* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
    color: white;
    overflow: hidden;
}

/* Dynamischer Hintergrund */
.dynamic-background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #3498db, #8e44ad);
    z-index: 0;
}

.dynamic-background::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle, transparent 20%, #000 80%);
    opacity: 0.7;
}

.login-container {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 40px;
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
    width: 100%;
    max-width: 420px;
    text-align: center;
    position: relative;
    z-index: 1;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.login-header {
    margin-bottom: 30px;
}

.logo-container {
    margin-bottom: 20px;
}

.logo-container i {
    font-size: 64px;
    color: #667eea;
    margin-bottom: 15px;
    text-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); }
    100% { transform: scale(1); }
}

.login-header h1 {
    color: #333;
    margin-bottom: 8px;
    font-size: 32px;
    font-weight: 700;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.login-header p {
    color: #666;
    font-size: 16px;
    font-weight: 400;
}

.alert {
    padding: 15px;
    border-radius: 10px;
    margin-bottom: 25px;
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 500;
    animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.alert.error {
    background: rgba(255, 235, 238, 0.9);
    color: #c62828;
    border: 1px solid rgba(198, 40, 40, 0.3);
}

.alert.success {
    background: rgba(232, 245, 233, 0.9);
    color: #2e7d32;
    border: 1px solid rgba(46, 125, 50, 0.3);
}

.login-form {
    margin-bottom: 25px;
}

.form-group {
    margin-bottom: 25px;
    text-align: left;
}

.form-group label {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 10px;
    font-weight: 600;
    color: #333;
    font-size: 16px;
}

.input-container {
    position: relative;
    display: flex;
    align-items: center;
}

.form-group input {
    width: 100%;
    padding: 15px 50px 15px 15px;
    border: 2px solid #e1e5e9;
    border-radius: 10px;
    font-size: 16px;
    transition: all 0.3s ease;
    background: rgba(255, 255, 255, 0.9);
}

.form-group input:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 4px rgba(102, 126, 234, 0.1);
    background: rgba(255, 255, 255, 1);
}

.toggle-password {
    position: absolute;
    right: 15px;
    background: none;
    border: none;
    color: #666;
    cursor: pointer;
    padding: 5px;
    border-radius: 5px;
    transition: color 0.3s ease;
}

.toggle-password:hover {
    color: #667eea;
}

.btn-login {
    width: 100%;
    padding: 15px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
}

.btn-login:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.4);
}

.btn-login:active {
    transform: translateY(0);
}

.btn-login:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.login-footer {
    padding-top: 20px;
    border-top: 1px solid rgba(0, 0, 0, 0.1);
}

.back-link {
    color: #667eea;
    text-decoration: none;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: all 0.3s ease;
    padding: 10px;
    border-radius: 8px;
    font-weight: 500;
}

.back-link:hover {
    color: #5a6fd8;
    background: rgba(102, 126, 234, 0.1);
    transform: translateX(-2px);
}

/* Loading State */
.btn-login.loading {
    pointer-events: none;
}

.btn-login.loading i {
    animation: spin 1s linear infinite;
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* Responsive Design */
@media (max-width: 480px) {
    body {
        padding: 15px;
    }
    
    .login-container {
        padding: 30px 25px;
        border-radius: 15px;
    }
    
    .login-header h1 {
        font-size: 28px;
    }
    
    .logo-container i {
        font-size: 56px;
    }
    
    .form-group input {
        padding: 12px 45px 12px 12px;
        font-size: 16px; /* Prevents zoom on iOS */
    }
    
    .btn-login {
        padding: 12px;
        font-size: 16px;
    }
}

@media (max-width: 320px) {
    .login-container {
        padding: 25px 20px;
    }
    
    .login-header h1 {
        font-size: 24px;
    }
    
    .logo-container i {
        font-size: 48px;
    }
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
    .login-container {
        background: rgba(30, 30, 30, 0.65);
        border: 1px solid rgba(255, 255, 255, 0.1);
    }
    
    .login-header h1 {
        color: #fff;
    }
    
    .login-header p {
        color: #ccc;
    }
    
    .form-group label {
        color: #fff;
    }
    
    .form-group input {
        background: rgba(255, 255, 255, 0.1);
        border-color: rgba(255, 255, 255, 0.2);
        color: #fff;
    }
    
    .form-group input:focus {
        background: rgba(255, 255, 255, 0.15);
        border-color: #667eea;
    }
    
    .toggle-password {
        color: #ccc;
    }
    
    .toggle-password:hover {
        color: #667eea;
    }
}