:root{--bg: #f6f7f5;--surface: #ffffff;--border: #dfe3de;--text: #1f2620;--text-muted: #62685f;--accent: #1d6f5c;--accent-dark: #0f4d3e;--accent-soft: #e3f2ec;--danger: #b3413c;--danger-soft: #fbeae9;--radius: 10px;font-family:Segoe UI,system-ui,-apple-system,sans-serif}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text)}.app-shell{min-height:100vh;display:flex;flex-direction:column}.topbar{display:flex;align-items:center;justify-content:space-between;padding:14px 24px;background:var(--surface);border-bottom:1px solid var(--border)}.topbar .brand{font-weight:600;font-size:18px;color:var(--accent-dark)}.topbar .who{font-size:14px;color:var(--text-muted);display:flex;gap:12px;align-items:center}main.page{flex:1;padding:24px;max-width:960px;width:100%;margin:0 auto}.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:20px;margin-bottom:16px}.card h2{margin-top:0;font-size:16px;font-weight:600}.row{display:flex;gap:10px;flex-wrap:wrap;align-items:center}input,select{padding:8px 10px;border:1px solid var(--border);border-radius:8px;font-size:14px}button{padding:8px 14px;border-radius:8px;border:1px solid var(--accent);background:var(--accent);color:#fff;font-size:14px;cursor:pointer}button.secondary{background:transparent;color:var(--accent-dark)}button:disabled{opacity:.5;cursor:default}.error-text{color:var(--danger);background:var(--danger-soft);padding:8px 10px;border-radius:8px;font-size:13px}table{width:100%;border-collapse:collapse;font-size:14px}th,td{text-align:left;padding:8px 6px;border-bottom:1px solid var(--border)}.badge{display:inline-block;padding:2px 8px;border-radius:999px;font-size:12px;background:var(--accent-soft);color:var(--accent-dark)}.step-list{list-style:none;padding:0;margin:0;display:flex;flex-direction:column;gap:8px}.step-item{display:flex;align-items:center;gap:10px;padding:10px 12px;border:1px solid var(--border);border-radius:8px;background:var(--bg)}.step-item .idx{font-weight:600;color:var(--accent-dark);min-width:20px}.step-item .label{flex:1}.step-item .arrows{display:flex;gap:4px}.step-item .arrows button{padding:2px 8px;font-size:12px}.feedback-item{padding:8px 10px;border-radius:8px;font-size:13px;margin-bottom:6px}.feedback-item.pass{background:var(--accent-soft);color:var(--accent-dark)}.feedback-item.fail{background:var(--danger-soft);color:var(--danger)}.score-badge{font-size:28px;font-weight:600;color:var(--accent-dark)}.student-shell{--radius: 16px;--accent-warm: #e0791f;--accent-warm-soft: #fdecd8}.student-shell .card{border-radius:16px}.greeting-banner{background:linear-gradient(0deg,var(--accent-soft),var(--accent-soft));border-radius:16px;padding:18px 20px;margin-bottom:16px;display:flex;align-items:center;justify-content:space-between}.greeting-banner h1{font-size:20px;margin:0 0 4px;color:var(--accent-dark)}.greeting-banner p{margin:0;font-size:13px;color:var(--text-muted)}.module-tile{display:flex;align-items:center;gap:12px;padding:14px;border:1px solid var(--border);border-radius:16px;cursor:pointer;background:var(--surface);transition:transform .08s ease,border-color .15s ease}.module-tile:hover{border-color:var(--accent);transform:translateY(-1px)}.module-tile .emoji{font-size:26px}.module-tile .info{flex:1}.module-tile .info .name{font-size:14px;font-weight:600}.module-tile .info .sub{font-size:12px;color:var(--text-muted)}.score-badge.big{font-size:36px}.score-celebrate{font-size:13px;color:var(--accent-dark);margin-top:-4px}.chat-box{border:1px solid var(--border);border-radius:16px;overflow:hidden;background:var(--surface)}.chat-header{padding:10px 14px;font-size:13px;font-weight:600;background:var(--accent-soft);color:var(--accent-dark)}.chat-messages{padding:12px 14px;max-height:280px;overflow-y:auto;display:flex;flex-direction:column;gap:8px}.chat-bubble-row{display:flex}.chat-bubble-row.me{justify-content:flex-end}.chat-bubble-row.them{justify-content:flex-start}.chat-bubble{max-width:75%;padding:8px 12px;border-radius:14px;font-size:13px;background:var(--bg);border:1px solid var(--border)}.chat-bubble-row.me .chat-bubble{background:var(--accent);color:#fff;border-color:var(--accent)}.chat-sender{font-size:11px;color:var(--text-muted);margin-bottom:2px}.chat-input-row{display:flex;gap:8px;padding:10px 14px;border-top:1px solid var(--border)}.app-ribbon{display:flex;gap:20px;padding:10px 12px;border:1px solid var(--border);border-bottom:none;border-radius:8px 8px 0 0;background:var(--bg);margin-bottom:0}.ribbon-group{display:flex;flex-direction:column;gap:4px;padding-right:16px;border-right:1px solid var(--border)}.ribbon-group:last-child{border-right:none}.ribbon-group-label{font-size:10px;color:var(--text-muted);text-transform:uppercase;letter-spacing:.03em}.browser-chrome{border:1px solid var(--border);border-radius:10px;overflow:hidden;background:var(--surface)}.browser-toolbar{display:flex;align-items:center;gap:8px;padding:8px 12px;background:var(--bg);border-bottom:1px solid var(--border)}.browser-page{padding:16px;min-height:220px}.flowchart-list{display:flex;flex-direction:column;align-items:center;gap:4px}.flowchart-node{display:flex;flex-direction:column;align-items:center;width:100%}.flow-shape{display:flex;align-items:center;justify-content:center;min-height:48px;min-width:220px;max-width:360px;padding:8px 16px;background:var(--surface);border:1.5px solid var(--accent);color:var(--text);font-size:13px;text-align:center;position:relative}.flow-oval{border-radius:999px;background:var(--accent-soft)}.flow-rect{border-radius:6px}.flow-parallelogram{border-radius:6px;transform:skew(-12deg)}.flow-parallelogram .flow-label{display:inline-block;transform:skew(12deg)}.flow-diamond{border-radius:6px;background:var(--danger-soft);border-color:var(--danger);min-width:180px}.flow-arrow-down{color:var(--accent);font-size:16px;line-height:1;margin:2px 0}.flowchart-node .arrows{display:flex;gap:4px;margin-top:4px}.flowchart-node .arrows button{padding:2px 8px;font-size:12px}.office-app{border:1px solid #8ba7cf;border-radius:4px;overflow:hidden;font-family:Segoe UI,Tahoma,Arial,sans-serif;box-shadow:0 1px 4px #00000026}.office-titlebar{display:flex;align-items:center;gap:8px;padding:5px 10px;color:#fff;font-size:12px;font-weight:600}.office-titlebar.word{background:linear-gradient(180deg,#3f74c8,#1f4e96)}.office-titlebar.excel{background:linear-gradient(180deg,#3e8e57,#1a5c34)}.office-titlebar.powerpoint{background:linear-gradient(180deg,#d9633b,#b8451f)}.office-titlebar-icon{width:16px;height:16px;border-radius:50%;background:radial-gradient(circle at 30% 30%,#fff,#ffcf6b 60%,#d99a1f);flex-shrink:0}.office-tabs{display:flex;background:linear-gradient(180deg,#e4ecf9,#cddaf0);border-bottom:1px solid #8ba7cf;padding:4px 8px 0;gap:2px}.office-tab{padding:5px 14px;font-size:12px;color:#1f3864;border-radius:4px 4px 0 0}.office-tab.active{background:linear-gradient(180deg,#fff,#f2f6fc);border:1px solid #8ba7cf;border-bottom:1px solid #f2f6fc;margin-bottom:-1px;font-weight:600}.office-tab.disabled{opacity:.45}.office-ribbon{display:flex;gap:0;padding:6px 8px;background:linear-gradient(180deg,#f5f8fd,#dde8f7);flex-wrap:wrap}.office-group{display:flex;flex-direction:column;align-items:center;gap:4px;padding:2px 12px;border-right:1px solid #b9cbe8}.office-group:last-child{border-right:none}.office-group-btns{display:flex;gap:3px;align-items:center;flex:1}.office-group-caption{font-size:10px;color:#3a5a8c;margin-top:2px}.office-btn{background:linear-gradient(180deg,#fff,#dbe6f6);border:1px solid #aec3e2;border-radius:3px;padding:4px 7px;font-size:12px;color:#1f3864;cursor:pointer;min-width:26px}.office-btn:hover:not(:disabled){background:linear-gradient(180deg,#fff3c4,#ffdd6b);border-color:#e3af1f}.office-btn.active{background:linear-gradient(180deg,#ffdd6b,#ffc531);border-color:#d99a1f}.office-btn:disabled{opacity:.35;cursor:not-allowed}.office-color-swatch{width:16px;height:16px;padding:0;border-radius:2px;cursor:pointer}.office-color-swatch:disabled{cursor:not-allowed}.office-body{background:#fff;padding:12px}