/* ==========================================================================
   4LLab — Data Analytics Group, Adelaide University
   Shared site theme. Palette based on Adelaide University brand:
   "North Terrace" purple #6956CC with deep ink-purple supports.
   ========================================================================== */

:root {
  --au-purple: #6956CC;        /* brand accent */
  --au-purple-dark: #4938A8;   /* hover / emphasis, AA on white */
  --au-purple-deep: #2B2260;   /* headers, near-navy purple */
  --au-purple-ink: #1E1745;    /* darkest — hero gradient end */
  --au-purple-tint: #F1EEFB;   /* light wash backgrounds */
  --au-purple-tint-2: #E2DCF7; /* slightly stronger wash */
  --au-text: #211D35;
  --au-muted: #5A5570;
  --bs-link-color: var(--au-purple-dark);
}

/* -------------------------------------------------------------- dark mode */
:root[data-theme="dark"] {
  --au-purple: #9d8df0;
  --au-purple-dark: #b9aef5;     /* lighter for contrast on dark bg */
  --au-purple-deep: #cfc6f8;
  --au-purple-tint: #211b3d;     /* dark wash backgrounds */
  --au-purple-tint-2: #322a55;
  --au-text: #ECE9F7;
  --au-muted: #B3ADC9;
  --bs-link-color: #b9aef5;
}
:root[data-theme="dark"] body { background-color: #14101f; color: var(--au-text); }
:root[data-theme="dark"] .bg-light { background-color: var(--au-purple-tint) !important; color: var(--au-text); }
:root[data-theme="dark"] .card-soft,
:root[data-theme="dark"] .member-card,
:root[data-theme="dark"] .project-card,
:root[data-theme="dark"] .pub-toolbar { background: var(--au-purple-tint); border-color: var(--au-purple-tint-2); color: var(--au-text); }
:root[data-theme="dark"] .text-muted { color: var(--au-muted) !important; }
:root[data-theme="dark"] .list-group-item { background-color: transparent; color: var(--au-text); }
:root[data-theme="dark"] .card.card-body { background-color: var(--au-purple-tint); color: var(--au-text); }
:root[data-theme="dark"] code { color: #e6a3f0; }
:root[data-theme="dark"] [role="main"] h2.border-bottom,
:root[data-theme="dark"] main h2.border-bottom,
:root[data-theme="dark"] .section-title { color: var(--au-purple-deep); }

/* theme toggle button */
#themeToggle {
  background: transparent;
  border: 1px solid rgba(255,255,255,.4);
  color: #fff;
  border-radius: .4rem;
  padding: .2rem .55rem;
  margin-left: .5rem;
}
#themeToggle:hover { background: rgba(255,255,255,.12); }

/* ------------------------------------------------------------------ base */
body {
  color: var(--au-text);
  font-family: "Segoe UI", system-ui, -apple-system, Roboto, "Helvetica Neue", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--au-purple-dark); }
a:hover, a:focus { color: var(--au-purple-ink); }

/* visible keyboard focus everywhere */
a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible {
  outline: 3px solid var(--au-purple);
  outline-offset: 2px;
  border-radius: 2px;
}

/* skip link for keyboard / screen-reader users */
.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  z-index: 2000;
  background: var(--au-purple-ink);
  color: #fff;
  padding: .6rem 1rem;
  border-radius: 0 0 .5rem 0;
}
.skip-link:focus {
  left: 0;
  color: #fff;
}

/* ---------------------------------------------------------------- header */
.site-header {
  background: linear-gradient(135deg, var(--au-purple-deep) 0%, var(--au-purple-ink) 55%, #171134 100%);
  color: #fff;
}
.site-header .site-title {
  font-size: clamp(1.15rem, 2.5vw, 1.75rem);
  font-weight: 700;
  letter-spacing: .02em;
  padding: .65rem 1rem .1rem;
}
.site-header .site-title .accent { color: #BFB2F3; }

.site-header .navbar { background: transparent !important; }
.site-header .nav-link {
  color: rgba(255, 255, 255, .85);
  border-radius: .4rem;
  margin: 0 .1rem;
  transition: background-color .2s ease, color .2s ease;
}
.site-header .nav-link:hover,
.site-header .nav-link:focus {
  color: #fff;
  background-color: rgba(255, 255, 255, .12);
}
.site-header .nav-link.active {
  color: #fff;
  background-color: var(--au-purple);
  font-weight: 600;
}

/* ------------------------------------------------------------------ hero */
.hero {
  background:
    radial-gradient(1100px 420px at 85% -10%, rgba(105, 86, 204, .45), transparent 60%),
    linear-gradient(135deg, var(--au-purple-deep), var(--au-purple-ink));
  color: #fff;
  border-radius: 1rem;
  padding: 3rem 1.5rem;
}
@media (min-width: 768px) { .hero { padding: 4rem 3rem; } }
.hero h1 { font-weight: 700; }
.hero .lead { color: #E6E1FA; max-width: 60ch; }
.hero .btn-hero {
  background: #fff;
  color: var(--au-purple-deep);
  font-weight: 600;
  border: 0;
}
.hero .btn-hero:hover { background: var(--au-purple-tint-2); color: var(--au-purple-ink); }

/* ----------------------------------------------------------- components */
.section-title {
  border-bottom: 3px solid var(--au-purple);
  padding-bottom: .5rem;
  margin-top: 2.5rem;
  font-weight: 650;
  color: var(--au-purple-deep);
}

.card-soft {
  background: var(--au-purple-tint);
  border: 1px solid var(--au-purple-tint-2);
  border-radius: .85rem;
  transition: transform .18s ease, box-shadow .18s ease;
}
.card-soft:hover {
  transform: translateY(-3px);
  box-shadow: 0 .6rem 1.4rem rgba(43, 34, 96, .14);
}

/* generic light boxes reused from old design get a purple tint */
.bg-light { background-color: var(--au-purple-tint) !important; }

.btn-outline-primary {
  --bs-btn-color: var(--au-purple-dark);
  --bs-btn-border-color: var(--au-purple-dark);
  --bs-btn-hover-bg: var(--au-purple-dark);
  --bs-btn-hover-border-color: var(--au-purple-dark);
  --bs-btn-hover-color: #fff;
  --bs-btn-active-bg: var(--au-purple-deep);
  --bs-btn-active-border-color: var(--au-purple-deep);
}
.btn-primary {
  --bs-btn-bg: var(--au-purple-dark);
  --bs-btn-border-color: var(--au-purple-dark);
  --bs-btn-hover-bg: var(--au-purple-deep);
  --bs-btn-hover-border-color: var(--au-purple-deep);
  --bs-btn-active-bg: var(--au-purple-ink);
  --bs-btn-active-border-color: var(--au-purple-ink);
}
.text-primary, .link-primary { color: var(--au-purple-dark) !important; }

.list-group-item-action:hover, .list-group-item-action:focus {
  background-color: var(--au-purple-tint);
}

/* member cards */
.member-card {
  background: #fff;
  border: 1px solid var(--au-purple-tint-2);
  border-radius: .85rem;
  padding: 1rem;
  height: 100%;
  transition: transform .18s ease, box-shadow .18s ease;
}
.member-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 .5rem 1.2rem rgba(43, 34, 96, .12);
}
.member-card img {
  object-fit: cover;
  border: 3px solid var(--au-purple-tint-2);
}

/* project cards */
.project-card {
  border: 1px solid var(--au-purple-tint-2);
  border-radius: .85rem;
  overflow: hidden;
  transition: transform .18s ease, box-shadow .18s ease;
}
.project-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 .6rem 1.4rem rgba(43, 34, 96, .14);
}
.project-card img { max-width: 300px; height: auto; }

/* ---------------------------------------------------------------- footer */
.site-footer {
  margin-top: 3rem;
  background: var(--au-purple-ink);
  color: #CFC8EF;
  padding: 1.5rem 1rem;
  border-radius: 1rem 1rem 0 0;
}
.site-footer a { color: #E6E1FA; }
.site-footer a:hover { color: #fff; }

/* ----------------------------------------------------------- back to top */
#backToTop {
  position: fixed;
  right: 1.25rem;
  bottom: 1.25rem;
  z-index: 1500;
  width: 2.9rem;
  height: 2.9rem;
  border-radius: 50%;
  border: 0;
  background: var(--au-purple-dark);
  color: #fff;
  font-size: 1.2rem;
  box-shadow: 0 .4rem 1rem rgba(30, 23, 69, .35);
  opacity: 0;
  pointer-events: none;
  transition: opacity .25s ease;
}
#backToTop.show { opacity: 1; pointer-events: auto; }
#backToTop:hover { background: var(--au-purple-deep); }

/* ------------------------------------------------------------ animations */
@media (prefers-reduced-motion: no-preference) {
  .fade-in-up {
    opacity: 0;
    transform: translateY(14px);
    transition: opacity .5s ease, transform .5s ease;
  }
  .fade-in-up.visible { opacity: 1; transform: none; }
}

/* ---------------------------------------------------------- publications */
.pub-toolbar {
  background: var(--au-purple-tint);
  border: 1px solid var(--au-purple-tint-2);
  border-radius: .85rem;
}
.pub-toolbar input[type="text"] {
  border: 1px solid var(--au-purple-tint-2);
  border-radius: .5rem;
  padding: .45rem .75rem;
  min-width: min(22rem, 80vw);
}
.bibtex_structure .group {
  color: var(--au-purple-deep);
  scroll-margin-top: 5rem;
}

/* legacy markup adapters: style old-page patterns without editing content */
[role="main"] h2.border-bottom, main h2.border-bottom {
  border-bottom: 3px solid var(--au-purple) !important;
  color: var(--au-purple-deep);
  font-weight: 650;
}
[role="main"] .rounded-3.border {
  border: 1px solid var(--au-purple-tint-2) !important;
  border-radius: .85rem !important;
  transition: transform .18s ease, box-shadow .18s ease;
}
[role="main"] .rounded-3.border:hover {
  transform: translateY(-3px);
  box-shadow: 0 .6rem 1.4rem rgba(43, 34, 96, .14);
}
[role="main"] img.rounded-start { border-radius: .6rem !important; }

/* print: hide chrome, keep content */
@media print {
  .site-header, .site-footer, #backToTop, .skip-link, .pub-toolbar { display: none !important; }
}