/* StudyCollab - Modern UI with Tailwind CSS */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

/* Tailwind CSS CDN - Latest version */
@import url('https://cdn.jsdelivr.net/npm/tailwindcss@3.3.0/dist/tailwind.min.css');

/* Custom CSS Variables */
:root {
  --primary-blue: #3B82F6;
  --primary-blue-dark: #2563EB;
  --primary-blue-light: #60A5FA;
  --accent-purple: #8B5CF6;
  --accent-green: #10B981;
  --accent-orange: #F59E0B;
  --accent-red: #EF4444;
  --gray-50: #F8FAFC;
  --gray-100: #F1F5F9;
  --gray-200: #E2E8F0;
  --gray-300: #CBD5E1;
  --gray-400: #94A3B8;
  --gray-500: #64748B;
  --gray-600: #475569;
  --gray-700: #334155;
  --gray-800: #1E293B;
  --gray-900: #0F172A;
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
  color: var(--gray-700);
  line-height: 1.6;
  overflow-x: hidden;
}

/* Modern Scrollbar */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: var(--gray-100);
}

::-webkit-scrollbar-thumb {
  background: var(--gray-300);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--gray-400);
}

/* Animations */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes slideIn {
  from { transform: translateX(-100%); }
  to { transform: translateX(0); }
}

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); }
}

@keyframes shimmer {
  0% { background-position: -200px 0; }
  100% { background-position: calc(200px + 100%) 0; }
}

/* Utility Classes */
.fade-in {
  animation: fadeIn 0.6s ease-out;
}

.slide-in {
  animation: slideIn 0.5s ease-out;
}

.hover-pulse:hover {
  animation: pulse 0.3s ease-in-out;
}

.glass-effect {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.gradient-text {
  background: linear-gradient(135deg, var(--primary-blue), var(--accent-purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.loading-shimmer {
  background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
  background-size: 200px 100%;
  animation: shimmer 1.5s infinite;
}

/* Modern Card Styles */
.modern-card {
  background: white;
  border-radius: 16px;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.modern-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

/* Modern Button Styles */
.btn-modern {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  font-size: 14px;
  font-weight: 600;
  border-radius: 12px;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
  border: none;
  text-decoration: none;
  position: relative;
  overflow: hidden;
}

.btn-modern::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(45deg, transparent 30%, rgba(255, 255, 255, 0.3) 50%, transparent 70%);
  transform: translateX(-100%);
  transition: transform 0.5s;
}

.btn-modern:hover::before {
  transform: translateX(100%);
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-blue), var(--primary-blue-dark));
  color: white;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 20px rgba(59, 130, 246, 0.3);
}

.btn-secondary {
  background: white;
  color: var(--gray-700);
  border: 2px solid var(--gray-200);
}

.btn-secondary:hover {
  background: var(--gray-50);
  border-color: var(--primary-blue);
  transform: translateY(-2px);
}

/* Modern Form Styles */
.form-modern {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.form-group {
  position: relative;
}

.form-label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  color: var(--gray-700);
  margin-bottom: 8px;
}

.form-input {
  width: 100%;
  padding: 16px;
  border: 2px solid var(--gray-200);
  border-radius: 12px;
  font-size: 16px;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  background: white;
}

.form-input:focus {
  outline: none;
  border-color: var(--primary-blue);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
  transform: translateY(-1px);
}

.form-input:invalid {
  border-color: var(--accent-red);
}

/* Modern Navigation */
.nav-modern {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.2);
  position: sticky;
  top: 0;
  z-index: 1000;
}

/* Modern Grid Layouts */
.grid-modern {
  display: grid;
  gap: 24px;
}

.grid-1 { grid-template-columns: 1fr; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

@media (max-width: 768px) {
  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }
}

/* Status Indicators */
.status-online {
  background: var(--accent-green);
  color: white;
}

.status-offline {
  background: var(--gray-400);
  color: white;
}

.status-pending {
  background: var(--accent-orange);
  color: white;
}

/* Modern Alert Styles */
.alert-modern {
  padding: 16px 20px;
  border-radius: 12px;
  font-weight: 500;
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.alert-success {
  background: rgba(16, 185, 129, 0.1);
  color: var(--accent-green);
  border: 1px solid rgba(16, 185, 129, 0.2);
}

.alert-error {
  background: rgba(239, 68, 68, 0.1);
  color: var(--accent-red);
  border: 1px solid rgba(239, 68, 68, 0.2);
}

.alert-warning {
  background: rgba(245, 158, 11, 0.1);
  color: var(--accent-orange);
  border: 1px solid rgba(245, 158, 11, 0.2);
}

.alert-info {
  background: rgba(59, 130, 246, 0.1);
  color: var(--primary-blue);
  border: 1px solid rgba(59, 130, 246, 0.2);
}

/* Modern Typography */
.text-hero {
  font-size: 3.5rem;
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.text-title {
  font-size: 2.5rem;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.01em;
}

.text-subtitle {
  font-size: 1.25rem;
  font-weight: 500;
  color: var(--gray-600);
  line-height: 1.5;
}

/* Modern Responsive Utilities */
@media (max-width: 640px) {
  .text-hero { font-size: 2.5rem; }
  .text-title { font-size: 2rem; }
  .btn-modern { padding: 10px 20px; font-size: 13px; }
  .modern-card { border-radius: 12px; }
}

/* Dark Mode Support */
@media (prefers-color-scheme: dark) {
  :root {
    --gray-50: #0F172A;
    --gray-100: #1E293B;
    --gray-200: #334155;
    --gray-300: #475569;
    --gray-400: #64748B;
    --gray-500: #94A3B8;
    --gray-600: #CBD5E1;
    --gray-700: #E2E8F0;
    --gray-800: #F1F5F9;
    --gray-900: #F8FAFC;
  }
  
  body {
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
    color: var(--gray-700);
  }
  
  .modern-card {
    background: rgba(30, 41, 59, 0.8);
    border: 1px solid rgba(255, 255, 255, 0.1);
  }
}