#calculator {
    min-width: 400px;
    max-width: 500px;
    margin: 20px auto;
    background: #ffffff;
    font-size: 14px;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.15);
    border-radius: 8px;
    overflow: hidden;
}

#calculator h2 {
    margin: 0;
    padding: 12px 16px;
    font-weight: 600;
    font-size: 15px;
    letter-spacing: 0.3px;
    text-transform: uppercase;
    text-align: left;
    border-bottom: 1px solid #e0dcd0;
}

.calc-row {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 16px;
    border-bottom: 1px solid #e0dcd0;
    flex-wrap: wrap;
}

.calc-row:last-of-type {
    border-bottom: 1px solid #e0dcd0;
}

.calc-row > label {
    min-width: 60px;
    font-weight: 600;
    font-size: 14px;
}

.calc-row .field-group {
    display: flex;
    align-items: center;
    gap: 8px;
}

.calc-row .field-group label {
    min-width: auto;
    font-weight: 400;
    font-size: 13px;
}

.calc-row input {
    padding: 6px 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
    font-size: 14px;
    width: 80px;
    font-family: system-ui, -apple-system, sans-serif;
}

.calc-row input.rank-input {
    width: 60px;
    text-transform: uppercase;
}

#calculator button {
    display: block;
    margin: 16px auto;
    padding: 10px 32px;
    font-size: 14px;
    font-weight: 600;
    letter-spacing: 0.3px;
    text-transform: uppercase;
    border: none;
    border-radius: 6px;
    background: #2d2d2d;
    color: #fff;
    cursor: pointer;
}

#calculator button:hover {
    background: #444;
}

#result {
    padding: 10px 16px;
    border-bottom: 1px solid #e0dcd0;
    text-align: left;
    font-size: 18px;
    font-weight: 700;
    background: #fafafa;
}

#result.error {
    color: #c0392b;
    background: #fdecea;
}

#result .label {
    font-weight: 400;
    font-size: 14px;
    color: #555;
}

.hint {
    padding: 10px 16px;
    text-align: center;
    font-size: 12px;
    color: #888;
}