*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{
  --bg:#f5f4fa;
  --bg-card:#fff;
  --text:#1a1a2e;
  --text-muted:#6b6b80;
  --text-dim:#999;
  --border:#e4e3ed;
  --primary:#534ab7;
  --primary-light:#eeedfe;
  --primary-dark:#3c3489;
  --accent:#d85a30;
  --accent-bg:#faece7;
  --success:#1d9e75;
  --success-bg:#e1f5ee;
  --warning:#ba7517;
  --warning-bg:#faeeda;
  --radius:12px;
  --radius-sm:8px;
  --font:-apple-system,BlinkMacSystemFont,"Segoe UI","Noto Sans SC","PingFang SC",sans-serif;
  --mono:"SF Mono","Fira Code","Cascadia Code",monospace;
}
[data-theme="dark"]{
  --bg:#1a1a2e;
  --bg-card:#232340;
  --text:#e8e8f0;
  --text-muted:#9696b0;
  --text-dim:#7a7a95;
  --border:#34345a;
  --primary:#7c72d8;
  --primary-light:#2f2f55;
  --primary-dark:#a99ef0;
  --accent:#e8734a;
  --accent-bg:#3d2520;
  --success:#2abf91;
  --success-bg:#1a3a30;
  --warning:#d4943a;
  --warning-bg:#352a15;
}
html,body{height:100%;overflow:hidden}
body{font-family:var(--font);background:var(--bg);color:var(--text);display:flex;flex-direction:column}
.app{display:flex;flex-direction:column;height:100vh;max-width:760px;margin:0 auto;width:100%;padding:0 16px;position:relative}
@media screen and (max-width:480px){.app{padding:0 12px}}

/* Header */
.app-header{padding:14px 0 8px;flex-shrink:0;transition:padding .2s ease;position:relative;z-index:10}
@media screen and (max-width:480px){.app-header{padding:8px 0 4px}}
.app-header.shrink{padding:6px 0}
.app-header.shrink .app-title{font-size:15px}
.app-header.shrink .app-subtitle,
.app-header.shrink .header-meta{opacity:0;max-height:0;overflow:hidden;padding:0;margin:0;transition:opacity .15s,max-height .2s}
.header-top{display:flex;align-items:center;justify-content:space-between;transition:all .2s;position:relative}
.header-left{display:flex;align-items:center;gap:6px;flex-shrink:0}
.header-right{display:flex;align-items:center;gap:6px;flex-shrink:0}
.header-icon-btn{
  width:34px;height:34px;border:1px solid var(--border);border-radius:50%;background:var(--bg-card);
  cursor:pointer;color:var(--text-dim);display:flex;align-items:center;justify-content:center;
  transition:all .15s;flex-shrink:0;position:relative;
}
.header-icon-btn::after{
  content:attr(data-tooltip);position:absolute;top:calc(100% + 6px);left:50%;transform:translateX(-50%);
  background:rgba(0,0,0,.78);color:#fff;font-size:11px;padding:4px 10px;border-radius:6px;
  white-space:nowrap;pointer-events:none;opacity:0;transition:opacity .1s ease .15s;z-index:999;
}
.header-icon-btn:hover::after{opacity:1}
.header-icon-btn:hover{border-color:var(--primary);color:var(--primary);background:var(--primary-light)}
.header-icon-btn.danger:hover{border-color:var(--danger,#ef4444);color:var(--danger,#ef4444);background:#fef2f2}
.app-title{
  font-size:16px;font-weight:600;color:var(--primary);letter-spacing:-.3px;
  position:absolute;left:50%;transform:translateX(-50%);white-space:nowrap;
}
.app-subtitle{font-size:11px;color:var(--text-muted);margin-top:1px}
.header-meta{font-size:11px;color:var(--text-dim);margin-top:4px;display:flex;align-items:center;gap:6px;justify-content:center}
.meta-dot{color:var(--border)}

/* Q&A main area */
.qa-main{flex:1;overflow-y:auto;padding:4px 0 8px;-webkit-overflow-scrolling:touch}
.qa-main::-webkit-scrollbar{width:4px}
.qa-main::-webkit-scrollbar-thumb{background:var(--border);border-radius:2px}

/* Welcome */
.welcome{text-align:center;padding:32px 20px 40px}
.welcome-icon{margin-bottom:12px}
.welcome-banner{max-width:420px;width:100%;height:auto;border-radius:var(--radius);display:block;margin:0 auto}
.welcome-title{font-size:17px;font-weight:600;color:var(--text);margin-bottom:6px}
.section-title{
  font-size:12px;font-weight:600;color:var(--primary);text-align:left;
  max-width:420px;margin:8px auto 4px;padding:0 4px;
}
.welcome-hint{font-size:13px;color:var(--text-muted);margin-bottom:16px}
.welcome-suggestions{margin:0 auto}
.sc-grid{display:grid;grid-template-columns:1fr 1fr 1fr;gap:8px;max-width:420px;margin:0 auto}
.sc-card{
  display:flex;flex-direction:column;align-items:center;justify-content:center;gap:4px;
  padding:14px 8px;border:1px solid var(--border);border-radius:12px;
  background:var(--bg-card);cursor:pointer;transition:all .15s;user-select:none;
}
.sc-card:hover{border-color:var(--primary);background:var(--primary-light);transform:translateY(-1px)}
.sc-icon{display:flex;align-items:center;justify-content:center;height:26px;color:var(--primary);margin-bottom:2px}
.sc-card:hover .sc-icon{color:var(--primary-dark)}
.sc-label{font-size:13px;font-weight:500;color:var(--text);text-align:center;line-height:1.3}
.sc-card:hover .sc-label{color:var(--primary)}
.welcome-calc-btn{
  display:inline-flex;align-items:center;gap:6px;margin-top:14px;padding:8px 18px;font-size:13px;font-family:var(--font);
  border:1px solid var(--primary);border-radius:20px;background:var(--primary);color:#fff;
  cursor:pointer;transition:all .15s;font-weight:500;
}
.welcome-calc-btn:hover{opacity:.85}
.welcome-actions{display:flex;gap:8px;justify-content:center;margin-top:10px;flex-wrap:wrap}

/* Welcome action buttons row */
.welcome-actions-bar{
  display:flex;align-items:center;justify-content:center;gap:10px;margin-top:10px;flex-wrap:wrap
}
.welcome-btn{
  display:inline-flex;align-items:center;gap:6px;padding:9px 20px;font-size:13px;font-family:var(--font);
  border-radius:20px;cursor:pointer;transition:all .15s;font-weight:500;border:1px solid transparent
}
.welcome-btn-primary{
  background:var(--primary);color:#fff;border-color:var(--primary)
}
.welcome-btn-primary:hover{opacity:.85}
.welcome-btn-secondary{
  background:var(--bg-card);color:var(--text);border-color:var(--border)
}
.welcome-btn-secondary:hover{border-color:var(--primary);color:var(--primary);background:var(--primary-light)}

/* Q&A history */
.qa-history{display:flex;flex-direction:column;gap:14px;padding-bottom:8px}
.qa-item{display:flex;flex-direction:column;max-width:100%}

/* User question bubble */
.qa-question{
  align-self:flex-end;max-width:85%;
  background:var(--primary);color:#fff;padding:10px 16px;
  font-size:14px;line-height:1.4;margin-bottom:4px;white-space:pre-wrap;word-break:break-word;
  border-radius:16px 16px 16px 4px;
}

/* Answer card */
.qa-answer{
  background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);
  padding:12px 14px;margin-top:4px;animation:fadeIn .3s ease;
  position:relative;
}
@keyframes fadeIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}

/* Answer actions */
.qa-answer-actions{
  position:absolute;top:10px;right:10px;display:flex;gap:4px;
}
.qa-action-btn{
  width:28px;height:28px;border:1px solid var(--border);border-radius:50%;background:var(--bg-card);
  cursor:pointer;color:var(--text-dim);display:flex;align-items:center;justify-content:center;
  font-size:11px;transition:all .12s;
}
.qa-action-btn:hover{border-color:var(--primary);color:var(--primary);background:var(--primary-light)}

.qa-answer-header{display:flex;align-items:center;gap:8px;margin-bottom:6px;padding-right:74px}
.qa-answer-badge{
  font-size:11px;padding:2px 8px;border-radius:4px;background:var(--primary-light);
  color:var(--primary);font-weight:500;flex-shrink:0;
}
.qa-answer-badge.danger{background:var(--accent-bg);color:var(--accent)}
.qa-answer-badge.success{background:var(--success-bg);color:var(--success)}
.qa-answer-title{font-size:14px;font-weight:600;color:var(--text)}

/* Answer body - formatted content */
.qa-answer-body{
  font-size:13px;line-height:1.5;color:var(--text);word-break:break-word;
}
.qa-answer-body strong{color:var(--primary-dark);font-weight:600}
.qa-answer-body .highlight-num{background:var(--warning-bg);color:var(--warning);padding:1px 5px;border-radius:3px;font-weight:600}
.qa-answer-body .formula-box{
  display:inline-block;background:var(--primary-light);color:var(--primary-dark);padding:1px 6px;border-radius:3px;font-weight:500;font-size:12px;
}
.qa-answer-body p{margin:4px 0}
.qa-answer-body ul{padding-left:18px;margin:4px 0}
.qa-answer-body li{margin-bottom:4px}

/* AI 回答专用样式 */
.ai-answer-body{line-height:1.8;font-size:14px}
.ai-answer-body br+br{margin-bottom:4px}
.ai-answer-body strong{color:var(--primary-dark)}
.ai-answer-body .highlight{background:var(--warning-bg);color:var(--warning);padding:1px 5px;border-radius:3px;font-weight:600}
.ai-answer-body table{width:100%;border-collapse:collapse;margin:8px 0;font-size:13px}
.ai-answer-body table th{background:var(--primary-light);color:var(--primary-dark);padding:6px 8px;border:1px solid var(--border);font-weight:500;text-align:left}
.ai-answer-body table td{padding:5px 8px;border:1px solid var(--border)}
.ai-answer-body table tr:nth-child(even){background:var(--bg-secondary)}

/* Answer info table */
.answer-table{width:100%;border-collapse:collapse;margin:0;font-size:12px;table-layout:fixed}
.answer-table th,.answer-table td{
  border:1px solid var(--border);padding:6px 8px;text-align:left;vertical-align:middle;box-sizing:border-box;
}
.answer-table th{background:var(--primary-light);color:var(--primary-dark);font-weight:500}
.answer-table td{font-weight:400}
.answer-table tr:nth-child(even){background:var(--bg)}

.qa-answer-tags{display:flex;flex-wrap:wrap;gap:4px;margin-top:10px;padding-top:8px;border-top:1px solid var(--border)}
.qa-answer-tag{font-size:11px;padding:2px 6px;border-radius:4px;background:var(--bg);color:var(--text-muted)}

/* Related questions */
.qa-related{margin-top:12px}
.qa-related-title{font-size:12px;font-weight:500;color:var(--text-muted);margin-bottom:6px}
.qa-related-item{
  display:block;padding:8px 12px;font-size:13px;border:1px solid var(--border);
  border-left:3px solid var(--primary-light);border-radius:0 var(--radius-sm) var(--radius-sm) 0;
  color:var(--text);cursor:pointer;transition:all .1s;margin-bottom:4px;
}
.qa-related-item:hover{background:var(--primary-light);border-left-color:var(--primary);color:var(--primary)}

/* Continue asking link */
.qa-continue{
  text-align:right;font-size:12px;color:var(--text-dim);margin-top:8px;cursor:pointer;
  transition:color .15s;
}
.qa-continue:hover{color:var(--primary)}

/* Thinking */
.qa-thinking{display:flex;align-items:center;gap:8px;padding:12px 0 4px 4px;animation:fadeIn .2s ease}
.thinking-dots{display:flex;gap:4px}
.thinking-dot{width:6px;height:6px;border-radius:50%;background:var(--text-dim);animation:bounce 1.4s infinite ease-in-out}
.thinking-dot:nth-child(2){animation-delay:.2s}
.thinking-dot:nth-child(3){animation-delay:.4s}
@keyframes bounce{0%,80%,100%{transform:scale(0)}40%{transform:scale(1)}}
.qa-thinking-text{font-size:13px;color:var(--text-muted)}

/* No match */
.qa-nomatch{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);padding:20px;text-align:center;animation:fadeIn .3s ease}
.qa-nomatch-icon{width:36px;height:36px;color:var(--text-dim);margin-bottom:8px}
.qa-nomatch-text{font-size:14px;color:var(--text-muted);margin-bottom:8px}
.qa-nomatch-hint{font-size:12px;color:var(--text-dim)}

/* Back to top */
.back-top-btn{
  position:fixed;bottom:80px;right:20px;width:36px;height:36px;border-radius:50%;
  background:var(--bg-card);border:1px solid var(--border);color:var(--text-muted);
  cursor:pointer;display:none;align-items:center;justify-content:center;
  box-shadow:0 2px 8px rgba(0,0,0,.1);z-index:100;transition:all .15s;
}
@media screen and (min-width:768px){.back-top-btn{bottom:calc(80px + env(safe-area-inset-bottom,0px))}}
.back-top-btn.show{display:flex}
.back-top-btn:hover{color:var(--primary);border-color:var(--primary)}

/* Toast notification */
.toast{
  position:fixed;top:50%;left:50%;transform:translate(-50%,-50%) scale(.9);
  background:rgba(0,0,0,.75);color:#fff;padding:10px 24px;border-radius:8px;
  font-size:13px;z-index:2000;opacity:0;pointer-events:none;transition:all .2s;
  backdrop-filter:blur(4px);
}
.toast.show{opacity:1;transform:translate(-50%,-50%) scale(1)}

/* ===== INPUT BAR - compact card ===== */
.input-bar{flex-shrink:0;padding:6px 0 12px;background:var(--bg)}
@media screen and (max-width:480px){.input-bar{padding:6px 0 8px;padding-bottom:calc(8px + env(safe-area-inset-bottom,0px))}}
@media screen and (min-width:768px){.input-bar{padding:6px 0 20px;padding-bottom:calc(12px + env(safe-area-inset-bottom,0px))}}

.input-bar-inner{
  max-width:480px;margin:0 auto;
  background:var(--bg-card);border:1.5px solid var(--border);border-radius:16px;
  padding:10px 14px 8px;transition:border-color .2s,box-shadow .2s;
}
.input-bar-inner:focus-within{border-color:var(--primary);box-shadow:0 0 0 3px rgba(83,74,183,.1)}

.ibar-input-row{display:flex;}
.ibar-input-row .qa-input{
  flex:1;border:none;outline:none;font-size:16px;font-family:var(--font);background:transparent;
  color:var(--text);padding:2px 0;resize:none;max-height:80px;line-height:1.5;min-height:28px;
}
.ibar-input-row .qa-input::placeholder{color:var(--text-dim)}

.ibar-bottom-row{
  display:flex;align-items:center;justify-content:space-between;margin-top:6px;padding-top:6px;
  border-top:1px solid var(--border-light,var(--border));
}

.ibar-left{display:flex;flex-direction:column;align-items:flex-start;gap:6px;flex:1}

/* 点击展开模式选择 */
.mode-dropdown{position:relative;width:100%}
.mode-trigger{
  display:flex;align-items:center;gap:4px;padding:5px 10px;font-size:12px;font-family:var(--font);
  border:1px solid var(--border);border-radius:8px;background:var(--bg);color:var(--text);
  cursor:pointer;transition:all .15s;user-select:none;
}
.mode-trigger:hover{border-color:var(--primary);color:var(--primary)}
.mode-trigger svg{transition:transform .2s;color:var(--text-dim)}
.mode-trigger:hover svg{color:var(--primary)}
.mode-trigger.open svg{transform:rotate(180deg)}

.mode-panel{
  display:none;position:absolute;bottom:calc(100% + 4px);left:0;right:0;
  background:var(--bg-card);border:1px solid var(--border);border-radius:10px;
  box-shadow:0 4px 16px rgba(0,0,0,.1);z-index:50;overflow:hidden;
}
.mode-panel.open{display:block;animation:panelSlide .15s ease}
@keyframes panelSlide{from{opacity:0;transform:translateY(4px)}to{opacity:1;transform:translateY(0)}}

.mode-panel-item{
  display:flex;align-items:center;gap:8px;padding:9px 12px;cursor:pointer;
  transition:all .1s;user-select:none;
}
.mode-panel-item:not(:last-child){border-bottom:1px solid var(--border)}
.mode-panel-item:hover{background:var(--primary-light)}
.mode-panel-item.active{background:var(--primary-light)}
.mode-panel-item.active .mpi-title{color:var(--primary);font-weight:600}
.mpi-icon{font-size:16px;flex-shrink:0}
.mpi-text{display:flex;flex-direction:column;gap:1px;flex:1}
.mpi-title{font-size:13px;font-weight:500;color:var(--text)}
.mpi-desc{font-size:11px;color:var(--text-dim)}
.mpi-check{color:var(--primary);display:none}
.mode-panel-item.active .mpi-check{display:block}

/* 模型选择行 - 在面板内 */
.mode-panel-model{
  display:none;align-items:center;gap:8px;padding:8px 12px;
  background:var(--bg);border-top:1px solid var(--border);
}
.mode-panel-model .mpm-label{font-size:11px;color:var(--text-dim);flex-shrink:0}
.mode-panel-model select{
  flex:1;font-size:12px;font-family:var(--font);padding:4px 8px;border:1px solid var(--border);
  border-radius:6px;background:var(--bg-card);color:var(--text);cursor:pointer;outline:none;
}
.mode-panel-model select:focus{border-color:var(--primary)}

.send-btn{
  width:32px;height:32px;border:none;border-radius:50%;background:var(--primary);color:#fff;
  cursor:pointer;display:flex;align-items:center;justify-content:center;
  transition:opacity .15s;flex-shrink:0;
}
.send-btn:hover{opacity:.85}
.send-btn:disabled{opacity:.4;cursor:not-allowed}

/* Modals */
.modal-overlay{
  position:fixed;top:0;left:0;right:0;bottom:0;background:rgba(0,0,0,.35);
  display:none;align-items:center;justify-content:center;z-index:1000;
  padding:20px;backdrop-filter:blur(4px);
}
.modal-overlay.open{display:flex}
.calc-modal,.feedback-modal{
  background:var(--bg-card);border-radius:var(--radius);max-width:560px;width:100%;
  max-height:92vh;overflow-y:auto;box-shadow:0 4px 32px rgba(0,0,0,.12);
}
.feedback-modal{max-width:480px}
.calc-modal-header,.feedback-header{
  display:flex;align-items:center;justify-content:space-between;padding:16px 20px 12px;border-bottom:1px solid var(--border);
}
.calc-modal-header h3,.feedback-header h3{font-size:15px;font-weight:600}
.calc-modal-close,.feedback-header .calc-modal-close{
  width:28px;height:28px;border:1px solid var(--border);border-radius:50%;background:var(--bg-card);
  cursor:pointer;font-size:13px;color:var(--text-dim);display:flex;align-items:center;justify-content:center;
}
.calc-modal-close:hover{background:var(--primary-light);color:var(--primary)}
.calc-form,.feedback-body{padding:16px 20px 20px}
.calc-result{padding:0 20px 20px}
.calc-row{display:flex;gap:12px;margin-bottom:10px}
.calc-field{flex:1;display:flex;flex-direction:column;gap:3px}
.calc-field label{font-size:12px;font-weight:500;color:var(--text-muted)}
.calc-field input,.calc-field select{
  padding:8px 10px;font-size:13px;font-family:var(--font);border:1px solid var(--border);
  border-radius:var(--radius-sm);background:var(--bg);color:var(--text);outline:none;
}
.calc-field input:focus,.calc-field select:focus{border-color:var(--primary)}
.calc-checkbox{flex-direction:row;align-items:center;gap:8px;padding-top:6px}
.calc-checkbox input[type="checkbox"]{width:16px;height:16px}
.calc-checkbox label{font-size:13px;color:var(--text)}
.calc-submit{
  width:100%;padding:10px;font-size:14px;font-family:var(--font);font-weight:500;
  border:none;border-radius:var(--radius-sm);background:var(--primary);color:#fff;
  cursor:pointer;transition:opacity .15s;margin-top:6px;
}
.calc-submit:hover{opacity:.85}
.calc-submit:disabled{opacity:.5;cursor:not-allowed}
.calc-field.error input,.calc-field.error select{border-color:var(--accent);background:#fff5f5}
.calc-error{color:var(--accent);font-size:12px;text-align:center;padding:6px 0;display:none;line-height:1.5}
.calc-error.show{display:block}
.feedback-textarea{
  width:100%;padding:10px;font-size:13px;font-family:var(--font);border:1px solid var(--border);
  border-radius:var(--radius-sm);background:var(--bg);color:var(--text);outline:none;resize:vertical;
}
.feedback-textarea:focus{border-color:var(--primary)}

/* Order query modal */
.oq-modal{background:var(--bg-card);border-radius:var(--radius-sm);width:100%;max-width:500px;box-shadow:var(--shadow-lg);max-height:85vh;overflow-y:auto}
.oq-header{display:flex;align-items:center;justify-content:space-between;padding:16px 20px;border-bottom:1px solid var(--border)}
.oq-header h3{font-size:16px;font-weight:600}
.oq-body{padding:16px 20px 20px}
.oq-search-row{display:flex;gap:8px}
.oq-input{
  flex:1;padding:10px 14px;font-size:14px;font-family:var(--font);border:1px solid var(--border);
  border-radius:var(--radius-sm);background:var(--bg);color:var(--text);outline:none;
}
.oq-input:focus{border-color:var(--primary);box-shadow:0 0 0 3px rgba(83,74,183,.1)}
.oq-input::placeholder{color:var(--text-dim)}
.oq-btn{
  padding:10px 20px;font-size:14px;font-family:var(--font);font-weight:500;
  border:none;border-radius:var(--radius-sm);background:var(--primary);color:#fff;
  cursor:pointer;transition:opacity .15s;white-space:nowrap;
}
.oq-btn:hover{opacity:.85}
.oq-result{margin-top:14px}
.oq-empty{padding:20px;text-align:center;font-size:14px;color:var(--text-dim)}
.oq-card{background:var(--bg);border:1px solid var(--border);border-radius:var(--radius-sm);overflow:hidden;animation:fadeIn .2s ease}
.oq-card-row{display:flex;justify-content:space-between;padding:8px 14px;font-size:13px;border-bottom:1px solid var(--border)}
.oq-card-row:last-child{border-bottom:none}
.oq-label{color:var(--text-muted);flex-shrink:0;margin-right:12px}
.oq-val{color:var(--text);font-weight:500;text-align:right}
.oq-green{color:var(--success)}
.oq-red{color:var(--accent)}

/* Tracking timeline */
.tracking-result{min-height:60px}
.tracking-list{position:relative;padding-left:20px}
.tracking-list::before{content:'';position:absolute;left:6px;top:8px;bottom:8px;width:2px;background:var(--border);border-radius:1px}
.tracking-item{display:flex;align-items:flex-start;gap:10px;padding-bottom:16px;position:relative}
.tracking-item:last-child{padding-bottom:0}
.tracking-dot{width:14px;height:14px;border-radius:50%;background:var(--border);flex-shrink:0;margin-top:3px;position:relative;z-index:1;border:2px solid var(--bg-card)}
.tracking-last .tracking-dot{background:var(--primary);border-color:var(--primary-light)}
.tracking-body{flex:1;min-width:0}
.tracking-time{font-size:12px;color:var(--text-dim);margin-bottom:2px}
.tracking-text{font-size:13px;color:var(--text);line-height:1.4}
.tracking-last .tracking-text{color:var(--primary);font-weight:500}

/* Calculator result */
.calc-result-card{background:var(--success-bg);border-radius:var(--radius-sm);padding:14px;margin-bottom:8px;animation:fadeIn .3s ease}
.calc-result-card-title{font-size:12px;color:var(--success);font-weight:500;margin-bottom:6px}
.calc-result-row{display:flex;justify-content:space-between;padding:4px 0;font-size:13px;border-bottom:1px solid rgba(0,0,0,.06)}
.calc-result-row:last-child{border-bottom:none;font-weight:600;font-size:14px}
.calc-result-row .label{color:var(--text-muted)}
.calc-result-row .value{color:var(--text);font-weight:500}
.calc-result-row .positive{color:var(--success)}
.calc-result-row .negative{color:var(--accent)}

/* Responsive */
@media(max-width:480px){
  .app{padding:0 10px}
  .app-title{font-size:15px}
  .header-meta{font-size:10px;padding-left:38px;flex-wrap:wrap}
  .welcome{padding:24px 12px 8px}
  .welcome-title{font-size:16px}
  .qa-question{max-width:92%;font-size:13px}
  .qa-answer{padding:12px 14px}
  .calc-row{flex-direction:column;gap:8px}
  .answer-table{font-size:11px}
  .answer-table th,.answer-table td{padding:4px 6px}
  .back-top-btn{bottom:70px;right:14px;width:32px;height:32px}
}

/* Desktop optimization */
@media(min-width:769px){
  .app{max-width:860px;padding:0 24px}
  .welcome{
    padding:36px 20px 50px;
    display:grid;grid-template-columns:minmax(0,1fr);text-align:left;
  }
  .welcome-icon{display:contents}
  .welcome-banner{max-width:810px;width:100%;border-radius:var(--radius-lg);grid-column:1;grid-row:1}
  /* 快速提问叠在 Banner 左上 */
  .welcome p.section-title:nth-of-type(1){
    grid-column:1;grid-row:1;z-index:2;margin:14px 0 0 16px;align-self:start;justify-self:start;
    color:#fff;text-shadow:0 1px 3px rgba(0,0,0,.3);
  }
  .welcome-suggestions{
    grid-column:1;grid-row:1;z-index:2;margin:36px 0 10px 16px;align-self:stretch;justify-self:start;
    display:flex;flex-direction:column;
    width:auto;min-width:0;
  }
  .sc-grid{display:flex;flex-direction:column;flex:1;justify-content:space-evenly;gap:0;width:min-content}
  .sc-card{padding:7px 14px;border-radius:20px;gap:8px;background:rgba(255,255,255,.92);backdrop-filter:blur(4px);border:none;box-shadow:0 2px 8px rgba(0,0,0,.08);flex-direction:row;align-items:center;width:max-content}
  .sc-icon{margin-bottom:0;height:auto}
  .sc-label{text-align:left;white-space:nowrap}
  /* 快捷功能在 Banner 下方横排 */
  .welcome p.section-title:nth-of-type(2){margin:16px 0 8px}
  .welcome-actions-bar{flex-direction:row;margin:0;gap:10px;justify-content:flex-start}
  .input-bar-inner{max-width:810px}
  .input-bar{padding:6px 0 28px}
}

::-webkit-scrollbar{width:4px}
::-webkit-scrollbar-thumb{background:var(--border);border-radius:2px}