*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #0f0f0f;
  --sidebar-bg: #171717;
  --surface: #1e1e1e;
  --border: #2a2a2a;
  --text: #e8e8e8;
  --text-muted: #888;
  --accent: #cc0000;
  --accent-hover: #e60000;
  --user-bg: #1e1e1e;
  --model-bg: transparent;
  --tool-bg: #1a1a2e;
  --tool-text: #6c8ebf;
}

body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif; background: var(--bg); color: var(--text); height: 100vh; overflow: hidden; }

.hidden { display: none !important; }

/* Login */
.login-screen { display: flex; align-items: center; justify-content: center; height: 100vh; background: var(--bg); }
.login-box { background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 48px; width: 340px; text-align: center; }
.login-box h1 { font-size: 2rem; color: var(--accent); margin-bottom: 8px; }
.login-box p { color: var(--text-muted); margin-bottom: 32px; font-size: 0.9rem; }
.login-box input { width: 100%; padding: 12px 16px; border-radius: 8px; border: 1px solid var(--border); background: var(--bg); color: var(--text); font-size: 1rem; margin-bottom: 12px; }
.login-box button { width: 100%; padding: 12px; background: var(--accent); color: white; border: none; border-radius: 8px; font-size: 1rem; cursor: pointer; font-weight: 600; }
.login-box button:hover { background: var(--accent-hover); }
.error { color: #ff6b6b; font-size: 0.875rem; margin-top: 8px; }

/* App layout */
.app { display: flex; height: 100vh; }

/* Sidebar */
.sidebar { width: 260px; background: var(--sidebar-bg); border-right: 1px solid var(--border); display: flex; flex-direction: column; flex-shrink: 0; }
.sidebar-header { padding: 20px 16px 12px; border-bottom: 1px solid var(--border); }
.logo { font-size: 1.1rem; font-weight: 700; color: var(--accent); }
.client-list { padding: 12px 8px 4px; }
.client-btn { width: 100%; padding: 10px 12px; background: transparent; border: 1px solid var(--border); border-radius: 8px; color: var(--text); cursor: pointer; text-align: left; font-size: 0.9rem; margin-bottom: 4px; transition: background 0.15s; }
.client-btn:hover, .client-btn.active { background: var(--surface); border-color: var(--accent); }
.sidebar-section-label { padding: 16px 16px 6px; font-size: 0.75rem; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.08em; }
.conversation-list { flex: 1; overflow-y: auto; padding: 0 8px; }
.conv-item { padding: 8px 12px; border-radius: 6px; cursor: pointer; font-size: 0.875rem; color: var(--text-muted); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; display: flex; justify-content: space-between; align-items: center; }
.conv-item:hover { background: var(--surface); color: var(--text); }
.conv-item.active { background: var(--surface); color: var(--text); }
.conv-delete { opacity: 0; font-size: 0.75rem; color: var(--text-muted); background: none; border: none; cursor: pointer; padding: 2px 4px; }
.conv-item:hover .conv-delete { opacity: 1; }
.new-chat-btn { margin: 12px 8px; padding: 10px; background: transparent; border: 1px dashed var(--border); border-radius: 8px; color: var(--text-muted); cursor: pointer; font-size: 0.875rem; }
.new-chat-btn:hover { border-color: var(--accent); color: var(--text); }

/* Chat panel */
.chat-panel { flex: 1; display: flex; flex-direction: column; overflow: hidden; }
.chat-header { padding: 16px 24px; border-bottom: 1px solid var(--border); font-weight: 600; color: var(--text-muted); font-size: 0.9rem; }
.messages { flex: 1; overflow-y: auto; padding: 24px; display: flex; flex-direction: column; gap: 0; }
.empty-state { margin: auto; text-align: center; color: var(--text-muted); }
.empty-state h2 { font-size: 1.4rem; margin-bottom: 8px; color: var(--text); }

/* Messages */
.message { padding: 20px 0; border-bottom: 1px solid var(--border); }
.message:last-child { border-bottom: none; }
.message.user .content { font-size: 1rem; color: var(--text); }
.message.model .content { font-size: 0.95rem; line-height: 1.7; }
.message .role-label { font-size: 0.75rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.06em; margin-bottom: 8px; }
.message.user .role-label { color: var(--text-muted); }
.message.model .role-label { color: var(--accent); }
.message .content p { margin-bottom: 12px; }
.message .content p:last-child { margin-bottom: 0; }
.message .content ul, .message .content ol { margin: 8px 0 12px 20px; }
.message .content code { background: var(--surface); padding: 2px 6px; border-radius: 4px; font-family: monospace; font-size: 0.875em; }
.message .content pre { background: var(--surface); padding: 16px; border-radius: 8px; overflow-x: auto; margin: 12px 0; }
.message .content pre code { background: none; padding: 0; }

/* Tool indicator */
.tool-indicator { display: flex; align-items: center; gap: 8px; padding: 8px 12px; background: var(--tool-bg); border-radius: 6px; font-size: 0.8rem; color: var(--tool-text); margin: 8px 0; }
.tool-indicator .spinner { width: 12px; height: 12px; border: 2px solid var(--tool-text); border-top-color: transparent; border-radius: 50%; animation: spin 0.8s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

/* Composer */
.composer { padding: 16px 24px 24px; border-top: 1px solid var(--border); display: flex; gap: 12px; align-items: flex-end; }
#message-input { flex: 1; padding: 12px 16px; background: var(--surface); border: 1px solid var(--border); border-radius: 10px; color: var(--text); font-size: 0.95rem; resize: none; max-height: 200px; line-height: 1.5; font-family: inherit; }
#message-input:focus { outline: none; border-color: var(--accent); }
#send-btn { padding: 12px 20px; background: var(--accent); color: white; border: none; border-radius: 10px; font-weight: 600; cursor: pointer; font-size: 0.9rem; white-space: nowrap; }
#send-btn:disabled { opacity: 0.4; cursor: not-allowed; }
#send-btn:not(:disabled):hover { background: var(--accent-hover); }

/* Scrollbar */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }