/* ============================================
   MAIN CSS - CSS PRACTICAL HANDBOOK LANDING PAGE
   ============================================ */

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    overflow-x: hidden;
}

/* ============================================
   HEADER STYLES
   ============================================ */

.header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 40px 20px;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
    animation: slideDown 0.6s ease-out;
}

@keyframes slideDown {
    from {
        transform: translateY(-100%);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.header-content {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 40px;
}

.logo h1 {
    font-size: 2rem;
    margin-bottom: 8px;
    animation: fadeInUp 0.8s ease-out;
}

.logo p {
    font-size: 1.1rem;
    opacity: 0.9;
    animation: fadeInUp 0.8s ease-out 0.1s both;
}

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

/* ============================================
   NAVIGATION MENU
   ============================================ */

.nav-menu {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
}

.nav-btn {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.3);
    padding: 10px 20px;
    border-radius: 25px;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.95rem;
    transition: all 0.3s ease;
    animation: fadeInDown 0.8s ease-out 0.2s both;
}

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

.nav-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
    border-color: rgba(255, 255, 255, 0.5);
}

.nav-btn.active {
    background: white;
    color: #667eea;
    border-color: white;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

/* ============================================
   MAIN CONTENT
   ============================================ */

.main-content {
    max-width: 1400px;
    margin: 0 auto;
    padding: 40px 20px;
}

.practicals-section {
    margin-bottom: 60px;
    animation: fadeIn 0.8s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.section-title {
    font-size: 2rem;
    color: white;
    margin-bottom: 30px;
    text-align: center;
    animation: slideInLeft 0.8s ease-out;
}

@keyframes slideInLeft {
    from {
        transform: translateX(-30px);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

/* ============================================
   PRACTICALS GRID
   ============================================ */

.practicals-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 25px;
    margin-bottom: 30px;
}

/* ============================================
   PRACTICAL CARD STYLES
   ============================================ */

.practical-card {
    background: white;
    border-radius: 15px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    transform: translateY(30px);
    opacity: 0;
    cursor: pointer;
    border-top: 4px solid;
    display: none;
}

.practical-card.beginner {
    border-top-color: #4CAF50;
}

.practical-card.intermediate {
    border-top-color: #FF9800;
}

.practical-card.advanced {
    border-top-color: #F44336;
}

.practical-card.visible {
    display: block;
    transform: translateY(0);
    opacity: 1;
    animation: scaleIn 0.5s ease-out;
}

@keyframes scaleIn {
    from {
        transform: scale(0.95) translateY(30px);
        opacity: 0;
    }
    to {
        transform: scale(1) translateY(0);
        opacity: 1;
    }
}

.practical-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 16px 48px rgba(0, 0, 0, 0.2);
}

/* ============================================
   CARD HEADER
   ============================================ */

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.1), rgba(118, 75, 162, 0.1));
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.practical-number {
    font-weight: 700;
    color: #667eea;
    font-size: 0.9rem;
}

.difficulty-badge {
    font-size: 0.75rem;
    font-weight: 700;
    padding: 4px 12px;
    border-radius: 12px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.beginner .difficulty-badge {
    background: #E8F5E9;
    color: #2E7D32;
}

.intermediate .difficulty-badge {
    background: #FFF3E0;
    color: #E65100;
}

.advanced .difficulty-badge {
    background: #FFEBEE;
    color: #C62828;
}

/* ============================================
   CARD CONTENT
   ============================================ */

.card-content {
    padding: 20px;
}

.card-content h3 {
    font-size: 1.3rem;
    color: #333;
    margin-bottom: 12px;
    font-weight: 700;
}

.description {
    color: #666;
    font-size: 0.95rem;
    line-height: 1.6;
    margin-bottom: 15px;
}

.topics {
    font-size: 0.85rem;
    color: #888;
    padding: 12px;
    background: #f5f5f5;
    border-radius: 8px;
    border-left: 3px solid #667eea;
}

.topics strong {
    color: #667eea;
}

/* ============================================
   CARD FOOTER
   ============================================ */

.card-footer {
    padding: 15px 20px;
    border-top: 1px solid #e0e0e0;
    text-align: center;
}

.view-btn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.95rem;
}

.view-btn:hover {
    transform: translateX(5px);
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
}

.view-btn:active {
    transform: scale(0.98);
}

/* ============================================
   FOOTER
   ============================================ */

.footer {
    background: rgba(0, 0, 0, 0.3);
    color: white;
    padding: 30px 20px;
    text-align: center;
    margin-top: 40px;
    backdrop-filter: blur(10px);
    animation: slideUp 0.8s ease-out;
}

@keyframes slideUp {
    from {
        transform: translateY(30px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.footer p {
    margin: 8px 0;
    font-size: 0.95rem;
}

.footer p:first-child {
    font-weight: 700;
    font-size: 1rem;
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */

@media (max-width: 1024px) {
    .header-content {
        flex-direction: column;
        text-align: center;
        gap: 20px;
    }

    .logo h1 {
        font-size: 1.7rem;
    }

    .practicals-grid {
        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
        gap: 20px;
    }
}

@media (max-width: 768px) {
    .header {
        padding: 25px 15px;
    }

    .logo h1 {
        font-size: 1.4rem;
    }

    .logo p {
        font-size: 0.95rem;
    }

    .nav-menu {
        justify-content: center;
        gap: 10px;
    }

    .nav-btn {
        padding: 8px 16px;
        font-size: 0.85rem;
    }

    .main-content {
        padding: 25px 15px;
    }

    .section-title {
        font-size: 1.5rem;
        margin-bottom: 20px;
    }

    .practicals-grid {
        grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
        gap: 15px;
    }

    .card-content h3 {
        font-size: 1.1rem;
    }

    .description {
        font-size: 0.9rem;
    }
}

@media (max-width: 480px) {
    .header {
        padding: 20px 10px;
    }

    .header-content {
        gap: 15px;
    }

    .logo h1 {
        font-size: 1.2rem;
        margin-bottom: 5px;
    }

    .logo p {
        font-size: 0.85rem;
    }

    .nav-menu {
        gap: 8px;
    }

    .nav-btn {
        padding: 7px 12px;
        font-size: 0.75rem;
    }

    .main-content {
        padding: 15px 10px;
    }

    .section-title {
        font-size: 1.2rem;
        margin-bottom: 15px;
    }

    .practicals-grid {
        grid-template-columns: 1fr;
        gap: 12px;
    }

    .card-content {
        padding: 15px;
    }

    .card-content h3 {
        font-size: 1rem;
        margin-bottom: 8px;
    }

    .description {
        font-size: 0.85rem;
        margin-bottom: 10px;
    }

    .topics {
        font-size: 0.75rem;
        padding: 8px;
    }

    .view-btn {
        padding: 8px 16px;
        font-size: 0.85rem;
    }

    .footer p {
        font-size: 0.8rem;
    }
}

/* ============================================
   CUSTOM SCROLLBAR
   ============================================ */

::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.1);
}

::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.3);
    border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.5);
}

/* ============================================
   ANIMATION UTILITIES
   ============================================ */

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.7;
    }
}

@keyframes bounce {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-5px);
    }
}

.view-btn:active {
    animation: bounce 0.4s ease;
}