:root{--gap: 1.2rem;--radius: 8px;--shadow: rgba(0, 0, 0, .1);--color-bg: #fff;--color-fg: #333;--color-muted: #666;--header-height: auto}*{box-sizing:border-box;margin:0;padding:0}body{font-family:sans-serif;color:var(--color-fg);background:#f9f9f9;display:flex;justify-content:center;padding:var(--gap);min-height:100vh}#app{width:100%;max-width:1200px;display:flex;gap:var(--gap)}#heading-container{display:flex;align-items:flex-start;justify-content:space-between;flex-wrap:wrap;gap:var(--gap)}#instructions-container{flex:1 1 400px}#instructions-container h2{margin-bottom:.25em}#instructions{line-height:1.5;color:var(--color-muted);padding-top:1.5rem}#btn-container{display:flex;gap:.5rem}button{padding:.6rem 1.2rem;font-size:1rem;border:1px solid var(--color-fg);border-radius:var(--radius);background:var(--color-bg);color:var(--color-fg);cursor:pointer;transition:background-color .2s,color .2s;width:7rem}button:hover:not(:disabled),button:focus:not(:disabled){background:var(--color-fg);color:var(--color-bg)}button:disabled{background:#e0e0e0;color:var(--color-muted);border-color:#aaa;cursor:not-allowed}#chat{display:flex;flex-direction:column;gap:var(--gap);max-height:calc(100vh - 200px);overflow-y:auto;padding:1.5rem}.chat-card{background:var(--color-bg);border-radius:var(--radius);padding:1rem;box-shadow:0 4px 12px var(--shadow);position:relative;width:600px}.chat-card.assistant{align-self:flex-start}.chat-card.user{align-self:flex-end}.chat-card .role{font-weight:700;margin-bottom:.5rem}.chat-card .timestamp{position:absolute;top:.8rem;right:.8rem;font-size:.75rem;color:var(--color-muted)}.chat-card .content{margin-bottom:.75rem}.chat-card .scores{display:flex;gap:1rem;font-size:.8rem;color:var(--color-muted)}.chat-session{cursor:pointer;display:flex;flex-direction:column;gap:var(--gap);padding:1rem;border:1px solid var(--color-fg);border-radius:var(--radius);background:var(--color-bg);box-shadow:0 2px 6px var(--shadow);transition:background-color .2s,border-color .2s;margin:10px 0}#chat-history-sidebar{background:#f0f0f0;padding:1rem;border-radius:var(--radius);box-shadow:0 2px 6px var(--shadow);max-height:calc(100vh - 200px);overflow-y:auto}