/* ---------- Base Theme ---------- */
body {
    margin: 0;
    font-family: "Segoe UI", Arial, sans-serif;
    background: #F3F4F6;
    color: #2C2C2C;
    transition: background 0.3s ease, color 0.3s ease;
}

/* ---------- Dark Mode ---------- */
body.dark {
    background: #0D0D0D;
    color: #E5E5E5;
}

body.dark header,
body.dark footer,
body.dark .navbar {
    background: #111111;
}

body.dark .card {
    background: #1A1A1A;
    box-shadow: 0 4px 10px rgba(255,255,255,0.05);
}

body.dark a {
    color: #9BB8FF;
}

/* ---------- Navigation Bar ---------- */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: #1F1F2E;
    color: white;
    padding: 15px 25px;
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar a {
    color: white;
    margin-left: 20px;
    text-decoration: none;
    font-weight: 500;
}

.navbar a:hover {
    color: #6C63FF;
}

.theme-btn {
    background: none;
    border: none;
    color: white;
    font-size: 1.3rem;
    cursor: pointer;
}

/* ---------- Header ---------- */
header {
    background: #1F1F2E;
    color: white;
    padding: 40px 20px;
    text-align: center;
}

header h1 {
    margin: 0;
    font-size: 2.8rem;
}

/* ---------- Content ---------- */
.container {
    max-width: 900px;
    margin: 40px auto;
    padding: 0 20px;
}

h2 {
    margin-top: 40px;
    color: #1F1F2E;
    border-left: 5px solid #6C63FF;
    padding-left: 10px;
}

body.dark h2 {
    color: #E5E5E5;
}

/* ---------- Cards ---------- */
.link-grid {