body {
    font-family: 'Inter', Arial, sans-serif;
    background: #f5f7fb;
    margin: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    color: #333;
}
.login-card {
    background: #fff;
    border-radius: 16px;
    box-shadow: 0 12px 30px rgba(15, 23, 42, 0.12);
    padding: 2.5rem;
    width: 100%;
    max-width: 380px;
    box-sizing: border-box;
}
@media (max-width: 480px) {
    .login-card {
        padding: 2rem 1.5rem;
        max-width: 100%;
        border-radius: 0;
        box-shadow: none;
    }
    .login-card h1 {
        font-size: 1.4rem;
    }
}
.login-card h1 {
    font-size: 1.6rem;
    margin: 0 0 1.5rem;
    text-align: center;
    color: #1f2937;
}
.form-group {
    margin-bottom: 1.2rem;
}
label {
    display: block;
    font-weight: 600;
    margin-bottom: 0.35rem;
}
input[type="text"],
input[type="password"] {
    width: 100%;
    padding: 0.75rem;
    border-radius: 10px;
    border: 1px solid #d1d5db;
    background: #f9fafb;
    font-size: 0.95rem;
}
input[type="text"]:focus,
input[type="password"]:focus {
    outline: none;
    border-color: #2563eb;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}
.btn-primary {
    width: 100%;
    padding: 0.85rem;
    border: none;
    border-radius: 10px;
    background: linear-gradient(135deg, #2563eb, #1d4ed8);
    color: #fff;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
}
.btn-primary:hover {
    background: linear-gradient(135deg, #1d4ed8, #1e40af);
}
.alert {
    border-radius: 10px;
    padding: 0.9rem 1rem;
    margin-bottom: 1rem;
    font-size: 0.9rem;
}
.alert-error {
    background: #fee2e2;
    color: #b91c1c;
    border: 1px solid #fecaca;
}
.env-hint {
    font-size: 0.8rem;
    color: #6b7280;
    text-align: center;
    margin-top: 1.5rem;
}