body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  max-width: 1060px;
  margin: 0 auto;
  padding: 0 24px 80px;
  color: #333;
  line-height: 1.7;
}

nav {
  position: sticky;
  top: 0;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid #eee;
  padding: 14px 0;
  margin-bottom: 48px;
  z-index: 100;
}
nav a { margin-right: 20px; color: #555; text-decoration: none; font-size: 0.9em; }
nav a:hover { color: #2980b9; }
.logo {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  background: #2980b9;
  color: #fff !important;
  border-radius: 6px;
  font-weight: 700;
  font-size: 0.75em;
  letter-spacing: 0.04em;
  margin-right: 24px;
  text-decoration: none !important;
  vertical-align: middle;
  flex-shrink: 0;
}
.logo:hover { background: #1f6391; text-decoration: none !important; }

a { color: #2980b9; text-decoration: none; }
a:hover { text-decoration: underline; }

code {
  background: #f4f4f4;
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.9em;
}

pre {
  background: #f4f4f4;
  padding: 16px;
  border-radius: 6px;
  overflow-x: auto;
  font-size: 0.88em;
  line-height: 1.6;
}

ol, ul { padding-left: 20px; }
li { margin-bottom: 8px; }
.subtitle { color: #666; margin-top: 0; }

#nav-toggle { display: none; }
.nav-hamburger { display: none; }
#nav-collapse-toggle { display: none; } /* desktop-only, shown below */

/* Desktop: persistent left sidebar instead of a top bar -- the top bar
   kept overflowing/squeezing as more projects got added. Mobile keeps the
   existing collapsible top bar untouched (see the max-width query below). */
@media (min-width: 641px) {
  nav {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: 200px;
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
    align-content: flex-start;
    padding: 20px 16px;
    margin-bottom: 0;
    border-bottom: none;
    border-right: 1px solid #eee;
    overflow-y: auto;
    box-sizing: border-box;
  }
  /* flex-wrap + per-item flex-basis is what lets some items (logo, page
     links) each force their own full-width row, while others (contact,
     theme toggle) stay natural-width and share a row -- all without
     touching nav.js's DOM order, just CSS `order` to reshuffle it. */
  nav .logo { flex: 0 0 100%; margin-right: 0; margin-bottom: 10px; }
  nav #nav-collapse-toggle {
    display: block;
    order: 0;
    flex: 0 0 100%;
    background: none;
    border: none;
    cursor: pointer;
    color: #999;
    font-size: 0.85em;
    text-align: left;
    padding: 2px 0 14px;
    margin: 0;
  }
  nav #nav-collapse-toggle:hover { color: #2980b9; }
  nav #contact-nav {
    order: 1;
    flex: 0 0 auto;
    margin-right: 10px;
    width: auto;
    padding: 0;
    font-size: 0.88em;
  }
  nav #theme-toggle {
    order: 2;
    flex: 0 0 auto;
    /* nav.js sets margin-left inline -- !important is the only way an
       external stylesheet can win against that. */
    margin: 0 !important;
  }
  nav a:not(.logo):not(#contact-nav) {
    order: 3;
    flex: 0 0 100%;
    margin-right: 0;
    margin-top: 14px;
    width: 100%;
    padding: 8px 0;
    font-size: 0.88em;
  }
  /* divider between the contact/theme row and the page links -- lives on
     the first page link so it spans the full sidebar width regardless of
     how wide the contact/theme row happens to be. */
  nav a:not(.logo):not(#contact-nav):nth-of-type(2) {
    margin-top: 14px;
    padding-top: 14px;
    border-top: 1px solid #eee;
  }

  nav, body { transition: width 0.15s ease, margin-left 0.15s ease; }
  body { margin: 0 0 0 200px; max-width: 1060px; }

  /* Collapsed: icon-only rail -- just the logo and the expand toggle.
     Everything else (contact, theme, page links) hides rather than
     shrinking to icons, since there's no icon set for the project list. */
  [data-nav="collapsed"] nav { width: 56px; padding: 20px 8px; }
  [data-nav="collapsed"] nav .logo { flex-basis: auto; margin-bottom: 8px; }
  [data-nav="collapsed"] nav #nav-collapse-toggle {
    flex-basis: auto;
    text-align: center;
    padding: 4px 0;
    border: none;
  }
  [data-nav="collapsed"] nav a:not(.logo),
  [data-nav="collapsed"] nav #theme-toggle {
    display: none;
  }
  [data-nav="collapsed"] body { margin-left: 56px; }
}

@media (max-width: 640px) {
  nav {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    padding: 10px 0;
  }
  .logo { order: 0; margin-right: auto; }
  .nav-hamburger {
    order: 1;
    display: inline-block;
    cursor: pointer;
    font-size: 1.3em;
    padding: 2px 8px;
  }
  nav button { order: 2; }
  nav a:not(.logo) {
    order: 3;
    display: none;
    width: 100%;
    padding: 8px 0;
    margin-right: 0;
    font-size: 0.9em;
    border-bottom: 1px solid #eee;
  }
  #nav-toggle:checked ~ a:not(.logo) { display: block; }
}