/* Root theme classes */
:root {
    --bg-light: #f9f9f9;
    --bg-dark: #1e1e1e;
    --card-light: #ffffff;
    --card-dark: #2b2b2b;
    --text-light: #2c3e50;
    --text-dark: #ecf0f1;
    --title-blue: #0077cc;
    --desc-gray: #6c757d;
    --sepia-bg: #f4ecd8;
    --green-bg: #e9f7ef;
    --blue-bg: #e3f2fd;
    --transition: all 0.4s ease;
}

body {
    background: var(--bg-light);
    color: var(--text-light);
    font-family: 'Segoe UI', sans-serif;
    transition: var(--transition);
}

body.dark {
    background: var(--bg-dark);
    color: var(--text-dark);
}

/* Notes Grid Layout */
.notes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 24px;
    padding: 20px;
    max-width: 900px;
    margin: 0 auto;
}

/* Notes Cards */
.notes-card {
    background: var(--card-light);
    border-radius: 12px;
    padding: 20px;
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.08);
    transition: var(--transition);
    position: relative;
}

body.dark .notes-card {
    background: var(--card-dark);
}

.notes-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
}

.notes-card a {
    text-decoration: none;
    color: inherit;
    display: block;
}

.notes-title {
    font-size: 20px;
    font-weight: bold;
    color: var(--title-blue);
    margin-bottom: 8px;
}

body.dark .notes-title {
    color: #4da6ff;
}

.notes-description {
    font-size: 15px;
    color: var(--desc-gray);
}

body.dark .notes-description {
    color: #bbb;
}

.notes-number {
    position: absolute;
    top: 12px;
    right: 16px;
    font-size: 13px;
    color: #aaa;
}

/* Category Card Grid */
.category-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    padding: 20px;
    justify-content: center;
}

.category-card {
    background: var(--card-light);
    padding: 20px;
    border-radius: 10px;
    width: 220px;
    text-align: center;
    transition: var(--transition);
    box-shadow: 0 3px 12px rgba(0, 0, 0, 0.08);
}

body.dark .category-card {
    background: var(--card-dark);
}

.category-card a {
    text-decoration: none;
    color: inherit;
}

.category-card i {
    font-size: 32px;
    margin-bottom: 10px;
    color: var(--title-blue);
}

.category-card h3 {
    font-size: 18px;
    margin: 0;
}

/* Theme Variants */
.theme-blue .notes-card { background: var(--blue-bg); }
.theme-sepia .notes-card { background: var(--sepia-bg); }
.theme-green .notes-card { background: var(--green-bg); }

/* Responsive */
@media (max-width: 768px) {
    .notes-grid {
        grid-template-columns: 1fr;
    }

    .category-grid {
        flex-direction: column;
        align-items: center;
    }
}