:root{--canvas: #F2F2F7;--card: #FFFFFF;--raised: #E5E5EA;--text: #000000;--text-secondary: rgba(0, 0, 0, .6);--text-tertiary: rgba(0, 0, 0, .4);--border: rgba(0, 0, 0, .08);--border-strong: rgba(0, 0, 0, .14);--accent: #34C759;--healthy: #30D158;--low: #FF9F0A;--critical: #FF453A;--cyan: #32ADE6;--sans: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;--mono: ui-monospace, SFMono-Regular, Menlo, monospace;--shadow-sm: 0 1px 2px rgba(0, 0, 0, .04), 0 1px 1px rgba(0, 0, 0, .03);--shadow-md: 0 8px 24px rgba(0, 0, 0, .06), 0 2px 6px rgba(0, 0, 0, .04);--shadow-lg: 0 24px 60px rgba(0, 0, 0, .09), 0 6px 16px rgba(0, 0, 0, .05);color-scheme:light}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--canvas);color:var(--text);font:400 16px/1.55 var(--sans);-webkit-font-smoothing:antialiased}button{font:inherit;cursor:pointer}h1,h2,h3,p{margin-top:0}.shell{width:min(760px,calc(100% - 32px));margin:auto}.sr-only{clip:rect(0,0,0,0);clip-path:inset(50%);height:1px;overflow:hidden;position:absolute;white-space:nowrap;width:1px}.skip-link{background:var(--accent);color:#fff;font-weight:700;left:16px;padding:8px 13px;position:fixed;top:-60px;z-index:20;border-radius:8px}.skip-link:focus{top:16px}:focus-visible{outline:3px solid var(--cyan);outline-offset:3px}.card{background:var(--card);border:1px solid var(--border);border-radius:16px;box-shadow:var(--shadow-sm);padding:22px}.app-header{position:sticky;top:0;z-index:5;background:#f2f2f7d1;backdrop-filter:blur(14px) saturate(1.4);border-bottom:1px solid var(--border)}.app-header-inner{min-height:60px;display:flex;align-items:center;justify-content:space-between}.brand{display:inline-flex;align-items:center;gap:8px;font-size:18px;font-weight:700;letter-spacing:-.4px;color:var(--text)}.brand svg{width:22px;color:var(--accent)}.brand span{color:var(--accent)}.app-header-tag{background:var(--raised);color:var(--text-secondary);font:600 11px var(--mono);letter-spacing:.4px;padding:4px 9px;border-radius:999px}.app-main{padding:20px 0 60px;display:flex;flex-direction:column;gap:18px}.button{appearance:none;border:1px solid var(--accent);background:var(--accent);color:#fff;padding:12px 18px;font-weight:600;border-radius:12px;font-size:14px;transition:transform .15s ease,background .15s ease,box-shadow .15s ease;box-shadow:var(--shadow-sm)}.button:hover{background:#2fb350;transform:translateY(-1px);box-shadow:var(--shadow-md)}.button:disabled{opacity:.5;cursor:default;transform:none}.button-outline{background:transparent;color:var(--text-secondary);border:1px solid var(--border-strong)}.button-outline:hover{transform:none;box-shadow:none;background:var(--raised)}.button-small{padding:8px 13px;font-size:12px;border-radius:10px}.fine-print{color:var(--text-tertiary);font-size:12px;margin:10px 0 0;line-height:1.5}.text-link{color:var(--accent);font-weight:600}.privacy-banner{background:#34c7591a;border:1px solid rgba(52,199,89,.3);color:#1e8f3e;border-radius:14px;padding:12px 16px;font-size:13px;line-height:1.5}.privacy-banner strong{color:#17762f}.camera-card-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:14px}.camera-card-head h2{font-size:17px;letter-spacing:-.2px}.status-pill{background:var(--raised);color:var(--text-secondary);font:600 11px var(--mono);padding:5px 11px;border-radius:999px;letter-spacing:.2px}.status-pill.is-live{background:#30d15824;color:#1e8f3e}.status-pill.is-warn{background:#ff9f0a29;color:#b96b00}.status-pill.is-error{background:#ff453a24;color:#c62b21}.camera-stage{position:relative;background:#000;border-radius:14px;overflow:hidden;aspect-ratio:4 / 3;max-height:320px;margin:0 auto}.preview{width:100%;height:100%;object-fit:cover;transform:scaleX(-1);display:block}.camera-overlay-msg{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;text-align:center;padding:20px;background:#000000b8;color:#fff;font-size:14px;line-height:1.5}.camera-actions{display:flex;gap:10px;margin-top:16px;flex-wrap:wrap}.dashboard-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px}.gauge-card{display:flex;flex-direction:column;align-items:center;justify-content:center}.bpm-gauge{position:relative;width:150px;height:150px;margin:0 auto}.bpm-gauge-ring{width:100%;height:100%;transform:rotate(-90deg)}.bpm-gauge-track{fill:none;stroke:var(--raised);stroke-width:10}.bpm-gauge-fill{fill:none;stroke:var(--healthy);stroke-width:10;stroke-linecap:round;stroke-dasharray:377;stroke-dashoffset:377;transition:stroke-dashoffset .6s ease,stroke .6s ease}.bpm-gauge-readout{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center}.bpm-gauge-readout strong{font:600 38px/1 var(--mono);color:var(--text);transition:color .6s ease}.bpm-gauge-readout small{color:var(--text-tertiary);font-size:11px;margin-top:4px}.bpm-status{margin-top:16px}.zone-badge{display:inline-flex;align-items:center;padding:5px 12px;border-radius:999px;font:600 12px var(--sans);letter-spacing:.2px;background:var(--raised);color:var(--text-secondary);transition:background .3s ease,color .3s ease}.zone-healthy{background:#30d15824;color:#1e8f3e}.zone-low{background:#ff9f0a29;color:#b96b00}.zone-critical{background:#ff453a24;color:#c62b21}.stats-card{display:flex;flex-direction:column}.stat-row{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;margin:0 0 18px;padding:0 0 16px;border-bottom:1px solid var(--border)}.stat-row div{text-align:center}.stat-row dt{color:var(--text-tertiary);font-size:10px;text-transform:uppercase;letter-spacing:.5px;margin-bottom:4px}.stat-row dd{margin:0;font:600 15px var(--mono);color:var(--text)}.chips-label{font-size:11px;text-transform:uppercase;letter-spacing:.5px;color:var(--text-tertiary);margin-bottom:8px}.session-chips{display:flex;flex-wrap:wrap;gap:7px}.chip{background:var(--raised);border:1px solid transparent;color:var(--text-secondary);font-size:12px;font-weight:600;padding:7px 12px;border-radius:999px;transition:background .15s ease,color .15s ease}.chip:hover{background:#dcdce2}.chip.is-active{background:var(--accent);color:#fff}.docked-row{display:flex;align-items:center;justify-content:space-between;gap:14px;margin-top:18px;padding-top:16px;border-top:1px solid var(--border)}.docked-copy strong{display:block;font-size:13px;margin-bottom:3px}.docked-copy p{color:var(--text-tertiary);font-size:11px;margin:0;line-height:1.5}.switch{flex-shrink:0;width:46px;height:27px;border-radius:999px;background:var(--raised);border:1px solid var(--border-strong);position:relative;transition:background .2s ease;padding:0}.switch[aria-checked=true]{background:var(--accent);border-color:var(--accent)}.switch-knob{position:absolute;top:2px;left:2px;width:21px;height:21px;border-radius:50%;background:#fff;box-shadow:var(--shadow-sm);transition:transform .2s ease}.switch[aria-checked=true] .switch-knob{transform:translate(19px)}.history-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:14px}.history-head h2{font-size:17px;letter-spacing:-.2px}.history-chart{display:flex;align-items:flex-end;gap:4px;height:90px;margin-bottom:16px;padding:8px;background:var(--canvas);border-radius:10px}.history-bar{flex:1;min-width:4px;border-radius:3px 3px 0 0;background:var(--healthy);transition:height .3s ease}.history-chart-empty{color:var(--text-tertiary);font-size:12px;margin:auto}.history-list{list-style:none;margin:0;padding:0}.history-item{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:12px 0;border-bottom:1px solid var(--border);font-size:13px}.history-item:last-child{border-bottom:none}.history-item-main{display:flex;flex-direction:column;gap:2px}.history-item-main strong{font-size:14px}.history-item-main span{color:var(--text-tertiary);font-size:12px}.history-item-stats{display:flex;align-items:center;gap:10px}.history-bpm{font:600 14px var(--mono)}.disclaimer-card h2{font-size:16px;margin-bottom:10px}.disclaimer-card p{color:var(--text-secondary);font-size:13px;line-height:1.6;margin:0 0 10px}.disclaimer-card p:last-child{margin-bottom:0}.app-footer{border-top:1px solid var(--border);padding:24px 0;text-align:center}.app-footer .fine-print{margin:0}.toast{background:var(--card);border:1px solid var(--border);border-left:4px solid var(--accent);border-radius:12px;bottom:20px;box-shadow:var(--shadow-lg);color:var(--text);display:flex;flex-direction:column;gap:3px;max-width:360px;opacity:0;padding:14px 18px;pointer-events:none;position:fixed;right:20px;left:20px;margin:0 auto;transform:translateY(16px);transition:.25s ease;z-index:30}.toast.is-visible{opacity:1;pointer-events:auto;transform:translateY(0)}.toast strong{font-size:13px}.toast span{color:var(--text-secondary);font-size:12px}@media (min-width: 480px){.toast{left:auto;right:20px}}@media (max-width: 640px){.dashboard-grid{grid-template-columns:1fr}.camera-actions{flex-direction:column}.camera-actions .button,.camera-actions .button-outline{width:100%}}@media (prefers-reduced-motion: reduce){html{scroll-behavior:auto}.bpm-gauge-fill,.bpm-gauge-readout strong,.zone-badge,.switch,.switch-knob,.history-bar,.toast,.button{transition:none}}