:root{--text:#6b6375;--text-h:#08060d;--bg:#fff;--border:#e5e4e7;--code-bg:#f4f3ec;--accent:#aa3bff;--accent-bg:#aa3bff1a;--accent-border:#aa3bff80;--social-bg:#f4f3ec80;--shadow:#0000001a 0 10px 15px -3px, #0000000d 0 4px 6px -2px;--sans:system-ui, "Segoe UI", Roboto, sans-serif;--heading:system-ui, "Segoe UI", Roboto, sans-serif;--mono:ui-monospace, Consolas, monospace;font:18px/145% var(--sans);letter-spacing:.18px;--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light dark;color:var(--text);background:var(--bg);font-synthesis:none;text-rendering:optimizelegibility;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}@media (prefers-color-scheme:dark){:root{--lightningcss-light: ;--lightningcss-dark:initial}}@media (width<=1024px){:root{font-size:16px}}@media (prefers-color-scheme:dark){:root{--text:#9ca3af;--text-h:#f3f4f6;--bg:#16171d;--border:#2e303a;--code-bg:#1f2028;--accent:#c084fc;--accent-bg:#c084fc26;--accent-border:#c084fc80;--social-bg:#2f303a80;--shadow:#0006 0 10px 15px -3px, #00000040 0 4px 6px -2px}#social .button-icon{filter:invert()brightness(2)}}#root{text-align:center;border-inline:1px solid var(--border);box-sizing:border-box;flex-direction:column;width:1126px;max-width:100%;min-height:100svh;margin:0 auto;display:flex}body{margin:0}h1,h2{font-family:var(--heading);color:var(--text-h);font-weight:500}h1{letter-spacing:-1.68px;margin:32px 0;font-size:56px}@media (width<=1024px){h1{margin:20px 0;font-size:36px}}h2{letter-spacing:-.24px;margin:0 0 8px;font-size:24px;line-height:118%}@media (width<=1024px){h2{font-size:20px}}p{margin:0}code,.counter{font-family:var(--mono);color:var(--text-h);border-radius:4px;display:inline-flex}code{background:var(--code-bg);padding:4px 8px;font-size:15px;line-height:135%}.app-shell{flex-direction:column;flex:auto;height:100svh;min-height:0;display:flex}.app-view{text-align:left;flex-direction:column;flex:auto;min-height:0;display:flex;overflow:hidden}.bottom-nav{border-top:1px solid var(--border);background:var(--bg);padding-bottom:env(safe-area-inset-bottom,0);flex:none;display:flex}.bottom-nav-item{font:inherit;color:var(--text);cursor:pointer;background:0 0;border:none;flex:1;justify-content:center;align-items:center;padding:14px 0;display:flex}.bottom-nav-item.active{color:var(--accent)}.bottom-nav-icon{font-size:24px;line-height:1}.swipe-view{flex-direction:column;flex:auto;min-height:0;display:flex;position:relative}.goal-toast{z-index:300;background:var(--accent);color:var(--bg);box-shadow:var(--shadow);pointer-events:none;border-radius:999px;align-items:center;gap:6px;padding:8px 16px;font-size:13px;font-weight:600;display:inline-flex;position:absolute;top:16px;left:50%;transform:translate(-50%)}.card-stack{flex:auto;justify-content:center;align-items:center;min-height:0;padding:12px 16px;display:flex;position:relative}.swipe-empty{text-align:center;color:var(--text);flex-direction:column;align-items:center;gap:6px;display:flex}.swipe-empty-title{color:var(--text-h);font-size:22px;font-weight:600}.swipe-empty-sub{align-items:center;gap:4px;margin-top:8px;font-size:14px;display:inline-flex}.swipe-actions{z-index:200;pointer-events:none;justify-content:center;gap:40px;display:flex;position:absolute;bottom:12px;left:0;right:0}.icon-button{pointer-events:auto;border:2px solid var(--border);background:var(--bg);width:52px;height:52px;color:var(--text-h);box-shadow:var(--shadow);cursor:pointer;border-radius:50%;flex:none;justify-content:center;align-items:center;font-size:22px;line-height:1;display:flex}.icon-button:hover{border-color:var(--accent-border)}.icon-button-sm{width:36px;height:36px;box-shadow:none;font-size:16px}.icon-button-warning{color:#d97706;background:#d977061a;border-color:#d9770680}.icon-button-positive{color:#16a34a;background:#16a34a1a;border-color:#16a34a80}.problem-card{border:1px solid var(--border);background:var(--bg);width:min(700px,94vw);height:min(760px,100%);box-shadow:var(--shadow);cursor:grab;touch-action:pan-y;border-radius:16px;position:absolute}.problem-card:active{cursor:grabbing}.card-stamp{z-index:10;text-transform:uppercase;letter-spacing:1px;pointer-events:none;border:3px solid;border-radius:8px;padding:6px 14px;font-size:20px;font-weight:700;position:absolute;top:24px}.card-stamp-reviewed{color:#16a34a;border-color:#16a34a;left:20px;transform:rotate(-12deg)}.card-stamp-revisit{color:#d97706;border-color:#d97706;right:20px;transform:rotate(12deg)}.card-inner{width:100%;height:100%;transform-style:preserve-3d;transition:transform .5s;position:relative}.card-inner.flipped{transform:rotateY(180deg)}.card-face{backface-visibility:hidden;text-align:center;border-radius:16px;flex-direction:column;padding:24px 24px 76px;display:flex;position:absolute;inset:0;overflow-y:auto}.card-top-actions-left{z-index:5;position:absolute;top:16px;left:16px}.card-top-actions-right{z-index:5;position:absolute;top:16px;right:16px}.card-back{text-align:left;transform:rotateY(180deg)}.card-front-header{justify-content:center;gap:8px;margin-bottom:12px;display:flex}.card-title{margin:0 0 4px}.card-category{color:var(--text);margin-bottom:16px;font-size:13px}.card-solution{text-align:left;flex:auto;margin:0}.solution-code.card-solution{overflow-x:hidden}.card-flip-hint{color:var(--text);opacity:.6;margin-top:12px;font-size:12px}.card-back .card-title{text-align:center}.stats-view{flex-direction:column;flex:auto;gap:16px;padding:24px 20px;display:flex;overflow-y:auto}.stats-card{border:1px solid var(--border);border-radius:12px;padding:18px 20px}.stats-card-header{justify-content:space-between;align-items:center;font-size:14px;display:flex}.stats-card-header h3{color:var(--text-h);margin:0;font-size:14px;font-weight:600}.stats-progress-bar{background:var(--border);border-radius:999px;height:8px;margin-top:10px;overflow:hidden}.stats-progress-fill{background:var(--accent);height:100%;transition:width .3s}.stats-streak{flex-direction:column;align-items:center;gap:4px;padding:28px 20px;display:flex}.stats-streak-number{color:var(--accent);font-size:48px;font-weight:700;line-height:1}.stats-streak-label{color:var(--text);align-items:center;gap:4px;font-size:14px;display:inline-flex}.heatmap-cell{background:var(--border);border-radius:3px;flex:none;width:12px;height:12px}.heatmap-cell.level-0{background:var(--border)}.heatmap-cell.level-1{background:color-mix(in srgb, var(--accent) 25%, var(--border))}.heatmap-cell.level-2{background:color-mix(in srgb, var(--accent) 50%, var(--border))}.heatmap-cell.level-3{background:color-mix(in srgb, var(--accent) 75%, var(--border))}.heatmap-cell.level-4{background:var(--accent)}.heatmap-legend{color:var(--text);align-items:center;gap:4px;margin-top:10px;font-size:11px;display:flex}.category-stats{flex-direction:column;gap:14px;margin-top:12px;display:flex}.category-stat-header{color:var(--text-h);justify-content:space-between;margin-bottom:6px;font-size:13px;display:flex}.category-heat-row{flex-wrap:wrap;gap:3px;display:flex}.settings-view{flex-direction:column;flex:auto;gap:16px;padding:24px 20px;display:flex;overflow-y:auto}.view-title{letter-spacing:-.3px;margin:0 0 4px;font-size:24px}.learn-view{text-align:left;flex:auto;padding:24px 20px;overflow-y:auto}.learn-list{flex-direction:column;gap:10px;margin-top:16px;display:flex}.learn-card{border:1px solid var(--border);border-radius:12px;overflow:hidden}.learn-card-header{width:100%;font:inherit;color:var(--text-h);cursor:pointer;text-align:left;background:0 0;border:none;align-items:center;gap:10px;padding:14px 16px;display:flex}.learn-card-title{flex:1;font-weight:600}.learn-card-count{color:var(--text);font-size:12px}.learn-card-body{flex-direction:column;gap:16px;padding:0 16px 18px;display:flex}.settings-stepper{align-items:center;gap:16px;margin-top:12px;display:flex}.settings-stepper-value{color:var(--text-h);text-align:center;min-width:2ch;font-size:20px;font-weight:700}.settings-hint{color:var(--text);margin-top:4px;font-size:13px}.settings-size-pills{flex-wrap:wrap;gap:8px;margin-top:12px;display:flex}.settings-preview{margin-top:16px}.filter-pill{font:inherit;border:1px solid var(--border);color:var(--text);cursor:pointer;background:0 0;border-radius:999px;padding:6px 12px;font-size:13px;transition:border-color .2s,color .2s}.filter-pill:hover{border-color:var(--accent-border)}.filter-pill.active{border-color:var(--accent);color:var(--accent);background:var(--accent-bg)}.chevron{border-top:5px solid;border-left:4px solid #0000;border-right:4px solid #0000;width:0;height:0;transition:transform .15s}.chevron.collapsed{transform:rotate(-90deg)}.difficulty-badge{white-space:nowrap;border-radius:999px;padding:2px 7px;font-size:11px;font-weight:600}.difficulty-easy{color:#16a34a;background:#16a34a1f}.difficulty-medium{color:#d97706;background:#d977061f}.difficulty-hard{color:#dc2626;background:#dc26261f}.pattern-tag{color:var(--accent);background:var(--accent-bg);border-radius:999px;padding:3px 9px;font-size:12px;font-weight:600}.detail-block h3{text-transform:uppercase;letter-spacing:.4px;color:var(--text);margin:0 0 6px;font-size:14px}.detail-block p{line-height:155%}.detail-complexity p{margin:2px 0}.solution-code{font-family:var(--mono);font-size:var(--code-font-size,13px);background:var(--code-bg);white-space:pre;border-radius:6px;padding:16px;line-height:155%;overflow-x:auto}.solution-code code{font-size:inherit;background:0 0;border-radius:0;padding:0;display:block}