:root{color-scheme:light;--ink:#1e3035;--muted:#67767b;--line:#dce3e3;--paper:#fff;--accent:#316b60;--soft:#eaf1ed;--amber:#a46618;font-family:Inter,"Segoe UI","Microsoft YaHei",sans-serif;font-size:16px}*{box-sizing:border-box}body{margin:0;background:#f5f7f7;color:var(--ink)}button,input,a{-webkit-tap-highlight-color:transparent}button{font:inherit;color:inherit;cursor:pointer}button:focus-visible,a:focus-visible,input:focus-visible{outline:3px solid #4d927e;outline-offset:3px}button{border:1px solid var(--line);background:white;border-radius:6px;padding:8px 12px;font-size:.875rem}button:hover{background:#eef3f1}button[aria-pressed=true],button[aria-selected=true]{background:var(--ink);color:white;border-color:var(--ink)}a{color:var(--accent);text-decoration:none}a:hover{text-decoration:underline}.app-header{height:90px;background:white;border-bottom:1px solid var(--line);padding:16px 28px;display:flex;gap:24px;align-items:center;justify-content:space-between}.brand{display:flex;align-items:center;gap:14px}.brand-mark{width:48px;height:48px;background:var(--ink);color:#e4eee8;border-radius:8px;display:flex;align-items:center;justify-content:center;font-size:1rem;letter-spacing:-1px}.brand-mark span{font-size:1.6rem;font-weight:600}.brand h1{font-size:1.22rem;font-weight:600;margin:0 0 6px}.brand p{font-size:.7rem;letter-spacing:2px;color:var(--muted);margin:0}.header-note{display:flex;align-items:center;gap:12px;font-size:.8rem;color:var(--muted);margin-left:auto}.tag{border:1px solid #becfc7;background:#f1f6f3;border-radius:4px;padding:5px 8px;color:var(--accent);white-space:nowrap}.quiet{background:transparent;font-size:.82rem;border-color:transparent;color:var(--muted)}.workspace{display:grid;grid-template-columns:226px minmax(380px,1fr) 310px;min-height:620px;height:calc(100dvh - 128px);max-height:1100px}.parts-panel,.info-panel{background:white;overflow-y:auto;scrollbar-width:thin}.parts-panel{border-right:1px solid var(--line);padding:24px 14px 12px}.panel-heading{display:flex;justify-content:space-between;align-items:center;margin:0 8px}.panel-heading h2{font-size:.95rem;margin:0}.panel-heading span{color:var(--muted);font-size:.75rem}.panel-hint{font-size:.75rem;line-height:1.7;color:var(--muted);margin:9px 8px 20px}.part-section{font-size:.72rem;letter-spacing:1px;color:#82908e;margin:22px 8px 8px}.part-row{display:flex;align-items:center;gap:5px;padding:3px 6px;border-radius:6px;margin:2px 0}.part-row.selected{background:var(--soft)}.part-row input{accent-color:var(--accent);width:15px;height:15px;flex-shrink:0;cursor:pointer}.part-row button{border:0;background:transparent;flex:1;text-align:left;padding:7px 3px;min-width:0;line-height:1.4;font-size:.84rem}.part-row small{display:block;color:var(--muted);font-size:.68rem;font-family:Consolas,monospace;line-height:1.45}.part-row .dot{font-size:.65rem;color:var(--amber)}.list-footer{display:flex;justify-content:space-between;margin-top:20px;padding-top:10px;border-top:1px solid var(--line)}.stage-panel{min-width:0;display:flex;flex-direction:column;background:#eef2f2;position:relative}.view-modes{display:flex;justify-content:center;gap:4px;padding:17px 10px;z-index:2}.view-modes button{font-size:.8rem;background:transparent;border-color:transparent;padding:8px 13px}.view-modes button[aria-pressed=true]{background:var(--ink);color:white;box-shadow:0 3px 7px #18363b1a}.stage-panel #viewport{position:relative;flex:1;min-height:380px;overflow:hidden}.stage-caption{position:absolute;top:8px;left:24px;display:flex;flex-direction:column;gap:6px;z-index:1;pointer-events:none}.stage-caption span:first-child{font-size:.84rem;font-weight:500}.stage-caption span:last-child{font-size:.72rem;color:var(--muted)}#canvas-host,#labels-layer{position:absolute;inset:0}canvas{display:block;width:100%;height:100%;touch-action:none}#labels-layer{pointer-events:none;overflow:hidden}.model-label{position:absolute;padding:4px 8px;background:#fffffff2;border:1px solid #c4d4ce;border-radius:4px;font-size:.7rem;color:#334d44;white-space:nowrap;box-shadow:0 2px 5px #2441390c;transform:translate(-50%,-100%);pointer-events:auto;cursor:pointer}.model-label.selected{background:#285b50;color:white;border-color:#285b50}.model-label.lube{border-color:#cead70;color:#87530c}.view-buttons{position:absolute;right:16px;bottom:44px;display:flex;flex-direction:column;gap:6px}.view-buttons button{background:#ffffffdf;font-size:.72rem;min-width:46px;padding:7px 9px}.stage-instructions{position:absolute;bottom:14px;left:23px;right:20px;display:flex;justify-content:space-between;gap:8px;font-size:.7rem;color:var(--muted);pointer-events:none}#render-state{font-family:Consolas,monospace;font-size:.68rem}.stage-controls{background:#f9fbfa;padding:17px 24px 12px;border-top:1px solid #dbe3e0}.explosion-label{display:flex;justify-content:space-between;align-items:center;font-size:.84rem}.explosion-label output{font-family:Consolas,monospace;color:var(--accent)}#explode{width:100%;accent-color:var(--accent);margin:12px 0 8px;height:20px;cursor:pointer}.toggle-row{display:flex;gap:22px;align-items:center;font-size:.78rem;flex-wrap:wrap}.toggle-row label{display:flex;align-items:center;gap:5px}.toggle-row input{accent-color:var(--accent)}.toggle-row .quiet{margin-left:auto;padding:4px 6px}.model-boundary{font-size:.7rem;line-height:1.6;color:var(--muted);margin:11px 0 0}.info-panel{border-left:1px solid var(--line)}.info-tabs{position:sticky;top:0;display:flex;gap:4px;padding:18px 18px 12px;background:white;z-index:2;border-bottom:1px solid var(--line)}.info-tabs button{flex:1;font-size:.82rem;border-color:transparent;padding:8px}.info-content{padding:25px 23px}.eyebrow{font-size:.66rem;letter-spacing:2px;font-weight:600;color:#8a9692;margin-bottom:12px}.info-content h2{font-size:1.25rem;line-height:1.4;margin:0 0 5px;font-weight:600}.part-english{font-size:.8rem;color:var(--muted);margin:0 0 18px}.part-number{font-size:.78rem;font-family:Consolas,monospace;background:#f1f4f3;display:inline-block;padding:6px 9px;border-radius:4px;margin-bottom:18px;max-width:100%;overflow-wrap:anywhere}.info-content p{font-size:.875rem;line-height:1.85;margin:0 0 18px;color:#536466}.info-content h3{font-size:.84rem;margin:22px 0 10px;color:var(--ink)}.info-note{font-size:.76rem;line-height:1.8;padding:13px 14px;background:#f4f6f5;border-radius:5px;color:var(--muted);margin-top:18px}.lube-note{border-left:3px solid #c5a066;background:#faf7ef;padding:13px 14px;margin:18px 0}.lube-note strong{font-size:.78rem;color:#8c6327}.lube-note p{font-size:.79rem;margin:8px 0 0;line-height:1.8}.source-links{display:flex;flex-wrap:wrap;gap:6px}.source-links button{font-size:.75rem;color:var(--accent);background:#f6faf7;padding:6px 9px;border-color:#d7e3db}.selection-actions{display:flex;gap:8px;margin-top:18px}.selection-actions button{font-size:.78rem}.source-card{display:block;width:100%;text-align:left;margin:8px 0;padding:13px;background:#f9fbfa}.source-card strong{font-size:.85rem;display:block;font-weight:500}.source-card span{display:block;font-size:.75rem;color:var(--muted);margin-top:6px}.photo-grid{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin-bottom:20px}.photo-card{padding:0;border-radius:5px;overflow:hidden;text-align:left}.photo-card img{width:100%;height:93px;object-fit:cover;display:block}.photo-card span{display:block;padding:7px;font-size:.66rem;line-height:1.5}.info-content>a{display:block;font-size:.8rem;line-height:1.8;margin-bottom:10px}.care-step{border-bottom:1px solid var(--line);padding:14px 0}.care-step h3{margin:0 0 7px;line-height:1.6}.care-step p{font-size:.82rem;margin:0 0 9px}.app-footer{height:38px;display:flex;align-items:center;justify-content:space-between;gap:12px;border-top:1px solid var(--line);font-size:.7rem;color:var(--muted);padding:0 24px;background:white}dialog{padding:0;border:1px solid #d8e0dc;border-radius:9px;width:min(1100px,94vw);max-height:94dvh;box-shadow:0 22px 90px #0004}dialog::backdrop{background:#122124a6;backdrop-filter:blur(3px)}.dialog-bar{display:flex;align-items:center;justify-content:space-between;gap:20px;padding:15px 20px;position:sticky;top:0;background:white;border-bottom:1px solid var(--line);z-index:2}.dialog-bar strong{font-size:.95rem}.dialog-bar p{font-size:.75rem;color:var(--muted);margin:6px 0 0;line-height:1.6}.dialog-bar>div:last-child{display:flex;align-items:center;gap:16px;flex-shrink:0}.dialog-bar a{font-size:.78rem}.source-image-wrap{background:#e8edeb;padding:20px;text-align:center;overflow:auto;max-height:calc(94dvh - 90px)}.source-image-wrap img{display:block;max-width:100%;height:auto;margin:auto;background:white}#error-message{position:absolute;inset:80px 30px auto;background:white;padding:25px;border:1px solid #c89979;line-height:1.8;z-index:20}#error-message[hidden]{display:none}[hidden]{display:none!important}
@media(min-width:1600px){.workspace{grid-template-columns:250px minmax(500px,1fr) 350px}.info-content{padding:28px}.part-row button{font-size:.9rem}}
@media(max-width:1120px){.workspace{grid-template-columns:196px minmax(300px,1fr) 265px}.app-header{padding:16px}.header-note>span:last-child{display:none}.parts-panel{padding:20px 9px}.info-content{padding:20px 17px}.view-modes button{padding:8px 9px;font-size:.76rem}.stage-controls{padding:15px}.toggle-row{gap:12px}.stage-caption{left:16px}}
@media(max-width:850px){.app-header{height:auto;min-height:85px;gap:12px}.brand h1{font-size:1.05rem}.brand p{font-size:.58rem}.header-note{display:none}.workspace{height:auto;max-height:none;min-height:0;grid-template-columns:200px minmax(0,1fr)}.stage-panel{grid-column:2;grid-row:1;min-height:660px}.parts-panel{grid-column:1;grid-row:1;max-height:660px}.info-panel{grid-column:1/-1;border-top:1px solid var(--line);border-left:0}.info-content{max-width:800px;margin:auto}.info-tabs{position:static}.photo-grid{grid-template-columns:repeat(3,1fr)}.app-footer{height:auto;min-height:45px;flex-wrap:wrap;padding:10px 16px}.dialog-bar{flex-wrap:wrap;gap:10px}.source-image-wrap{padding:8px}}
@media(max-width:540px){.workspace{display:flex;flex-direction:column}.stage-panel{order:0;min-height:610px}.parts-panel{order:1;max-height:none;border-right:0;border-top:1px solid var(--line)}.info-panel{order:2}.brand-mark{width:38px;height:40px}.app-header>.quiet{font-size:.74rem;padding:7px}.brand{gap:10px}.view-modes{padding:12px 4px}.view-modes button{padding:8px 11px}.stage-panel #viewport{min-height:390px}.stage-controls{padding:15px 17px}.stage-instructions{font-size:.62rem;left:15px;right:14px}.stage-instructions span{display:none}#parts-list{display:grid;grid-template-columns:1fr 1fr;gap:0 8px}.part-section{grid-column:1/-1;margin:15px 8px 7px}.part-row button{font-size:.81rem}.toggle-row{gap:14px}.model-boundary{font-size:.69rem}.dialog-bar a{font-size:.74rem}.dialog-bar>div:last-child{width:100%;justify-content:space-between}.photo-grid{grid-template-columns:1fr 1fr}}
/* Detailed parts and source-backed service lessons. */
.part-row.selected button[data-select]{color:var(--ink)}
.workspace{grid-template-columns:244px minmax(380px,1fr) 340px}.parts-panel{padding-top:20px}.panel-hint{margin-bottom:12px}#part-search{width:100%;padding:10px 11px;border:1px solid var(--line);border-radius:6px;font:inherit;font-size:.78rem;background:#f9fbfa}.catalog-tools{display:flex;justify-content:space-between;margin:5px 0}.catalog-tools button{font-size:.72rem;padding:7px}.part-row{gap:3px;padding:3px 2px}.part-row .expand-part{flex:0 0 20px;width:20px;text-align:center;color:var(--accent);padding:6px 0}.tree-spacer{width:20px;flex-shrink:0}.child-row{margin-left:10px;border-left:1px solid #dce6e0;border-radius:0}.child-row .tree-spacer{width:5px}.child-row button{font-size:.77rem}.child-row small{font-size:.64rem}.parent-link{display:block;text-align:left;font-size:.73rem;margin:0 0 17px;color:var(--accent);padding:7px 9px;background:var(--soft)}.part-children{display:flex;flex-wrap:wrap;gap:5px}.part-children button{font-size:.73rem;padding:6px 8px;text-align:left}.part-children small{font-family:Consolas,monospace;color:var(--muted)}.selection-actions{flex-wrap:wrap}.selection-actions button:first-child{background:var(--soft);color:var(--accent)}.learning-launch{display:flex;align-items:center;justify-content:center;gap:8px;margin:0 14px 8px;padding:9px 12px;background:#e3ece7;border:1px solid #d4e1d9;border-radius:7px}.learning-launch>span{font-size:.72rem;color:#597264}.learning-launch button{font-size:.77rem;padding:7px 10px;border-color:#c6d6cd}.learning-launch small{font-size:.65rem;opacity:.7;margin-left:5px}.view-modes{padding:13px 8px 10px}.model-label.selected{max-width:250px;white-space:normal;text-align:center;line-height:1.5}#hover-label{position:absolute;z-index:8;pointer-events:none;background:#213f37ed;color:white;padding:8px 11px;border-radius:5px;font-size:.75rem;max-width:220px;line-height:1.5;box-shadow:0 3px 15px #122b3320}.info-tabs{padding:16px 14px 11px}.info-tabs button{font-size:.79rem;padding:8px 6px}.sequence-type-label{font-size:.77rem;display:block;margin-bottom:7px}#sequence-type{width:100%;font:inherit;font-size:.77rem;border:1px solid var(--line);padding:10px 7px;border-radius:5px;background:#f6f9f7;color:var(--ink)}.info-content .sequence-scope{font-size:.74rem;line-height:1.7;margin:12px 0 20px;color:var(--muted)}.step-progress{display:flex;align-items:center;justify-content:space-between;margin:4px 0 11px}#step-count{font-size:1.3rem;font-family:Consolas,monospace;color:var(--accent)}#step-kind{font-size:.72rem;color:#855c21;background:#f5eee0;padding:4px 7px;border-radius:4px}.step-nav{display:flex;justify-content:space-between;gap:8px;margin:0 0 20px}.step-nav button{flex:1;font-size:.77rem}button:disabled{opacity:.4;cursor:default}#step-title{font-size:1.1rem;margin-bottom:14px}#step-body{font-size:.85rem}.step-phase{display:flex;gap:6px;border-top:1px solid var(--line);padding-top:16px}.step-phase button{flex:1;font-size:.78rem}.info-content #step-state{font-size:.72rem;color:var(--muted);line-height:1.7;margin:9px 0 18px}.step-part{display:flex;align-items:center;justify-content:space-between;gap:12px;text-align:left;width:100%;font-size:.77rem;padding:8px 10px;margin:5px 0}.step-part small{font-family:Consolas,monospace;color:var(--muted);text-align:right;overflow-wrap:anywhere;max-width:45%}#step-sources{margin-top:15px}.step-view{display:flex;flex-wrap:wrap;gap:7px;margin:16px 0}.step-view button{font-size:.74rem}.steps-outline{border-top:1px solid var(--line);padding-top:15px;margin-top:18px}.steps-outline summary{font-size:.8rem;color:var(--accent);cursor:pointer;padding:4px 0 10px}#step-list{display:flex;flex-direction:column;gap:3px}#step-list button{text-align:left;display:flex;gap:8px;line-height:1.7;font-size:.73rem;border-color:transparent;padding:7px}#step-list button span{font-family:Consolas,monospace;color:var(--muted)}#step-list button.current{background:var(--soft);color:var(--accent)}#exit-sequence{font-size:.75rem;margin-top:15px;padding:7px 0}.info-content h3{line-height:1.6}
@media(min-width:1600px){.workspace{grid-template-columns:265px minmax(500px,1fr) 370px}}
@media(max-width:1120px){.workspace{grid-template-columns:215px minmax(310px,1fr) 285px}.learning-launch{margin:0 8px 8px;padding:8px 5px;gap:5px}.learning-launch>span{display:none}.learning-launch button{font-size:.74rem}.info-content{padding:20px 17px}}
@media(max-width:850px){.workspace{grid-template-columns:215px minmax(0,1fr)}.stage-panel,.parts-panel{min-height:700px}.parts-panel{max-height:700px}.learning-launch>span{display:inline}.info-content #step-body{max-width:650px}.step-part{max-width:600px}.step-nav{max-width:600px}}
@media(max-width:540px){.workspace{display:flex}.stage-panel{min-height:640px}.parts-panel{min-height:0;max-height:540px}.learning-launch{margin:0 10px 8px;padding:9px 6px}.learning-launch>span{font-size:.65rem}.learning-launch button{padding:7px}.learning-launch small{display:none}.stage-panel #viewport{min-height:370px}.model-label.selected{max-width:185px;font-size:.67rem}#parts-list{display:block}.part-row button{font-size:.82rem}.child-row button{font-size:.78rem}.part-section{margin-top:16px}.info-panel{min-height:520px}.info-content{padding:23px 20px}.view-buttons{right:10px}.app-footer span:last-child{font-size:.66rem}}
/* Beginner animation player and original-video references. */
.beginner-entry{color:#26594c!important;border-color:#a9c4b6!important;background:#f8fcf9!important;font-weight:600}.learning-launch{flex-wrap:wrap}.lesson-list{display:grid;gap:8px;margin:18px 0}.lesson-card{display:block;text-align:left;padding:13px 12px;border:1px solid #d7e2db;background:#f7faf8}.lesson-card strong{display:block;font-size:.8rem;line-height:1.65;font-weight:600}.lesson-card span{display:block;font-size:.73rem;line-height:1.75;margin:6px 0;color:#607368}.lesson-card small{font-size:.66rem;color:#75867f}.lesson-card[aria-pressed=true]{background:#e4efe8;color:var(--accent);border-color:#89b49c}.lesson-card[aria-pressed=true] span,.lesson-card[aria-pressed=true] small{color:#456c59}#lesson-chapter-panel{border:1px solid #d9e4dc;background:#f9fbf9;padding:0 12px 12px;border-radius:6px}#lesson-chapters{display:flex;flex-direction:column;gap:5px;margin-bottom:13px}#lesson-chapters button{font-size:.73rem;text-align:left;line-height:1.6;padding:8px}#lesson-chapters button span{font: .68rem Consolas,monospace;opacity:.65;margin-right:9px}.info-content .lesson-source{font-size:.69rem;line-height:1.7;margin:12px 0 0;color:var(--muted)}#lesson-controls{padding:15px 22px 12px;background:#f7fbf8;border-top:1px solid #cbded0}.lesson-playing-heading{display:flex;gap:12px;justify-content:space-between;align-items:center}.lesson-playing-heading strong{font-size:.85rem;font-weight:600}#lesson-time{font:.74rem Consolas,monospace;white-space:nowrap;color:var(--accent)}#lesson-caption{font-size:.77rem;line-height:1.75;color:#52685a;margin:8px 0;min-height:2.8em}#lesson-progress{width:100%;accent-color:var(--accent);cursor:pointer;margin:5px 0 9px}.lesson-playback{display:flex;gap:8px;align-items:center;flex-wrap:wrap}.lesson-playback button{font-size:.76rem;padding:7px 11px}.lesson-playback label{font-size:.73rem;margin-left:5px;color:var(--muted)}#lesson-play{background:#2a6150;color:white;border-color:#2a6150;min-width:77px}#lesson-speed{font:inherit;font-size:.73rem;padding:7px 3px;border:1px solid var(--line);border-radius:4px;background:white;color:var(--ink)}#lesson-stop{margin-left:auto}.lesson-boundary{font-size:.68rem;line-height:1.6;color:var(--muted);margin:9px 0 0}.info-content .video-section-title{margin-top:26px;padding-top:20px;border-top:1px solid var(--line);font-size:.98rem}.info-content .video-scope{font-size:.72rem;line-height:1.7;color:var(--muted)}.video-card{border:1px solid var(--line);border-radius:6px;padding:14px 12px;margin:12px 0;background:#fff}.video-level{font-size:.65rem;letter-spacing:.5px;color:#8a714a;margin-bottom:7px}.video-card h4{font-size:.88rem;line-height:1.6;margin:0 0 4px}.video-card p{font-size:.74rem;line-height:1.75;margin:8px 0}.video-card .video-by{font-size:.69rem;color:#667c70;margin:2px 0 10px}.video-card details{background:#f5f7f5;padding:9px;border-radius:4px;font-size:.71rem;line-height:1.7;color:var(--muted)}.video-card summary{cursor:pointer;color:#647369}.video-card small{font-size:.64rem}.video-card .video-original-title{font-size:.68rem}.video-clips{display:flex;flex-direction:column;gap:5px;margin-top:11px}.video-clips button{display:flex;align-items:center;gap:9px;text-align:left;font-size:.73rem;padding:8px;border-color:#d9e7dd;color:var(--accent)}.video-clips span{font: .7rem Consolas,monospace;white-space:nowrap}.video-actions{display:flex;align-items:center;flex-wrap:wrap;gap:9px;margin:12px 0}.video-actions button,.video-actions a{font-size:.7rem;padding:5px}.video-actions button{background:#f4f7f5;border-color:transparent}.video-card .source-links button{font-size:.68rem;padding:4px 6px}#video-dialog{width:min(1000px,94vw)}#video-player{background:#172220;min-height:200px}#video-player iframe{display:block;width:100%;aspect-ratio:16/9;min-height:200px;border:0}.video-dialog-notes{padding:16px 22px}.video-dialog-notes p{font-size:.81rem;line-height:1.8;margin:0 0 10px}.video-dialog-notes a{font-size:.85rem;display:inline-block;margin:3px 0 9px}.video-dialog-notes span{display:block;font-size:.73rem;color:var(--muted);line-height:1.6}
@media(max-width:1120px){.learning-launch{gap:5px}.learning-launch button{padding:7px;font-size:.7rem}.learning-launch small{display:none}.info-tabs{gap:1px;padding-left:8px;padding-right:8px}.info-tabs button{font-size:.75rem}.lesson-playback{gap:5px}#lesson-controls{padding:13px 15px}}
@media(max-width:540px){.learning-launch{gap:5px;padding:8px 4px}.learning-launch button{padding:7px 6px;font-size:.68rem}.lesson-playing-heading strong{font-size:.8rem}.lesson-playback label{margin-left:0}.lesson-playback button{font-size:.72rem;padding:6px 9px}#lesson-caption{font-size:.74rem}#lesson-stop{margin-left:0}.video-dialog-notes{padding:14px}.video-dialog-notes p{font-size:.75rem}.lesson-card span{font-size:.75rem}}
@media(max-width:540px){.info-panel{order:1}.parts-panel{order:2}}