:root{--bg: #ffffff;--text: #1a1a1a;--text-secondary: #666666;--panel-bg: #f5f5f5;--panel-border: #e0e0e0;--button-bg: #e8e8e8;--button-text: #1a1a1a;--button-hover: #d4d4d4;--overlay-bg: rgba(0, 0, 0, .3);--slider-track: #d0d0d0;--slider-fill: #2D9CDB;--input-bg: #ffffff;--input-border: #cccccc;--circle-color: rgba(128, 128, 128, .15);--font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif}@media (prefers-color-scheme: dark){:root{--bg: #0d0d0d;--text: #e0e0e0;--text-secondary: #999999;--panel-bg: #1a1a1a;--panel-border: #333333;--button-bg: #2a2a2a;--button-text: #e0e0e0;--button-hover: #3a3a3a;--overlay-bg: rgba(0, 0, 0, .6);--slider-track: #3a3a3a;--slider-fill: #2D9CDB;--input-bg: #2a2a2a;--input-border: #444444;--circle-color: rgba(255, 255, 255, .1)}}.hidden{display:none!important}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}html,body{height:100%;overflow:hidden}body{background-color:var(--bg);color:var(--text);font-family:var(--font-family);-webkit-font-smoothing:antialiased;transition:background-color .5s ease}#app{display:flex;align-items:center;justify-content:center;height:100%;position:relative}#main-content{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:1.5rem;z-index:1;width:100%;max-width:400px;padding:2rem 1rem}.icon-btn{background:none;border:none;cursor:pointer;font-size:1.5rem;color:var(--text);padding:.5rem;line-height:1;border-radius:50%;width:2.5rem;height:2.5rem;display:flex;align-items:center;justify-content:center;transition:background-color .2s}.icon-btn:hover{background-color:var(--button-bg)}#settings-toggle{position:fixed;top:1rem;right:1rem;z-index:10}#settings-overlay{position:fixed;top:0;right:0;bottom:0;left:0;z-index:100;display:flex;justify-content:flex-end}#settings-overlay.hidden{display:none}#settings-overlay:before{content:"";position:absolute;top:0;right:0;bottom:0;left:0;background:var(--overlay-bg)}#settings-panel{position:relative;width:100%;max-width:380px;height:100%;background:var(--panel-bg);border-left:1px solid var(--panel-border);overflow-y:auto;padding:1.5rem;animation:slideIn .25s ease-out}@keyframes slideIn{0%{transform:translate(100%)}to{transform:translate(0)}}#settings-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:1.5rem}#settings-header h2{font-size:1.25rem;font-weight:600}#settings-content details{margin-bottom:1rem;border-bottom:1px solid var(--panel-border);padding-bottom:.75rem}#settings-content summary{font-weight:600;font-size:.95rem;cursor:pointer;padding:.5rem 0;-webkit-user-select:none;user-select:none}.setting-group{margin-top:.75rem}.setting-group label{display:flex;justify-content:space-between;align-items:center;font-size:.85rem;color:var(--text-secondary);margin-bottom:.25rem}.setting-group label span.value{font-weight:600;color:var(--text);min-width:2rem;text-align:right}.setting-group input[type=range]{-webkit-appearance:none;-moz-appearance:none;appearance:none;width:100%;height:6px;border-radius:3px;background:var(--slider-track);outline:none;margin:.25rem 0 .75rem}.setting-group input[type=range]::-webkit-slider-thumb{-webkit-appearance:none;-moz-appearance:none;appearance:none;width:18px;height:18px;border-radius:50%;background:var(--slider-fill);cursor:pointer;border:2px solid var(--panel-bg)}.setting-group select{width:100%;padding:.5rem;border:1px solid var(--input-border);border-radius:6px;background:var(--input-bg);color:var(--text);font-size:.85rem;margin-bottom:.5rem}.setting-group input[type=color]{width:36px;height:36px;border:1px solid var(--input-border);border-radius:6px;cursor:pointer;padding:2px;background:var(--input-bg)}.color-pickers{display:flex;gap:1rem;align-items:center;margin-bottom:.5rem}.color-pickers label{display:flex;flex-direction:column;align-items:center;gap:.25rem;font-size:.75rem;color:var(--text-secondary)}.theme-presets{display:grid;grid-template-columns:1fr 1fr;gap:.5rem;margin-bottom:.75rem}.theme-preset-btn{padding:.6rem;border:2px solid var(--panel-border);border-radius:8px;background:var(--input-bg);color:var(--text);cursor:pointer;font-size:.8rem;text-align:left}.theme-preset-btn.active{border-color:var(--slider-fill)}.theme-swatch{display:flex;gap:4px;margin-top:4px}.theme-swatch span{width:16px;height:16px;border-radius:50%;display:inline-block}.toggle-row{display:flex;justify-content:space-between;align-items:center;margin-bottom:.5rem;font-size:.85rem}.toggle-switch{position:relative;display:inline-block;width:44px;height:24px}.toggle-switch input{opacity:0;width:0;height:0}.toggle-slider{position:absolute;cursor:pointer;top:0;right:0;bottom:0;left:0;background-color:var(--slider-track);border-radius:24px;transition:.3s}.toggle-slider:before{position:absolute;content:"";height:18px;width:18px;left:3px;bottom:3px;background-color:#fff;border-radius:50%;transition:.3s}.toggle-switch input:checked+.toggle-slider{background-color:var(--slider-fill)}.toggle-switch input:checked+.toggle-slider:before{transform:translate(20px)}.tone-freq-group{display:flex;gap:.5rem;margin-bottom:.5rem}.tone-freq-group>div{flex:1}.tone-freq-group label{display:block;font-size:.8rem;color:var(--text-secondary);margin-bottom:.2rem}.tone-freq-group input[type=number]{width:100%;padding:.4rem;border:1px solid var(--input-border);border-radius:6px;background:var(--input-bg);color:var(--text);font-size:.85rem}#viz-container{position:relative;width:min(70vw,70vh,280px);height:min(70vw,70vh,280px);display:flex;align-items:center;justify-content:center}#breath-circle-el{position:absolute;width:100%;height:100%;border-radius:50%;background-color:var(--circle-color);transform:scale(.4);transition:background-color .5s ease}#ring-timer-svg{position:absolute;width:110%;height:110%;pointer-events:none}#ring-timer-svg circle{transition:stroke .3s ease}#phase-label{font-size:1.5rem;font-weight:500;text-align:center;min-height:2rem;color:var(--text);transition:opacity .3s}#timer-display{font-size:3rem;font-weight:300;text-align:center;font-variant-numeric:tabular-nums;color:var(--text);min-height:3.5rem;letter-spacing:.05em}#button-row{display:flex;gap:.75rem;align-items:center}#start-btn,#reset-btn{padding:.9rem 2.5rem;font-size:1.1rem;font-weight:600;border:none;border-radius:12px;cursor:pointer;transition:background-color .2s,transform .1s;min-width:140px}#start-btn{background:var(--button-bg);color:var(--button-text)}#reset-btn{background:transparent;color:var(--text-secondary);border:2px solid var(--panel-border)}#start-btn:hover,#reset-btn:hover{background:var(--button-hover)}#reset-btn:hover{border-color:var(--text-secondary)}#start-btn:active,#reset-btn:active{transform:scale(.97)}.complete-message{font-size:1.2rem;text-align:center;color:var(--text);line-height:1.6}@media (max-width: 480px){#main-content{gap:1rem;padding:1rem}#phase-label{font-size:1.25rem}#timer-display{font-size:2.5rem}#start-btn,#reset-btn{padding:.8rem 2rem;font-size:1rem}#settings-panel{max-width:100%}}@media (prefers-reduced-motion: reduce){#breath-circle-el{transition:none!important}#settings-panel{animation:none}body{transition:none!important}}