*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
  :root{
    --bg:#f5f7fa;--surface:#ffffff;--card:#ffffff;--border:#e4e7ed;
    --text:#303133;--text2:#909399;--accent:#409eff;--accent2:#67c23a;
    --warn:#e6a23c;--danger:#f56c6c;--radius:8px;--shadow:0 1px 4px rgba(0,0,0,.08);
    --font:system-ui,-apple-system,'Segoe UI',Roboto,sans-serif;
    --mono:'JetBrains Mono','Fira Code','Consolas',monospace;
  }
  html{font-size:15px}
  body{font-family:var(--font);background:var(--bg);color:var(--text);min-height:100vh;display:flex}
  a{color:var(--accent);text-decoration:none}
  a:hover{text-decoration:underline}
  ::-webkit-scrollbar{width:6px;height:6px}
  ::-webkit-scrollbar-track{background:var(--surface)}
  ::-webkit-scrollbar-thumb{background:var(--border);border-radius:3px}

  .sidebar{
    width:220px;background:var(--surface);border-right:1px solid var(--border);
    display:flex;flex-direction:column;position:fixed;top:0;left:0;bottom:0;z-index:100;
    transition:transform .3s;
  }
  .sidebar-header{
    padding:20px 18px 14px;border-bottom:1px solid var(--border);
  }
  .sidebar-header h1{font-size:1.15rem;font-weight:700;letter-spacing:-.3px}
  .sidebar-header h1 span{color:var(--accent)}
  .sidebar-header p{font-size:.75rem;color:var(--text2);margin-top:2px}
  .nav-list{flex:1;overflow-y:auto;padding:8px 0}
  .nav-item{
    display:flex;align-items:center;gap:10px;padding:9px 18px;cursor:pointer;
    color:var(--text2);font-size:.88rem;transition:all .15s;border-left:3px solid transparent;
  }
  .nav-item:hover{color:var(--text);background:rgba(64,158,255,.04)}
  .nav-item.active{color:var(--accent);background:rgba(64,158,255,.08);border-left-color:var(--accent);font-weight:600}
  .nav-item .icon{font-size:1.1rem;width:22px;text-align:center;flex-shrink:0}
  a.nav-link{display:flex;align-items:center;gap:10px;padding:9px 18px;color:var(--text2);font-size:.88rem;text-decoration:none;border-left:3px solid transparent;transition:all .15s}
  a.nav-link:hover{color:var(--text);background:rgba(64,158,255,.04)}
  a.nav-link.active{color:var(--accent);background:rgba(64,158,255,.08);border-left-color:var(--accent);font-weight:600}

  .main{margin-left:220px;flex:1;min-height:100vh;display:flex;flex-direction:column}
  .topbar{
    display:none;padding:12px 16px;background:var(--surface);border-bottom:1px solid var(--border);
    align-items:center;justify-content:space-between;
  }
  .topbar h1{font-size:1rem;font-weight:700}
  .topbar h1 span{color:var(--accent)}
  .menu-btn{background:none;border:none;color:var(--text);font-size:1.3rem;cursor:pointer;padding:4px}

  .content{flex:1;padding:16px 20px;max-width:1200px;width:100%;margin:0 auto}
  .tool-pane{display:none;animation:fadeIn .25s ease}
  .tool-pane.active{display:block}
  @keyframes fadeIn{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:translateY(0)}}

  .card{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:20px 24px;margin-bottom:18px}
  .card h2{font-size:1.05rem;font-weight:600;margin-bottom:14px;color:var(--text)}
  .card-row{display:flex;gap:12px;flex-wrap:wrap}
  .card-row > *{flex:1;min-width:180px}

  textarea,.input,.select{width:100%;padding:9px 12px;background:var(--surface);border:1px solid var(--border);
    border-radius:6px;color:var(--text);font-size:.88rem;font-family:var(--mono);resize:vertical;
    transition:border .2s;outline:none}
  textarea:focus,.input:focus,.select:focus{border-color:var(--accent);box-shadow:0 0 0 2px rgba(88,166,255,.2)}
  textarea{min-height:80px;font-size:.82rem;line-height:1.5}
  .select{font-family:var(--font);cursor:pointer}
  .select option{background:var(--surface);color:var(--text)}
  .btn{display:inline-flex;align-items:center;gap:6px;padding:8px 18px;border:none;border-radius:6px;
    cursor:pointer;font-size:.85rem;font-weight:500;transition:all .15s}
  .btn-primary{background:var(--accent);color:#fff}
  .btn-primary:hover{filter:brightness(1.1)}
  .btn-success{background:var(--accent2);color:#fff}
  .btn-success:hover{filter:brightness(1.1)}
  .btn-danger{background:var(--danger);color:#fff}
  .btn-danger:hover{filter:brightness(1.1)}
  .btn-outline{background:transparent;border:1px solid var(--border);color:var(--text)}
  .btn-outline:hover{background:var(--surface)}
  .btn-sm{padding:5px 12px;font-size:.8rem}
  .btn-group{display:flex;gap:8px;flex-wrap:wrap;margin:10px 0}
  .output{background:var(--surface);border:1px solid var(--border);border-radius:6px;padding:10px 14px;
    font-family:var(--mono);font-size:.82rem;line-height:1.5;min-height:40px;word-break:break-all;
    margin-top:8px;white-space:pre-wrap}
  .output.success{border-color:var(--accent2)}
  .output.error{border-color:var(--danger);color:var(--danger)}
  .hint{font-size:.78rem;color:var(--text2);margin-top:4px}
  .badge{display:inline-block;padding:2px 8px;border-radius:10px;font-size:.72rem;font-weight:600}
  .badge-info{background:rgba(88,166,255,.15);color:var(--accent)}
  .badge-success{background:rgba(63,185,80,.15);color:var(--accent2)}
  .badge-danger{background:rgba(248,81,73,.15);color:var(--danger)}
  .badge-warning{background:rgba(230,162,60,.15);color:var(--warn)}
  .inline-flex{display:inline-flex;align-items:center;gap:8px}

  .grid-2{display:grid;grid-template-columns:1fr 1fr;gap:12px}
  .grid-3{display:grid;grid-template-columns:1fr 1fr 1fr;gap:12px}
  @media(max-width:700px){.grid-2{grid-template-columns:1fr}.grid-3{grid-template-columns:1fr}}

  @media(max-width:768px){
    .sidebar{transform:translateX(-100%)}
    .sidebar.open{transform:translateX(0)}
    .main{margin-left:0}
    .topbar{display:flex}
    .content{padding:16px}
    .overlay{display:none;position:fixed;inset:0;background:rgba(0,0,0,.5);z-index:99}
    .overlay.show{display:block}
    .card{padding:14px 16px}
  }

  table{table-layout:fixed;width:100%;border-collapse:collapse;font-size:.82rem;margin-top:6px}
  th,td{text-align:left;padding:6px 10px;border:1px solid var(--border)}
  th{background:rgba(64,158,255,.06);font-weight:600;color:var(--text)}
  td{color:var(--text2)}

  .flex-center{display:flex;align-items:center;gap:8px}
  .mt-8{margin-top:8px}
  .mb-8{margin-bottom:8px}
  .w-full{width:100%}
  .copy-btn{background:none;border:1px solid var(--border);color:var(--text2);border-radius:4px;
    padding:2px 8px;font-size:.72rem;cursor:pointer;transition:all .15s;margin-left:6px}
  .copy-btn:hover{color:var(--text);border-color:var(--accent)}
  .result-bar{display:flex;align-items:center;justify-content:space-between;margin-top:6px}
  .result-bar .label{font-size:.82rem;color:var(--text2)}

  .sub-nav{display:flex;gap:6px;flex-wrap:wrap;margin-bottom:16px;padding:10px 0;border-bottom:1px solid var(--border)}
  .sub-nav-item{padding:6px 14px;border-radius:6px;cursor:pointer;font-size:.82rem;color:var(--text2);transition:all .15s;border:1px solid transparent}
  .sub-nav-item:hover{color:var(--text);background:rgba(64,158,255,.04);border-color:var(--border)}
  .sub-nav-item.active{color:var(--accent);background:rgba(64,158,255,.08);border-color:var(--accent);font-weight:600}

  .footer{text-align:center;padding:16px;font-size:.78rem;color:var(--text2);border-top:1px solid var(--border);margin-top:auto;background:var(--surface)}
  .footer a{color:var(--text2)}.footer a:hover{color:var(--accent)}

  
  
  
  
  
  
  
  

  .zone-table{width:100%;border-collapse:collapse;font-size:.82rem;margin-top:8px}
  .zone-table th,.zone-table td{text-align:left;padding:4px 8px;border:1px solid var(--border)}
  .zone-table th{background:rgba(64,158,255,.06);font-weight:600}
  .zone-tag{display:inline-block;padding:2px 8px;border-radius:8px;font-size:.7rem;font-weight:600;color:#fff;width:60px;text-align:center}
  .zone-tag.rec{background:#409eff}
  .zone-tag.fat{background:#67c23a}
  .zone-tag.cardio{background:#e6a23c}
  .zone-tag.hiit{background:#f56c6c}
  .zone-tag.max{background:#b37feb}


.donation-btn:hover{color:#409eff;border-color:#409eff}

.donation-modal.show{display:flex}
.donation-box{background:#fff;border-radius:10px;padding:14px 18px;text-align:center;max-width:240px;width:85%;box-shadow:0 4px 20px rgba(0,0,0,.12);position:relative;animation:fadeIn .2s ease}
.donation-box .title{font-size:.85rem;font-weight:600;color:#303133;margin-bottom:4px}
.donation-box .desc{font-size:.75rem;color:#909399;margin-bottom:10px;line-height:1.4}
.donation-box img{max-width:150px;border-radius:6px;margin-bottom:6px}
.donation-box .hint{font-size:.65rem;color:#c0c4cc}
.donation-box .close-btn{background:none;border:none;font-size:.9rem;color:#c0c4cc;cursor:pointer;position:absolute;top:5px;right:8px}
.donation-box .close-btn:hover{color:#909399}



.donation-modal.show{display:flex}
.donation-box{background:#fff;border-radius:10px;padding:14px 18px;text-align:center;max-width:240px;width:85%;box-shadow:0 4px 20px rgba(0,0,0,.12);position:relative;animation:fadeIn .2s ease}
.donation-box .title{font-size:.85rem;font-weight:600;color:#303133;margin-bottom:4px}
.donation-box .desc{font-size:.75rem;color:#909399;margin-bottom:10px;line-height:1.4}
.donation-box img{max-width:150px;border-radius:6px;margin-bottom:6px}
.donation-box .hint{font-size:.65rem;color:#c0c4cc}
.donation-box .close-btn{background:none;border:none;font-size:.9rem;color:#c0c4cc;cursor:pointer;position:absolute;top:5px;right:8px}
.donation-box .close-btn:hover{color:#909399}

.donation-btn:hover{color:#409eff;border-color:#409eff}

.tool-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:10px;margin:16px 0}
.tool-card{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:14px 16px;display:block;text-decoration:none;color:var(--text);transition:all .15s}
.tool-card:hover{border-color:var(--accent);box-shadow:0 2px 12px rgba(64,158,255,.1);transform:translateY(-1px)}
.tool-card h3{font-size:.9rem;font-weight:600;margin:0}
.tool-card p{font-size:.78rem;color:var(--text2);margin:4px 0 0}