:root {
    --primary: #2563eb;
    --dark: #1e293b;
    --light: #f8fafc;
    --gray: #64748b;
    --white: #ffffff;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    background-color: var(--light);
    color: var(--dark);
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navbar - Flexbox Example */
.navbar {
    background: var(--dark);
    color: var(--white);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

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

.nav-links {
    display: flex;
    list-style: none;
    gap: 20px;
}

.nav-links a {
    color: var(--white);
    text-decoration: none;
    font-size: 0.9rem;
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 60px 0;
}

.hero h2 { font-size: 2.5rem; color: var(--primary); }

/* Cards */
.card {
    background: var(--white);
    padding: 30px;
    border-radius: 12px;
    margin-bottom: 30px;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

/* Grid Layout Example */
.layout-demo {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-top: 20px;
}

/* Framework Table Styling */
.comparison-table-wrapper {
    overflow-x: auto;
    margin: 20px 0;
}

.framework-table {
    width: 100%;
    border-collapse: collapse;
    background: #fff;
    border-radius: 8px;
    overflow: hidden;
}

.framework-table th, .framework-table td {
    padding: 15px;
    text-align: left;
    border-bottom: 1px solid #e2e8f0;
}

.framework-table th {
    background: var(--dark);
    color: white;
    font-size: 0.9rem;
}

.framework-table tr:hover {
    background: #f1f5f9;
}

/* Theory Boxes */
.theory-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-top: 20px;
}

.theory-box {
    background: #f8fafc;
    padding: 20px;
    border-radius: 8px;
    border: 1px solid #e2e8f0;
}

.theory-box h4 {
    color: var(--primary);
    margin-bottom: 10px;
}

@media (max-width: 600px) {
    .theory-grid { grid-template-columns: 1fr; }
}

.demo-box {
    padding: 20px;
    border-radius: 8px;
    border: 2px dashed var(--gray);
}

.flex-demo { background: #eff6ff; }
.grid-demo { background: #f0fdf4; }

/* Interactive Elements */
button {
    background: var(--primary);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    cursor: pointer;
    font-weight: bold;
    transition: opacity 0.2s;
}

button:hover { opacity: 0.9; }

.check-list {
    margin-left: 20px;
    margin-top: 10px;
}