/* Custom styles for Algorithm Dive */

/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    scroll-behavior: smooth;
}

/* Custom scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: #1f2937;
}

::-webkit-scrollbar-thumb {
    background: #4f46e5;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #6366f1;
}

/* Navigation styles */
.nav-link {
    position: relative;
    color: #d1d5db;
    text-decoration: none;
    transition: color 0.3s ease;
    font-weight: 500;
}

.nav-link:hover {
    color: #ffffff;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, #3b82f6, #8b5cf6);
    transition: width 0.3s ease;
}

.nav-link:hover::after {
    width: 100%;
}

/* Button styles */
.btn-primary {
    display: inline-flex;
    align-items: center;
    padding: 12px 24px;
    background: linear-gradient(135deg, #3b82f6, #8b5cf6);
    color: white;
    text-decoration: none;
    border-radius: 12px;
    font-weight: 600;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(59, 130, 246, 0.4);
}

.btn-secondary {
    display: inline-flex;
    align-items: center;
    padding: 12px 24px;
    background: linear-gradient(135deg, #ef4444, #f97316);
    color: white;
    text-decoration: none;
    border-radius: 12px;
    font-weight: 600;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
}

.btn-secondary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(239, 68, 68, 0.4);
}

.btn-outline {
    display: inline-flex;
    align-items: center;
    padding: 12px 24px;
    background: transparent;
    color: #d1d5db;
    text-decoration: none;
    border: 2px solid #374151;
    border-radius: 12px;
    font-weight: 600;
    transition: all 0.3s ease;
    cursor: pointer;
}

.btn-outline:hover {
    background: #374151;
    color: white;
    transform: translateY(-2px);
}

.youtube-btn {
    display: inline-flex;
    align-items: center;
    padding: 8px 16px;
    background: linear-gradient(135deg, #ff0000, #cc0000);
    color: white;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.3s ease;
    gap: 8px;
}

.youtube-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 6px 20px rgba(255, 0, 0, 0.4);
}

/* Social links */
.social-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    background: rgba(255, 255, 255, 0.1);
    color: #d1d5db;
    text-decoration: none;
    border-radius: 12px;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
}

.social-link:hover {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    transform: translateY(-2px);
}

/* Category buttons */
.category-btn {
    padding: 8px 16px;
    background: rgba(255, 255, 255, 0.1);
    color: #d1d5db;
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 8px;
    font-weight: 500;
    transition: all 0.3s ease;
    cursor: pointer;
    backdrop-filter: blur(10px);
}

.category-btn:hover,
.category-btn.active {
    background: linear-gradient(135deg, #3b82f6, #8b5cf6);
    color: white;
    border-color: transparent;
}

/* Card styles */
.project-card {
    background: rgba(31, 41, 55, 0.8);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 16px;
    overflow: hidden;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
}

.project-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
    border-color: rgba(59, 130, 246, 0.5);
}

.video-card {
    background: rgba(31, 41, 55, 0.8);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 16px;
    overflow: hidden;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
    position: relative;
}

.video-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.3);
}

.video-thumbnail {
    position: relative;
    width: 100%;
    height: 200px;
    background: #1f2937;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.video-thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.play-button {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 60px;
    height: 60px;
    background: rgba(255, 0, 0, 0.9);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 24px;
    transition: all 0.3s ease;
}

.play-button:hover {
    background: rgba(255, 0, 0, 1);
    transform: translate(-50%, -50%) scale(1.1);
}



/* Form styles */
.form-input {
    width: 100%;
    padding: 12px 16px;
    background: rgba(31, 41, 55, 0.8);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 8px;
    color: white;
    font-size: 16px;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
}

.form-input:focus {
    outline: none;
    border-color: #3b82f6;
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.form-input::placeholder {
    color: #9ca3af;
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in-up {
    animation: fadeInUp 0.6s ease-out;
}

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

.pulse {
    animation: pulse 2s infinite;
}

/* Responsive design */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .hero p {
        font-size: 1rem;
    }
    
    .btn-primary,
    .btn-secondary,
    .btn-outline {
        padding: 10px 20px;
        font-size: 14px;
    }
    
    .social-link {
        width: 40px;
        height: 40px;
    }
    
    .video-thumbnail {
        height: 180px;
    }
    
    .play-button {
        width: 50px;
        height: 50px;
        font-size: 20px;
    }
}

/* Loading states */
.loading {
    opacity: 0.7;
    pointer-events: none;
}

.loading::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 20px;
    height: 20px;
    border: 2px solid #3b82f6;
    border-top: 2px solid transparent;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    transform: translate(-50%, -50%);
}

@keyframes spin {
    0% { transform: translate(-50%, -50%) rotate(0deg); }
    100% { transform: translate(-50%, -50%) rotate(360deg); }
}

/* Utility classes */
.text-gradient {
    background: linear-gradient(135deg, #3b82f6, #8b5cf6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.glass {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.hover-glow:hover {
    box-shadow: 0 0 20px rgba(59, 130, 246, 0.4);
}

/* Custom scrollbar for containers */
.scrollbar-custom {
    scrollbar-width: thin;
    scrollbar-color: #4f46e5 #1f2937;
}

.scrollbar-custom::-webkit-scrollbar {
    width: 6px;
}

.scrollbar-custom::-webkit-scrollbar-track {
    background: #1f2937;
}

.scrollbar-custom::-webkit-scrollbar-thumb {
    background: #4f46e5;
    border-radius: 3px;
}

/* Print styles */
@media print {
    .no-print {
        display: none !important;
    }
}

/* High contrast mode */
@media (prefers-contrast: high) {
    .btn-primary,
    .btn-secondary {
        border: 2px solid white;
    }
    
    .social-link {
        border: 1px solid white;
    }
}

/* Smooth scrolling for anchor links */
html {
  scroll-behavior: smooth;
}

/* Text selection color */
::selection {
  background-color: #3b82f6;
  color: white;
}

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

.fade-in {
  animation: fadeIn 0.5s ease-out forwards;
}

/* Card hover effect enhancement */
.project-card {
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.project-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 25px -5px rgba(59, 130, 246, 0.3);
}

/* Custom gradient text effect */
.gradient-text {
  background: linear-gradient(to right, #3b82f6, #8b5cf6);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* Button pulse animation */
@keyframes pulse {
  0% {
    box-shadow: 0 0 0 0 rgba(59, 130, 246, 0.7);
  }
  70% {
    box-shadow: 0 0 0 10px rgba(59, 130, 246, 0);
  }
  100% {
    box-shadow: 0 0 0 0 rgba(59, 130, 246, 0);
  }
}

.pulse-btn:hover {
  animation: pulse 1.5s infinite;
}

/* Mobile menu animation */
.mobile-menu-enter {
  opacity: 0;
  transform: translateX(-100%);
}

.mobile-menu-enter-active {
  opacity: 1;
  transform: translateX(0);
  transition: opacity 300ms, transform 300ms;
}

.mobile-menu-exit {
  opacity: 1;
  transform: translateX(0);
}

.mobile-menu-exit-active {
  opacity: 0;
  transform: translateX(-100%);
  transition: opacity 300ms, transform 300ms;
}

/* Hero section parallax effect */
.parallax {
  background-attachment: fixed;
  background-position: center;
  background-repeat: no-repeat;
  background-size: cover;
}