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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: #e8e8e8;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.hero {
    width: 100%;
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.card-system {
    background: white;
    border-radius: 12px;
    padding: 40px 35px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 420px;
}

.card-system h3 {
    font-size: 26px;
    font-weight: 600;
    color: #333;
    text-align: center;
    margin-bottom: 8px;
}

.card-system p {
    color: #888;
    text-align: center;
    font-size: 14px;
    margin-bottom: 25px;
}

.form-control {
    border: 1px solid #ddd;
    padding: 14px 16px;
    border-radius: 8px;
    font-size: 14px;
    transition: border-color 0.3s;
    background: #fff;
}

.form-control:focus {
    border-color: #4a7cfe;
    box-shadow: 0 0 0 0.15rem rgba(74, 124, 254, 0.15);
    outline: none;
}

.form-control::placeholder {
    color: #aaa;
}

.input-group .form-control {
    border-right: none;
}

.input-group .btn-outline-secondary {
    border: 1px solid #ddd;
    border-left: none;
    background: #fff;
    border-radius: 0 8px 8px 0;
    color: #888;
    padding: 0 16px;
}

.input-group .btn-outline-secondary:hover {
    background: #f8f8f8;
    color: #555;
}

.input-group .btn-outline-secondary:focus {
    box-shadow: none;
    border-color: #ddd;
}

.btn-primary {
    background: #4a7cfe;
    border: none;
    padding: 14px;
    font-weight: 600;
    border-radius: 8px;
    transition: background 0.3s;
    font-size: 15px;
}

.btn-primary:hover {
    background: #3a6ae8;
}

.alert {
    border-radius: 8px;
    font-size: 14px;
}

.text-center a {
    color: #4a7cfe;
    text-decoration: none;
    font-size: 14px;
}

.text-center a:hover {
    text-decoration: underline;
}

.app-footer {
    width: 100%;
    background: #2d2d2d;
    color: #888;
    padding: 12px 30px;
    font-size: 12px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.app-footer span {
    font-weight: 400;
}