.mobile-toggle,
.mobile-overlay,
.mobile-panel {
  display: none;
}

@media (max-width: 900px) {
  .site-header .container {
    position: relative;
    justify-content: center;
    padding: 14px 0;
  }

  .brand {
    align-items: center;
    text-align: center;
  }

  .brand span {
    display: none;
  }

  .site-nav {
    display: none;
  }

  .mobile-toggle {
    display: inline-flex;
    position: absolute;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
    border: 1px solid var(--line);
    background: var(--card);
    color: var(--ink);
    font-size: 1.2rem;
    padding: 8px 12px;
    border-radius: 8px;
    cursor: pointer;
  }

  .mobile-overlay {
    display: block;
    position: fixed;
    inset: 0;
    background: rgba(31, 45, 56, 0.28);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s ease;
    z-index: 1000;
  }

  .mobile-panel {
    display: block;
    position: fixed;
    left: 50%;
    top: 50%;
    width: min(92vw, 520px);
    transform: translate(-50%, -60%);
    opacity: 0;
    pointer-events: none;
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: 16px;
    box-shadow: var(--shadow);
    padding: 24px;
    transition: opacity 0.2s ease, transform 0.2s ease;
    z-index: 1001;
  }

  .mobile-panel nav {
    display: grid;
    gap: 14px;
    font-size: 1rem;
    color: var(--ink);
  }

  .mobile-panel a {
    padding: 6px 0;
    border-bottom: 1px solid var(--line);
  }

  .mobile-panel a:last-child {
    border-bottom: none;
  }

  body.mobile-panel-open {
    overflow: hidden;
  }

  body.mobile-panel-open .mobile-overlay {
    opacity: 1;
    pointer-events: auto;
  }

  body.mobile-panel-open .mobile-panel {
    opacity: 1;
    pointer-events: auto;
    transform: translate(-50%, -50%);
  }
}