:root {
    --primary-color: #3498db;
    --secondary-color: #2c3e50;
    --success-color: #2ecc71;
    --danger-color: #e74c3c;
    --light-bg: #f8f9fa;

    /* Dark Mode Variablen */
    --dark-bg: #1c1c1c;
    --dark-secondary: #34495e;
    --dark-text: #eaeaea;
    --dark-border: #444;
    --dark-input-bg: #2a2a2a;
    --dark-input-focus-bg: #2c2c2c;
    --dark-btn-hover: #2980b9;
    --dark-link: #5dade2;
}

body {
    background-color: #f5f5f5;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    height: 100vh;
    display: flex;
    align-items: center;
    color: #333;
    transition: background-color 0.3s, color 0.3s;
}

.login-card {
    width: 100%;
    max-width: 450px;
    border: none;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    background-color: #fff;
    transition: background-color 0.3s, color 0.3s;
}

.card-header {
    background: linear-gradient(135deg, var(--secondary-color), #34495e);
    color: white;
    text-align: center;
    padding: 1.5rem;
    border-bottom: none;
    transition: background 0.3s;
}

.card-body {
    padding: 2rem;
}

.form-control {
    border-radius: 8px;
    padding: 12px 15px;
    border: 1px solid #ddd;
    background-color: #fff;
    color: #333;
    transition: background-color 0.3s, color 0.3s, border-color 0.3s;
}

.form-control:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 0.25rem rgba(52, 152, 219, 0.25);
    background-color: #fff;
    color: #333;
}

.btn-login {
    background-color: var(--primary-color);
    border: none;
    padding: 12px;
    font-weight: 600;
    border-radius: 8px;
    transition: all 0.3s;
    color: white;
    cursor: pointer;
}

.btn-login:hover {
    background-color: var(--dark-btn-hover);
    transform: translateY(-2px);
}

.alert {
    border-radius: 8px;
}

.login-footer {
    text-align: center;
    margin-top: 1.5rem;
    color: #666;
}

.login-footer a {
    color: var(--primary-color);
    font-weight: 600;
    text-decoration: none;
    transition: color 0.3s;
}

/* Dark Mode */

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

body.dark-mode .login-card {
    background-color: var(--dark-input-bg);
    color: var(--dark-text);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.7);
}

body.dark-mode .card-header {
    background: linear-gradient(135deg, var(--dark-secondary), #2c3e50);
    color: var(--dark-text);
}

body.dark-mode .form-control {
    background-color: var(--dark-input-bg);
    border-color: var(--dark-border);
    color: var(--dark-text);
}

body.dark-mode .form-control:focus {
    background-color: var(--dark-input-focus-bg);
    border-color: #555;
    box-shadow: none;
    color: var(--dark-text);
}

body.dark-mode .btn-login {
    background-color: var(--primary-color);
    color: white;
}

body.dark-mode .btn-login:hover {
    background-color: #1f5a86; /* dunkleres blau für hover */
}

body.dark-mode .login-footer {
    color: #aaa;
}

body.dark-mode .login-footer a {
    color: var(--dark-link);
}