:root{--bg:#f8fafc;--panel:#ffffff;--border:#e2e8f0;--text:#0f172a;--muted:#64748b;--primary:#2563eb;--primary-text:#ffffff;--inbound:#dbeafe;--outbound:#f1f5f9;--note:#fef3c7;--error:#fee2e2;--error-text:#991b1b}*{box-sizing:border-box}body,html{margin:0;padding:0;background:var(--bg);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;font-size:14px;line-height:1.5;height:100%}body{min-height:100vh}a{color:var(--primary);text-decoration:none}a:hover{text-decoration:underline}button{font:inherit;cursor:pointer}input,textarea{font:inherit;color:inherit}.btn{background:var(--primary);color:var(--primary-text);border:0;padding:8px 14px;border-radius:6px;font-weight:500}.btn:hover{filter:brightness(1.1)}.btn:disabled{opacity:.5;cursor:not-allowed}.btn-secondary{color:var(--text)}.btn-secondary,.input,.textarea{background:var(--panel);border:1px solid var(--border)}.input,.textarea{width:100%;padding:8px 10px;border-radius:6px}.input:focus,.textarea:focus{outline:none;border-color:var(--primary);box-shadow:0 0 0 3px rgba(37,99,235,.1)}.error{background:var(--error);color:var(--error-text);padding:8px 12px;border-radius:6px;font-size:13px}.layout{display:grid;grid-template-columns:280px 1fr;height:100vh}.sidebar{border-right:1px solid var(--border);background:var(--panel);overflow-y:auto}.sidebar-header{padding:16px;display:flex;justify-content:space-between;align-items:center;font-weight:600}.conversation-item,.sidebar-header{border-bottom:1px solid var(--border)}.conversation-item{display:block;padding:12px 16px;text-decoration:none;color:inherit}.conversation-item.active,.conversation-item:hover{background:var(--bg);text-decoration:none}.conversation-item-title{font-weight:500;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.conversation-item-meta{font-size:12px;color:var(--muted);margin-top:2px}.main{display:flex;flex-direction:column;height:100vh}.thread{flex:1 1;overflow-y:auto;padding:24px;display:flex;flex-direction:column;gap:12px}.thread-empty{color:var(--muted);text-align:center;margin-top:64px}.message{max-width:70%;padding:10px 14px;border-radius:12px;word-wrap:break-word}.message-inbound{align-self:flex-start;background:var(--inbound)}.message-outbound{align-self:flex-end;background:var(--outbound)}.message-note{align-self:stretch;background:var(--note);border:1px dashed #d97706}.message-meta{font-size:11px;color:var(--muted);margin-top:4px}.message-status-draft{border:2px dashed var(--primary);background:#eff6ff}.composer{border-top:1px solid var(--border);background:var(--panel);padding:12px;display:flex;flex-direction:column;gap:8px}.composer-row{display:flex;gap:8px;align-items:flex-end}.composer textarea{flex:1 1;resize:vertical;min-height:60px;max-height:200px}.composer-toolbar{gap:8px;font-size:12px;color:var(--muted)}.composer-toolbar,.login-page{display:flex;align-items:center}.login-page{min-height:100vh;justify-content:center;background:var(--bg)}.login-card{background:var(--panel);border:1px solid var(--border);border-radius:12px;padding:32px;width:360px;max-width:90vw}.login-card h1{margin-top:0}.login-card form{display:flex;flex-direction:column;gap:12px}.empty-state{display:flex;align-items:center;justify-content:center;height:100%;color:var(--muted)}