:root {
    --bg-primary: #f8f9fa;
    --bg-secondary: #e9ecef;
    --text-primary: #212529;
    --grid-bg: #ffffff;
    --icon-color: #495057;
}

.dark-mode {
    --bg-primary: #0a1929;
    --bg-secondary: #122c44;
    --text-primary: #e9ecef;
    --grid-bg: #1e3a5f;
    --icon-color: #a0d2ff;
}

* {
    transition: background 0.3s ease, color 0.3s ease;
}

body {
    font-family: 'Segoe UI', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    margin: 0;
    padding: 20px;
    height: calc(100vh - 40px);
    width: calc(100vw - 40px);
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 5%;
    background: var(--bg-secondary);
    border-radius: 12px;
    margin-bottom: 30px;
}

.logo {
    font-size: 1.8rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo img {
    width: 60px;
    height: 60px;
}

#theme-toggle {
    background: transparent;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--icon-color);
}

.grid-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 25px;
    padding: 0 5%;
}

.grid-item {
    background: var(--grid-bg);
    border-radius: 12px;
    padding: 25px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.08);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    cursor: pointer;
}

.grid-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.15);
}

.grid-item i {
    font-size: 2.5rem;
    margin-bottom: 15px;
    color: var(--icon-color);
}

.grid-item h3 {
    margin: 10px 0;
    font-size: 1.2rem;
}

.grid-item p {
    margin: 0;
    font-size: 0.9rem;
    opacity: 0.8;
}

footer {
    text-align: center;
    padding: 25px;
    margin-top: 40px;
    font-size: 0.9rem;
    opacity: 0.7;
}

@media (max-width: 768px) {
    .grid-container {
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    }
}