:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --accent-color: #f59e0b;
    --bg-color: #f8fafc;
    --text-color: #1e293b;
    --white: #ffffff;
}

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

body {
    font-family: 'Open Sans', sans-serif;
    line-height: 1.6;
    background-color: var(--bg-color);
    color: var(--text-color);
    padding-bottom: 50px;
}

header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: var(--white);
    padding: 60px 20px;
    text-align: center;
    margin-bottom: 40px;
}

h1 {
    font-family: 'Montserrat', sans-serif;
    font-size: 2.5rem;
    margin-bottom: 10px;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 20px;
}

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

h2 {
    font-family: 'Montserrat', sans-serif;
    color: var(--primary-color);
    border-bottom: 2px solid var(--bg-color);
    padding-bottom: 10px;
    margin-bottom: 20px;
}

.alert {
    background-color: #fee2e2;
    border-left: 5px solid #ef4444;
    padding: 15px;
    margin: 20px 0;
    font-weight: 600;
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-top: 20px;
}

.card {
    background: var(--bg-color);
    padding: 20px;
    border-radius: 8px;
    border: 1px solid #e2e8f0;
}

.card h3 {
    color: var(--secondary-color);
    margin-bottom: 10px;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
    background: var(--white);
}

th,
td {
    text-align: left;
    padding: 12px;
    border: 1px solid #e2e8f0;
}

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

tr:nth-child(even) {
    background-color: #f1f5f9;
}

code {
    background: #272822;
    color: #f8f8f2;
    padding: 15px;
    display: block;
    border-radius: 5px;
    overflow-x: auto;
    font-family: 'Courier New', Courier, monospace;
    margin: 20px 0;
}

.tip {
    background-color: #fef3c7;
    border-left: 5px solid var(--accent-color);
    padding: 15px;
    margin-top: 20px;
}

footer {
    text-align: center;
    font-size: 0.9rem;
    color: #64748b;
    margin-top: 40px;
}

@media (max-width: 600px) {
    h1 {
        font-size: 1.8rem;
    }

    section {
        padding: 20px;
    }
}