*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{
  --bg:#ffffff;--bg-2:#f6f7fb;--bg-3:#eceff5;--border:#dde1ea;
  --text:#1a1d24;--text-2:#525866;--text-3:#8b93a3;
  --accent:#5b3eff;--accent-2:#7c5cff;--accent-soft:rgba(91,62,255,.10);
  --error:#dc2952;--success:#16a34a;
  --shadow:0 1px 3px rgba(15,17,21,.06),0 4px 14px rgba(15,17,21,.05);
  --radius:10px;--radius-sm:6px;
}
html,body{height:100%}
body{
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  background:var(--bg);color:var(--text);font-size:14px;line-height:1.5;
  -webkit-font-smoothing:antialiased;
}
button{font:inherit;color:inherit;cursor:pointer;border:none;background:none}
input,textarea,select{font:inherit;color:inherit}
svg{width:20px;height:20px;flex-shrink:0}

/* ===== LOGIN ===== */
.login-page{display:flex;align-items:center;justify-content:center;min-height:100vh;
  background:radial-gradient(ellipse at top,rgba(124,92,255,.12),transparent 60%),var(--bg);padding:20px}
.login-container{width:100%;max-width:400px}
.login-card{background:#fff;border:1px solid var(--border);border-radius:16px;padding:36px 32px;
  box-shadow:var(--shadow)}
.logo{text-align:center;margin-bottom:28px}
.logo-icon{width:56px;height:56px;margin:0 auto 16px;display:flex;align-items:center;justify-content:center;
  background:linear-gradient(135deg,var(--accent),var(--accent-2));border-radius:14px;color:#fff}
.logo-icon svg{width:28px;height:28px}
.logo h1{font-size:24px;font-weight:600;margin-bottom:4px}
.logo p{color:var(--text-2);font-size:14px}
.login-form{display:flex;flex-direction:column;gap:16px}
.form-group{display:flex;flex-direction:column;gap:6px}
.form-group label{font-size:13px;color:var(--text-2);font-weight:500}
.form-group input{padding:11px 14px;background:#fff;border:1px solid var(--border);border-radius:var(--radius);
  color:var(--text);outline:none;transition:border-color .15s,box-shadow .15s}
.form-group input:focus{border-color:var(--accent);box-shadow:0 0 0 3px var(--accent-soft)}
.error-message{color:var(--error);font-size:13px;min-height:18px;opacity:0;transition:opacity .2s}
.error-message.show{opacity:1}
.btn-primary{padding:12px;background:linear-gradient(135deg,var(--accent),var(--accent-2));color:#fff;
  border-radius:var(--radius);font-weight:600;transition:transform .1s,filter .15s}
.btn-primary:hover{filter:brightness(1.08)}
.btn-primary:active{transform:scale(.98)}
.btn-primary:disabled{opacity:.6;cursor:not-allowed}
.login-footer{margin-top:24px;text-align:center;color:var(--text-3);font-size:12px}

/* ===== CHAT ===== */
.chat-page{overflow:hidden}
.app{display:flex;height:100vh}
.sidebar{width:280px;background:var(--bg-2);border-right:1px solid var(--border);
  display:flex;flex-direction:column;overflow-y:auto;flex-shrink:0;
  transition:margin-left .2s ease}
.app.sidebar-collapsed .sidebar{margin-left:-280px}
.sidebar-header{padding:14px 16px;display:flex;align-items:center;justify-content:space-between;
  border-bottom:1px solid var(--border)}
.logo-small{display:flex;align-items:center;gap:8px;font-weight:600}
.logo-small svg{width:22px;height:22px;color:var(--accent)}
.sidebar-section{padding:16px;border-bottom:1px solid var(--border)}
.sidebar-section h3{font-size:11px;font-weight:600;text-transform:uppercase;letter-spacing:.5px;
  color:var(--text-3);margin-bottom:10px}
.sidebar-footer{margin-top:auto;padding:16px;border-top:1px solid var(--border)}

.select-input,.text-input,.textarea-input{width:100%;padding:9px 12px;background:#fff;
  border:1px solid var(--border);border-radius:var(--radius-sm);color:var(--text);outline:none;
  font-size:13px;transition:border-color .15s,box-shadow .15s}
.select-input:focus,.text-input:focus,.textarea-input:focus{border-color:var(--accent);box-shadow:0 0 0 3px var(--accent-soft)}
.textarea-input{resize:vertical;min-height:60px;font-family:inherit}
.btn-secondary{padding:8px 12px;background:#fff;border:1px solid var(--border);
  border-radius:var(--radius-sm);color:var(--text);font-size:13px;display:inline-flex;align-items:center;
  justify-content:center;gap:6px;transition:background .15s,border-color .15s}
.btn-secondary:hover{background:var(--bg-2);border-color:var(--text-3)}
.btn-secondary svg{width:16px;height:16px}
.btn-small{padding:6px 10px;font-size:12px;width:100%}
.btn-icon{width:32px;height:32px;display:flex;align-items:center;justify-content:center;
  border-radius:var(--radius-sm);color:var(--text-2);transition:background .15s,color .15s}
.btn-icon:hover{background:var(--bg-3);color:var(--text)}
.btn-icon-small{width:32px;height:32px;display:flex;align-items:center;justify-content:center;
  background:#fff;border:1px solid var(--border);border-radius:var(--radius-sm);color:var(--text-2)}
.btn-icon-small svg{width:16px;height:16px}
.btn-icon-small:hover{color:var(--text)}
.hint{font-size:11px;color:var(--text-3);margin-top:6px}
.param-label{display:block;font-size:13px;color:var(--text-2);margin-bottom:10px}
.param-label span{display:flex;justify-content:space-between;margin-bottom:6px}
.range-input{width:100%;accent-color:var(--accent)}

/* ===== MAIN ===== */
.main{flex:1;display:flex;flex-direction:column;min-width:0;background:var(--bg)}
.main-header{padding:12px 20px;display:flex;align-items:center;justify-content:space-between;gap:12px;
  border-bottom:1px solid var(--border);background:#fff}
.model-badge{padding:5px 11px;background:var(--accent-soft);color:var(--accent);
  border-radius:999px;font-size:12px;font-weight:600}

.messages{flex:1;overflow-y:auto;padding:20px;display:flex;flex-direction:column;gap:16px}
.welcome{margin:auto;text-align:center;max-width:560px;padding:20px}
.welcome-icon{width:64px;height:64px;margin:0 auto 16px;display:flex;align-items:center;justify-content:center;
  background:linear-gradient(135deg,var(--accent),var(--accent-2));border-radius:16px;color:#fff;
  box-shadow:0 8px 24px rgba(91,62,255,.25)}
.welcome h2{font-size:24px;margin-bottom:6px}
.welcome p{color:var(--text-2);margin-bottom:24px}
.suggestions{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.suggestion-card{padding:14px;background:#fff;border:1px solid var(--border);
  border-radius:var(--radius);text-align:left;display:flex;flex-direction:column;gap:3px;
  transition:border-color .15s,box-shadow .15s,transform .1s}
.suggestion-card:hover{border-color:var(--accent);box-shadow:var(--shadow);transform:translateY(-1px)}
.suggestion-card span{font-weight:500;font-size:13px}
.suggestion-card small{color:var(--text-3);font-size:12px}

.message{display:flex;gap:12px;max-width:800px;width:100%;margin:0 auto;align-items:flex-start}
.message-avatar{width:30px;height:30px;border-radius:8px;display:flex;align-items:center;justify-content:center;
  flex-shrink:0;font-size:12px;font-weight:600}
.message.user .message-avatar{background:var(--bg-3);color:var(--text)}
.message.assistant .message-avatar{background:linear-gradient(135deg,var(--accent),var(--accent-2));color:#fff}
.message-body{flex:1;min-width:0}
.message-role{font-size:12px;color:var(--text-3);margin-bottom:4px;font-weight:500}
.message-content{white-space:pre-wrap;word-wrap:break-word;line-height:1.6;color:var(--text)}
.message-content code{background:var(--bg-3);padding:1px 5px;border-radius:4px;font-size:.9em;
  font-family:Consolas,Menlo,monospace;color:#9333ea}
.message-content pre{background:var(--bg-2);border:1px solid var(--border);padding:12px;border-radius:var(--radius);
  overflow-x:auto;margin:8px 0}
.message-content pre code{background:none;padding:0;color:var(--text)}
.message.error .message-content{color:var(--error)}
.typing{display:inline-flex;gap:4px;align-items:center}
.typing span{width:6px;height:6px;border-radius:50%;background:var(--text-3);animation:typing 1.2s infinite}
.typing span:nth-child(2){animation-delay:.2s}
.typing span:nth-child(3){animation-delay:.4s}
@keyframes typing{0%,60%,100%{opacity:.3;transform:translateY(0)}30%{opacity:1;transform:translateY(-3px)}}

.composer{padding:12px 20px 16px;border-top:1px solid var(--border);background:#fff}
.composer-inner{max-width:800px;margin:0 auto;display:flex;gap:8px;align-items:flex-end;
  background:#fff;border:1px solid var(--border);border-radius:14px;padding:8px;
  transition:border-color .15s,box-shadow .15s;box-shadow:var(--shadow)}
.composer-inner:focus-within{border-color:var(--accent);box-shadow:0 0 0 3px var(--accent-soft)}
#messageInput{flex:1;background:none;border:none;outline:none;color:var(--text);
  resize:none;padding:8px 10px;max-height:200px;line-height:1.5;font-family:inherit}
#messageInput::placeholder{color:var(--text-3)}
.btn-send{width:36px;height:36px;background:linear-gradient(135deg,var(--accent),var(--accent-2));
  color:#fff;border-radius:10px;display:flex;align-items:center;justify-content:center;
  transition:filter .15s,opacity .15s}
.btn-send:hover{filter:brightness(1.08)}
.btn-send:disabled{opacity:.4;cursor:not-allowed}
.btn-send svg{width:18px;height:18px}
.composer-hint{text-align:center;color:var(--text-3);font-size:11px;margin-top:6px}

/* scrollbar */
::-webkit-scrollbar{width:8px;height:8px}
::-webkit-scrollbar-track{background:transparent}
::-webkit-scrollbar-thumb{background:var(--border);border-radius:4px}
::-webkit-scrollbar-thumb:hover{background:var(--text-3)}

/* responsive */
@media (max-width:768px){
  .sidebar{position:fixed;left:0;top:0;bottom:0;z-index:10;background:#fff;margin-left:0;
    transition:transform .2s ease;transform:translateX(-100%)}
  .app.sidebar-collapsed .sidebar{margin-left:0;transform:translateX(-100%)}
  .app:not(.sidebar-collapsed) .sidebar{transform:translateX(0);box-shadow:0 0 40px rgba(15,17,21,.15)}
  .suggestions{grid-template-columns:1fr}
}