* { margin:0; padding:0; box-sizing:border-box; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif; background: #f1f4f9; display: flex; justify-content: center; align-items: center; min-height: 100vh; padding: 20px; margin:0; }
.chat-container { max-width:820px; width:100%; height:92vh; max-height:820px; background:#ffffff; border-radius:32px; box-shadow: 0 20px 60px rgba(0,0,0,0.06), 0 8px 24px rgba(0,0,0,0.02); display:flex; flex-direction:column; overflow:hidden; position:relative; }
.header { padding:20px 28px 14px 28px; border-bottom:1px solid #edf2f7; display:flex; justify-content:space-between; align-items:center; flex-shrink:0; }
.header-left { display:flex; align-items:center; gap:12px; }
.header-left h1 { font-weight:600; font-size:20px; letter-spacing:-0.3px; color:#0a0f1a; }
.header-left .badge { background:#eef2f6; color:#475569; font-size:11px; font-weight:500; padding:2px 12px; border-radius:20px; letter-spacing:0.3px; }
.header-right { display:flex; align-items:center; gap:16px; font-size:13px; color:#64748b; }
.header-right .status { display:flex; align-items:center; gap:6px; }
.status .dot { width:8px; height:8px; border-radius:50%; background:#94a3b8; display:inline-block; }
.status .dot.online { background:#22c55e; }
.status .dot.busy { background:#3b82f6; animation:pulse-dot 1.2s infinite; }
.status .dot.error { background:#ef4444; }
@keyframes pulse-dot { 0%,100%{opacity:1;transform:scale(1)} 50%{opacity:0.4;transform:scale(0.8)} }
.header-right .token-info { background:#f1f4f9; padding:2px 14px; border-radius:30px; font-feature-settings:"tnum"; }
.header-right .action-buttons { display:flex; gap:8px; }
.header-right .action-btn { background:transparent; border:1px solid #d1d9e6; border-radius:20px; padding:4px 12px; font-size:12px; color:#475569; cursor:pointer; transition:all 0.2s; }
.header-right .action-btn:hover { background:#f1f4f9; border-color:#94a3b8; }
.header-right .action-btn.clear { color:#dc2626; border-color:#fca5a5; }
.header-right .action-btn.clear:hover { background:#fee2e2; }
.messages { flex:1; overflow-y:auto; padding:20px 28px 12px 28px; display:flex; flex-direction:column; gap:20px; background:#fafbfc; }
.messages:empty::before { content:"发送你的问题，我将为你推理…"; color:#94a3b8; font-size:15px; text-align:center; padding:60px 0; width:100%; }
.message { display:flex; flex-direction:column; max-width:80%; animation:fadeIn 0.25s ease; }
.message.user { align-self:flex-end; }
.message.assistant { align-self:flex-start; }
.message.system { align-self:center; max-width:90%; }
.message.system .bubble { background:#f0f4ff; color:#1e293b; border:1px solid #c7d2fe; border-radius:12px; font-size:14px; text-align:center; opacity:0.9; box-shadow:0 2px 8px rgba(0,0,0,0.02); }
@keyframes fadeIn { from { opacity:0; transform:translateY(8px); } to { opacity:1; transform:translateY(0); } }
.message .bubble { padding:14px 20px; border-radius:20px; font-size:15px; line-height:1.6; word-break:break-word; box-shadow:0 2px 8px rgba(0,0,0,0.02); }
.message.user .bubble { background:#e9edf2; color:#1e293b; border-bottom-right-radius:6px; }
.message.assistant .bubble { background:#ffffff; color:#1e293b; border:1px solid #e2e8f0; border-bottom-left-radius:6px; box-shadow:0 4px 12px rgba(0,0,0,0.02); }
.message .meta { font-size:12px; color:#94a3b8; margin-top:4px; padding:0 4px; }
.message.user .meta { text-align:right; }
.step-list { margin-top:10px; border-top:1px dashed #e2e8f0; padding-top:10px; display:flex; flex-direction:column; gap:6px; }
.step-item { display:flex; flex-direction:column; gap:2px; }
.step-item .step-header { display:flex; align-items:center; gap:6px; cursor:pointer; padding:4px 0; font-weight:500; color:#334155; user-select:none; border-radius:4px; transition:background 0.1s; }
.step-item .step-header:hover { background:#f1f5f9; }
.step-item .step-arrow { display:inline-block; font-size:12px; transition:transform 0.2s ease; }
.step-item .step-content { padding:6px 12px; margin-left:24px; background:#f8fafc; border-left:2px solid #cbd5e1; border-radius:6px; font-size:14px; line-height:1.5; word-break:break-word; white-space:pre-wrap; overflow-x:auto; }
.step-item .step-content code { background:transparent; font-family:'Menlo','Consolas',monospace; font-size:13px; }
.step-item .icon { flex-shrink:0; font-size:14px; }
.step-item .content { word-break:break-word; line-height:1.5; }
.step-item .content .label { font-weight:500; color:#334155; margin-right:4px; }
.final-answer { font-weight:500; font-size:16px; color:#0f172a; background:#f1f5f9; padding:8px 16px; border-radius:12px; display:inline-block; margin-top:2px; }
.upload-area { display:flex; align-items:center; gap:12px; padding:4px 28px 4px 28px; border-bottom:1px solid #edf2f7; background:#fafbfc; flex-shrink:0; flex-wrap:wrap; }
.upload-btn { background:transparent; border:1px dashed #d1d9e6; border-radius:40px; padding:6px 16px; font-size:13px; color:#475569; cursor:pointer; transition:all 0.2s; display:flex; align-items:center; gap:6px; flex-shrink:0; }
.upload-btn:hover { border-color:#94a3b8; background:#f1f4f9; }
.upload-btn .icon { font-size:16px; }
.file-status-container { display:flex; flex-wrap:wrap; gap:8px; align-items:center; flex:1; min-width:0; }
.file-status-item { display:flex; align-items:center; gap:6px; background:#f1f4f9; padding:4px 10px 4px 6px; border-radius:20px; font-size:13px; color:#475569; border:1px solid #e2e8f0; flex-shrink:0; max-width:100%; }
.file-status-item .file-preview { width:28px; height:28px; border-radius:4px; object-fit:cover; border:1px solid #d1d9e6; flex-shrink:0; }
.file-status-item .file-name { max-width:120px; overflow:hidden; text-overflow:ellipsis; white-space:nowrap; }
.file-status-item .remove { cursor:pointer; color:#94a3b8; font-weight:bold; margin-left:4px; flex-shrink:0; }
.file-status-item .remove:hover { color:#dc2626; }
.file-more { background:#f1f4f9; border:1px solid #e2e8f0; border-radius:20px; padding:4px 12px; font-size:13px; color:#64748b; cursor:default; flex-shrink:0; }

/* ---------- 清除全部按钮（简约大气设计） ---------- */
.clear-all-btn {
    display: none;
    align-items: center;
    gap: 4px;
    background: transparent;
    border: 1px solid #d1d9e6;
    border-radius: 40px;
    padding: 5px 16px 5px 12px;
    font-size: 13px;
    font-weight: 450;
    color: #64748b;
    cursor: pointer;
    transition: all 0.25s ease;
    flex-shrink: 0;
    white-space: nowrap;
}
.clear-all-btn:hover {
    background: #fef2f2;
    border-color: #fca5a5;
    color: #dc2626;
}
.clear-all-btn:active {
    transform: scale(0.95);
}
.clear-all-btn .clear-icon {
    font-size: 14px;
    line-height: 1;
}
.clear-all-btn .clear-label {
    font-size: 13px;
}

.input-area { padding: 16px 28px 24px 28px; border-top: 1px solid #edf2f7; display: flex; gap: 12px; align-items: flex-end; flex-shrink: 0; background: #ffffff; }
.input-area textarea { flex: 1; padding: 12px 18px; border: 1.5px solid #e2e8f0; border-radius: 24px; font-size: 15px; background: #f8fafc; color: #1e293b; outline: none; resize: none; overflow: hidden; min-height: 48px; max-height: 200px; font-family: inherit; line-height: 1.5; transition: border 0.2s, box-shadow 0.2s; }
.input-area textarea:focus { border-color: #94a3b8; box-shadow: 0 0 0 4px rgba(148, 163, 184, 0.12); background: #ffffff; }
.input-area textarea::placeholder { color: #94a3b8; }
.input-area button { padding: 12px 32px; border: none; border-radius: 40px; background: #1e293b; color: #ffffff; font-weight: 500; font-size: 15px; cursor: pointer; transition: background 0.2s, transform 0.1s, box-shadow 0.2s; white-space: nowrap; letter-spacing: 0.3px; flex-shrink: 0; height: 48px; align-self: flex-end; }
.input-area button:hover { background: #0f172a; box-shadow: 0 8px 24px rgba(30, 41, 59, 0.12); }
.input-area button:active { transform: scale(0.97); }
.input-area button:disabled { opacity: 0.5; cursor: not-allowed; transform: none; box-shadow: none; }
.messages::-webkit-scrollbar { width:4px; }
.messages::-webkit-scrollbar-track { background:transparent; }
.messages::-webkit-scrollbar-thumb { background:#d1d9e6; border-radius:12px; }
.step-image { max-width: 200px; max-height: 200px; border-radius: 8px; margin-top: 4px; border: 1px solid #e2e8f0; display: block; }
#toast-container { position: fixed; top: 24px; right: 24px; z-index: 9999; display: flex; flex-direction: column; gap: 10px; max-width: 360px; }
.toast { background: #ffffff; color: #1e293b; padding: 14px 20px; border-radius: 16px; box-shadow: 0 12px 40px rgba(0,0,0,0.10), 0 4px 12px rgba(0,0,0,0.04); font-size: 14px; line-height: 1.5; opacity: 0; transform: translateX(40px); animation: toastIn 0.3s ease forwards; display: flex; align-items: center; gap: 10px; border-left: 4px solid #22c55e; }
.toast.error { border-left-color: #ef4444; }
.toast.info { border-left-color: #3b82f6; }
.toast .icon { font-size: 18px; flex-shrink: 0; }
.toast .close { margin-left: auto; cursor:pointer; color:#94a3b8; font-size:16px; background:transparent; border:none; }
.toast .close:hover { color:#475569; }
@keyframes toastIn { from { opacity:0; transform:translateX(40px); } to { opacity:1; transform:translateX(0); } }
@keyframes toastOut { from { opacity:1; transform:translateX(0); } to { opacity:0; transform:translateX(40px); } }
#confirm-overlay { position: fixed; inset: 0; background: rgba(0,0,0,0.30); backdrop-filter: blur(4px); display: none; align-items: center; justify-content: center; z-index: 10000; animation: overlayIn 0.2s ease; }
#confirm-overlay.active { display:flex; }
@keyframes overlayIn { from { opacity:0; } to { opacity:1; } }
.confirm-modal { background: #ffffff; border-radius: 28px; padding: 32px 36px 28px; max-width: 420px; width: 90%; box-shadow: 0 24px 80px rgba(0,0,0,0.20); animation: modalIn 0.25s ease; }
@keyframes modalIn { from { opacity:0; transform:scale(0.95) translateY(10px); } to { opacity:1; transform:scale(1) translateY(0); } }
.confirm-modal h3 { font-size:18px; font-weight:600; color:#0a0f1a; margin-bottom:8px; }
.confirm-modal p { font-size:15px; color:#475569; margin-bottom:24px; line-height:1.6; }
.confirm-buttons { display:flex; gap:12px; justify-content:flex-end; }
.confirm-buttons button { padding:8px 24px; border-radius:40px; font-size:14px; font-weight:500; cursor:pointer; border:none; transition:all 0.2s; }
.confirm-cancel { background:#f1f4f9; color:#475569; }
.confirm-cancel:hover { background:#e2e8f0; }
.confirm-ok { background:#dc2626; color:#ffffff; }
.confirm-ok:hover { background:#b91c1c; box-shadow:0 8px 20px rgba(220,38,38,0.25); }
@media (max-width:640px) {
    body { padding: 2px; }
    .chat-container { border-radius: 16px; height: 98vh; max-height: none; width: 100%; max-width: 100%; }
    .header { padding: 12px 14px 10px 14px; flex-wrap:wrap; gap:4px; }
    .header-left h1 { font-size:17px; }
    .header-right { font-size:11px; gap:6px; flex-wrap:wrap; }
    .header-right .action-buttons { gap:3px; }
    .header-right .action-btn { padding:2px 8px; font-size:11px; }
    .messages { padding:12px 14px 8px 14px; gap:14px; }
    .message { max-width:92%; }
    .message .bubble { font-size:14px; padding:10px 14px; }
    .input-area { padding: 10px 14px 16px 14px; gap: 8px; }
    .input-area textarea { font-size: 16px; padding: 10px 14px; min-height: 42px; border-radius: 20px; }
    .input-area button { font-size: 14px; padding: 10px 16px; height: 42px; }
    .upload-area { padding:4px 12px; gap:6px; flex-wrap:wrap; }
    .upload-btn { font-size:12px; padding:4px 12px; }
    .file-status-container { gap:4px; }
    .file-status-item { padding: 2px 6px 2px 4px; gap: 3px; font-size: 11px; border-radius: 14px; }
    .file-status-item .file-preview { width: 18px; height: 18px; border-radius: 3px; }
    .file-status-item .file-name { max-width: 50px; font-size: 11px; }
    .file-status-item .remove { font-size: 11px; margin-left: 2px; padding: 0 2px; }
    .file-more { padding: 2px 8px; font-size: 11px; border-radius: 14px; }
    /* 手机端清除全部按钮 - 更简约 */
    .clear-all-btn {
        padding: 3px 10px 3px 8px;
        font-size: 12px;
        border-radius: 30px;
        gap: 3px;
        background: #f8fafc;
        border-color: #e2e8f0;
        color: #94a3b8;
    }
    .clear-all-btn .clear-icon { font-size: 12px; }
    .clear-all-btn .clear-label { font-size: 12px; }
    .clear-all-btn:active {
        background: #fee2e2;
        border-color: #fca5a5;
        color: #dc2626;
    }
    #toast-container { top:8px; right:8px; max-width:260px; }
    .toast { padding:10px 14px; font-size:13px; }
    .confirm-modal { padding:20px 16px; }
    .step-item .step-content { font-size:13px; padding:4px 8px; margin-left:16px; }
}
@media (max-width:400px) {
    body { padding: 4px; }
    .chat-container { border-radius: 12px; height: 99vh; }
    .header-left h1 { font-size:16px; }
    .header .badge { font-size:10px; padding:0 8px; }
    .message .bubble { font-size:13px; padding:8px 12px; }
    .step-item { font-size:13px; }
    .file-status-item .file-name { max-width: 35px; }
    .input-area textarea { font-size:14px; padding:8px 12px; min-height:36px; }
    .input-area button { font-size:13px; padding:8px 12px; height:36px; }
    .clear-all-btn {
        padding: 2px 8px 2px 6px;
        font-size: 11px;
        border-radius: 24px;
    }
    .clear-all-btn .clear-icon { font-size: 11px; }
    .clear-all-btn .clear-label { font-size: 11px; }
}