body {
    background-color: #f4f6f9;
    display: flex; 
    justify-content: center; 
    align-items: center; 
    min-height: 100vh; 
    margin: 0;
    font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
}
.login-card {
    background: #ffffff; 
    padding: 45px 40px; 
    border-radius: 12px;
    box-shadow: 0 8px 30px rgba(0,0,0,0.04); 
    width: 100%; 
    max-width: 360px;
}
.login-header {
    text-align: center;
    margin-bottom: 30px;
}
.login-header h2 { 
    color: #0f172a; 
    font-size: 26px;
    font-weight: 700;
    margin: 0 0 5px 0; 
}
.login-header p { 
    color: #94a3b8; 
    font-size: 14px; 
    margin: 0; 
}

.form-group { margin-bottom: 20px; }
.form-group label { 
    display: block; 
    font-size: 13px; 
    font-weight: 600; 
    color: #334155; 
    margin-bottom: 8px; 
}
.form-control { 
    width: 100%; 
    padding: 12px 15px; 
    border: 1px solid #e2e8f0; 
    border-radius: 6px; 
    font-size: 14px; 
    color: #334155;
    box-sizing: border-box; 
    background: #ffffff;
    transition: 0.2s;
    outline: none;
}
.form-control:focus { 
    border-color: #3b82f6; 
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1); 
}

.password-wrapper {
    position: relative;
}
.password-wrapper .fa-eye, .password-wrapper .fa-eye-slash {
    position: absolute;
    right: 15px;
    top: 50%;
    transform: translateY(-50%);
    color: #94a3b8;
    cursor: pointer;
    font-size: 16px;
}

.btn-submit { 
    background: #334155; 
    color: #ffffff; 
    border: none; 
    padding: 14px; 
    border-radius: 6px; 
    width: 100%; 
    font-weight: 600; 
    cursor: pointer; 
    font-size: 15px; 
    margin-top: 10px;
    transition: background 0.3s;
}
.btn-submit:hover { background: #1e293b; }

.alerta-error { 
    background: #fee2e2; 
    color: #991b1b; 
    padding: 12px; 
    border-radius: 6px; 
    margin-bottom: 20px; 
    font-size: 13px; 
    text-align: center; 
    border: 1px solid #fecaca; 
}

.register-link {
    text-align: center;
    margin-top: 25px;
    font-size: 13px;
    color: #64748b;
}
.register-link a {
    color: #334155;
    font-weight: bold;
    text-decoration: none;
}
.register-link a:hover {
    text-decoration: underline;
}

@media (max-width: 480px) {
    body { padding: 15px; box-sizing: border-box; }
    .login-card { padding: 30px 20px; }
}