*,*::before,*::after{margin:0;padding:0;box-sizing:border-box}
html,body{height:100%;font-family:-apple-system,'Microsoft YaHei','PingFang SC',sans-serif;background:linear-gradient(135deg,#f0f4f8 0%,#e8edf5 100%);color:#333;font-size:15px;line-height:1.6}

/* ===== 布局 ===== */
#app{display:flex;height:100vh;overflow:hidden}

/* ===== 左侧内容区 ===== */
#content-area{flex:1;overflow-y:auto;padding:32px 40px;min-width:0;background:rgba(255,255,255,.4)}
#content-area h1{font-size:22px;color:#2c3e50;margin-bottom:24px;padding-bottom:12px;border-bottom:2px solid #e8edf3;background:linear-gradient(90deg,#4A90D9,#357ABD);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}

/* 阶段 Tabs */
#stage-tabs{display:flex;gap:6px;margin-bottom:24px;flex-wrap:wrap}
.stage-tab{padding:10px 20px;border:2px solid #dce3ed;border-radius:10px;background:#fff;cursor:pointer;font-size:14px;font-weight:600;color:#5a6a7a;transition:all .3s cubic-bezier(.34,1.56,.64,1);position:relative;overflow:hidden}
.stage-tab::after{content:'';position:absolute;top:0;left:0;right:0;bottom:0;background:linear-gradient(135deg,#4A90D9,#357ABD);opacity:0;transition:opacity .3s;border-radius:8px}
.stage-tab:hover{border-color:#4A90D9;color:#4A90D9;background:#f5f9ff;transform:translateY(-2px);box-shadow:0 4px 12px rgba(74,144,217,.2)}
.stage-tab.active{background:#4A90D9;color:#fff;border-color:#4A90D9;box-shadow:0 4px 16px rgba(74,144,217,.4);transform:scale(1.03)}

/* 阶段内容面板 - 动画入场 */
.stage-panel{display:none}
.stage-panel.active{display:block;animation:panelEnter .5s cubic-bezier(.22,1,.36,1)}
@keyframes panelEnter{from{opacity:0;transform:translateY(16px) scale(.98)}to{opacity:1;transform:translateY(0) scale(1)}}

.stage-panel h2{font-size:19px;color:#2c3e50;margin-bottom:14px;animation:fadeSlideIn .4s ease}
.stage-panel p{margin-bottom:12px;color:#444;animation:fadeSlideIn .4s ease}
.stage-panel .highlight{background:linear-gradient(135deg,#fff8e1,#fff3cd);padding:16px 20px;border-radius:10px;border-left:4px solid #ffc107;margin:16px 0;animation:fadeSlideIn .5s ease;transition:transform .3s,box-shadow .3s}
.stage-panel .highlight:hover{transform:translateY(-2px);box-shadow:0 6px 20px rgba(255,193,7,.2)}
.stage-panel .highlight strong{color:#e67e22}
.stage-panel ul{padding-left:22px;margin:8px 0 16px}
.stage-panel ul li{margin:6px 0;animation:fadeSlideIn .4s ease}
.stage-panel .formula{background:linear-gradient(135deg,#eef5ff,#e3edfa);padding:14px 20px;border-radius:10px;border:1px solid #d0e1f9;text-align:center;font-size:17px;margin:12px 0;color:#2c3e50;animation:formulaGlow 3s ease-in-out infinite, fadeSlideIn .5s ease;position:relative;overflow:hidden}
.stage-panel .formula::before{content:'';position:absolute;top:-50%;left:-50%;width:200%;height:200%;background:radial-gradient(circle,rgba(74,144,217,.08) 0%,transparent 70%);animation:formulaShimmer 4s ease-in-out infinite}
.stage-panel .formula span{font-weight:700;color:#4A90D9;position:relative}
.stage-panel .tip{padding:14px 18px;background:linear-gradient(135deg,#e8f8f0,#d5f0e5);border-radius:8px;border-left:4px solid #2ecc71;color:#27ae60;margin:12px 0;animation:fadeSlideIn .6s ease}
.stage-panel .exercise{margin:12px 0;padding:16px;background:#fafbfc;border-radius:8px;border:1px solid #e8edf3;counter-increment:ex;animation:fadeSlideIn .5s ease;transition:transform .3s,box-shadow .3s}
.stage-panel .exercise:hover{transform:translateY(-2px);box-shadow:0 6px 20px rgba(0,0,0,.06)}
.stage-panel .exercise::before{content:'第 ' counter(ex) ' 题';font-weight:700;color:#4A90D9;display:block;margin-bottom:6px}
.stage-panel .example-box{background:#f5f7fe;border-radius:12px;padding:16px 20px;margin:16px 0;border:1px solid #dce5f5;animation:fadeSlideIn .4s ease;transition:transform .3s,box-shadow .3s}
.stage-panel .example-box:hover{transform:translateY(-2px);box-shadow:0 8px 24px rgba(0,0,0,.06)}
.stage-panel .example-box .calc-step{font-family:monospace;background:#eef2fa;padding:6px 12px;border-radius:8px;margin-top:8px;display:inline-block}

/* 入场动画关键帧 */
@keyframes fadeSlideIn{from{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}

/* 公式呼吸光效 */
@keyframes formulaGlow{0%,100%{box-shadow:0 0 0 0 rgba(74,144,217,.1),0 2px 8px rgba(0,0,0,.04)}50%{box-shadow:0 0 20px 4px rgba(74,144,217,.15),0 2px 8px rgba(0,0,0,.04)}}
@keyframes formulaShimmer{0%,100%{transform:translate(-50%,-50%) rotate(0deg)}50%{transform:translate(-50%,-50%) rotate(180deg)}}

/* ===== 3D CSS 立体方块 ===== */
.cube-3d{width:60px;height:60px;position:relative;transform-style:preserve-3d;animation:cubeSpin 8s ease-in-out infinite}
.cube-3d .face{position:absolute;width:60px;height:60px;border:2px solid rgba(74,144,217,.5);display:flex;align-items:center;justify-content:center;font-size:10px;font-weight:700;color:#4A90D9;backface-visibility:hidden}
.cube-3d .face.front{background:rgba(74,144,217,.2);transform:translateZ(30px)}
.cube-3d .face.back{background:rgba(74,144,217,.15);transform:rotateY(180deg) translateZ(30px)}
.cube-3d .face.right{background:rgba(74,144,217,.18);transform:rotateY(90deg) translateZ(30px)}
.cube-3d .face.left{background:rgba(74,144,217,.15);transform:rotateY(-90deg) translateZ(30px)}
.cube-3d .face.top{background:rgba(74,144,217,.22);transform:rotateX(90deg) translateZ(30px)}
.cube-3d .face.bottom{background:rgba(74,144,217,.15);transform:rotateX(-90deg) translateZ(30px)}
@keyframes cubeSpin{0%,100%{transform:rotateX(-20deg) rotateY(0deg)}50%{transform:rotateX(-20deg) rotateY(360deg)}}

/* Three.js canvas 容器统一样式 */
#app #three-container canvas, #app [id^="s1-"] canvas, #app [id^="s2-"] canvas{display:block;width:100%;height:100%}

/* 对话气泡入场 - 依次弹入 */
.dialogue-1{animation:fadeSlideIn .4s ease both;animation-delay:.2s}
.dialogue-2{animation:fadeSlideIn .4s ease both;animation-delay:.5s}

/* ===== 虚拟形象 ===== */
#avatar-btn{position:fixed;bottom:28px;right:28px;width:68px;height:68px;border-radius:50%;cursor:pointer;z-index:9999;box-shadow:0 4px 16px rgba(74,144,217,.35);transition:opacity .3s,transform .3s;border:3px solid #fff;overflow:hidden;background:linear-gradient(145deg,#4A90D9,#357ABD)}
#avatar-btn img{width:100%;height:100%;object-fit:cover;display:block}
#avatar-btn.hidden{opacity:0;pointer-events:none;transform:scale(.6)}

/* ===== 侧边栏 ===== */
#chat-sidebar{position:fixed;bottom:0;right:0;width:400px;height:100vh;background:#fff;box-shadow:-4px 0 30px rgba(0,0,0,.12);z-index:9998;display:flex;flex-direction:column;transform:scale(0);opacity:0;transform-origin:bottom right;transition:none;overflow:hidden}
#chat-sidebar.active{animation:sidebarExpand .55s cubic-bezier(.34,1.56,.64,1) forwards}
#chat-sidebar.closing{animation:sidebarShrink .35s ease-in forwards}
@keyframes sidebarExpand{from{transform:scale(.15);opacity:0}to{transform:scale(1);opacity:1}}
@keyframes sidebarShrink{from{transform:scale(1);opacity:1}to{transform:scale(.1);opacity:0}}

/* 侧边栏头部 */
#chat-header{display:flex;align-items:center;padding:16px 20px;background:linear-gradient(135deg,#4A90D9,#357ABD);color:#fff;flex-shrink:0;gap:12px}
#chat-header .avatar{width:44px;height:44px;border-radius:50%;display:flex;align-items:center;justify-content:center;flex-shrink:0;transition:transform .3s;overflow:hidden;background:rgba(255,255,255,.2)}
#chat-header .avatar.speaking{animation:talk .35s ease-in-out infinite}
#chat-header .avatar img{width:100%;height:100%;object-fit:cover;display:block;border-radius:50%}
#chat-header .name{font-size:16px;font-weight:700;flex:1}
#chat-header .status{font-size:11px;opacity:.75;font-weight:400;display:block;margin-top:-2px}
#close-btn{background:rgba(255,255,255,.2);border:none;color:#fff;width:32px;height:32px;border-radius:50%;cursor:pointer;font-size:16px;display:flex;align-items:center;justify-content:center;transition:background .2s}
#close-btn:hover{background:rgba(255,255,255,.35)}

/* 对话消息区 */
#chat-messages{flex:1;overflow-y:auto;padding:20px;display:flex;flex-direction:column;gap:14px;}
#chat-messages .msg{display:flex;gap:10px;max-width:88%;animation:msgIn .3s ease}
#chat-messages .msg.user{align-self:flex-end;flex-direction:row-reverse}
#chat-messages .msg.ai{align-self:flex-start}
#chat-messages .msg .bubble{padding:12px 16px;border-radius:16px;font-size:14px;line-height:1.7;word-break:break-word;white-space:pre-wrap}
#chat-messages .msg.user .bubble{background:#4A90D9;color:#fff;border-bottom-right-radius:4px}
#chat-messages .msg.ai .bubble{background:#f0f4f8;color:#333;border-bottom-left-radius:4px}
#chat-messages .msg .avatar-mini{width:32px;height:32px;border-radius:50%;background:linear-gradient(145deg,#4A90D9,#357ABD);flex-shrink:0;display:flex;align-items:center;justify-content:center;font-size:14px;color:#fff;font-weight:700;align-self:flex-end}

@keyframes msgIn{from{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}

/* Markdown 渲染样式 */
.msg.ai .bubble p{margin-bottom:8px}
.msg.ai .bubble p:last-child{margin-bottom:0}
.msg.ai .bubble ul,.msg.ai .bubble ol{padding-left:20px;margin-bottom:8px}
.msg.ai .bubble li{margin-bottom:4px}
.msg.ai .bubble code{background:#e8edf3;padding:1px 6px;border-radius:4px;font-size:13px;font-family:'Consolas','Courier New',monospace;word-break:break-all}
.msg.ai .bubble pre{background:#f5f6f8;padding:12px 14px;border-radius:8px;overflow-x:auto;margin-bottom:8px;font-size:13px;border:1px solid #e8edf3}
.msg.ai .bubble pre code{background:none;padding:0;font-size:13px}
.msg.ai .bubble strong{font-weight:700}
.msg.ai .bubble table{border-collapse:collapse;margin-bottom:8px;width:100%;font-size:13px}
.msg.ai .bubble th,.msg.ai .bubble td{border:1px solid #dce3ed;padding:6px 10px;text-align:left}
.msg.ai .bubble th{background:#f0f4f8;font-weight:600}
.msg.ai .bubble hr{border:none;border-top:1px solid #e8edf3;margin:12px 0}
.msg.ai .bubble blockquote{border-left:3px solid #4A90D9;padding:4px 12px;margin:8px 0;color:#5a6a7a;background:#f8faff;border-radius:0 6px 6px 0}
.msg.ai .bubble h1,.msg.ai .bubble h2,.msg.ai .bubble h3,.msg.ai .bubble h4{font-size:inherit;font-weight:700;margin:10px 0 6px}
.msg.ai .bubble a{color:#4A90D9;text-decoration:underline}
.think-content p{margin-bottom:6px}
.think-content ul,.think-content ol{padding-left:18px;margin-bottom:6px}
.think-content code{background:#f0e6c0;padding:1px 5px;border-radius:3px;font-size:12px;font-family:'Consolas',monospace}
.think-content strong{font-weight:700}
.think-content pre{background:#f5f0e0;padding:10px;border-radius:6px;overflow-x:auto;margin-bottom:6px;font-size:12px}
.think-content pre code{background:none;padding:0}

/* 打字光标 */
.typing-cursor .bubble::after{content:'|';display:inline;animation:blink .7s step-end infinite;color:#4A90D9;font-weight:700;margin-left:2px}
@keyframes blink{50%{opacity:0}}

/* 思考过程折叠区 */
.think-section{margin-bottom:8px;border-radius:10px;background:#fff8e1;border:1px solid #ffe082;overflow:hidden;font-size:13px}
.think-toggle{display:flex;align-items:center;gap:6px;padding:6px 12px;width:100%;border:none;background:#fff3cd;cursor:pointer;font-size:12px;color:#856404;font-weight:600;transition:background .2s}
.think-toggle:hover{background:#ffe082}
.think-toggle .arrow{display:inline-block;transition:transform .25s;font-size:10px}
.think-toggle .arrow.open{transform:rotate(180deg)}
.think-content{padding:4px 12px 12px;display:none;color:#6b5a00;line-height:1.7;white-space:pre-wrap;max-height:200px;overflow-y:auto;font-size:13px}
.think-content.open{display:block}

/* 思考模式开关 */
.thinking-toggle-wrap{display:flex;align-items:center;gap:4px;margin-right:6px}
.thinking-toggle-wrap label{font-size:11px;color:rgba(255,255,255,.8);cursor:pointer;white-space:nowrap;user-select:none}
.switch{position:relative;display:inline-block;width:32px;height:18px;flex-shrink:0}
.switch input{position:absolute;opacity:0;width:100%;height:100%;cursor:pointer;z-index:1;margin:0}
.switch .slider{position:absolute;pointer-events:none;top:0;left:0;right:0;bottom:0;background:rgba(255,255,255,.25);transition:.3s;border-radius:18px}
.switch .slider::before{content:'';position:absolute;height:14px;width:14px;left:2px;bottom:2px;background:#fff;transition:.3s;border-radius:50%}
.switch input:checked+.slider{background:#ffc107;box-shadow:0 0 6px rgba(255,193,7,.4)}
.switch input:checked+.slider::before{transform:translateX(14px)}

/* 底部输入区 */
#chat-input-area{flex-shrink:0;padding:14px 16px 18px;border-top:1px solid #e8edf3;background:#fafbfc;display:flex;gap:8px;flex-wrap:wrap}
#chat-input-area .input-row{display:flex;gap:8px;width:100%}
#chat-input-area #chat-input{flex:1;padding:10px 14px;border:2px solid #dce3ed;border-radius:22px;font-size:14px;outline:none;transition:border-color .25s;background:#fff}
#chat-input-area #chat-input:focus{border-color:#4A90D9}
#chat-input-area #chat-input:disabled{background:#f5f6f8;cursor:not-allowed}
#chat-input-area #send-btn{padding:10px 22px;border:none;background:linear-gradient(135deg,#4A90D9,#357ABD);color:#fff;border-radius:22px;font-size:14px;font-weight:600;cursor:pointer;transition:all .3s;white-space:nowrap}
#chat-input-area #send-btn:hover{opacity:.92;transform:scale(1.03);box-shadow:0 4px 12px rgba(74,144,217,.3)}
#chat-input-area #send-btn:disabled{opacity:.5;cursor:not-allowed;transform:none}
#mic-btn{width:36px;height:36px;border-radius:50%;border:2px solid #dce3ed;background:#fff;cursor:pointer;font-size:16px;display:flex;align-items:center;justify-content:center;transition:all .25s;flex-shrink:0;color:#5a6a7a}
#mic-btn:hover{border-color:#4A90D9;color:#4A90D9;transform:scale(1.08)}
#mic-btn.recording{border-color:#e74c3c;color:#e74c3c;background:#fef0ef;animation:micPulse 1s ease-in-out infinite}
#mic-btn.loading{border-color:#f39c12;color:#f39c12;background:#fef9e7;pointer-events:none;animation:micSpin .8s linear infinite}
@keyframes micPulse{50%{box-shadow:0 0 0 6px rgba(231,76,60,.2)}}
@keyframes micSpin{from{transform:rotate(0)}to{transform:rotate(360deg)}}
#streaming-indicator{width:100%;text-align:center;font-size:12px;color:#4A90D9;padding:4px 0 0}

/* ===== 动画关键帧 ===== */
@keyframes breathe{
  0%,100%{transform:translateY(0);box-shadow:0 4px 16px rgba(74,144,217,.35)}
  50%{transform:translateY(-7px);box-shadow:0 12px 32px rgba(74,144,217,.45)}
}
#avatar-btn.breathe{animation:breathe 3s ease-in-out infinite}

@keyframes jumpGreet{
  0%{transform:scale(1) translateY(0) rotate(0)}
  25%{transform:scale(1.12) translateY(-22px) rotate(-8deg)}
  45%{transform:scale(1.2) translateY(-34px) rotate(5deg)}
  65%{transform:scale(1.08) translateY(-12px) rotate(-3deg)}
  100%{transform:scale(1) translateY(0) rotate(0)}
}
#avatar-btn.jump-greet{animation:jumpGreet .65s cubic-bezier(.22,1,.36,1) forwards;animation-fill-mode:forwards}

@keyframes talk{
  0%,100%{transform:scaleY(1) scaleX(1)}
  25%{transform:scaleY(1.08) scaleX(.97)}
  50%{transform:scaleY(.94) scaleX(1.04)}
  75%{transform:scaleY(1.06) scaleX(.98)}
}

/* 滚动条 */
#chat-messages::-webkit-scrollbar{width:4px}
#chat-messages::-webkit-scrollbar-thumb{background:#d0d8e4;border-radius:4px}
#content-area::-webkit-scrollbar{width:6px}
#content-area::-webkit-scrollbar-thumb{background:#d0d8e4;border-radius:4px}
@media(max-width:820px){
  #chat-sidebar{width:100%}
  #content-area{padding:20px 18px}
  #stage-tabs .stage-tab{font-size:13px;padding:8px 14px}
  #content-area h1{font-size:19px}
  .stage-panel h2{font-size:17px}
  #app #three-container{height:260px}
  .compare-bar{height:20px}
}
@media(max-width:600px){
  #content-area{padding:14px 12px}
  #content-area h1{font-size:17px;margin-bottom:16px}
  #stage-tabs .stage-tab{font-size:12px;padding:6px 10px;border-radius:8px}
  #app #three-container{height:220px}
  .stage-panel{padding:0}
  .stage-panel h2{font-size:16px;margin-bottom:10px}
  .stage-panel p,.stage-panel .exercise,.stage-panel .highlight{font-size:14px}
  .stage-panel .formula{font-size:15px;padding:12px 14px}
  .stage-panel .highlight{padding:12px 14px}
  .stage-panel .example-box{padding:12px 14px}
  #avatar-btn{width:56px;height:56px;bottom:16px;right:16px}
  #chat-sidebar{font-size:14px}
  #chat-messages{padding:14px}
  #chat-messages .msg .bubble{font-size:13px;padding:10px 14px}
  #chat-header{padding:12px 16px}
  #chat-header .avatar{width:36px;height:36px}
  #chat-header .name{font-size:14px}
  #close-btn{width:28px;height:28px;font-size:14px}
  #chat-input-area{padding:10px 12px 14px}
  #chat-input-area #chat-input{font-size:13px;padding:8px 12px}
  #chat-input-area #send-btn{font-size:13px;padding:8px 16px}
  #mic-btn{width:32px;height:32px;font-size:14px}
  #chat-messages .msg{max-width:92%}
  #content-area,#chat-messages{-webkit-overflow-scrolling:touch}
  .stage-tab,.stage-panel .exercise,.stage-panel .highlight,.stage-panel .example-box,#send-btn,#mic-btn,#close-btn,#avatar-btn,#chat-input{touch-action:manipulation}
}
@media(max-width:480px){
  #content-area{padding:10px 8px}
  #content-area h1{font-size:15px;margin-bottom:12px;padding-bottom:8px}
  #stage-tabs{gap:4px}
  #stage-tabs .stage-tab{font-size:11px;padding:5px 8px;border-width:1px}
  #three-container{height:180px!important;border-radius:6px!important}
  .stage-panel h2{font-size:15px}
  .stage-panel p,.stage-panel .exercise,.stage-panel .highlight{font-size:13px}
  .stage-panel .formula{font-size:14px;padding:10px 12px;border-radius:8px}
  .stage-panel .highlight{padding:10px 12px;border-radius:8px}
  .stage-panel .example-box{padding:10px 12px;border-radius:8px}
  .stage-panel .exercise{padding:12px}
  .stage-panel .exercise::before{font-size:13px}
  .stage-panel .tip{font-size:12px;padding:10px 12px}
  .stage-panel .formula span{font-size:inherit}
  .stage-panel ul{padding-left:16px}
  .stage-panel ul li{font-size:13px}
  #three-container .compare-bar{height:18px}
  .chat-placeholder{padding:24px}
  .chat-placeholder svg{width:44px;height:44px}
  .chat-placeholder p{font-size:12px}
  #chat-input-area #chat-input{font-size:12px;padding:7px 10px}
  #chat-input-area #send-btn{font-size:12px;padding:7px 14px;border-radius:18px}
  #mic-btn{width:30px;height:30px;font-size:13px}
  #avatar-btn{width:48px;height:48px;bottom:12px;right:12px;border-width:2px}
  #chat-messages .msg{max-width:96%}
  #chat-messages .msg .bubble{font-size:12px;padding:8px 12px}
}

.chat-placeholder{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;color:#b0bccf;gap:12px;padding:40px}
.chat-placeholder svg{width:60px;height:60px;opacity:.3}
.chat-placeholder p{font-size:14px}

/* 数字跳动 */
@keyframes countUp{from{opacity:0;transform:scale(.5)}to{opacity:1;transform:scale(1)}}
.anim-count{animation:countUp .5s cubic-bezier(.34,1.56,.64,1) both}
.anim-count-1{animation-delay:0s}
.anim-count-2{animation-delay:.3s}
.anim-count-3{animation-delay:.6s}

/* 进度条动画 */
.compare-bar{height:24px;background:#e8edf3;border-radius:12px;overflow:hidden;position:relative}
.compare-bar .fill{height:100%;border-radius:12px;transition:width 1.2s cubic-bezier(.22,1,.36,1);position:relative}
.compare-bar .fill::after{content:'';position:absolute;top:0;left:0;right:0;height:50%;background:linear-gradient(180deg,rgba(255,255,255,.35),transparent);border-radius:12px 12px 0 0}