.calculator-form {
    display: grid;
    gap: 1rem;
    max-width: 480px;
    margin: 1.5rem 0;
}

.calculator-form fieldset {
    border: 1px solid var(--color-border);
    border-radius: 0.5rem;
    padding: 1rem;
    margin: 0;
    display: grid;
    gap: 1rem;
}

.calculator-form legend {
    font-weight: 600;
    font-size: 0.9rem;
    padding: 0 0.3rem;
}

.calculator-form__group {
    display: grid;
    gap: 0.35rem;
}

.calculator-form__group label {
    font-weight: 600;
    font-size: 0.9rem;
}

.calculator-form__group input,
.calculator-form__group select {
    padding: 0.6rem 0.75rem;
    border: 1px solid var(--color-border);
    border-radius: 0.375rem;
    font-size: 1rem;
    width: 100%;
}

.calculator-form__group input:focus,
.calculator-form__group select:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 1px;
}

.calculator-form__row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.calculator-results {
    margin: 1.5rem 0;
    padding: 1.25rem;
    background: var(--color-surface);
    border-radius: 0.5rem;
    border: 1px solid var(--color-border);
    max-width: 480px;
}

.calculator-results__headline {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--color-primary-dark);
    margin: 0 0 0.5rem;
}

.calculator-results__row {
    display: flex;
    justify-content: space-between;
    padding: 0.25rem 0;
    font-size: 0.9rem;
    border-bottom: 1px solid var(--color-border);
}

.calculator-results__row:last-child {
    border-bottom: none;
}

.calculator-schedule {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1rem;
    font-size: 0.85rem;
}

.calculator-schedule th,
.calculator-schedule td {
    text-align: left;
    padding: 0.4rem 0.6rem;
    border-bottom: 1px solid var(--color-border);
}

.calculator-explainer {
    max-width: 720px;
    margin-top: 2.5rem;
}

.calculator-explainer h2 {
    margin-top: 2rem;
}

@media (max-width: 640px) {
    .calculator-form__row {
        grid-template-columns: 1fr;
    }
}

.calculator-keypad {
    max-width: 320px;
    margin: 1rem 0;
}

.calculator-keypad__display {
    width: 100%;
    box-sizing: border-box;
    margin-bottom: 0.5rem;
    padding: 0.75rem;
    border: 1px solid var(--color-border);
    border-radius: 0.5rem;
    background: var(--color-surface);
    color: var(--color-text);
    font-size: 1.5rem;
    font-weight: 600;
    text-align: right;
}

.calculator-keypad__grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0.5rem;
}

.calculator-keypad__btn {
    padding: 0.75rem 0;
    border: 1px solid var(--color-border);
    border-radius: 0.5rem;
    background: var(--color-bg);
    color: var(--color-text);
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.1s ease, border-color 0.1s ease;
}

.calculator-keypad__btn:hover {
    border-color: var(--color-primary);
}

.calculator-keypad__btn:active {
    background: var(--color-primary-bg);
}

.calculator-keypad__btn--fn {
    background: var(--color-surface);
    color: var(--color-muted);
}

.calculator-keypad__btn--op {
    background: var(--color-accent-bg);
    color: var(--color-accent-dark);
}

.calculator-keypad__btn--eq {
    background: var(--color-primary);
    border-color: var(--color-primary);
    color: #fff;
}

.calculator-keypad__btn--eq:hover {
    background: var(--color-primary-dark);
    border-color: var(--color-primary-dark);
}

.calculator-keypad__btn--wide {
    grid-column: span 2;
}