:root {
    --primary-color: #007bff;
    --primary-hover: #0056b3;
    --bg-color: #0f0f0f;
    --card-bg: #1a1a1a;
    --text-main: #ffffff;
    --text-dim: #a0a0a0;
    --border-color: #333;
    --success: #28a745;
    --error: #dc3545;
}

body {
    font-family: 'Inter', -apple-system, system-ui, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    display: flex;
    justify-content: center;
    min-height: 100vh;
    margin: 0;
    padding: 20px;
    line-height: 1.6;
}

.container {
    max-width: 800px;
    width: 100%;
}

.card {
    background: var(--card-bg);
    padding: 40px;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
    border: 1px solid var(--border-color);
    margin-bottom: 20px;
}

.header {
    text-align: center;
    margin-bottom: 40px;
}

.logo {
    width: 120px;
    height: auto;
    margin-bottom: 20px;
    border-radius: 20px; /* Optional: if you want rounded logo */
}

h1, h2, h3, h4, h5, h6 {
    color: var(--text-main);
    margin-top: 1.5em;
    margin-bottom: 0.5em;
    font-weight: 700;
}

h1 { font-size: 2.5rem; margin-top: 0; text-align: center; }
h2 { font-size: 1.8rem; border-bottom: 1px solid var(--border-color); padding-bottom: 10px; }
h3 { font-size: 1.4rem; }

p {
    color: var(--text-dim);
    margin-bottom: 1.2em;
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.2s;
}

a:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

ul, ol {
    color: var(--text-dim);
    margin-bottom: 1.2em;
    padding-left: 20px;
}

li {
    margin-bottom: 0.5em;
}

blockquote {
    border-left: 4px solid var(--primary-color);
    margin: 0;
    padding-left: 20px;
    font-style: italic;
    color: var(--text-dim);
}

code {
    background: #2d2d2d;
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.9em;
}

pre {
    background: #2d2d2d;
    padding: 15px;
    border-radius: 8px;
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 1.5em;
}

th, td {
    padding: 12px;
    border: 1px solid var(--border-color);
    text-align: left;
}

th {
    background-color: #252525;
    color: var(--text-main);
}

/* Footer & Navigation */
.nav-buttons {
    display: flex;
    justify-content: center;
    gap: 15px;
    flex-wrap: wrap;
    margin-top: 40px;
    border-top: 1px solid var(--border-color);
    padding-top: 20px;
}

.btn {
    display: inline-block;
    background: var(--card-bg);
    color: var(--text-main);
    padding: 12px 24px;
    border-radius: 10px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.2s;
    border: 1px solid var(--border-color);
    cursor: pointer;
    text-align: center;
}

.btn:hover {
    background: #252525;
    transform: translateY(-2px);
    border-color: var(--primary-color);
    color: var(--primary-color);
    text-decoration: none;
}

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

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

.btn-back {
    margin-bottom: 20px;
}

/* Responsive */
@media (max-width: 600px) {
    .card {
        padding: 20px;
    }
    
    h1 { font-size: 2rem; }
    
    .nav-buttons {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
        box-sizing: border-box;
    }
}