.calculator-shell { max-width: 460px; }
.calculator-card, .calculator-guide { border: 2px solid var(--ink); background: rgba(226,227,222,.94); box-shadow: 7px 7px 0 rgba(17,18,16,.14); }
.calculator-card { padding: 26px 18px 22px; }
.calculator-heading > p:first-child, .formula-note, .calculator-local, .calculator-tabs, .calculator-panel label > span, .calculator-result > div, .calculator-actions, .calculator-guide > header > span { font-family: "DM Mono",monospace; letter-spacing: .075em; }
.calculator-heading > p:first-child { margin: 0 0 15px; font-size: 8px; }
.calculator-heading h1 { margin: 0; font-family: "Archivo Black",sans-serif; font-size: clamp(37px,10vw,48px); line-height: .92; letter-spacing: -.055em; }
.calculator-heading > p:last-child { margin: 18px 0 0; color: var(--muted); font-size: 12px; line-height: 1.6; }
.calculator-tabs { display: grid; grid-template-columns: repeat(2,1fr); margin-top: 0; border: 1px solid var(--ink); }
.calculator-tabs button { min-height: 44px; border: 0; background: transparent; font: 500 10px "DM Mono",monospace; letter-spacing: .055em; cursor: pointer; }
.calculator-tabs button:nth-child(even) { border-left: 1px solid var(--ink); }
.calculator-tabs button:nth-child(n+3) { border-top: 1px solid var(--ink); }
.calculator-tabs button[aria-selected="true"] { background: var(--ink); color: var(--white); }
.calculator-panels { margin-top: 12px; }
.calculator-panel[hidden], .calc-grid[hidden] { display: none; }
.calc-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.calc-grid label:last-child:nth-child(odd) { grid-column: 1 / -1; }
.calculator-panel label > span { display: block; margin-bottom: 7px; color: var(--muted); font-size: 7px; line-height: 1.35; }
.calculator-panel input, .calculator-panel select { width: 100%; height: 52px; border: 1px solid var(--ink); border-radius: 0; background: rgba(246,246,241,.7); padding: 0 12px; color: var(--ink); font: 700 18px Inter,sans-serif; outline: none; }
.calculator-panel input:focus, .calculator-panel select:focus { box-shadow: inset 0 0 0 3px #777873; }
.input-unit { position: relative; }
.input-unit input { padding-right: 37px; }
.input-unit b { position: absolute; right: 13px; top: 50%; transform: translateY(-50%); font: 500 11px "DM Mono",monospace; }
.formula-note { margin: 13px 0 0; color: var(--muted); font-size: 7px; line-height: 1.5; }
.submode-switch { display: grid; grid-template-columns: 1fr 1fr; margin-bottom: 12px; border: 1px solid var(--ink); }
.submode-switch button { min-height: 36px; border: 0; background: transparent; font: 500 8px "DM Mono",monospace; cursor: pointer; }
.submode-switch button + button { border-left: 1px solid var(--ink); }
.submode-switch button.active { background: #4b4c48; color: #eee; }
.calculator-result { margin-top: 15px; border: 1px solid var(--ink); background: #cfd0ca; padding: 17px; }
.calculator-result > div { display: flex; justify-content: space-between; align-items: center; font-size: 8px; }
.calculator-result button { border: 1px solid var(--ink); background: transparent; padding: 6px 9px; font: 500 8px "DM Mono",monospace; cursor: pointer; }
.calculator-result output { display: block; margin-top: 19px; overflow-wrap: anywhere; font: 900 clamp(34px,10vw,48px)/1 Inter,sans-serif; letter-spacing: -.045em; }
.calculator-result p { margin: 10px 0 0; color: var(--muted); font: 9px/1.5 "DM Mono",monospace; overflow-wrap: anywhere; }
.calculator-result.error { background: #bdbeb8; }
.calculator-actions button { width: 100%; min-height: 42px; margin-top: 10px; border: 1px solid var(--ink); background: transparent; font: 500 8px "DM Mono",monospace; letter-spacing: .06em; cursor: pointer; }
.calculator-actions button:hover { background: var(--ink); color: var(--white); }
.calculator-local { margin: 15px 0 0; color: var(--muted); font-size: 6px; line-height: 1.55; text-align: center; }
.calculator-guide { margin-top: 14px; padding: 24px 18px; }
.calculator-guide > header { padding-bottom: 20px; border-bottom: 1px solid var(--ink); }
.calculator-guide > header > span { font-size: 7px; }
.calculator-guide h2 { margin: 12px 0 0; font-family: "Archivo Black",sans-serif; font-size: 31px; line-height: .94; letter-spacing: -.05em; }
.calculator-guide > section { display: grid; grid-template-columns: 28px minmax(0,1fr); gap: 9px; padding: 20px 0; border-bottom: 1px solid rgba(17,18,16,.3); }
.calculator-guide > section > b { font: 500 7px "DM Mono",monospace; }
.calculator-guide h3 { margin: 0; font-family: "Archivo Black",sans-serif; font-size: 18px; letter-spacing: -.035em; }
.calculator-guide section p, .calculator-guide aside p { margin: 10px 0 0; color: var(--muted); font-size: 11px; line-height: 1.7; }
.calculator-guide aside { margin-top: 20px; border: 1px solid var(--ink); padding: 15px; background: #c6c7c1; }
.calculator-guide aside strong { font: 500 8px "DM Mono",monospace; letter-spacing: .08em; }
.calculator-shell .site-footer { margin-top: 14px; }
@media (max-width:380px) { .calc-grid { grid-template-columns: 1fr; } .calc-grid label:last-child:nth-child(odd) { grid-column: auto; } }