/* STEMClub Learning Platform - Main Stylesheet */
/* Professional design with engaging colors for classroom display */

:root {
  /* Primary Color Palette - Vibrant but Professional */
  --primary-blue: #2563eb;
  --primary-blue-light: #3b82f6;
  --primary-blue-dark: #1d4ed8;
  
  /* Secondary Colors - STEM-inspired */
  --secondary-green: #10b981;
  --secondary-green-light: #34d399;
  --secondary-purple: #8b5cf6;
  --secondary-orange: #f59e0b;
  --secondary-pink: #ec4899;
  
  /* Accent Colors */
  --accent-cyan: #06b6d4;
  --accent-lime: #84cc16;
  --accent-rose: #f43f5e;
  
  /* Neutral Colors */
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
  
  /* Background Colors */
  --bg-primary: #ffffff;
  --bg-secondary: var(--gray-50);
  --bg-dark: var(--gray-900);
  
  /* Text Colors */
  --text-primary: var(--gray-900);
  --text-secondary: var(--gray-600);
  --text-light: var(--gray-400);
  --text-white: #ffffff;
  
  /* Success/Error Colors */
  --success: var(--secondary-green);
  --warning: var(--secondary-orange);
  --error: var(--accent-rose);
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  
  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.375rem;
  --radius-lg: 0.5rem;
  --radius-xl: 0.75rem;
  --radius-2xl: 1rem;
  
  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-normal: 250ms ease-in-out;
  --transition-slow: 350ms ease-in-out;
}

/* Reset and Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-secondary);
  font-feature-settings: 'cv02', 'cv03', 'cv04', 'cv11';
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 0.5em;
}

h1 {
  font-size: 2.5rem;
  background: linear-gradient(135deg, var(--primary-blue), var(--secondary-purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

h2 {
  font-size: 2rem;
  color: var(--primary-blue-dark);
}

h3 {
  font-size: 1.5rem;
  color: var(--text-primary);
}

p {
  margin-bottom: 1rem;
  color: var(--text-secondary);
}

/* Layout Components */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
}

.container-fluid {
  width: 100%;
  padding: 0 1rem;
}

/* Header Styles */
.header {
  background: linear-gradient(135deg, var(--primary-blue) 0%, var(--secondary-purple) 100%);
  color: var(--text-white);
  padding: 1rem 0;
  box-shadow: var(--shadow-lg);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.5rem;
  font-weight: 700;
  text-decoration: none;
  color: var(--text-white);
}

.logo-icon {
  width: 40px;
  height: 40px;
  background: var(--text-white);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  color: var(--primary-blue);
}

/* Navigation */
.nav {
  display: flex;
  gap: 2rem;
  align-items: center;
}

.nav-link {
  color: var(--text-white);
  text-decoration: none;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  font-weight: 500;
}

.nav-link:hover {
  background: rgba(255, 255, 255, 0.1);
  transform: translateY(-1px);
}

.nav-link.active {
  background: rgba(255, 255, 255, 0.2);
}

/* Button Styles */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: var(--radius-lg);
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  font-size: 0.875rem;
  line-height: 1;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-blue), var(--primary-blue-light));
  color: var(--text-white);
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-secondary {
  background: var(--secondary-green);
  color: var(--text-white);
}

.btn-secondary:hover {
  background: var(--secondary-green-light);
  transform: translateY(-1px);
}

.btn-outline {
  background: transparent;
  border: 2px solid var(--primary-blue);
  color: var(--primary-blue);
}

.btn-outline:hover {
  background: var(--primary-blue);
  color: var(--text-white);
}

.btn-lg {
  padding: 1rem 2rem;
  font-size: 1rem;
}

.btn-sm {
  padding: 0.5rem 1rem;
  font-size: 0.75rem;
}

/* Card Components */
.card {
  background: var(--bg-primary);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-md);
  overflow: hidden;
  transition: all var(--transition-normal);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
}

.card-header {
  padding: 1.5rem;
  background: linear-gradient(135deg, var(--gray-50), var(--gray-100));
  border-bottom: 1px solid var(--gray-200);
}

.card-body {
  padding: 1.5rem;
}

.card-footer {
  padding: 1rem 1.5rem;
  background: var(--gray-50);
  border-top: 1px solid var(--gray-200);
}

/* Form Styles */
.form-group {
  margin-bottom: 1.5rem;
}

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

.form-input {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 2px solid var(--gray-200);
  border-radius: var(--radius-lg);
  font-size: 1rem;
  transition: all var(--transition-fast);
  background: var(--bg-primary);
}

.form-input:focus {
  outline: none;
  border-color: var(--primary-blue);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-select {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 2px solid var(--gray-200);
  border-radius: var(--radius-lg);
  font-size: 1rem;
  background: var(--bg-primary);
  cursor: pointer;
}

/* Alert Styles */
.alert {
  padding: 1rem 1.5rem;
  border-radius: var(--radius-lg);
  margin-bottom: 1rem;
  border-left: 4px solid;
}

.alert-success {
  background: rgba(16, 185, 129, 0.1);
  border-color: var(--success);
  color: #065f46;
}

.alert-warning {
  background: rgba(245, 158, 11, 0.1);
  border-color: var(--warning);
  color: #92400e;
}

.alert-error {
  background: rgba(244, 63, 94, 0.1);
  border-color: var(--error);
  color: #991b1b;
}

/* Grid System */
.grid {
  display: grid;
  gap: 1.5rem;
}

.grid-2 {
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

.grid-4 {
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-1 { margin-top: 0.25rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-3 { margin-top: 1rem; }
.mt-4 { margin-top: 1.5rem; }
.mt-5 { margin-top: 2rem; }

.mb-1 { margin-bottom: 0.25rem; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-3 { margin-bottom: 1rem; }
.mb-4 { margin-bottom: 1.5rem; }
.mb-5 { margin-bottom: 2rem; }

.p-1 { padding: 0.25rem; }
.p-2 { padding: 0.5rem; }
.p-3 { padding: 1rem; }
.p-4 { padding: 1.5rem; }
.p-5 { padding: 2rem; }

.hidden { display: none; }
.block { display: block; }
.flex { display: flex; }
.inline-flex { display: inline-flex; }

.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }

.gap-1 { gap: 0.25rem; }
.gap-2 { gap: 0.5rem; }
.gap-3 { gap: 1rem; }
.gap-4 { gap: 1.5rem; }

/* Responsive Design */
@media (max-width: 768px) {
  .container {
    padding: 0 0.5rem;
  }
  
  .header-content {
    flex-direction: column;
    gap: 1rem;
  }
  
  .nav {
    gap: 1rem;
  }
  
  h1 {
    font-size: 2rem;
  }
  
  h2 {
    font-size: 1.5rem;
  }
  
  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }
}

/* Loading Animation */
.loading {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 3px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  border-top-color: var(--text-white);
  animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* Hover Effects for Interactive Elements */
.interactive:hover {
  transform: translateY(-2px);
  transition: transform var(--transition-fast);
}

/* STEM-themed Background Patterns */
.bg-pattern {
  background-image: 
    radial-gradient(circle at 25% 25%, rgba(37, 99, 235, 0.1) 0%, transparent 50%),
    radial-gradient(circle at 75% 75%, rgba(139, 92, 246, 0.1) 0%, transparent 50%);
}

/* Classroom-friendly high contrast text */
.high-contrast {
  color: var(--gray-900);
  font-weight: 600;
}

/* Fun accent elements */
.accent-border {
  border-left: 4px solid;
  border-image: linear-gradient(45deg, var(--secondary-green), var(--accent-cyan), var(--secondary-purple)) 1;
}