.calc-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 0.4rem;
    border-bottom: 1px solid var(--tool-border);
    padding-bottom: 0.75rem;
}

.calc-tab {
    border: 1px solid var(--tool-border);
    background: transparent;
    color: var(--tool-muted);
    border-radius: 999px;
    padding: 0.45rem 0.95rem;
    font: inherit;
    font-size: 0.88rem;
    cursor: pointer;
    transition: all 0.15s ease;
}

.calc-tab:hover { color: var(--tool-text); }

.calc-tab.is-active {
    background: var(--tool-accent);
    border-color: var(--tool-accent);
    color: #10110e;
    font-weight: 600;
}

.calc-panel { display: none; margin-top: 1.25rem; }
.calc-panel.is-active { display: block; }

.calc-display {
    width: 100%;
    font-family: var(--font-mono);
    font-size: 1.3rem;
    padding: 0.85rem 1rem;
    border: 1px solid var(--tool-border);
    border-radius: var(--tool-radius-sm);
    background: rgba(255, 255, 255, 0.03);
    color: var(--tool-text);
}

.calc-result {
    font-family: var(--font-mono);
    font-size: 2rem;
    font-weight: 700;
    text-align: right;
    padding: 0.6rem 0.2rem 1rem;
    color: var(--tool-accent);
    word-break: break-all;
}

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

.calc-key {
    padding: 0.95rem 0;
    font-size: 1.1rem;
    border: 1px solid var(--tool-border);
    border-radius: var(--tool-radius-sm);
    background: rgba(255, 255, 255, 0.04);
    color: var(--tool-text);
    cursor: pointer;
    transition: background 0.12s ease;
}

.calc-key:hover { background: rgba(255, 255, 255, 0.1); }
.calc-key.key-op { color: var(--tool-accent); }
.calc-key.key-fn { color: var(--tool-muted); }
.calc-key.key-eq { background: var(--tool-accent); color: #10110e; font-weight: 700; }

.calc-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--tool-border);
}

.calc-inline-input {
    width: 84px;
    padding: 0.3rem 0.5rem;
    border: 1px solid var(--tool-border);
    border-radius: 6px;
    background: rgba(255, 255, 255, 0.04);
    color: var(--tool-text);
    font: inherit;
}

.calc-out {
    font-family: var(--font-mono);
    font-weight: 700;
    color: var(--tool-accent);
    font-size: 1.1rem;
    white-space: nowrap;
}

.calc-out-big {
    font-size: 1.4rem;
    font-weight: 700;
    margin: 1rem 0;
    color: var(--tool-accent);
}