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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: #f0f2f5;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    color: #333;
}

.login-container {
    width: 100%;
    max-width: 420px;
    padding: 1rem;
}

.login-card {
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 16px rgba(0, 0, 0, 0.12);
    padding: 2.5rem 2rem;
}

.login-header {
    text-align: center;
    margin-bottom: 2rem;
}

.login-header h1 {
    font-size: 1.75rem;
    font-weight: 700;
    color: #1a56db;
    margin-bottom: 0.25rem;
}

.login-header p {
    color: #6b7280;
    font-size: 0.9rem;
}

.alert {
    padding: 0.75rem 1rem;
    border-radius: 6px;
    margin-bottom: 1.25rem;
    font-size: 0.875rem;
}

.alert-error {
    background: #fef2f2;
    border: 1px solid #fca5a5;
    color: #b91c1c;
}

.alert-success {
    background: #f0fdf4;
    border: 1px solid #86efac;
    color: #166534;
}

.form-group {
    margin-bottom: 1.25rem;
}

.form-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 0.375rem;
    color: #374151;
}

.form-group input {
    width: 100%;
    padding: 0.625rem 0.875rem;
    border: 1px solid #d1d5db;
    border-radius: 6px;
    font-size: 0.95rem;
    transition: border-color 0.15s, box-shadow 0.15s;
    outline: none;
}

.form-group input:focus {
    border-color: #1a56db;
    box-shadow: 0 0 0 3px rgba(26, 86, 219, 0.15);
}

.btn-submit {
    width: 100%;
    padding: 0.75rem;
    background: #1a56db;
    color: #fff;
    border: none;
    border-radius: 6px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.15s;
    margin-top: 0.5rem;
}

.btn-submit:hover {
    background: #1e429f;
}

.btn-submit:active {
    background: #1e3a8a;
}

@media (max-width: 480px) {
    .login-card {
        padding: 2rem 1.25rem;
    }
}