/* V3.4 上架基礎：PWA、存檔、設定、診斷 */
.system-shell{width:100%;max-width:620px;display:flex;flex-direction:column;gap:14px}
.system-section{border:1px solid rgba(255,255,255,.14);background:rgba(255,255,255,.07);border-radius:18px;padding:14px;text-align:left}
.system-section h2{font-size:18px;margin:0 0 6px;color:var(--yellow)}
.system-section>p{font-size:13px;line-height:1.6;margin:0 0 12px;color:var(--chalk-dim)}
.system-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:9px}
.system-stat{border-radius:12px;background:rgba(15,29,52,.42);border:1px solid rgba(255,255,255,.1);padding:10px}
.system-stat small{display:block;color:var(--chalk-dim);font-size:11px;margin-bottom:4px}
.system-stat b{font-size:13px;color:var(--chalk)}
.setting-list{display:flex;flex-direction:column;gap:8px}
.setting-row{display:flex;align-items:center;justify-content:space-between;gap:12px;border-radius:12px;padding:9px 10px;background:rgba(15,29,52,.35);border:1px solid rgba(255,255,255,.08)}
.setting-row span{display:flex;flex-direction:column;gap:2px}
.setting-row b{font-size:13px}.setting-row small{font-size:10px;color:var(--chalk-dim)}
.setting-switch{appearance:none;width:48px;height:27px;border-radius:999px;background:#596477;position:relative;cursor:pointer;flex:0 0 auto;transition:.18s}
.setting-switch::after{content:"";position:absolute;width:21px;height:21px;top:3px;left:3px;border-radius:50%;background:white;transition:.18s;box-shadow:0 2px 5px rgba(0,0,0,.25)}
.setting-switch:checked{background:var(--teal)}
.setting-switch:checked::after{transform:translateX(21px)}
.setting-switch:focus-visible{outline:3px solid var(--yellow);outline-offset:2px}
.backup-actions{display:grid;grid-template-columns:repeat(2,1fr);gap:8px}
.backup-actions .btn{width:100%}
.backup-mode{display:grid;grid-template-columns:1fr 180px;gap:10px;align-items:center;margin-top:10px;font-size:12px;color:var(--chalk-dim)}
.backup-mode select{width:100%;padding:8px;border-radius:10px;border:1px solid rgba(255,255,255,.18);background:#23334b;color:#fff;font-family:inherit}
.system-note{margin-top:9px;border-left:4px solid var(--teal);padding:8px 10px;background:rgba(79,207,184,.1);border-radius:8px;font-size:11px;line-height:1.55;color:var(--chalk-dim)}
.app-toast{position:fixed;left:50%;bottom:24px;transform:translate(-50%,18px);max-width:min(90vw,520px);z-index:9999;padding:10px 14px;border-radius:12px;background:#1f2d43;color:#fff;border:1px solid rgba(255,255,255,.16);box-shadow:0 10px 30px rgba(0,0,0,.3);opacity:0;pointer-events:none;transition:.22s;font-size:13px;text-align:center}
.app-toast.show{opacity:1;transform:translate(-50%,0)}
.app-toast.success{border-color:rgba(88,220,153,.65)}
.app-toast.error{border-color:rgba(255,107,107,.7)}
.app-toast.info{border-color:rgba(116,196,255,.65)}
body.reduced-motion *,body.reduced-motion *::before,body.reduced-motion *::after{animation-duration:.001ms!important;animation-iteration-count:1!important;scroll-behavior:auto!important;transition-duration:.001ms!important}
body.large-text{font-size:18px}
body.large-text .btn{font-size:16px}
body.large-text small{font-size:12px!important}
body.high-contrast{--chalk:#fff;--chalk-dim:#e6e6e6;--line:#fff;--yellow:#ffe44d;--teal:#55f0d2}
body.high-contrast .board{box-shadow:0 0 0 3px #fff inset}
.main-menu #btnSystemSettings{grid-column:1/-1;min-height:44px}
@media(max-width:520px){.system-grid{grid-template-columns:1fr}.backup-actions{grid-template-columns:1fr}.backup-mode{grid-template-columns:1fr}.system-section{padding:12px}}

/* V5.1S session-only test mode */
.test-mode-settings{border-color:rgba(94,234,212,.34)!important;background:linear-gradient(145deg,rgba(17,94,89,.18),rgba(15,23,42,.18))!important}
.test-mode-activation{display:grid;gap:10px}
.test-mode-activation>label{display:flex;align-items:center;justify-content:space-between;gap:14px;padding:12px 14px;border-radius:14px;border:1px solid rgba(255,255,255,.12);background:rgba(255,255,255,.05)}
.test-mode-activation>label span{display:grid;gap:3px;text-align:left}
.test-mode-activation>label small{color:var(--chalk-dim)}
#testModePassword{width:min(230px,42vw);padding:10px 12px;border-radius:10px;border:1px solid rgba(94,234,212,.45);background:rgba(4,30,28,.74);color:#fff;font:inherit;letter-spacing:.16em;text-align:center}
#testModePassword:focus{outline:3px solid rgba(94,234,212,.24);border-color:#5eead4}
.test-mode-actions{justify-content:flex-start!important}
.test-mode-status.active{border-color:rgba(94,234,212,.48);color:#d5fff9;background:rgba(13,148,136,.16)}
@media(max-width:620px){.test-mode-activation>label{align-items:stretch;flex-direction:column}#testModePassword{width:100%;box-sizing:border-box}.test-mode-actions .btn{width:100%}}

.setting-volume-row{align-items:center}.setting-volume{width:min(230px,42vw);accent-color:#d8a52a;cursor:pointer}.setting-volume-row output{font-weight:800;color:#f3c955}.setting-volume:focus-visible{outline:3px solid rgba(243,201,85,.45);outline-offset:4px}