/* Header dùng chung cho danh mục công cụ và Công bố điểm. */
header{background:#fff;border-bottom:1px solid #e5e7eb}
header .shell,header .header-inner{width:min(1100px,calc(100% - 32px));margin:0 auto;min-height:56px;display:flex;align-items:center;justify-content:space-between;gap:20px}
header .brand{font-size:22px;font-weight:700;color:#111827;white-space:nowrap}
header .brand span{color:#2563eb}
header a,header a:hover,header a:focus,header a:visited{text-decoration:none}
header nav{display:flex;align-items:center;gap:18px;flex-wrap:wrap}
header nav a,header .tools-link{font-size:15px;color:#4b5563}
header nav a:hover,header .tools-link:hover{color:#2563eb}
header a:focus-visible{outline:2px solid #2563eb;outline-offset:4px;border-radius:3px}
@media(max-width:560px){header .shell,header .header-inner{width:calc(100% - 22px);min-height:62px;gap:12px}header .brand{font-size:20px}header nav{gap:10px;justify-content:flex-end}header nav a{font-size:14px}}