:root{--text:#374151;--text-h:#111827;--bg:#f9fafb;--surface:#fff;--border:#e5e7eb;--primary:#2563eb;--primary-hover:#1d4ed8;--nudge-bg:#f0f9ff;--nudge-border:#bae6fd;--user-bg:#eff6ff;--ai-bg:#fff;--sans:system-ui, -apple-system, sans-serif;--mono:ui-monospace, Consolas, monospace}*{box-sizing:border-box;margin:0;padding:0}body{font:16px/1.5 var(--sans);color:var(--text);background:var(--bg)}#root{flex-direction:column;max-width:800px;min-height:100vh;margin:0 auto;display:flex}.login-container{flex-direction:column;justify-content:center;align-items:center;min-height:100vh;padding:20px;display:flex}.login-card{background:var(--surface);border:1px solid var(--border);border-radius:12px;width:100%;max-width:520px;padding:40px}.consent-card .study-description{color:var(--text-h);margin-bottom:24px;font-size:15px;line-height:1.5}.consent-options{flex-direction:column;gap:12px;margin-bottom:24px;display:flex}.consent-option{border:2px solid var(--border);cursor:pointer;border-radius:10px;align-items:flex-start;gap:12px;padding:16px;transition:border-color .15s,background .15s;display:flex}.consent-option:hover{border-color:var(--primary);background:#2563eb08}.consent-option.selected{border-color:var(--primary);background:#2563eb0f}.consent-option input[type=radio]{accent-color:var(--primary);flex-shrink:0;width:18px;height:18px;margin-top:3px}.consent-option-body{flex-direction:column;flex:1;gap:4px;display:flex}.consent-label{color:var(--text-h);font-size:15px;font-weight:600}.consent-detail{color:var(--text);font-size:13px;line-height:1.4}.student-id-input{border:1px solid var(--border);font-size:15px;font-family:var(--mono);letter-spacing:1px;border-radius:8px;width:100%;margin-top:10px;padding:10px 14px}.student-id-input:focus{outline:2px solid var(--primary);border-color:#0000}.login-card h1{color:var(--text-h);margin-bottom:8px;font-size:24px}.login-card p{color:var(--text);margin-bottom:24px;font-size:14px}.login-card button{background:var(--primary);color:#fff;cursor:pointer;border:none;border-radius:8px;width:100%;padding:12px;font-size:16px}.login-card button:hover{background:var(--primary-hover)}.login-card button:disabled{opacity:.5;cursor:not-allowed}.login-error{color:#dc2626;margin-bottom:12px;font-size:14px}.chat-container{flex-direction:column;min-height:100vh;display:flex}.chat-header{background:var(--surface);border-bottom:1px solid var(--border);z-index:10;justify-content:space-between;align-items:center;padding:12px 20px;display:flex;position:sticky;top:0}.chat-header h2{color:var(--text-h);font-size:16px}.session-info{color:var(--text);font-size:13px;font-family:var(--mono)}.chat-messages{flex-direction:column;flex:1;gap:16px;padding:20px;display:flex;overflow-y:auto}.message{white-space:pre-wrap;border-radius:12px;max-width:85%;padding:12px 16px;font-size:15px;line-height:1.6}.message.user{background:var(--user-bg);color:var(--text-h);border:1px solid #dbeafe;align-self:flex-end}.message.assistant{background:var(--ai-bg);border:1px solid var(--border);color:var(--text);align-self:flex-start}.message .nudge{border-top:1px solid var(--nudge-border);background:var(--nudge-bg);color:#0369a1;border-radius:0 0 12px 12px;margin:12px -16px -12px;padding:12px 16px;font-size:14px;font-style:italic;display:block}.message.system{color:var(--text);background:0 0;border:none;align-self:center;font-size:13px;font-style:italic}.typing-indicator{color:var(--text);align-self:flex-start;padding:12px 16px;font-size:14px;font-style:italic}.chat-input-container{background:var(--surface);border-top:1px solid var(--border);padding:16px 20px;position:sticky;bottom:0}.chat-input-form{gap:8px;display:flex}.chat-input-form textarea{border:1px solid var(--border);font-size:15px;font-family:var(--sans);resize:none;border-radius:8px;flex:1;min-height:48px;max-height:120px;padding:12px 16px}.chat-input-form textarea:focus{outline:2px solid var(--primary);border-color:#0000}.chat-input-form button{background:var(--primary);color:#fff;cursor:pointer;border:none;border-radius:8px;align-self:flex-end;padding:12px 20px;font-size:15px}.chat-input-form button:hover{background:var(--primary-hover)}.chat-input-form button:disabled{opacity:.5;cursor:not-allowed}.turn-count{text-align:center;color:var(--text);margin-top:8px;font-size:12px}.loading-container{min-height:100vh;color:var(--text);justify-content:center;align-items:center;font-size:15px;display:flex}.chat-header-right{align-items:center;gap:16px;display:flex}.finish-button{color:#dc2626;cursor:pointer;background:0 0;border:1px solid #dc2626;border-radius:6px;padding:8px 16px;font-size:13px;font-weight:500;transition:background .15s,color .15s}.finish-button:hover{color:#fff;background:#dc2626}.finish-button:disabled{opacity:.5;cursor:not-allowed}.modal-overlay{z-index:100;background:#00000080;justify-content:center;align-items:center;display:flex;position:fixed;inset:0}.modal{background:var(--surface);border:1px solid var(--border);border-radius:12px;width:90%;max-width:420px;padding:32px}.modal h3{color:var(--text-h);margin-bottom:12px;font-size:18px}.modal p{color:var(--text);margin-bottom:24px;font-size:14px;line-height:1.5}.modal-actions{justify-content:flex-end;gap:12px;display:flex}.modal-cancel{border:1px solid var(--border);cursor:pointer;color:var(--text);background:0 0;border-radius:8px;padding:10px 20px;font-size:14px}.modal-cancel:hover{background:var(--bg)}.modal-confirm{color:#fff;cursor:pointer;background:#dc2626;border:none;border-radius:8px;padding:10px 20px;font-size:14px}.modal-confirm:hover{background:#b91c1c}.modal-confirm:disabled,.modal-cancel:disabled{opacity:.5;cursor:not-allowed}.no-session-container{justify-content:center;align-items:center;min-height:100vh;padding:20px;display:flex}.no-session-card{background:var(--surface);border:1px solid var(--border);text-align:center;border-radius:12px;width:100%;max-width:480px;padding:40px}.no-session-card h1{color:var(--text-h);margin-bottom:16px;font-size:24px}.no-session-card p{color:var(--text);font-size:15px;line-height:1.5}.thankyou-container{justify-content:center;align-items:center;min-height:100vh;padding:20px;display:flex}.thankyou-card{background:var(--surface);border:1px solid var(--border);text-align:center;border-radius:12px;width:100%;max-width:480px;padding:40px}.thankyou-card h1{color:var(--text-h);margin-bottom:16px;font-size:24px}.thankyou-card p{color:var(--text);margin-bottom:8px;font-size:15px;line-height:1.6}.survey-container{flex-direction:column;align-items:center;min-height:100vh;padding:20px;display:flex}.survey-card{background:var(--surface);border:1px solid var(--border);border-radius:12px;width:100%;max-width:680px;margin:20px 0;padding:40px}.survey-card h1{color:var(--text-h);margin-bottom:8px;font-size:24px}.survey-intro{color:var(--text);margin-bottom:32px;font-size:14px;line-height:1.5}.survey-section{border-bottom:1px solid var(--border);margin-bottom:32px;padding-bottom:24px}.survey-section:last-of-type{border-bottom:none}.survey-section h2{color:var(--text-h);margin-bottom:16px;font-size:17px}.section-note{color:var(--text);margin-bottom:16px;font-size:13px;font-style:italic;line-height:1.5}.survey-question{margin-bottom:24px}.survey-question>label{color:var(--text-h);margin-bottom:12px;font-size:14px;font-weight:500;line-height:1.5;display:block}.survey-question.conditional{border-left:2px solid var(--primary);margin-left:16px;padding-left:16px}.survey-error{background:#fef2f2;border:1px solid #fca5a5;border-radius:8px;padding:12px}.session-code-display{color:var(--text);background:var(--bg);font-size:15px;font-family:var(--mono);border-radius:8px;padding:12px 16px}.likert-group{flex-direction:column;gap:6px;display:flex}.likert-option{border:1px solid var(--border);cursor:pointer;border-radius:8px;align-items:center;gap:10px;padding:8px 12px;font-size:14px;transition:border-color .15s,background .15s;display:flex}.likert-option:hover{border-color:var(--primary);background:#2563eb08}.likert-option.selected{border-color:var(--primary);background:#2563eb0f}.likert-option input[type=radio]{accent-color:var(--primary);flex-shrink:0;width:16px;height:16px}.likert-number{color:var(--text-h);min-width:16px;font-weight:600}.likert-label{color:var(--text)}.radio-group{flex-direction:column;gap:6px;display:flex}.radio-option{border:1px solid var(--border);cursor:pointer;color:var(--text);border-radius:8px;align-items:flex-start;gap:10px;padding:10px 12px;font-size:14px;line-height:1.4;transition:border-color .15s,background .15s;display:flex}.radio-option:hover{border-color:var(--primary);background:#2563eb08}.radio-option.selected{border-color:var(--primary);background:#2563eb0f}.radio-option input[type=radio]{accent-color:var(--primary);flex-shrink:0;width:16px;height:16px;margin-top:2px}.survey-question textarea{border:1px solid var(--border);width:100%;font-size:14px;font-family:var(--sans);resize:vertical;border-radius:8px;min-height:60px;padding:10px 14px}.survey-question textarea:focus{outline:2px solid var(--primary);border-color:#0000}.survey-select{border:1px solid var(--border);width:100%;font-size:14px;font-family:var(--sans);background:var(--surface);color:var(--text);cursor:pointer;border-radius:8px;padding:10px 14px}.survey-select:focus{outline:2px solid var(--primary);border-color:#0000}.survey-validation-message,.survey-submit-error{color:#dc2626;text-align:center;margin-bottom:12px;font-size:14px}.survey-submit{background:var(--primary);color:#fff;cursor:pointer;border:none;border-radius:8px;width:100%;padding:14px;font-size:16px;font-weight:500}.survey-submit:hover{background:var(--primary-hover)}.survey-submit:disabled{opacity:.5;cursor:not-allowed}