.chess-intro{margin-bottom:20px}.chess-category-bar{display:flex;align-items:center;gap:10px;margin-bottom:10px}.chess-category-bar label{font-weight:600;white-space:nowrap}.chess-category-bar select{flex:1;max-width:320px;padding:4px 8px;font-size:.95em;font-family:inherit;color:var(--foreground);background:var(--background);border:1px solid color-mix(in srgb,var(--foreground) 30%,transparent);cursor:pointer}.chess-category-bar select:focus{outline:1px solid var(--accent);border-color:var(--accent)}.chess-category-desc{color:color-mix(in srgb,var(--foreground) 65%,transparent);font-size:.9em;margin-bottom:4px;line-height:1.4}.chess-category-progress{color:color-mix(in srgb,var(--foreground) 50%,transparent);font-size:.85em;margin-bottom:16px}.chess-puzzle-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:15px;padding-bottom:10px;border-bottom:1px solid color-mix(in srgb,var(--foreground) 15%,transparent)}.chess-puzzle-info{display:flex;flex-direction:column;gap:2px}.chess-puzzle-title-row{display:flex;align-items:center;gap:8px}.chess-puzzle-title{font-weight:600}.chess-puzzle-difficulty{font-size:.75em;padding:1px 7px;border:1px solid;border-radius:3px;white-space:nowrap;text-transform:capitalize}.difficulty-beginner{color:var(--accent);border-color:color-mix(in srgb,var(--accent) 50%,transparent)}.difficulty-intermediate{color:color-mix(in srgb,var(--foreground) 70%,transparent);border-color:color-mix(in srgb,var(--foreground) 30%,transparent)}.difficulty-advanced{color:#e8960c;border-color:color-mix(in srgb,#e8960c 50%,transparent)}.chess-puzzle-desc{color:color-mix(in srgb,var(--foreground) 60%,transparent);font-size:.9em}.chess-puzzle-nav{display:flex;align-items:center;gap:8px}.chess-puzzle-nav button{padding:2px 10px;font-size:.9em}.chess-layout{display:flex;gap:24px;align-items:flex-start}.chess-board-wrapper{position:relative;flex-shrink:0}.chess-board{display:grid;grid-template-columns:repeat(8,1fr);grid-template-rows:repeat(8,1fr);width:360px;height:360px;border:2px solid var(--foreground)}.chess-square{display:flex;align-items:center;justify-content:center;font-size:2rem;cursor:pointer;user-select:none;position:relative;line-height:1}.chess-square.light{background:color-mix(in srgb,var(--foreground) 5%,var(--background))}.chess-square.dark{background:color-mix(in srgb,var(--foreground) 18%,var(--background))}.chess-square.piece-sliding{z-index:10;transition:transform .25s ease-in-out}.chess-square.piece-arrived{animation:piece-arrive .2s ease-out}@keyframes piece-arrive{0%{transform:scale(1.08)}100%{transform:scale(1)}}.chess-square.piece-captured{animation:piece-capture .2s ease-in forwards;z-index:5}@keyframes piece-capture{0%{opacity:1;transform:scale(1)}100%{opacity:0;transform:scale(.3)}}.chess-square.solve-ripple{animation:solve-ripple .5s ease-out}@keyframes solve-ripple{0%{background:color-mix(in srgb,var(--accent) 60%,var(--background))}100%{background:inherit}}.chess-square.piece-enter{animation:piece-enter .3s ease-out both}@keyframes piece-enter{from{opacity:0;transform:scale(.7)}to{opacity:1;transform:scale(1)}}.chess-square.hint-pulse{animation:hint-pulse 1.2s ease-in-out infinite}@keyframes hint-pulse{0%,100%{background:color-mix(in srgb,var(--accent) 30%,var(--background));box-shadow:none}50%{background:color-mix(in srgb,var(--accent) 55%,var(--background));box-shadow:inset 0 0 10px color-mix(in srgb,var(--accent) 30%,transparent)}}.chess-board-wrapper.solved .chess-board{border-color:var(--accent);box-shadow:0 0 0 3px var(--accent),0 0 16px color-mix(in srgb,var(--accent) 40%,transparent)}.chess-board-wrapper.solved .chess-coords{color:var(--accent)}.chess-square.selected{background:color-mix(in srgb,var(--accent) 45%,var(--background))!important}.chess-square.valid-move{cursor:pointer}.chess-square.valid-move::after{content:"";position:absolute;width:12px;height:12px;border-radius:50%;background:color-mix(in srgb,var(--accent) 50%,transparent)}.chess-square.valid-move.has-piece::after{width:100%;height:100%;border-radius:0;background:color-mix(in srgb,var(--accent) 25%,transparent);border:3px solid color-mix(in srgb,var(--accent) 60%,transparent)}.chess-square.last-move{background:color-mix(in srgb,var(--accent) 20%,var(--background))!important}.chess-square.check{background:color-mix(in srgb,#ff4444 40%,var(--background))!important}.chess-square.wrong-move{animation:shake .3s ease-in-out}@keyframes shake{0%,100%{transform:translateX(0)}25%{transform:translateX(-4px)}75%{transform:translateX(4px)}}.chess-coords{position:absolute;display:flex;color:color-mix(in srgb,var(--foreground) 40%,transparent);font-size:.75em}.chess-coords-files{bottom:-20px;left:0;right:0;justify-content:space-around}.chess-coords-ranks{top:0;bottom:0;left:-18px;flex-direction:column;justify-content:space-around;align-items:center}.chess-sidebar{flex:1;min-width:0}.chess-status{padding:8px 12px;margin-bottom:12px;border:1px solid color-mix(in srgb,var(--foreground) 25%,transparent);font-size:.95em}.chess-status.status-error{border-color:#f44;color:#f44}.chess-status.status-solved{border-color:var(--accent);color:var(--accent);font-weight:600}.chess-status.status-check{border-color:#fa0;color:#fa0}.chess-controls{display:flex;gap:8px;margin-bottom:16px}.chess-controls button{padding:4px 14px;font-size:.9em}.chess-move-log h3{margin:0 0 8px;font-size:.95em}.chess-move-log ol{margin:0;padding:0;list-style:none;font-size:.9em;color:color-mix(in srgb,var(--foreground) 70%,transparent)}.chess-move-log li{padding:2px 0}.chess-move-log li::marker{content:none}.chess-move-log .move-pair{display:flex;gap:12px}.chess-move-log .move-number{color:color-mix(in srgb,var(--foreground) 40%,transparent);min-width:3ch}.chess-move-log .move-white,.chess-move-log .move-black{min-width:7ch}.chess-turn-indicator{display:flex;align-items:center;gap:8px;padding:8px 12px;margin-bottom:12px;border:1px solid color-mix(in srgb,var(--foreground) 25%,transparent);font-size:.95em;font-weight:600}.chess-turn-icon{font-size:1.4em;line-height:1}.chess-legend{display:flex;gap:14px;margin-top:16px;padding-top:12px;border-top:1px solid color-mix(in srgb,var(--foreground) 15%,transparent);font-size:.85em;color:color-mix(in srgb,var(--foreground) 60%,transparent)}.chess-legend-item{display:flex;align-items:center;gap:4px}.chess-legend-piece{font-size:1.3em;line-height:1;vertical-align:middle}.chess-learn-progress{color:color-mix(in srgb,var(--foreground) 60%,transparent);font-size:.9em;margin-bottom:16px}.chess-lesson-list{list-style:none;margin:0;padding:0}.chess-lesson-item{display:flex;align-items:center;gap:12px;padding:12px 8px;border-bottom:1px solid color-mix(in srgb,var(--foreground) 12%,transparent);cursor:pointer;transition:background .15s}.chess-lesson-item:hover{background:color-mix(in srgb,var(--accent) 8%,transparent)}.chess-lesson-item.completed{opacity:.75}.chess-lesson-num{font-weight:600;min-width:2ch;color:color-mix(in srgb,var(--foreground) 50%,transparent)}.chess-lesson-info{display:flex;flex-direction:column;gap:2px;flex:1;min-width:0}.chess-lesson-item-title{font-weight:600}.chess-lesson-item-desc{font-size:.9em;color:color-mix(in srgb,var(--foreground) 60%,transparent)}.chess-lesson-indicator{font-size:1.1em;color:color-mix(in srgb,var(--foreground) 40%,transparent);min-width:2ch;text-align:right}.chess-lesson-item.completed .chess-lesson-indicator{color:var(--accent);font-weight:600}.chess-learn-back{padding:4px 12px;font-size:.9em;margin-bottom:16px;cursor:pointer}.chess-lesson-title{margin:0 0 12px;font-size:1.3em}.chess-lesson-text{margin-bottom:20px;line-height:1.6}.chess-lesson-text p{margin:0 0 12px}.chess-lesson-text p:last-child{margin-bottom:0}.chess-position-tabs{display:flex;gap:6px;margin-bottom:16px}.chess-position-tab{padding:4px 12px;font-size:.85em;border:1px solid color-mix(in srgb,var(--foreground) 25%,transparent);background:0 0;color:var(--foreground);cursor:pointer}.chess-position-tab.active{border-color:var(--accent);color:var(--accent);font-weight:600}.chess-position-tab:hover{border-color:var(--accent)}.chess-learn-position-info{display:flex;flex-direction:column;gap:2px;margin-bottom:12px}.chess-learn-position-title{font-weight:600}.chess-learn-position-desc{font-size:.9em;color:color-mix(in srgb,var(--foreground) 60%,transparent)}.chess-step-comment{padding:8px 12px;margin-bottom:12px;border:1px solid color-mix(in srgb,var(--foreground) 20%,transparent);font-size:.95em;line-height:1.5;min-height:3em}.chess-step-controls{display:flex;gap:8px;margin-bottom:12px}.chess-step-controls button{padding:4px 14px;font-size:.9em}.chess-step-counter{font-size:.85em;color:color-mix(in srgb,var(--foreground) 50%,transparent)}.chess-lesson-complete{margin-top:20px;padding:12px;border:1px solid var(--accent);text-align:center}.chess-lesson-complete p{margin:0 0 10px;font-weight:600;color:var(--accent)}.chess-lesson-complete button{padding:6px 18px;font-size:.95em}@media(max-width:640px){.chess-layout{flex-direction:column}.chess-board{width:calc(100vw - 60px);height:calc(100vw - 60px);max-width:360px;max-height:360px}.chess-square{font-size:calc((100vw - 60px)/14)}.chess-puzzle-header{flex-direction:column;align-items:flex-start;gap:8px}.chess-category-bar select{max-width:100%}.chess-position-tabs{flex-wrap:wrap}}.chess-opening-list{list-style:none;margin:0;padding:0}.chess-opening-item{display:flex;align-items:center;gap:12px;padding:12px 8px;border-bottom:1px solid color-mix(in srgb,var(--foreground) 12%,transparent);cursor:pointer;transition:background .15s}.chess-opening-item:hover{background:color-mix(in srgb,var(--accent) 8%,transparent)}.chess-opening-item-info{display:flex;flex-direction:column;gap:2px;flex:1;min-width:0}.chess-opening-item-title{font-weight:600}.chess-opening-item-desc{font-size:.9em;color:color-mix(in srgb,var(--foreground) 60%,transparent)}.chess-opening-stats{font-size:.85em;color:color-mix(in srgb,var(--foreground) 50%,transparent);white-space:nowrap}.chess-opening-desc{color:color-mix(in srgb,var(--foreground) 65%,transparent);font-size:.9em;margin:0 0 16px;line-height:1.4}.chess-status-white{background:color-mix(in srgb,var(--foreground) 8%,var(--background));border-color:color-mix(in srgb,var(--foreground) 30%,transparent);color:var(--foreground);font-size:.9em;margin-bottom:12px}.chess-drill-info{padding:8px 12px;margin-bottom:12px;border:1px solid color-mix(in srgb,var(--accent) 40%,transparent);color:var(--accent);font-weight:600;font-size:.95em}.chess-drill-moves h3{margin:0 0 8px;font-size:.95em}.chess-drill-moves ol{margin:0;padding:0;list-style:none;font-size:.9em;color:color-mix(in srgb,var(--foreground) 70%,transparent)}.chess-drill-moves li{padding:2px 0}.drill-current-move{color:var(--accent);font-weight:600}.drill-future-move{color:color-mix(in srgb,var(--foreground) 30%,transparent)}.chess-drill-complete{margin-top:20px;padding:12px;border:1px solid var(--accent);text-align:center}.chess-drill-complete p{margin:0 0 10px}.chess-drill-complete p:first-child{font-weight:600;color:var(--accent)}.chess-drill-complete button{padding:6px 18px;font-size:.95em}