:root {
    --gold:       #b8860b;
    --gold-light: #d4a843;
    --gold-pale:  #f5e6c8;
    --bg-0:       #faf8f5;
    --bg-1:       #ffffff;
    --bg-2:       #f6f3ee;
    --text-0:     #1a1612;
    --text-1:     #4a433a;
    --text-2:     #8a8279;
    --text-3:     #b5afa6;
    --border:     #e8e2d8;
    --border-light:#f0ece4;
    --danger:     #c0392b;
    --success:    #27ae60;
    --shadow-xs:  0 1px 2px rgba(80,60,40,0.05);
    --shadow-sm:  0 3px 10px rgba(80,60,40,0.08),0 1px 3px rgba(80,60,40,0.05);
    --shadow:     0 8px 20px rgba(80,60,40,0.1),0 2px 6px rgba(80,60,40,0.06);
    --shadow-lg:  0 14px 30px rgba(80,60,40,0.13),0 4px 12px rgba(80,60,40,0.08);
    --shadow-card:0 8px 20px rgba(80,60,40,0.08);
    --radius-sm:  4px;
    --radius:     8px;
    --radius-lg:  14px;
    --radius-xl:  20px;
    --font-display:'Noto Serif SC','Georgia',serif;
    --font-body:  'DM Sans',-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;
    --ease-out:   cubic-bezier(0.16,1,0.3,1);
    --sidebar-w:  280px;
}

html,body{height:100%}
body{
    font-family:var(--font-body);font-size:14px;
    background:
        radial-gradient(circle at top left,rgba(184,134,11,0.12),transparent 24%),
        radial-gradient(circle at top right,rgba(184,134,11,0.06),transparent 22%),
        linear-gradient(180deg,#faf8f5 0%,#f0ece4 100%);
    color:var(--text-0);line-height:1.65;-webkit-font-smoothing:antialiased;overflow:hidden;
}

/* ===== 侧边栏 ===== */
.sidebar{
    position:fixed;top:0;left:0;bottom:0;width:var(--sidebar-w);
    background:var(--bg-1);border-right:1px solid var(--border);
    display:flex;flex-direction:column;z-index:1000;
    transform:translateX(-100%);transition:transform 0.3s var(--ease-out);
}
.sidebar.open{transform:translateX(0)}
.sidebar-overlay{
    position:fixed;inset:0;background:rgba(0,0,0,0.3);z-index:999;
    opacity:0;pointer-events:none;transition:opacity 0.3s;
}
.sidebar-overlay.active{opacity:1;pointer-events:auto}

.sidebar-header{display:flex;align-items:center;justify-content:space-between;padding:16px 16px 12px;border-bottom:1px solid var(--border-light)}
.sidebar-brand{display:flex;align-items:center;gap:8px}
.brand-mark-sm{
    width:28px;height:28px;border-radius:6px;
    background:linear-gradient(135deg,var(--gold),var(--gold-light));
    display:flex;align-items:center;justify-content:center;
    color:#fff;font-weight:700;font-size:13px;
}
.sidebar-title{font-weight:600;font-size:15px;color:var(--text-0)}
.sidebar-close-btn{background:none;border:none;cursor:pointer;color:var(--text-2);padding:4px;border-radius:4px;display:flex;align-items:center}
.sidebar-close-btn:hover{background:var(--bg-2);color:var(--text-0)}

.new-chat-btn{
    margin:12px 16px 8px;padding:10px 14px;
    border:1.5px dashed var(--border);border-radius:var(--radius);
    background:transparent;color:var(--text-1);font-size:13px;font-weight:500;
    cursor:pointer;display:flex;align-items:center;gap:6px;transition:all 0.2s;
}
.new-chat-btn:hover{border-color:var(--gold);color:var(--gold);background:var(--gold-pale)}

.sidebar-sessions{flex:1;overflow-y:auto;padding:8px 12px}
.sidebar-sessions::-webkit-scrollbar{width:4px}
.sidebar-sessions::-webkit-scrollbar-thumb{background:var(--border);border-radius:4px}

.session-item{
    padding:10px 12px;border-radius:var(--radius);cursor:pointer;
    transition:all 0.15s;margin-bottom:2px;display:flex;align-items:flex-start;gap:8px;
}
.session-item:hover{background:var(--bg-2)}
.session-item.active{background:var(--gold-pale);border:1px solid rgba(184,134,11,0.2)}
.session-icon{
    width:20px;height:20px;border-radius:4px;background:var(--bg-2);
    display:flex;align-items:center;justify-content:center;
    font-size:10px;color:var(--text-2);flex-shrink:0;margin-top:1px;
}
.session-item.active .session-icon{background:var(--gold);color:#fff}
.session-info{flex:1;min-width:0}
.session-title{font-size:13px;font-weight:500;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;color:var(--text-0)}
.session-meta{font-size:11px;color:var(--text-3);margin-top:2px}
.session-delete{opacity:0;background:none;border:none;color:var(--text-3);cursor:pointer;padding:2px;border-radius:3px;flex-shrink:0}
.session-item:hover .session-delete{opacity:1}
.session-delete:hover{color:var(--danger);background:rgba(192,57,43,0.08)}

.sidebar-footer{padding:12px 16px;border-top:1px solid var(--border-light);display:flex;align-items:center;justify-content:space-between}
.sidebar-user{display:flex;align-items:center;gap:8px}
.user-avatar-sm{
    width:24px;height:24px;border-radius:50%;background:var(--gold-pale);
    display:flex;align-items:center;justify-content:center;font-size:11px;font-weight:600;color:var(--gold);
}
.logout-btn{background:none;border:none;cursor:pointer;color:var(--text-3);font-size:12px;padding:4px 8px;border-radius:4px}
.logout-btn:hover{color:var(--danger);background:rgba(192,57,43,0.08)}

/* ===== 主界面 ===== */
.shell{display:flex;flex-direction:column;height:100vh;overflow:hidden;transition:margin-left 0.3s var(--ease-out)}
.sidebar-toggle-btn{background:none;border:none;cursor:pointer;color:var(--text-2);padding:6px;border-radius:6px;display:flex;align-items:center;margin-right:4px}
.sidebar-toggle-btn:hover{background:var(--bg-2);color:var(--text-0)}

.header{display:flex;align-items:center;height:56px;flex-shrink:0;padding:0 16px;background:var(--bg-1);border-bottom:1px solid var(--border)}
.brand{display:flex;align-items:center;gap:10px}
.brand-mark{
    width:36px;height:36px;border-radius:10px;
    background:linear-gradient(135deg,var(--gold),var(--gold-light));
    display:flex;align-items:center;justify-content:center;
    color:#fff;font-family:var(--font-display);font-weight:700;font-size:17px;
}
.brand-text{display:flex;flex-direction:column}
.brand-name{font-weight:600;font-size:15px;color:var(--text-0);line-height:1.3}
.brand-sub{font-size:11px;color:var(--text-3);line-height:1.2}
.header-nav{margin-left:auto;display:flex;gap:4px}
.nav-link{
    display:flex;align-items:center;gap:5px;padding:6px 12px;border-radius:var(--radius);
    border:none;background:transparent;color:var(--text-2);font-size:12.5px;font-weight:500;
    cursor:pointer;transition:all .2s;font-family:var(--font-body);
}
.nav-link:hover{background:var(--bg-2);color:var(--text-0)}
.nav-link.active{background:var(--gold-pale);color:var(--gold)}

.main{flex:1;overflow-y:auto;padding:20px 0;scroll-behavior:smooth}
.main::-webkit-scrollbar{width:5px}
.main::-webkit-scrollbar-thumb{background:var(--border);border-radius:4px}

.welcome{max-width:560px;margin:60px auto;padding:0 20px;text-align:center;animation:fadeUp .6s var(--ease-out)}
@keyframes fadeUp{from{opacity:0;transform:translateY(16px)}to{opacity:1;transform:none}}
.welcome-icon{
    width:72px;height:72px;margin:0 auto 20px;border-radius:20px;
    background:linear-gradient(135deg,var(--gold),var(--gold-light));
    display:flex;align-items:center;justify-content:center;
    color:#fff;font-family:var(--font-display);font-weight:700;font-size:32px;
    box-shadow:0 8px 24px rgba(184,134,11,0.25);
}
.welcome-title{font-family:var(--font-display);font-size:22px;font-weight:600;margin-bottom:8px}
.welcome-desc{color:var(--text-2);font-size:14px;margin-bottom:28px}
.welcome-cards{display:grid;grid-template-columns:1fr 1fr;gap:10px;text-align:left}
.welcome-card{
    padding:14px;border-radius:var(--radius-lg);background:var(--bg-1);
    border:1px solid var(--border-light);cursor:pointer;transition:all .2s;
    display:flex;align-items:flex-start;gap:8px;
}
.welcome-card:hover{border-color:var(--gold);box-shadow:var(--shadow-sm);transform:translateY(-1px)}
.wc-icon{
    width:26px;height:26px;border-radius:6px;flex-shrink:0;
    background:var(--gold-pale);color:var(--gold);
    display:flex;align-items:center;justify-content:center;font-size:12px;font-weight:700;
}
.wc-text{font-size:12.5px;color:var(--text-1);line-height:1.4}

/* 消息气泡 */
.msg{max-width:720px;margin:0 auto 16px;padding:0 20px;display:flex;gap:10px;animation:msgIn .35s var(--ease-out)}
@keyframes msgIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}
.msg-avatar{width:32px;height:32px;border-radius:8px;flex-shrink:0;display:flex;align-items:center;justify-content:center;font-size:13px;font-weight:700}
.msg.user .msg-avatar{background:var(--gold-pale);color:var(--gold)}
.msg.ai .msg-avatar{background:linear-gradient(135deg,var(--gold),var(--gold-light));color:#fff}
.msg-body{flex:1;min-width:0}
.msg-name{font-size:11px;color:var(--text-3);margin-bottom:3px;font-weight:500}
.msg-content{padding:12px 16px;border-radius:var(--radius-lg);font-size:14px;line-height:1.7;white-space:pre-wrap;word-break:break-word}
.msg.user .msg-content{background:var(--gold-pale);color:var(--text-0);border-bottom-left-radius:4px}
.msg.ai .msg-content{background:var(--bg-1);color:var(--text-0);border:1px solid var(--border-light);border-bottom-right-radius:4px;white-space:normal}

/* 思维过程 */
.thinking-step{display:flex;align-items:center;gap:8px;padding:6px 0;font-size:13px;color:var(--text-2)}
.thinking-dot{width:6px;height:6px;border-radius:50%;background:var(--gold-light);animation:pulse 1.2s infinite}
@keyframes pulse{0%,100%{opacity:.4}50%{opacity:1}}
.thinking-step.done .thinking-dot{background:var(--success);animation:none}

.positive-voice{
    padding:8px 14px;margin:4px 0;border-radius:var(--radius);
    background:linear-gradient(135deg,rgba(39,174,96,0.08),rgba(39,174,96,0.03));
    border:1px solid rgba(39,174,96,0.15);color:var(--success);font-weight:500;font-size:13.5px;
    animation:fadeUp .4s var(--ease-out);
}

.sources{display:flex;flex-wrap:wrap;gap:4px;margin-top:8px}
.source-tag{padding:2px 8px;border-radius:10px;font-size:11px;background:var(--bg-2);color:var(--text-2);border:1px solid var(--border-light)}

/* 输入区 */
.footer{flex-shrink:0;padding:12px 20px 20px;background:transparent}
.input-row{display:flex;justify-content:center;margin-bottom:6px}
.topic-badge{display:flex;align-items:center;gap:4px;padding:3px 10px;border-radius:10px;background:var(--gold-pale);color:var(--gold);font-size:11px;font-weight:500}
.topic-clear{background:none;border:none;color:var(--gold);cursor:pointer;font-size:14px;padding:0 2px}
.input-bar{
    max-width:720px;margin:0 auto;display:flex;align-items:flex-end;gap:8px;
    padding:8px 12px;background:var(--bg-1);border:1px solid var(--border);
    border-radius:var(--radius-lg);box-shadow:var(--shadow-sm);transition:border-color .2s;
}
.input-bar:focus-within{border-color:var(--gold)}
.input-bar textarea{flex:1;border:none;outline:none;resize:none;font-family:var(--font-body);font-size:14px;line-height:1.5;color:var(--text-0);background:transparent;max-height:120px;min-height:20px}
.input-bar textarea::placeholder{color:var(--text-3)}
.input-bar button{width:36px;height:36px;border-radius:10px;border:none;background:linear-gradient(135deg,var(--gold),var(--gold-light));color:#fff;cursor:pointer;display:flex;align-items:center;justify-content:center;transition:transform .15s,box-shadow .15s;flex-shrink:0}
.input-bar button:hover{transform:scale(1.05);box-shadow:0 4px 12px rgba(184,134,11,0.3)}
.input-bar button:disabled{opacity:.4;cursor:not-allowed;transform:none;box-shadow:none}

/* 认证弹窗 */
.auth-modal{position:fixed;inset:0;display:flex;align-items:center;justify-content:center;background:rgba(0,0,0,0.4);z-index:2000;backdrop-filter:blur(4px)}
.auth-card{width:380px;max-width:90vw;background:var(--bg-1);border-radius:var(--radius-xl);box-shadow:var(--shadow-lg);padding:32px}
.auth-header{text-align:center;margin-bottom:24px}
.auth-avatar{width:56px;height:56px;border-radius:16px;margin:0 auto 12px;background:linear-gradient(135deg,var(--gold),var(--gold-light));display:flex;align-items:center;justify-content:center;color:#fff;font-family:var(--font-display);font-weight:700;font-size:24px}
.auth-header h2{font-family:var(--font-display);font-size:18px;margin-bottom:4px}
.auth-header p{color:var(--text-2);font-size:13px}
.auth-tabs{display:flex;gap:0;margin-bottom:20px;border-radius:var(--radius);overflow:hidden;border:1px solid var(--border)}
.auth-tab{flex:1;padding:10px;border:none;background:var(--bg-2);font-size:13px;font-weight:500;cursor:pointer;color:var(--text-2);transition:all .2s;font-family:var(--font-body)}
.auth-tab.active{background:var(--gold);color:#fff}
.auth-field{margin-bottom:14px}
.auth-field label{display:block;font-size:12px;font-weight:500;color:var(--text-2);margin-bottom:4px}
.auth-field input{width:100%;padding:10px 12px;border:1px solid var(--border);border-radius:var(--radius);font-size:14px;transition:border-color .2s;box-sizing:border-box}
.auth-field input:focus{outline:none;border-color:var(--gold)}
.auth-error{padding:8px 12px;border-radius:var(--radius);background:rgba(192,57,43,0.08);color:var(--danger);font-size:12px;margin-bottom:10px}
.auth-submit{width:100%;padding:12px;border:none;border-radius:var(--radius);background:linear-gradient(135deg,var(--gold),var(--gold-light));color:#fff;font-size:14px;font-weight:600;cursor:pointer;transition:all .2s;font-family:var(--font-body)}
.auth-submit:hover{box-shadow:0 4px 12px rgba(184,134,11,0.3)}
.auth-submit:disabled{opacity:.5;cursor:not-allowed}

/* 等待动画 */
.typing-indicator{display:flex;gap:4px;padding:4px 0}
.typing-indicator span{width:6px;height:6px;border-radius:50%;background:var(--text-3);animation:typingBounce 1.2s infinite}
.typing-indicator span:nth-child(2){animation-delay:.2s}
.typing-indicator span:nth-child(3){animation-delay:.4s}
@keyframes typingBounce{0%,60%,100%{transform:translateY(0)}30%{transform:translateY(-6px)}}

/* ===== 移动端适配 ===== */
@media(max-width:768px){
    .header{padding:0 10px}
    .brand-text .brand-sub{display:none}
    .header-nav .nav-link span{display:none}
    .header-nav .nav-link{padding:8px}
    .msg{padding:0 12px}
    .welcome{margin:30px auto;padding:0 16px}
    .welcome-cards{grid-template-columns:1fr}
    .footer{padding:8px 12px 16px}
    .sidebar{width:85vw;max-width:320px}
    .sidebar-toggle-btn{margin-right:2px}
}
@media(max-width:480px){
    .welcome-icon{width:56px;height:56px;font-size:24px;border-radius:16px}
    .welcome-title{font-size:18px}
    .msg-content{padding:10px 12px;font-size:13.5px}
    .auth-card{padding:24px 20px}
}


/* ========== Markdown 渲染样式 ========== */
.msg-content h1, .msg-content h2, .msg-content h3,
.msg-content h4, .msg-content h5, .msg-content h6 {
    margin: 0.8em 0 0.4em 0;
    font-weight: 600;
    line-height: 1.4;
}
.msg-content h1 { font-size: 1.4em; color: var(--primary); }
.msg-content h2 { font-size: 1.25em; color: var(--primary); border-bottom: 1px solid rgba(212,175,55,0.2); padding-bottom: 0.3em; }
.msg-content h3 { font-size: 1.1em; color: var(--text); }

.msg-content p { margin: 0.5em 0; line-height: 1.7; }

.msg-content ul, .msg-content ol { margin: 0.5em 0; padding-left: 1.5em; }
.msg-content li { margin: 0.25em 0; line-height: 1.6; }
.msg-content li::marker { color: var(--gold); }

.msg-content strong { color: var(--primary); font-weight: 600; }
.msg-content em { font-style: italic; color: var(--gold); }

.msg-content table {
    width: 100%;
    border-collapse: collapse;
    margin: 0.8em 0;
    font-size: 0.9em;
}
.msg-content thead { background: rgba(212,175,55,0.1); }
.msg-content th, .msg-content td {
    border: 1px solid rgba(212,175,55,0.2);
    padding: 0.5em 0.8em;
    text-align: left;
}
.msg-content th { font-weight: 600; color: var(--primary); }
.msg-content tr:nth-child(even) { background: rgba(0,0,0,0.02); }

.msg-content blockquote {
    border-left: 3px solid var(--gold);
    margin: 0.8em 0;
    padding: 0.3em 1em;
    background: rgba(212,175,55,0.05);
    color: var(--text-secondary);
}

.msg-content code {
    background: rgba(212,175,55,0.1);
    padding: 0.15em 0.4em;
    border-radius: 3px;
    font-size: 0.88em;
    font-family: 'Menlo', 'Consolas', monospace;
}
.msg-content pre {
    background: rgba(0,0,0,0.04);
    padding: 1em;
    border-radius: 6px;
    overflow-x: auto;
    margin: 0.8em 0;
}
.msg-content pre code {
    background: none;
    padding: 0;
    font-size: 0.85em;
}

.msg-content hr {
    border: none;
    border-top: 1px solid rgba(212,175,55,0.2);
    margin: 1em 0;
}

.msg-content a {
    color: var(--gold);
    text-decoration: underline;
}


/* ========== Markdown Render Styles ========== */
.msg-content h1,.msg-content h2,.msg-content h3,.msg-content h4,.msg-content h5,.msg-content h6{margin:12px 0 6px;font-weight:700;line-height:1.4;color:var(--text-primary)}
.msg-content h1{font-size:1.4em;border-bottom:1px solid var(--border);padding-bottom:6px}
.msg-content h2{font-size:1.25em;border-bottom:1px solid var(--border);padding-bottom:4px}
.msg-content h3{font-size:1.1em}
.msg-content h4{font-size:1em}
.msg-content p{margin:6px 0;line-height:1.7}
.msg-content ul,.msg-content ol{margin:6px 0;padding-left:20px}
.msg-content li{margin:3px 0;line-height:1.7}
.msg-content strong{font-weight:700;color:var(--text-primary)}
.msg-content em{font-style:italic}
.msg-content blockquote{margin:8px 0;padding:8px 14px;border-left:4px solid var(--gold);background:rgba(212,168,83,0.08);border-radius:0 6px 6px 0;color:var(--text-secondary)}
.msg-content table{width:100%;border-collapse:collapse;margin:10px 0;font-size:.92em}
.msg-content thead{background:var(--bg-secondary)}
.msg-content th,.msg-content td{border:1px solid var(--border);padding:8px 12px;text-align:left}
.msg-content th{font-weight:700;color:var(--text-primary)}
.msg-content tr:nth-child(even){background:rgba(0,0,0,.02)}
.msg-content code{background:var(--bg-secondary);padding:2px 6px;border-radius:4px;font-size:.9em;font-family:'Courier New',monospace;color:#e74c3c}
.msg-content pre{background:var(--bg-secondary);padding:12px;border-radius:8px;overflow-x:auto;margin:8px 0}
.msg-content pre code{background:none;padding:0;color:var(--text-primary)}
.msg-content hr{border:none;border-top:1px solid var(--border);margin:12px 0}
.msg-content a{color:var(--gold);text-decoration:underline}
.thinking-answer h1,.thinking-answer h2,.thinking-answer h3,.thinking-answer h4,.thinking-answer h5,.thinking-answer h6{margin:10px 0 5px;font-weight:700;line-height:1.4;color:var(--text-primary)}
.thinking-answer h2{font-size:1.2em}
.thinking-answer h3{font-size:1.1em}
.thinking-answer p{margin:5px 0;line-height:1.7}
.thinking-answer ul,.thinking-answer ol{margin:5px 0;padding-left:18px}
.thinking-answer li{margin:2px 0;line-height:1.7}
.thinking-answer strong{font-weight:700;color:var(--text-primary)}
.thinking-answer blockquote{margin:8px 0;padding:6px 12px;border-left:4px solid var(--gold);background:rgba(212,168,83,0.08);border-radius:0 6px 6px 0}
.thinking-answer table{width:100%;border-collapse:collapse;margin:8px 0;font-size:.92em}
.thinking-answer thead{background:var(--bg-secondary)}
.thinking-answer th,.thinking-answer td{border:1px solid var(--border);padding:6px 10px;text-align:left}
.thinking-answer th{font-weight:700}
.thinking-answer tr:nth-child(even){background:rgba(0,0,0,.02)}
.thinking-answer code{background:var(--bg-secondary);padding:2px 5px;border-radius:4px;font-size:.9em}
.thinking-answer pre{background:var(--bg-secondary);padding:10px;border-radius:8px;overflow-x:auto;margin:6px 0}
.thinking-answer pre code{background:none;padding:0}