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

:root {
    --primary: #0066cc;
    --primary-dark: #0052a3;
    --secondary: #00d4ff;
    --dark: #1a1a2e;
    --darker: #0f0f1a;
    --light: #f5f7fa;
    --gray: #6b7280;
    --success: #10b981;
    --white: #ffffff;
}

body {
    font-family: 'Inter', sans-serif;
    background: var(--light);
    color: var(--dark);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    background: var(--dark);
    color: var(--white);
    padding: 1rem 0;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--secondary);
}

.logo i {
    font-size: 1.8rem;
}

.nav {
    display: flex;
    gap: 2rem;
}

.nav-link {
    color: var(--white);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
    padding: 0.5rem 0;
    border-bottom: 2px solid transparent;
}

.nav-link:hover,
.nav-link.active {
    color: var(--secondary);
    border-bottom-color: var(--secondary);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--dark) 0%, var(--primary-dark) 100%);
    color: var(--white);
    padding: 8rem 0 4rem;
    text-align: center;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.2rem;
    opacity: 0.9;
}

/* Info Section */
.info-section {
    padding: 4rem 0;
    background: var(--white);
}

.info-section h2 {
    text-align: center;
    margin-bottom: 3rem;
    color: var(--dark);
    font-size: 1.8rem;
}

.info-section h2 i {
    color: var(--primary);
    margin-right: 10px;
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.info-card {
    background: var(--light);
    padding: 2rem;
    border-radius: 12px;
    text-align: center;
    transition: transform 0.3s, box-shadow 0.3s;
}

.info-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

.info-card i {
    font-size: 3rem;
    color: var(--primary);
    margin-bottom: 1rem;
}

.info-card h3 {
    margin-bottom: 0.5rem;
    color: var(--dark);
}

.info-card p {
    color: var(--gray);
    font-size: 0.95rem;
}

/* Downloads Section */
.downloads-section {
    padding: 4rem 0;
}

.downloads-section h2 {
    text-align: center;
    margin-bottom: 3rem;
    color: var(--dark);
    font-size: 1.8rem;
}

.downloads-section h2 i {
    color: var(--primary);
    margin-right: 10px;
}

.category {
    margin-bottom: 3rem;
}

.category h3 {
    font-size: 1.3rem;
    color: var(--dark);
    margin-bottom: 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--primary);
    display: inline-block;
}

.category h3 i {
    margin-right: 10px;
    color: var(--primary);
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.download-card {
    background: var(--white);
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    transition: transform 0.3s, box-shadow 0.3s;
    border: 1px solid #e5e7eb;
}

.download-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

.download-card.featured {
    border: 2px solid var(--primary);
    background: linear-gradient(135deg, #f0f9ff 0%, #ffffff 100%);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.card-header i {
    font-size: 2rem;
    color: var(--primary);
}

.badge {
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
}

.badge.windows {
    background: #e0f2fe;
    color: #0369a1;
}

.badge.mac {
    background: #f3e8ff;
    color: #7c3aed;
}

.badge.python {
    background: #fef3c7;
    color: #d97706;
}

.badge.android {
    background: #dcfce7;
    color: #16a34a;
}

.badge.docs {
    background: #f3f4f6;
    color: #374151;
}

.download-card h4 {
    font-size: 1.2rem;
    color: var(--dark);
    margin-bottom: 0.5rem;
}

.download-card p {
    color: var(--gray);
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.features {
    list-style: none;
    margin-bottom: 1.5rem;
}

.features li {
    font-size: 0.85rem;
    color: var(--gray);
    margin-bottom: 0.3rem;
}

.features i {
    color: var(--success);
    margin-right: 8px;
    font-size: 0.8rem;
}

.btn-download {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: var(--primary);
    color: var(--white);
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 500;
    transition: background 0.3s, transform 0.2s;
    width: 100%;
    justify-content: center;
}

.btn-download:hover {
    background: var(--primary-dark);
    transform: scale(1.02);
}

/* Install Guide */
.install-guide {
    background: var(--white);
    border-radius: 16px;
    padding: 2.5rem;
    margin-top: 1.5rem;
    box-shadow: 0 4px 20px rgba(0,0,0,0.06);
    border: 1px solid #e5e7eb;
}

.guide-header {
    display: flex;
    align-items: center;
    gap: 1.25rem;
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 2px solid var(--light);
}

.guide-icon {
    flex-shrink: 0;
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--white);
    box-shadow: 0 4px 12px rgba(0,102,204,0.3);
}

.guide-title h4 {
    font-size: 1.3rem;
    color: var(--dark);
    margin-bottom: 0.25rem;
}

.guide-title p {
    color: var(--gray);
    font-size: 0.95rem;
}

/* Timeline */
.timeline {
    position: relative;
    padding-left: 2.5rem;
    margin-bottom: 2rem;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 15px;
    top: 8px;
    bottom: 8px;
    width: 2px;
    background: linear-gradient(to bottom, var(--primary), var(--success));
    border-radius: 1px;
}

.timeline-item {
    position: relative;
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 0.75rem 0;
}

.timeline-dot {
    position: absolute;
    left: -2.5rem;
    top: 0.75rem;
    width: 30px;
    height: 30px;
    background: var(--primary);
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.8rem;
    z-index: 1;
    box-shadow: 0 2px 8px rgba(0,102,204,0.3);
}

.timeline-item.success .timeline-dot {
    background: var(--success);
    box-shadow: 0 2px 8px rgba(16,185,129,0.3);
    font-size: 0.75rem;
}

.timeline-content {
    flex: 1;
    padding: 0.5rem 1rem;
    background: var(--light);
    border-radius: 10px;
    transition: all 0.2s;
}

.timeline-content:hover {
    background: #e8f4fd;
    transform: translateX(4px);
}

.timeline-title {
    font-weight: 600;
    color: var(--dark);
    font-size: 0.95rem;
    margin-bottom: 0.2rem;
}

.timeline-desc {
    font-size: 0.88rem;
    color: var(--gray);
    line-height: 1.5;
}

.timeline-desc strong {
    color: var(--primary);
}

.timeline-desc code {
    background: #dbeafe;
    padding: 0.1rem 0.4rem;
    border-radius: 4px;
    font-size: 0.82rem;
    color: #1d4ed8;
    font-family: 'Courier New', monospace;
}

/* Info Cards */
.info-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.info-card-small {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem 1.25rem;
    background: var(--light);
    border-radius: 10px;
    border-left: 3px solid var(--primary);
    transition: all 0.2s;
}

.info-card-small:hover {
    background: #e8f4fd;
    transform: translateY(-2px);
}

.info-card-small i {
    flex-shrink: 0;
    font-size: 1.1rem;
    color: var(--primary);
    width: 20px;
    text-align: center;
}

.info-card-small strong {
    display: block;
    font-size: 0.85rem;
    color: var(--dark);
    margin-bottom: 0.15rem;
}

.info-card-small span {
    font-size: 0.8rem;
    color: var(--gray);
    line-height: 1.4;
}

/* Commands Details */
.commands-details {
    background: var(--darker);
    border-radius: 10px;
    overflow: hidden;
}

.commands-details summary {
    padding: 0.85rem 1.25rem;
    color: var(--secondary);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: background 0.2s;
    list-style: none;
}

.commands-details summary::-webkit-details-marker {
    display: none;
}

.commands-details summary::after {
    content: '\f078';
    font-family: 'Font Awesome 6 Free';
    font-weight: 900;
    margin-left: auto;
    font-size: 0.7rem;
    transition: transform 0.2s;
}

.commands-details[open] summary::after {
    transform: rotate(180deg);
}

.commands-details summary:hover {
    background: rgba(255,255,255,0.05);
}

.commands-grid {
    padding: 0 1.25rem 1rem;
}

.cmd-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.6rem 0;
    border-bottom: 1px solid rgba(255,255,255,0.08);
}

.cmd-row:last-child {
    border-bottom: none;
}

.cmd-row code {
    background: rgba(0,212,255,0.1);
    color: var(--secondary);
    padding: 0.3rem 0.75rem;
    border-radius: 5px;
    font-size: 0.82rem;
    font-family: 'Courier New', monospace;
}

.cmd-row span {
    color: var(--gray);
    font-size: 0.82rem;
}

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

.footer p {
    margin-bottom: 0.5rem;
    opacity: 0.8;
    font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 768px) {
    .header .container {
        flex-direction: column;
        gap: 1rem;
    }
    
    .nav {
        gap: 1rem;
    }
    
    .hero h1 {
        font-size: 1.8rem;
    }
    
    .hero p {
        font-size: 1rem;
    }
}