* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: Arial, sans-serif;
    background: #f4f6f8;
    color: #1f2933;
}

.page {
    max-width: 1200px;
    margin: 0 auto;
    padding: 24px;
}

.header {
    background: #ffffff;
    padding: 24px;
    border-radius: 14px;
    margin-bottom: 20px;
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.06);
}

.header h1 {
    margin: 0 0 8px;
    font-size: 26px;
}

.header p {
    margin: 0;
    color: #667085;
}

.layout {
    display: grid;
    grid-template-columns: 420px 1fr;
    gap: 20px;
    align-items: start;
}

.card {
    background: #ffffff;
    padding: 22px;
    border-radius: 14px;
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.06);
}

.card h2 {
    margin-top: 0;
    font-size: 22px;
}

.card h3 {
    margin-top: 20px;
    margin-bottom: 10px;
    font-size: 16px;
    border-bottom: 1px solid #e5e7eb;
    padding-bottom: 6px;
}

label {
    display: block;
    margin-top: 10px;
    margin-bottom: 5px;
    font-size: 14px;
    font-weight: 700;
}

input {
    width: 100%;
    padding: 10px;
    border: 1px solid #cfd6dd;
    border-radius: 8px;
    font-size: 15px;
}

input:focus {
    outline: none;
    border-color: #2563eb;
}

button {
    width: 100%;
    margin-top: 20px;
    padding: 13px;
    border: none;
    border-radius: 8px;
    background: #2563eb;
    color: #ffffff;
    font-size: 16px;
    font-weight: 700;
    cursor: pointer;
}

button:hover {
    background: #1d4ed8;
}

.results {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 14px;
}

.results div {
    background: #f8fafc;
    border: 1px solid #e5e7eb;
    padding: 14px;
    border-radius: 10px;
}

.results span {
    display: block;
    color: #667085;
    font-size: 13px;
    margin-bottom: 8px;
}

.results strong {
    font-size: 20px;
}

.recommendation {
    margin-top: 20px;
    padding: 16px;
    border-radius: 10px;
    background: #f8fafc;
    border: 1px solid #e5e7eb;
}

.recommendation h3 {
    margin-top: 0;
}

.error {
    margin-top: 14px;
    color: #b42318;
    font-size: 14px;
}

@media (max-width: 900px) {
    .layout {
        grid-template-columns: 1fr;
    }

    .results {
        grid-template-columns: 1fr;
    }
}
input[type="number"]::-webkit-outer-spin-button,
input[type="number"]::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

input[type="number"] {
    appearance: textfield;
}