:root{--sia-ink: #1e2a3b;--sia-muted: #5e6675;--sia-paper: #f6f3ec;--sia-surface: #ffffff;--sia-line: #e3ddd0;--sia-line-strong: #cfc6b3;--sia-teal: #1d6b66;--sia-teal-dark: #154f4b;--sia-teal-soft: rgba(29, 107, 102, 0.09);--sia-ochre: #a8691b;--sia-ochre-soft: rgba(168, 105, 27, 0.1);--sia-slate: #1f2633;--sia-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;--sia-shadow: 0 14px 34px rgba(30, 42, 59, 0.08);--primary: var(--sia-teal);--primary-dark: var(--sia-teal-dark);--border: var(--sia-line);--surface: var(--sia-surface);--surface-muted: var(--sia-paper);--shadow-soft: var(--sia-shadow);--text-main: var(--sia-ink);--text-muted: var(--sia-muted);}
.sia-page{color: var(--sia-ink);padding-bottom: 2.5rem;}
.sia-desk{background: var(--sia-surface);border: 1px solid var(--sia-line);border-radius: 14px;box-shadow: var(--sia-shadow);overflow: hidden;margin-bottom: 2.5rem;}
.sia-byline{display: flex;flex-wrap: wrap;justify-content: space-between;align-items: center;gap: 0.35rem 1rem;padding: 0.6rem 1.4rem;background: var(--sia-paper);border-bottom: 1px solid var(--sia-line);color: var(--sia-muted);font-size: 0.85rem;}
.sia-byline .author-link{color: var(--sia-teal-dark);font-weight: 600;text-decoration: none;}
.sia-byline .author-link:hover{text-decoration: underline;}
.sia-grid{display: grid;grid-template-columns: minmax(0, 5fr) minmax(0, 6fr);}
.sia-form{padding: 1.5rem 1.5rem 1.75rem;border-right: 1px solid var(--sia-line);display: flex;flex-direction: column;gap: 1.1rem;}
.sia-solve{border: 0;margin: 0;padding: 0;}
.sia-solve legend{font-size: 0.78rem;font-weight: 700;letter-spacing: 0.06em;text-transform: uppercase;color: var(--sia-muted);margin-bottom: 0.5rem;}
.sia-solve-row{display: grid;grid-template-columns: repeat(4, 1fr);border: 1px solid var(--sia-line-strong);border-radius: 10px;overflow: hidden;}
.sia-chip{margin: 0;cursor: pointer;position: relative;}
.sia-chip + .sia-chip{border-left: 1px solid var(--sia-line-strong);}
.sia-chip input{position: absolute;opacity: 0;pointer-events: none;}
.sia-chip span{display: block;text-align: center;padding: 0.55rem 0.25rem;font-size: 0.9rem;font-weight: 600;color: var(--sia-muted);transition: background 0.15s ease, color 0.15s ease;}
.sia-chip input:checked + span{background: var(--sia-teal);color: #ffffff;}
.sia-chip input:focus-visible + span{outline: 2px solid var(--sia-ochre);outline-offset: -3px;}
.sia-field{display: flex;flex-direction: column;gap: 0.35rem;}
.sia-field[hidden]{display: none;}
.sia-field label{font-weight: 600;font-size: 0.95rem;margin: 0;display: flex;align-items: center;gap: 0.5rem;}
.sia-field small{color: var(--sia-muted);font-size: 0.8rem;}
.sia-sym{display: inline-flex;align-items: center;justify-content: center;width: 1.6rem;height: 1.6rem;border-radius: 6px;background: var(--sia-ochre-soft);color: var(--sia-ochre);font-family: var(--sia-mono);font-weight: 700;font-size: 0.9rem;}
.sia-input{width: 100%;padding: 0.65rem 0.8rem;border: 1px solid var(--sia-line-strong);border-radius: 8px;font-size: 1rem;color: var(--sia-ink);background: var(--sia-surface);font-variant-numeric: tabular-nums;}
.sia-input:focus{outline: none;border-color: var(--sia-teal);box-shadow: 0 0 0 3px var(--sia-teal-soft);}
.sia-pair{display: grid;grid-template-columns: 1fr 8rem;gap: 0.5rem;}
.sia-msg{margin: 0;padding: 0.6rem 0.8rem;border-radius: 8px;background: #fbeee8;color: #8f3b22;font-size: 0.9rem;}
.sia-actions{display: flex;flex-wrap: wrap;gap: 0.6rem;}
.sia-btn{padding: 0.6rem 1.1rem;border-radius: 8px;border: 1px solid var(--sia-line-strong);background: var(--sia-surface);color: var(--sia-ink);font-weight: 600;font-size: 0.92rem;cursor: pointer;transition: border-color 0.15s ease, background 0.15s ease;}
.sia-btn:hover{border-color: var(--sia-teal);color: var(--sia-teal-dark);}
.sia-btn-solid{background: var(--sia-teal);border-color: var(--sia-teal);color: #ffffff;}
.sia-btn-solid:hover{background: var(--sia-teal-dark);border-color: var(--sia-teal-dark);color: #ffffff;}
.sia-btn:focus-visible{outline: 2px solid var(--sia-ochre);outline-offset: 2px;}
.sia-out{padding: 1.5rem 1.75rem 1.75rem;background: var(--sia-paper);}
.sia-empty{height: 100%;display: flex;flex-direction: column;justify-content: center;color: var(--sia-muted);}
.sia-empty[hidden]{display: none;}
.sia-empty-big{font-family: var(--sia-mono);font-size: clamp(1.8rem, 4vw, 2.6rem);color: var(--sia-line-strong);font-weight: 700;margin: 0 0 0.75rem;}
.sia-answer-label{margin: 0;font-size: 0.78rem;font-weight: 700;letter-spacing: 0.06em;text-transform: uppercase;color: var(--sia-ochre);}
.sia-answer{margin: 0.15rem 0 0.25rem;font-size: clamp(2rem, 4.5vw, 2.8rem);font-weight: 800;line-height: 1.1;color: var(--sia-ink);font-variant-numeric: tabular-nums;word-break: break-word;}
.sia-summary{margin: 0 0 1rem;color: var(--sia-muted);font-size: 0.95rem;}
.sia-steps{list-style: none;margin: 0 0 1.1rem;padding: 0.9rem 1.1rem;background: var(--sia-slate);border-radius: 10px;color: #e6e9ef;font-family: var(--sia-mono);font-size: 0.92rem;line-height: 1.7;overflow-x: auto;}
.sia-steps li{white-space: nowrap;}
.sia-steps li:last-child{color: #f2c27a;font-weight: 700;}
.sia-stats{display: grid;grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));gap: 0.6rem;margin: 0 0 1.1rem;}
.sia-stats div{background: var(--sia-surface);border: 1px solid var(--sia-line);border-radius: 8px;padding: 0.55rem 0.75rem;}
.sia-stats dt{font-size: 0.75rem;font-weight: 600;color: var(--sia-muted);}
.sia-stats dd{margin: 0;font-weight: 700;font-size: 1.05rem;font-variant-numeric: tabular-nums;}
.sia-ledger{border-top: 1px solid var(--sia-line);padding: 1.4rem 1.5rem 1.5rem;}
.sia-ledger[hidden]{display: none;}
.sia-ledger h3{font-size: 1.05rem;font-weight: 700;margin: 0 0 0.8rem;}
.sia-table-wrap{overflow-x: auto;max-height: 26rem;overflow-y: auto;border: 1px solid var(--sia-line);border-radius: 8px;}
.sia-table{width: 100%;border-collapse: collapse;font-size: 0.92rem;font-variant-numeric: tabular-nums;}
.sia-table th{position: sticky;top: 0;background: var(--sia-paper);text-align: right;font-weight: 600;color: var(--sia-muted);padding: 0.55rem 0.8rem;border-bottom: 1px solid var(--sia-line-strong);white-space: nowrap;}
.sia-table td{text-align: right;padding: 0.5rem 0.8rem;border-bottom: 1px solid var(--sia-line);white-space: nowrap;}
.sia-table th:first-child,.sia-table td:first-child{text-align: left;}
.sia-table tbody tr:last-child td{border-bottom: 0;}
.sia-table td:last-child{color: var(--sia-ochre);font-weight: 600;}
.sia-table-small{max-width: 28rem;border: 1px solid var(--sia-line);margin: 0.25rem 0 1rem;}
.sia-table-small td:last-child{color: var(--sia-ink);font-weight: 400;}
.sia-table-small th,.sia-table-small td{text-align: left;}
.sia-note{margin: 0.6rem 0 0;font-size: 0.82rem;color: var(--sia-muted);}
.sia-notes{margin: 0 auto 2.5rem;}
.sia-sec{margin-bottom: 2.25rem;}
.sia-sec h2{font-size: 1.45rem;font-weight: 700;margin-bottom: 0.75rem;}
.sia-sec h3{font-size: 1rem;font-weight: 700;margin-bottom: 0.4rem;}
.sia-sec p,.sia-sec li{line-height: 1.7;}
.sia-sec ul{padding-left: 1.2rem;}
.sia-sec li{margin-bottom: 0.4rem;}
.sia-sec a{color: var(--sia-teal-dark);font-weight: 600;}
.sia-sec code{font-family: var(--sia-mono);background: var(--sia-ochre-soft);color: var(--sia-ink);padding: 0.1rem 0.35rem;border-radius: 4px;}
.sia-work{font-family: var(--sia-mono);background: var(--sia-slate);color: #e6e9ef;padding: 1rem 1.2rem;border-radius: 10px;font-size: 0.95rem;line-height: 1.7;margin: 0.25rem 0 1rem;overflow-x: auto;}
.sia-split{display: grid;grid-template-columns: 1fr 1fr;gap: 0.9rem;margin: 0.5rem 0 1rem;}
.sia-card{border: 1px solid var(--sia-line);border-radius: 10px;padding: 1rem 1.1rem;background: var(--sia-surface);}
.sia-card p{margin: 0 0 0.5rem;color: var(--sia-muted);font-size: 0.92rem;}
.sia-card .sia-card-num{margin: 0;font-size: 1.5rem;font-weight: 800;color: var(--sia-teal-dark);font-variant-numeric: tabular-nums;}
.sia-limits{background: var(--sia-paper);border: 1px solid var(--sia-line);border-left: 4px solid var(--sia-ochre);border-radius: 10px;padding: 1.25rem 1.4rem 0.75rem;}
@media (max-width: 991px){.sia-grid{grid-template-columns: 1fr;}.sia-form{border-right: 0;border-bottom: 1px solid var(--sia-line);}}
@media (max-width: 576px){.sia-form,.sia-out,.sia-ledger{padding-left: 1rem;padding-right: 1rem;}.sia-byline{padding: 0.6rem 1rem;}.sia-split{grid-template-columns: 1fr;}.sia-pair{grid-template-columns: 1fr 6.5rem;}.sia-chip span{font-size: 0.82rem;}}