10b981;
  --emerald-glow: rgba(16, 185, 129, 0.2);
  --amber: #f59e0b;
  --amber-glow: rgba(245, 158, 11, 0.2);
  --cyan: #06b6d4;
  --cyan-glow: rgba(6, 182, 212, 0.2);
  --rose: #f43f5e;

  /* Typography Colors */
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --text-inverse: #0f172a;

  /* Fonts */
  --font-heading: 'Plus Jakarta Sans', system-ui, -apple-system, sans-serif;
  --font-body: 'Inter', system-ui, -apple-system, sans-serif;

  /* Elevation & Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.6);
  --shadow-glow: 0 0 35px var(--primary-glow);

  /* Radii */
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --radius-full: 9999px;

  /* Layout */
  --max-width: 1200px;
  --header-height: 72px;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  color-scheme: dark;
}

body {
  background-color: var(--bg-base);
  color: var(--text-primary);
  font-family: var(--font-body);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  background-image: 
    radial-gradient(circle at 15% 15%, rgba(99, 102, 241, 0.12) 0%, transparent 40%),
    radial-gradient(circle at 85% 85%, rgba(139, 92, 246, 0.10) 0%, transparent 45%);
  background-attachment: fixed;
}

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

h1 { font-size: clamp(2.2rem, 5vw, 3.6rem); letter-spacing: -0.03em; }
h2 { font-size: clamp(1.75rem, 3.5vw, 2.5rem); letter-spacing: -0.02em; }
h3 { font-size: clamp(1.25rem, 2.5vw, 1.75rem); letter-spacing: -0.01em; }
h4 { font-size: 1.2rem; font-weight: 600; }
p { color: var(--text-secondary); font-size: 1.05rem; }

a {
  color: var(--primary-light);
  text-decoration: none;
  transition: color 0.2s ease;
}
a:hover { color: #fff; }

/* Container */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Navbar */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  background: rgba(10, 13, 20, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-subtle);
  z-index: 1000;
  display: flex;
  align-items: center;
}

.navbar .nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-family: var(--font-heading);
  font-size: 1.35rem;
  font-weight: 800;
  color: #fff;
  letter-spacing: -0.02em;
  cursor: pointer;
}

.brand-badge {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: #fff;
  font-size: 0.75rem;
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-full);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
}

.homepage-tabs {
  gap: 0.2rem;
  padding: 0;
  background: transparent;
  border: 0;
  border-radius: 0;
}

.nav-link {
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.95rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

.nav-link:hover, .nav-link.active {
  color: #fff;
}

.homepage-tabs .nav-link {
  position: relative;
  display: block;
  padding: 0.5rem 0.7rem;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
}

.homepage-tabs .nav-link::after {
  content: '';
  position: absolute;
  left: 0.7rem;
  right: 0.7rem;
  bottom: 0.2rem;
  height: 2px;
  border-radius: 2px;
  background: rgba(255, 255, 255, 0.92);
  transform: scaleX(0);
  transform-origin: center;
  transition: transform 0.2s ease;
}

.homepage-tabs .nav-link:hover {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-primary);
}

.homepage-tabs .nav-link.active {
  background: rgba(255, 255, 255, 0.08);
  color: #fff;
  font-weight: 600;
}

.homepage-tabs .nav-link.active::after {
  transform: scaleX(1);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-family: var(--font-heading);
  font-size: 0.95rem;
  font-weight: 600;
  padding: 0.75rem 1.6rem;
  border-radius: var(--radius-full);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  text-decoration: none;
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: #fff;
  box-shadow: 0 4px 18px var(--primary-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(99, 102, 241, 0.4);
  color: #fff;
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.06);
  color: var(--text-primary);
  border-color: var(--border-card);
  backdrop-filter: blur(10px);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
  transform: translateY(-1px);
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
}

.btn-ghost:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.05);
}

.btn-sm {
  padding: 0.5rem 1.1rem;
  font-size: 0.85rem;
}

.btn-lg {
  padding: 0.9rem 2.2rem;
  font-size: 1.1rem;
}

/* Cards & Glassmorphism */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
}

.card:hover {
  border-color: rgba(99, 102, 241, 0.3);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
}

/* Badges & Pills */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.3rem 0.8rem;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.badge-primary {
  background: rgba(99, 102, 241, 0.15);
  color: var(--primary-light);
  border: 1px solid rgba(99, 102, 241, 0.3);
}

.badge-success {
  background: rgba(16, 185, 129, 0.15);
  color: var(--emerald);
  border: 1px solid rgba(16, 185, 129, 0.3);
}

.badge-amber {
  background: rgba(245, 158, 11, 0.15);
  color: var(--amber);
  border: 1px solid rgba(245, 158, 11, 0.3);
}

.badge-cyan {
  background: rgba(6, 182, 212, 0.15);
  color: var(--cyan);
  border: 1px solid rgba(6, 182, 212, 0.3);
}

/* Gradient Text */
.gradient-text {
  background: linear-gradient(135deg, #fff 20%, var(--primary-light) 70%, var(--secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* App View Containers */
.view-container {
  display: none;
  min-height: calc(100vh - var(--header-height));
  margin-top: var(--header-height);
}

.view-container.active {
  display: block;
  animation: fadeIn 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

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

/* Modal Overlay */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(8px);
  z-index: 2000;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
}

.modal-overlay.active {
  display: flex;
}

.modal-box {
  background: var(--bg-surface);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-xl);
  max-width: 620px;
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
  padding: 2.25rem;
  box-shadow: var(--shadow-lg);
  animation: modalScale 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

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

/* Form Controls */
.form-group {
  margin-bottom: 1.25rem;
}

.form-label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.form-input, .form-select, .form-textarea {
  width: 100%;
  background: rgba(15, 23, 42, 0.8);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  padding: 0.85rem 1.1rem;
  color: #fff;
  font-family: var(--font-body);
  font-size: 1rem;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.form-input:focus, .form-select:focus, .form-textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-glow);
}

/* Footer */
.footer {
  border-top: 1px solid var(--border-subtle);
  background: var(--bg-surface);
  padding: 3.5rem 0 2rem;
  margin-top: 5rem;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 2rem;
  margin-bottom: 2.5rem;
}

.footer-bottom {
  text-align: center;
  border-top: 1px solid var(--border-subtle);
  padding-top: 1.5rem;
  color: var(--text-muted);
  font-size: 0.85rem;
}

.footer-privacy-links { margin-top: 0.75rem; font-size: 0.78rem; }
.footer-privacy-links a { color: var(--text-muted); }
.footer-privacy-links a:hover { color: #fff; }
.footer-privacy-links span { margin: 0 0.45rem; color: var(--text-muted); }

/* Responsive adjustments */
@media (max-width: 768px) {
  .nav-links { display: none; }
  .homepage-tabs .nav-link { padding: 0.45rem 0.6rem; }
  .navbar .container { padding: 0 1rem; }
  .btn-lg { padding: 0.8rem 1.6rem; font-size: 1rem; }
}