:root {
    --bg-light: linear-gradient(135deg, #4facfe, #00f2fe);
    --bg-dark: linear-gradient(135deg, #141e30, #243b55);
    --card-light: #ffffff;
    --card-dark: #1f1f1f;
    --text-light: #ffffff;
    --text-dark: #000000;
}

body {
    margin: 0;
    font-family: Arial, sans-serif;
    background: var(--bg-light);
    transition: 0.3s;
    color: var(--text-light);
}

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

.container {
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

.login-box {
    background: rgba(255,255,255,0.15);
    padding: 40px;
    border-radius: 12px;
    text-align: center;
    backdrop-filter: blur(10px);
    width: 90%;
    max-width: 400px;
}

.login-box input {
    width: 100%;
    padding: 10px;
    margin: 10px 0;
    border-radius: 6px;
    border: none;
}

.login-box button {
    width: 100%;
    padding: 10px;
    background: #28a745;
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-weight: bold;
}

.login-box button:hover {
    background: #218838;
}

.error {
    color: red;
    margin-top: 10px;
}

.toggle-container {
    position: absolute;
    top: 20px;
    right: 20px;
}

.toggle-container button {
    padding: 8px 12px;
    border-radius: 50%;
    border: none;
    cursor: pointer;
}

.dashboard {
    padding: 50px;
    text-align: center;
}

.card-container {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 20px;
    margin-top: 30px;
}

.card {
    background: var(--card-light);
    color: black;
    padding: 20px;
    border-radius: 12px;
    width: 250px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.2);
}

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

.logout {
    margin-top: 30px;
    padding: 10px 20px;
    background: crimson;
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
}

@media(max-width: 768px) {
    .card-container {
        flex-direction: column;
        align-items: center;
    }
}