:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #64748b;
    --secondary-hover: #475569;
    --background: #ffffff;
    --surface: #f8fafc;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--background);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Navigation */
nav {
    background: white;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

nav .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
}

.nav-brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.nav-links {
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

.nav-links a {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

.nav-links a:hover {
    color: var(--primary-color);
    text-decoration: none;
}

.btn-nav-download {
    background: var(--primary-color);
    color: white !important;
    padding: 0.5rem 1.5rem;
    border-radius: 0.5rem;
    transition: background 0.2s;
}

.btn-nav-download:hover {
    background: var(--primary-hover);
    color: white !important;
}

/* Header */
header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 4rem 0;
    text-align: center;
}

header h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

.tagline {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.95;
}

.header-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 2rem;
    border-radius: 0.5rem;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.2s;
    border: none;
    cursor: pointer;
}

.btn-primary {
    background-color: white;
    color: #667eea;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.btn-secondary {
    background-color: rgba(255, 255, 255, 0.2);
    color: white;
    border: 2px solid white;
}

.btn-secondary:hover {
    background-color: rgba(255, 255, 255, 0.3);
}

/* Main Content */
main {
    padding: 4rem 0;
}

section {
    margin-bottom: 4rem;
}

h2 {
    font-size: 2rem;
    margin-bottom: 2rem;
    color: var(--text-primary);
    border-bottom: 3px solid var(--primary-color);
    padding-bottom: 0.5rem;
}

h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

/* Feature Grid */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.feature-card {
    background: var(--surface);
    padding: 2rem;
    border-radius: 0.75rem;
    border: 1px solid var(--border-color);
    transition: transform 0.2s, box-shadow 0.2s;
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    margin-bottom: 0.75rem;
}

.feature-card p {
    color: var(--text-secondary);
}

/* Quick Start */
.quick-start-section {
    background: var(--surface);
    padding: 1.5rem;
    border-radius: 0.5rem;
    margin-bottom: 1.5rem;
    border-left: 4px solid var(--primary-color);
}

.quick-start-section h3 {
    margin-bottom: 1rem;
}

.quick-start-section ol,
.quick-start-section ul {
    margin-left: 1.5rem;
}

.quick-start-section li {
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

code {
    background: #e2e8f0;
    padding: 0.2rem 0.5rem;
    border-radius: 0.25rem;
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
}

/* Requirements */
.requirements ul {
    list-style: none;
    background: var(--surface);
    padding: 2rem;
    border-radius: 0.5rem;
}

.requirements li {
    padding: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
    color: var(--text-secondary);
}

.requirements li:before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

/* License */
.license {
    text-align: center;
    padding: 2rem;
    background: var(--surface);
    border-radius: 0.5rem;
}

/* Documentation Styles */
.doc-section {
    background: var(--surface);
    padding: 1.5rem;
    border-radius: 0.5rem;
    margin-bottom: 1.5rem;
    border-left: 4px solid var(--primary-color);
}

.doc-section h3 {
    margin-top: 0;
    margin-bottom: 1rem;
}

.doc-section h4 {
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
    color: var(--primary-color);
    font-size: 1.1rem;
}

.doc-section ol,
.doc-section ul {
    margin-left: 1.5rem;
    margin-bottom: 1rem;
}

.doc-section li {
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

.doc-section p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.shortcuts-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1rem;
}

.shortcuts-table td {
    padding: 0.75rem;
    border-bottom: 1px solid var(--border-color);
}

.shortcuts-table tr:last-child td {
    border-bottom: none;
}

.shortcuts-table td:first-child {
    width: 30%;
    color: var(--primary-color);
}

.shortcuts-table td:last-child {
    color: var(--text-secondary);
}

/* Footer */
footer {
    background: var(--text-primary);
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: 4rem;
}

footer a {
    color: white;
    text-decoration: none;
    font-weight: 600;
}

footer a:hover {
    text-decoration: underline;
}

/* Links */
a {
    color: var(--primary-color);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

/* Responsive */
@media (max-width: 768px) {
    nav .container {
        padding: 1rem;
    }

    .nav-links {
        gap: 1rem;
    }

    .nav-brand {
        font-size: 1.25rem;
    }

    header h1 {
        font-size: 2rem;
    }

    .tagline {
        font-size: 1rem;
    }

    .container {
        padding: 0 1rem;
    }

    .feature-grid {
        grid-template-columns: 1fr;
    }

    .header-buttons {
        flex-direction: column;
    }
}