/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #64748b;
    --background: #ffffff;
    --surface: #f8fafc;
    --border: #e2e8f0;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
        'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue',
        sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    color: var(--text-primary);
    background-color: var(--surface);
    line-height: 1.6;
}

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

/* Header */
header {
    background: linear-gradient(135deg, var(--primary-color) 0%, #1e40af 100%);
    color: white;
    padding: 3rem 0;
    box-shadow: var(--shadow-lg);
}

header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

header .subtitle {
    font-size: 1.125rem;
    opacity: 0.9;
}

/* Main Content */
main {
    padding: 3rem 0;
    min-height: calc(100vh - 300px);
}

section {
    margin-bottom: 3rem;
}

h2 {
    font-size: 1.875rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
}

/* Intro Section */
.intro p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

/* Grid Layout */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 1.5rem;
    margin-top: 1.5rem;
}

/* Feature Cards */
.feature-card {
    background: var(--background);
    border: 1px solid var(--border);
    border-radius: 0.75rem;
    padding: 1.5rem;
    box-shadow: var(--shadow);
    transition: transform 0.2s, box-shadow 0.2s;
    display: flex;
    flex-direction: column;
}

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

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

.feature-header h3 {
    margin: 0;
    flex: 1;
}

.badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: var(--primary-color);
    color: white;
    border-radius: 1rem;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
}

.feature-description {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    flex: 1;
}

.feature-meta {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border);
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.625rem 1.25rem;
    border-radius: 0.5rem;
    text-decoration: none;
    font-weight: 500;
    text-align: center;
    transition: background-color 0.2s, transform 0.2s;
    cursor: pointer;
    border: none;
    font-size: 0.9375rem;
}

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

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

/* Info Section */
.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-top: 1.5rem;
}

.info-card {
    background: var(--background);
    border: 1px solid var(--border);
    border-radius: 0.75rem;
    padding: 1.5rem;
    box-shadow: var(--shadow);
}

.info-card h3 {
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.info-card ul {
    list-style: none;
}

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

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

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

footer a {
    color: white;
    text-decoration: underline;
}

footer a:hover {
    opacity: 0.8;
}

/* Back Button (for feature pages) */
.back-button {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    margin: 1rem 0;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: gap 0.2s;
}

.back-button:hover {
    gap: 0.75rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 1rem;
    }

    header h1 {
        font-size: 2rem;
    }

    header .subtitle {
        font-size: 1rem;
    }

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

    h2 {
        font-size: 1.5rem;
    }
}

/* Loading State */
.loading {
    text-align: center;
    padding: 3rem 1rem;
    color: var(--text-secondary);
    font-size: 1.125rem;
}

/* Utility Classes */
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

.text-center { text-align: center; }
.text-muted { color: var(--text-secondary); }