:root{--bg: #f6f7f9;--surface: #ffffff;--border: #d8dce3;--border-strong: #8b94a3;--text: #16191f;--text-muted: #5b6472;--accent: #1f6feb;--accent-contrast: #ffffff;--given: #16191f;--solved: #1f6feb;--danger: #c0353a;--danger-bg: #fdeaea;--given-bg: #eceff4;--peer-tint: rgb(31 111 235 / 9%);--selected-tint: rgb(31 111 235 / 20%);--grid-line: #d8dce3;--grid-line-strong: #8b94a3;--ok: #1a7f4b;--warn: #9a6700;--radius: 10px;--shadow: 0 1px 2px rgb(16 24 40 / 6%), 0 8px 24px rgb(16 24 40 / 6%);color-scheme:light dark}@media(prefers-color-scheme:dark){:root{--bg: #0f1115;--surface: #171a21;--border: #2b313c;--border-strong: #6b7484;--text: #e7eaf0;--text-muted: #9aa4b2;--accent: #4d9bff;--accent-contrast: #08111f;--given: #e7eaf0;--solved: #4d9bff;--danger: #ff6b6b;--danger-bg: #3a1d1f;--given-bg: #1e242f;--peer-tint: rgb(77 155 255 / 12%);--selected-tint: rgb(77 155 255 / 24%);--grid-line: #2b313c;--grid-line-strong: #6b7484;--ok: #4ec98a;--warn: #e3b341;--shadow: 0 1px 2px rgb(0 0 0 / 40%), 0 8px 24px rgb(0 0 0 / 30%)}}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font-family:ui-sans-serif,-apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif;line-height:1.5}.app{max-width:1040px;margin:0 auto;padding:32px 16px 48px}.header{display:flex;align-items:flex-start;justify-content:space-between;gap:16px;flex-wrap:wrap;margin-bottom:24px}.header__title{margin:0;font-size:1.75rem;letter-spacing:-.02em}.header__subtitle{margin:4px 0 0;color:var(--text-muted);font-size:.925rem}.badge{border:1px solid var(--border);border-radius:999px;padding:4px 12px;font-size:.8rem;color:var(--text-muted);background:var(--surface);white-space:nowrap}.badge--up{color:var(--ok);border-color:color-mix(in srgb,var(--ok) 40%,var(--border))}.badge--down{color:var(--danger);border-color:color-mix(in srgb,var(--danger) 40%,var(--border))}.layout{display:grid;grid-template-columns:minmax(0,auto) minmax(260px,1fr);gap:24px;align-items:start}@media(max-width:820px){.layout{grid-template-columns:1fr}.board-actions{grid-template-columns:repeat(2,minmax(0,1fr))}.level-picker .field__hint{display:none}.app{padding:8px 12px 24px}.header{margin-bottom:8px}.panel--board{gap:8px}.panel--board .hint{display:none}.header__title{font-size:1.25rem}.header__subtitle{display:none}.panel{padding:12px}}.panel{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);padding:20px}.panel--board{display:grid;justify-items:center;gap:12px}.grid{display:grid;grid-template-columns:repeat(9,minmax(0,1fr));width:min(100%,432px);aspect-ratio:1;border:2px solid var(--grid-line-strong);border-radius:6px;overflow:hidden;background:var(--surface)}.cell{box-sizing:border-box;border:0;border-right:1px solid var(--grid-line);border-bottom:1px solid var(--grid-line);outline:0;background-color:var(--surface);color:var(--solved);font-size:clamp(1rem,4vw,1.4rem);font-weight:500;text-align:center;padding:0;min-width:0;caret-color:var(--accent)}.cell:nth-child(9n){border-right:0}.cell:nth-child(n+73){border-bottom:0}.cell--box-right{border-right:2px solid var(--grid-line-strong)}.cell--box-bottom{border-bottom:2px solid var(--grid-line-strong)}.cell--locked{background-color:var(--given-bg)}.cell--given{color:var(--given);font-weight:700}.cell[readonly]{cursor:default;caret-color:transparent}.cell--peer{background-image:linear-gradient(var(--peer-tint),var(--peer-tint))}.cell--selected{background-image:linear-gradient(var(--selected-tint),var(--selected-tint))}.cell--conflict{background-color:var(--danger-bg);color:var(--danger)}.cell:focus-visible{outline:2px solid var(--accent);outline-offset:-2px}.level-picker{display:grid;gap:6px;width:min(100%,432px)}.board-actions{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:8px;width:min(100%,432px)}.board-actions .button{min-height:44px}.hint{margin:0;color:var(--text-muted);font-size:.85rem;text-align:center}.field__inline{display:flex;gap:8px;align-items:stretch}.field__inline .select{flex:1}.field__inline .button{white-space:nowrap}.field__hint{color:var(--text-muted);font-size:.78rem}.select,.button{font:inherit;border-radius:8px;border:1px solid var(--border);background:var(--surface);color:var(--text);padding:8px 14px;cursor:pointer}.select{width:100%}.button:disabled,.select:disabled{opacity:.55;cursor:not-allowed}.button:not(:disabled):hover{border-color:var(--border-strong)}.button--primary{background:var(--accent);border-color:var(--accent);color:var(--accent-contrast);font-weight:600}.button--ghost{background:transparent;color:var(--text-muted)}.checkbox{display:flex;gap:10px;align-items:flex-start;font-size:.9rem}.checkbox small{display:block;color:var(--text-muted);font-size:.78rem}.status__message{margin:0;width:min(100%,432px);font-size:.925rem;text-align:center}.status__message--idle{color:var(--text-muted)}.status__message--ok{color:var(--ok)}.status__message--warn{color:var(--warn)}.status__message--error{color:var(--danger)}.stats{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;margin:20px 0 0;border-top:1px solid var(--border);padding-top:16px}.stats__item dt{font-size:.72rem;text-transform:uppercase;letter-spacing:.06em;color:var(--text-muted)}.stats__item dd{margin:2px 0 0;font-variant-numeric:tabular-nums;font-size:1.05rem}.footer{display:flex;gap:8px;justify-content:center;margin-top:32px;color:var(--text-muted);font-size:.85rem}.footer a{color:var(--text-muted)}