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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto,
                 'PingFang SC', 'Microsoft YaHei', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.hidden {
    display: none;
}

.login-container {
    background: white;
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.3);
    width: 100%;
    max-width: 400px;
}

h1 {
    text-align: center;
    color: #4f46e5;
    margin-bottom: 30px;
    font-size: 1.8rem;
}

.error-message {
    background: #fef2f2;
    border: 1px solid #ef4444;
    color: #dc2626;
    padding: 12px;
    border-radius: 8px;
    margin-bottom: 20px;
    text-align: center;
}

.form-group {
    margin-bottom: 20px;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #374151;
}

input[type="password"] {
    width: 100%;
    padding: 14px;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

input[type="password"]:focus {
    outline: none;
    border-color: #4f46e5;
}

button {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, #4f46e5 0%, #7c3aed 100%);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
}

button:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(79, 70, 229, 0.4);
}

.footer {
    text-align: center;
    margin-top: 20px;
    color: #9ca3af;
    font-size: 0.9rem;
}