/* General Styling */
:root {
    --primary-color: #3498db; /* Biru */
    --secondary-color: #2ecc71; /* Hijau */
    --accent-color: #e74c3c; /* Merah */
    --text-color: #333;
    --light-bg: #f4f4f4;
    --dark-bg: #2c3e50; /* Biru gelap */
    --white: #ffffff;
    --gray-light: #ecf0f1;
    --gray-dark: #7f8c8d;
}

body {
    font-family: 'Arial', sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 0;
    color: var(--text-color);
    background-color: var(--light-bg);
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: auto;
    overflow: hidden;
    padding: 20px 0;
}

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

a:hover {
    text-decoration: underline;
}

h1, h2, h3 {
    color: var(--dark-bg);
    margin-bottom: 15px;
}

h1 {
    font-size: 2.8em;
    text-align: center;
    color: var(--white);
}

h2 {
    font-size: 2.2em;
    text-align: center;
    margin-bottom: 30px;
    position: relative;
    padding-bottom: 10px;
}

h2::after {
    content: '';
    position: absolute;
    left: 50%;
    bottom: 0;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background-color: var(--primary-color);
}

h3 {
    font-size: 1.8em;
}

p {
    margin-bottom: 15px;
}

ul {
    list-style: disc;
    margin-left: 20px;
    margin-bottom: 15px;
}

ol {
    list-style: decimal;
    margin-left: 20px;
    margin-bottom: 15px;
}

/* Header */
header {
    background: var(--dark-bg);
    color: var(--white);
    padding: 10px 0;
    border-bottom: var(--primary-color) 3px solid;
}

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

header .logo img {
    height: 50px; /* Adjust as needed */
}

header nav ul {
    padding: 0;
    list-style: none;
    display: flex;
}

header nav ul li {
    margin-left: 20px;
}

header nav ul li a {
    color: var(--white);
    text-decoration: none;
    font-weight: bold;
    transition: color 0.3s ease;
}

header nav ul li a:hover {
    color: var(--primary-color);
    text-decoration: none;
}

/* Hero Section */
.hero {
    background: var(--primary-color);
    color: var(--white);
    min-height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 50px 0;
}

.hero p {
    font-size: 1.2em;
    margin-bottom: 30px;
}

.btn-primary {
    display: inline-block;
    background: var(--secondary-color);
    color: var(--white);
    padding: 12px 25px;
    border-radius: 5px;
    text-decoration: none;
    font-weight: bold;
    transition: background 0.3s ease;
}

.btn-primary:hover {
    background: #27ae60; /* Darker green */
    text-decoration: none;
}

/* Section Styling */
.section {
    padding: 40px 0;
    background-color: var(--white);
    margin-bottom: 20px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.section:nth-of-type(even) {
    background-color: var(--gray-light);
}

/* Grid Container for Topics */
.grid-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    margin-top: 30px;
}

.card {
    background: var(--white);
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    text-align: center;
    transition: transform 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
}

.card h3 {
    color: var(--primary-color);
    margin-top: 0;
}

/* Table Styling */
table {
    width: 100%;
    border-collapse: collapse;
    margin: 30px auto;
    max-width: 800px;
}

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

table th {
    background-color: var(--primary-color);
    color: var(--white);
    font-weight: bold;
}

table tr:nth-child(even) {
    background-color: var(--gray-light);
}

table tr:hover {
    background-color: #ddd;
}

/* Social Links */
.social-links a {
    margin: 0 10px;
    font-size: 1.1em;
}

/* Footer */
footer {
    background: var(--dark-bg);
    color: var(--white);
    text-align: center;
    padding: 20px 0;
    margin-top: 20px;
}

footer p {
    margin: 5px 0;
}

/* Responsive Design */
@media (max-width: 768px) {
    header .container {
        flex-direction: column;
        text-align: center;
    }

    header nav ul {
        margin-top: 10px;
        flex-wrap: wrap;
        justify-content: center;
    }

    header nav ul li {
        margin: 5px 10px;
    }

    h1 {
        font-size: 2.2em;
    }

    h2 {
        font-size: 1.8em;
    }

    .hero {
        min-height: 300px;
    }

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

@media (max-width: 480px) {
    .container {
        width: 95%;
    }

    h1 {
        font-size: 1.8em;
    }

    h2 {
        font-size: 1.5em;
    }

    .btn-primary {
        padding: 10px 20px;
        font-size: 0.9em;
    }
}