/* ============================================================================
   Sema PTA landing — 02 — Header, logo, navigation, avatars
   ----------------------------------------------------------------------------
   To edit this section, open css/header.css. All rules are grouped here.
   ============================================================================ */

/* ========== Header ========== */

header {
    position: fixed; top: 20px; left: 50%; transform: translateX(-50%);
    z-index: 50;
    width: min(1400px, calc(100% - 40px));
    display: flex; justify-content: space-between; align-items: center;
    padding: 12px 24px;
    background: rgba(20, 16, 12, 0.55);
    backdrop-filter: blur(20px) saturate(140%);
    -webkit-backdrop-filter: blur(20px) saturate(140%);
    border: 1px solid var(--border);
    border-radius: 100px;
  }

.logo {
    display: flex; align-items: center; gap: 10px;
    font-weight: 600; font-size: 17px; letter-spacing: -0.02em;
  }

.logo-mark {
    width: 30px; height: 30px;
    border-radius: 9px;
    background: linear-gradient(135deg, var(--sema-500), var(--sema-700));
    display: flex; align-items: center; justify-content: center;
    box-shadow: 0 0 0 1px rgba(255,255,255,0.06) inset, 0 4px 20px rgba(255,138,76,0.35);
    position: relative;
  }

.logo-mark::after {
    content: ""; width: 12px; height: 12px;
    border-radius: 3px;
    background: var(--bg);
    transform: rotate(45deg);
  }

nav { display: flex; gap: 6px; }

nav a {
    padding: 8px 16px;
    font-size: 14px; font-weight: 500;
    color: var(--text-dim);
    border-radius: 100px;
    transition: color .2s, background .2s;
  }

nav a:hover { color: var(--text); background: rgba(255,255,255,0.04); }

.avatars { display: flex; }

.avatars span {
    width: 26px; height: 26px;
    border-radius: 50%;
    border: 2px solid var(--bg);
    background: linear-gradient(135deg, var(--sema-500), var(--sema-700));
    margin-left: -8px;
    display: inline-block;
  }

.avatars span:first-child { margin-left: 0; background: linear-gradient(135deg, var(--sema-300), var(--sema-600)); }

.avatars span:nth-child(2) { background: linear-gradient(135deg, var(--sema-600), var(--sema-900)); }

.avatars span:nth-child(3) { background: linear-gradient(135deg, var(--sema-500), var(--sema-700)); }