:root{
    --border:#e6e6ea;
    --bg:#f7f7fb;
    --card:#ffffff;
    --text:#111827;
    --muted:#6b7280;
    --shadow: 0 10px 30px rgba(0,0,0,.08);
  }
  
  *{ box-sizing:border-box; }
  body{
    margin:0;
    font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
    color:var(--text);
    background:var(--bg);
  }
  
  /* Layout global */
  .app-shell{ min-height:100vh; }
  .app-header{
    height:56px;
    display:flex;
    align-items:center;
    gap:12px;
    padding:0 16px;
    background:var(--card);
    border-bottom:1px solid var(--border);
  }
  .app-brand{
    color:var(--text);
    text-decoration:none;
    font-weight:600;
  }
  .header-spacer{ flex:1; }
  
  .app-main{
    padding:24px;
  }
  
  /* Hamburger */
  .hamburger{
    width:40px;
    height:40px;
    border:1px solid var(--border);
    background:var(--card);
    border-radius:10px;
    display:flex;
    flex-direction:column;
    justify-content:center;
    align-items:center;
    gap:5px;
    cursor:pointer;
  }
  .hamburger span{
    width:18px;
    height:2px;
    background:var(--text);
    display:block;
    border-radius:2px;
  }
  
  /* Nav drawer */
  .app-nav{
    position:fixed;
    top:0;
    left:0;
    height:100vh;
    width:min(320px, 86vw);
    background:var(--card);
    border-right:1px solid var(--border);
    box-shadow:var(--shadow);
    transform:translateX(-105%);
    transition:transform .18s ease;
    z-index:1000;
    padding:12px;
  }
  .nav-head{
    display:flex;
    align-items:center;
    justify-content:space-between;
    padding:8px 4px 12px 4px;
    border-bottom:1px solid var(--border);
    margin-bottom:10px;
  }
  .nav-title{ font-weight:600; }
  .nav-close{
    width:36px;
    height:36px;
    border:1px solid var(--border);
    border-radius:10px;
    background:var(--card);
    cursor:pointer;
    font-size:20px;
    line-height:0;
  }
  .nav-item{
    display:flex;
    align-items:center;
    gap:10px;
    padding:10px 10px;
    border-radius:10px;
    text-decoration:none;
    color:var(--text);
  }
  .nav-item:hover{
    background:#dcdce6;
  }
  
  .nav-overlay{
    position:fixed;
    inset:0;
    background:rgba(0,0,0,.25);
    opacity:0;
    pointer-events:none;
    transition:opacity .18s ease;
    z-index:999;
  }
  
  /* Open state */
  body.nav-open .app-nav{ transform:translateX(0); }
  body.nav-open .nav-overlay{
    opacity:1;
    pointer-events:auto;
  }
  
  /* petits ├®l├®ments utilitaires */
  .card{
    background:var(--card);
    border:1px solid var(--border);
    border-radius:14px;
    padding:16px;
    box-shadow: 0 6px 20px rgba(0,0,0,.05);
  }
  .muted{ color:var(--muted); }