/* Certificates page (dark theme, grid layout) */
:root{
  --bg:#0b1220;
  --panel:#0f1830;
  --card:#101a34;
  --ink:#e6ebf5;
  --muted:#9aa3b2;
  --brand:#60a5fa;
  --accent:#22d3ee;
  --border:rgba(255,255,255,0.08);
  --chip:rgba(255,255,255,0.06);
  --shadow:0 12px 40px rgba(0,0,0,0.35);
}
*{box-sizing:border-box}
html,body{height:100%}
html{scroll-behavior:smooth}
body{
  margin:0;
  font:16px/1.6 system-ui,-apple-system,Segoe UI,Roboto,Inter,Arial,sans-serif;
  color:var(--ink);
  background:
    radial-gradient(1200px 800px at 10% 10%, rgba(34,211,238,0.08), transparent 60%),
    radial-gradient(800px 500px at 90% 20%, rgba(96,165,250,0.12), transparent 60%),
    var(--bg);
}
.container{width:min(1180px,92%);margin-inline:auto}
.muted{color:var(--muted)}
.small{font-size:.9rem}
.overline{text-transform:uppercase;letter-spacing:.08em;font-size:.75rem;margin:0 0 .4rem 0;color:var(--muted)}

.btn{
  background:var(--brand);
  color:#f7fbff;
  border:none;
  padding:.55rem 1rem;
  border-radius:.7rem;
  font-weight:700;
  text-decoration:none;
  display:inline-flex;
  align-items:center;
  gap:.5rem;
  box-shadow:var(--shadow);
  cursor:pointer;
}
.btn.ghost{background:transparent;color:var(--ink);border:1px solid var(--border);box-shadow:none}
.card .btn{
  background:linear-gradient(135deg,var(--brand),#4f8ff5);
  color:#f7fbff;
  border:1px solid rgba(255,255,255,0.18);
}
.card .btn.ghost{
  background:rgba(255,255,255,0.06);
  color:var(--ink);
  border:1px solid var(--border);
}

.site-header{position:sticky;top:0;z-index:10;background:rgba(11,18,32,0.6);backdrop-filter:blur(10px);border-bottom:1px solid var(--border)}
.header-inner{display:flex;align-items:center;justify-content:space-between;padding:.6rem 0}
.brand{display:flex;align-items:center;gap:.6rem;text-decoration:none;color:var(--ink);font-weight:700}
.brand-mark{display:grid;place-items:center;width:36px;height:36px;border-radius:.8rem;background:linear-gradient(135deg,var(--brand),var(--accent));color:#0b1220;font-weight:900}
.main-nav a{color:var(--muted);text-decoration:none;margin-left:1rem;font-weight:600}
.main-nav a:hover,.main-nav a.active{color:var(--ink)}

.cert-page{padding:1.5rem 0 2.5rem}
.cert-grid{
  display:grid;
  gap:1.2rem;
  grid-template-columns:2fr 1fr;
  grid-template-areas:
    "viewer details"
    "list   list";
  align-items:start;
}
.card{
  background:var(--panel);
  border:1px solid var(--border);
  border-radius:1rem;
  padding:1rem;
  box-shadow:var(--shadow);
}
.viewer-card{display:flex;flex-direction:column;gap:.8rem;grid-area:viewer}
.details-card{grid-area:details}
.list-card{grid-area:list}

.viewer-toolbar{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:1rem;
  flex-wrap:wrap;
}
.viewer-actions{display:flex;gap:.6rem;flex-wrap:wrap}
.viewer-frame{
  width:100%;
  height:520px;
  background:#0d1427;
  border:1px solid var(--border);
  border-radius:.9rem;
  overflow:hidden;
}
.viewer-frame iframe{
  width:100%;
  height:100%;
  border:0;
  background:#0d1427;
}

.list-card{display:flex;flex-direction:column;gap:.8rem}
.cert-list{
  list-style:none;
  margin:0;
  padding:0;
  display:grid;
  gap:.65rem;
  grid-template-columns:repeat(auto-fit,minmax(260px,1fr));
}
.cert-item{
  width:100%;
  text-align:left;
  background:var(--panel);
  border:1px solid var(--border);
  border-radius:.7rem;
  padding:.7rem .8rem;
  color:var(--ink);
  cursor:pointer;
  display:grid;
  gap:.25rem;
  transition:background .15s ease,border-color .15s ease,transform .08s ease;
}
.cert-item:hover{background:var(--card);transform:translateY(-1px)}
.cert-item.active{border-color:var(--accent);box-shadow:0 0 0 1px rgba(34,211,238,0.3)}
.cert-item .meta{color:var(--muted);font-size:.9rem}
.chip-row{display:flex;flex-wrap:wrap;gap:.35rem}
.chip{
  background:linear-gradient(135deg,#f8fafc,#dce1eb);
  border:1px solid rgba(255,255,255,0.35);
  padding:.25rem .55rem;
  border-radius:.5rem;
  font-size:.8rem;
  color:#0f172a;
  box-shadow:0 10px 24px rgba(0,0,0,0.18);
}

.details-card{
  background:var(--card);
  border:1px solid var(--border);
  border-radius:1rem;
  padding:1rem;
  box-shadow:var(--shadow);
}
.tags{display:flex;flex-wrap:wrap;gap:.35rem;margin-top:.4rem}
.tags span{background:var(--chip);border:1px solid var(--border);padding:.25rem .55rem;border-radius:.5rem;font-size:.85rem;color:var(--muted)}

.site-footer{border-top:1px solid var(--border);padding:1rem 0;background:rgba(11,18,32,0.5);margin-top:1rem}

@media (max-width:900px){
  .cert-grid{
    grid-template-columns:1fr;
    grid-template-areas:
      "details"
      "viewer"
      "list";
  }
  .viewer-frame{height:480px}
  .viewer-toolbar{flex-direction:column;align-items:flex-start}
}