:root{color-scheme:light;--bg:#ffffff;--sidebar:#171717;--sidebar-soft:#212121;--sidebar-hover:#2f2f2f;--panel:#ffffff;--surface:#f7f7f8;--ink:#202123;--muted:#6b7280;--line:#e5e7eb;--accent:#10a37f;--danger:#dc2626;--shadow:0 12px 36px rgba(0,0,0,0.10)}*{box-sizing:border-box}body,html{margin:0;min-height:100%;background:var(--bg);color:var(--ink);font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif}button,input,select,textarea{font:inherit}button{cursor:pointer}.app-shell{display:grid;grid-template-columns:280px minmax(0,1fr);height:100vh;overflow:hidden}.sidebar{display:flex;min-height:0;flex-direction:column;gap:14px;background:var(--sidebar);color:#f5f5f5;padding:12px}.brand-row{display:grid;grid-gap:10px;gap:10px}.brand-title{margin:6px 8px 0;font-size:18px;font-weight:700}.logout-button,.new-chat-button{display:flex;align-items:center;gap:10px;min-height:44px;border:1px solid rgba(255,255,255,.18);border-radius:8px;background:transparent;color:#f5f5f5;padding:0 12px;text-align:left}.logout-button:hover,.new-chat-button:hover{background:var(--sidebar-hover)}.account-panel{display:grid;grid-template-columns:36px minmax(0,1fr);align-items:center;grid-gap:10px;gap:10px;border-top:1px solid rgba(255,255,255,.1);padding:12px 8px 0}.account-avatar{display:grid;place-items:center;width:36px;height:36px;border-radius:8px;background:#303030;color:#f5f5f5}.account-meta{display:grid;min-width:0;grid-gap:2px;gap:2px}.account-label{color:#f5f5f5;font-size:13px}.account-email{overflow:hidden;color:#b4b4b4;font-size:12px;text-overflow:ellipsis;white-space:nowrap}.conversation-list{display:flex;flex:1 1;min-height:0;flex-direction:column;gap:4px;overflow:auto}.conversation-item{display:grid;grid-template-columns:minmax(0,1fr) 32px;align-items:center;grid-gap:6px;gap:6px;min-height:42px;border:0;border-radius:8px;background:transparent;color:#ececec;padding:0 6px 0 12px;text-align:left}.conversation-item.active,.conversation-item:hover{background:var(--sidebar-soft)}.conversation-title{overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:14px}.delete-chat-button{display:grid;place-items:center;width:30px;height:30px;border-radius:6px;color:#cfcfcf;opacity:0}.conversation-item:hover .delete-chat-button{opacity:1}.delete-chat-button:hover{background:rgba(255,255,255,.12);color:#ffffff}.main{display:grid;grid-template-rows:58px minmax(0,1fr) auto;min-width:0;height:100vh;background:var(--panel)}.topbar{display:flex;align-items:center;justify-content:space-between;gap:16px;border-bottom:1px solid var(--line);padding:0 24px}.mobile-menu-button{display:none;place-items:center;width:40px;height:40px;border:0;border-radius:8px;background:transparent;color:var(--ink)}.mobile-menu-button:hover{background:var(--surface)}.sidebar-backdrop{display:none}.login-input,.model-select{min-height:38px;border:1px solid var(--line);border-radius:8px;background:var(--panel);color:var(--ink);padding:0 12px}.model-select{width:min(340px,60vw)}.messages{display:flex;min-height:0;flex-direction:column;gap:0;overflow:auto}.empty-state{display:grid;place-items:center;height:100%;color:var(--ink);text-align:center}.empty-state h2{margin:0;font-size:30px;font-weight:600}.message{display:flex;justify-content:center;width:100%;padding:24px}.message.assistant{background:var(--surface);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}.bubble{position:relative;width:min(100%,780px);line-height:1.7;font-size:15px}.copy-message-button{position:absolute;top:-4px;right:0;display:inline-flex;align-items:center;gap:5px;height:30px;border:1px solid var(--line);border-radius:7px;background:rgba(255,255,255,.88);color:var(--muted);padding:0 9px;font-size:12px;opacity:0;transition:opacity .14s ease,background .14s ease,color .14s ease}.copy-message-button:focus-visible,.message.assistant:hover .copy-message-button{opacity:1}.copy-message-button:hover{background:#ffffff;color:var(--ink)}.bubble p:first-child{margin-top:0}.bubble p:last-child{margin-bottom:0}.bubble pre{overflow:auto;border-radius:8px;background:#0f172a;color:#f8fafc;padding:14px}.bubble code{font-family:Cascadia Code,SFMono-Regular,Consolas,monospace;font-size:.92em}.bubble .katex-display{overflow-x:auto;overflow-y:hidden;padding:4px 0}.attachments{display:flex;flex-wrap:wrap;gap:8px;margin-top:10px}.attachment-pill{display:inline-flex;align-items:center;gap:6px;max-width:260px;border:1px solid var(--line);border-radius:999px;background:#fff;color:var(--muted);padding:5px 9px;font-size:13px}.attachment-pill button{display:grid;place-items:center;width:18px;height:18px;border:0;border-radius:999px;background:transparent;color:var(--muted);padding:0}.attachment-pill button:hover{background:var(--line)}.image-attachment{display:grid;grid-gap:6px;gap:6px;width:min(220px,100%);margin:0}.image-attachment-button{display:block;border:0;background:transparent;padding:0;text-align:left}.image-attachment img{display:block;width:100%;max-height:180px;border:1px solid var(--line);border-radius:8px;object-fit:cover;background:#ffffff}.image-attachment-button:hover img{border-color:var(--accent)}.image-attachment figcaption{overflow:hidden;color:var(--muted);font-size:12px;line-height:1.35;text-overflow:ellipsis;white-space:nowrap}.image-preview-backdrop{position:fixed;inset:0;z-index:60;display:grid;place-items:center;background:rgba(0,0,0,.72);padding:24px}.image-preview-close{position:fixed;top:16px;right:16px;display:grid;place-items:center;width:40px;height:40px;border:0;border-radius:8px;background:rgba(255,255,255,.14);color:#ffffff}.image-preview-close:hover{background:rgba(255,255,255,.24)}.image-preview-frame{display:grid;grid-gap:10px;gap:10px;max-width:min(92vw,980px);max-height:90vh;margin:0}.image-preview-frame img{display:block;max-width:100%;max-height:calc(90vh - 40px);border-radius:8px;object-fit:contain;background:#ffffff}.image-preview-frame figcaption{overflow:hidden;color:#ffffff;font-size:13px;text-align:center;text-overflow:ellipsis;white-space:nowrap}.composer-wrap{background:linear-gradient(0deg,#ffffff 86%,rgba(255,255,255,0));padding:16px 24px 24px}.composer{width:min(100%,780px);margin:0 auto;border:1px solid #d9d9e3;border-radius:8px;background:var(--panel);box-shadow:var(--shadow)}.composer-attachments{margin:0;padding:12px 12px 0}.upload-status{color:var(--muted);font-size:13px;padding:10px 14px 0}.message-input{display:block;width:100%;min-height:78px;max-height:240px;border:0;outline:none;resize:vertical;background:transparent;color:var(--ink);padding:14px 52px 8px 14px}.message-input:disabled{cursor:not-allowed;color:var(--muted)}.composer-footer{display:flex;align-items:center;justify-content:space-between;gap:12px;min-height:48px;padding:8px 10px}.icon-button,.send-button,.upload-button{display:inline-grid;place-items:center;width:36px;height:36px;border:0;border-radius:8px;background:transparent;color:var(--muted);padding:0}.file-input-hidden{position:absolute;width:1px;height:1px;opacity:0;pointer-events:none}.upload-button{cursor:pointer;position:relative}.upload-button span{display:none}.icon-button:hover,.upload-button:hover{background:var(--surface);color:var(--ink)}.send-button{background:var(--ink);color:#ffffff}.send-button:disabled{cursor:not-allowed;background:#d1d5db}.error-line{overflow-wrap:anywhere;color:var(--danger)}.error-line,.sending-line{font-size:13px;white-space:normal}.sending-line{color:var(--muted);padding:0 14px 4px}.success-line{color:#047857;font-size:13px}.text-link{color:var(--muted);font-size:13px;text-align:center;text-decoration:none}.text-link:hover{color:var(--ink);text-decoration:underline}.auth-mode-row{display:flex;gap:14px;color:var(--muted);font-size:14px}.auth-mode-row label{display:inline-flex;align-items:center;gap:6px}.login-page{display:grid;place-items:center;min-height:100vh;background:var(--surface);padding:24px}.login-panel{width:min(100%,420px);border:1px solid var(--line);border-radius:8px;background:var(--panel);padding:26px;box-shadow:var(--shadow)}.login-panel h1{margin:0 0 18px;font-size:24px}.login-form{display:grid;grid-gap:12px;gap:12px}.primary-button{display:inline-flex;align-items:center;justify-content:center;min-height:40px;border:0;border-radius:8px;background:var(--ink);color:white;padding:0 14px}.modal-backdrop{position:fixed;inset:0;display:grid;place-items:center;background:rgba(0,0,0,.38);padding:20px;z-index:20}.password-modal{display:grid;grid-gap:12px;gap:12px;width:min(100%,420px);border-radius:8px;background:var(--panel);padding:18px;box-shadow:var(--shadow)}.modal-title-row{display:flex;align-items:center;justify-content:space-between;gap:12px}.modal-title-row h2{margin:0;font-size:18px}@media (max-width:860px){.app-shell{grid-template-columns:1fr}.sidebar{position:fixed;inset:0 auto 0 0;z-index:30;display:flex;width:min(86vw,310px);transform:translateX(-100%);transition:transform .18s ease;box-shadow:16px 0 36px rgba(0,0,0,.24)}.sidebar.open{transform:translateX(0)}.sidebar-backdrop{position:fixed;inset:0;z-index:25;display:block;border:0;background:rgba(0,0,0,.38);padding:0}.topbar{grid-template-columns:40px minmax(0,1fr);align-items:center;padding:12px 16px}.mobile-menu-button,.topbar{display:grid}.model-select{width:100%}.message{padding:18px 16px}.copy-message-button{position:static;margin:0 0 8px auto;opacity:1}.upload-button{grid-auto-flow:column;grid-auto-columns:max-content;gap:6px;width:auto;min-width:76px;padding:0 10px}.upload-button span{display:inline;font-size:14px}.composer-wrap{padding:12px}}