/* style.css - Custom styling for YouTube Video Downloader */

/* Import Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

/* Root variables for consistent color palette */
:root {
  --primary-color: #2563eb;
  --primary-hover: #1d4ed8;
  --secondary-color: #64748b;
  --success-color: #059669;
  --danger-color: #dc2626;
  --warning-color: #d97706;
  --dark-color: #1e293b;
  --light-color: #f8fafc;
  --border-color: #e2e8f0;
  --text-primary: #0f172a;
  --text-secondary: #64748b;
  --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  --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);
}

/* Base styles */
* {
  box-sizing: border-box;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--light-color);
  color: var(--text-primary);
  line-height: 1.6;
  margin: 0;
  padding: 0;
}

/* Header styles */
.header-gradient {
  background: var(--gradient-primary);
  position: relative;
  overflow: hidden;
}

.header-gradient::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1000 100" fill="white" opacity="0.1"><polygon points="0,0 1000,0 1000,100 0,80"/></svg>');
  background-size: cover;
}

.header-content {
  position: relative;
  z-index: 1;
}

.header-title {
  font-weight: 700;
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
  text-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.header-subtitle {
  font-weight: 400;
  font-size: 1.1rem;
  opacity: 0.9;
  margin-bottom: 0;
}

/* Main content */
.main-container {
  min-height: calc(100vh - 200px);
  padding: 3rem 0;
}

/* Card styles */
.download-card {
  background: white;
  border-radius: 16px;
  box-shadow: var(--shadow-xl);
  border: 1px solid var(--border-color);
  overflow: hidden;
  transition: all 0.3s ease;
}

.download-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 25px 50px -12px rgb(0 0 0 / 0.25);
}

.card-header {
  background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
  padding: 2rem;
  border-bottom: 1px solid var(--border-color);
  text-align: center;
}

.card-title {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.card-description {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.card-body {
  padding: 2rem;
}

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

.form-label {
  display: block;
  font-weight: 500;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
  font-size: 0.95rem;
}

.form-control {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 2px solid var(--border-color);
  border-radius: 8px;
  font-size: 1rem;
  transition: all 0.2s ease;
  background: white;
}

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

.form-select {
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3e%3cpath stroke='%236b7280' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='m6 8 4 4 4-4'/%3e%3c/svg%3e");
  background-position: right 0.5rem center;
  background-repeat: no-repeat;
  background-size: 1.5em 1.5em;
  padding-right: 2.5rem;
  appearance: none;
}

/* Button styles */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
  font-weight: 500;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.2s ease;
  position: relative;
  overflow: hidden;
}

.btn-primary {
  background: var(--primary-color);
  color: white;
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  background: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-lg);
}

.btn-success {
  background: var(--success-color);
  color: white;
  box-shadow: var(--shadow-md);
}

.btn-success:hover {
  background: #047857;
  transform: translateY(-1px);
  box-shadow: var(--shadow-lg);
}

.btn-secondary {
  background: var(--secondary-color);
  color: white;
  box-shadow: var(--shadow-md);
}

.btn-secondary:hover {
  background: #475569;
  transform: translateY(-1px);
  box-shadow: var(--shadow-lg);
}

.btn-lg {
  padding: 1rem 2rem;
  font-size: 1.1rem;
  border-radius: 10px;
}

/* Alert styles */
.alert {
  padding: 1rem 1.5rem;
  border-radius: 8px;
  margin-bottom: 1rem;
  border: 1px solid transparent;
  font-weight: 500;
}

.alert-success {
  background-color: #dcfce7;
  border-color: #bbf7d0;
  color: #166534;
}

.alert-danger {
  background-color: #fef2f2;
  border-color: #fecaca;
  color: #991b1b;
}

.alert-warning {
  background-color: #fffbeb;
  border-color: #fed7aa;
  color: #92400e;
}

.alert-info {
  background-color: #eff6ff;
  border-color: #bfdbfe;
  color: #1e40af;
}

/* Progress styles */
.progress-container {
  margin: 1.5rem 0;
}

.progress {
  height: 8px;
  background-color: #e5e7eb;
  border-radius: 4px;
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  background: var(--gradient-primary);
  transition: width 0.3s ease;
  border-radius: 4px;
}

/* Features section */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin: 3rem 0;
}

.feature-card {
  background: white;
  padding: 1.5rem;
  border-radius: 12px;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--border-color);
  text-align: center;
  transition: all 0.3s ease;
}

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

.feature-icon {
  width: 48px;
  height: 48px;
  background: var(--gradient-primary);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1rem;
  color: white;
  font-size: 1.5rem;
  font-weight: bold;
}

.feature-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.feature-description {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.5;
}

/* Footer styles */
.footer {
  background: var(--dark-color);
  color: white;
  text-align: center;
  padding: 2rem 0;
  margin-top: 3rem;
}

.footer-content {
  font-size: 0.9rem;
  opacity: 0.8;
}

/* Responsive design */
@media (max-width: 768px) {
  .header-title {
    font-size: 2rem;
  }
  
  .header-subtitle {
    font-size: 1rem;
  }
  
  .card-header,
  .card-body {
    padding: 1.5rem;
  }
  
  .main-container {
    padding: 2rem 0;
  }
  
  .btn {
    width: 100%;
    margin-bottom: 0.5rem;
  }
  
  .features-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
}

/* Loading animation */
.loading {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 3px solid rgba(255,255,255,.3);
  border-radius: 50%;
  border-top-color: #fff;
  animation: spin 1s ease-in-out infinite;
  margin-right: 0.5rem;
}

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

/* 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: 3rem; }
.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: 3rem; }
.d-none { display: none; }
.d-block { display: block; }
.d-flex { display: flex; }
.justify-content-center { justify-content: center; }
.align-items-center { align-items: center; }
.w-100 { width: 100%; }
.h-100 { height: 100%; }

/* Animation classes */
.fade-in {
  animation: fadeIn 0.5s ease-in;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.slide-up {
  animation: slideUp 0.3s ease-out;
}

@keyframes slideUp {
  from { transform: translateY(20px); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}