:root {
    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent-color: #38bdf8;
    --border-color: #334155;
}

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

nav {
    padding: 1rem 2rem;
    background: rgba(15, 23, 42, 0.9);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    position: sticky;
    top: 0;
    z-index: 100;
}

nav a { color: var(--text-primary); text-decoration: none; font-weight: 600; }
nav a:hover { color: var(--accent-color); }

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 4rem 2rem;
}

h1 { font-size: 2.5rem; margin-bottom: 0.5rem; }
.subtitle { color: var(--accent-color); margin-bottom: 3rem; font-size: 1.2rem; }

h2 {
    border-bottom: 2px solid var(--accent-color);
    display: inline-block;
    padding-bottom: 0.5rem;
    margin-top: 3rem;
    margin-bottom: 1.5rem;
}

.figure-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.figure-grid.three-cols {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.figure-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
}

.figure-card img {
    width: 100%;
    border-radius: 8px;
    margin-bottom: 1rem;
    background-color: #fff; 
}

.figure-caption {
    font-size: 0.9rem;
    color: var(--text-secondary);
    text-align: justify;
    width: 100%;
}

.equation-box {
    font-family: 'JetBrains Mono', monospace;
    padding: 1.5rem;
    background: #000;
    border-radius: 8px;
    text-align: center;
    margin: 1.5rem 0;
    font-size: 1.1rem;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    margin: 2rem 0;
    font-family: 'Inter', sans-serif;
    background: var(--card-bg);
    border-radius: 8px;
    overflow: hidden;
    border: 1px solid var(--border-color);
}
.data-table th, .data-table td {
    border: 1px solid var(--border-color);
    padding: 1rem;
    text-align: center;
}
.data-table th {
    background-color: rgba(56, 189, 248, 0.1);
    color: var(--accent-color);
    font-weight: 600;
}
.data-table tr:nth-child(even) {
    background-color: rgba(255, 255, 255, 0.02);
}

.discussion-box {
    background: rgba(56, 189, 248, 0.05);
    border-left: 4px solid var(--accent-color);
    padding: 1.5rem;
    margin-top: 2rem;
    border-radius: 0 8px 8px 0;
}

/* footer */
footer {
    padding: 3rem 2rem;
    text-align: center;
    border-top: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.875rem;
    background-color: var(--bg-color);
}

footer p {
    margin-bottom: 0.5rem;
}

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

footer a:hover {
    text-decoration: underline;
}