@import url('https://fonts.googleapis.com/css2?family=DM+Serif+Display:ital@0;1&family=DM+Sans:wght@300;400;500&display=swap');

/* ═══════════════════════════════════════════════
   SHARED STYLES
   Used by index.html, research.html, teaching.html
═══════════════════════════════════════════════ */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:        #F8F6F1;
  --ink:       #1A1916;
  --ink-muted: #8A8780;
  --accent:    #C8A96E;
  --border:    #E2DED6;
  --white:     #FFFFFF;
  --sidebar-w: 280px;
}

html { scroll-behavior: smooth; }

body {
  background: var(--white);
  color: var(--ink);
  font-family: 'DM Sans', sans-serif;
  font-weight: 300;
  line-height: 1.6;
  overflow-x: hidden;
  display: flex;
}

/* ── SIDEBAR ── */
#sidebar {
  position: fixed;
  top: 0; left: 0; bottom: 0;
  width: var(--sidebar-w);
  background: var(--bg);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 2.5rem 1.75rem 2rem;
  z-index: 200;
  overflow-y: auto;
}

.sidebar-photo {
  width: 130px;
  height: 130px;
  border-radius: 50%;
  overflow: hidden;
  border: 3px solid var(--border);
  margin-bottom: 1.2rem;
  flex-shrink: 0;
}
.sidebar-photo img { width: 100%; height: 100%; object-fit: cover; }

.sidebar-photo-placeholder {
  width: 100%; height: 100%;
  background: linear-gradient(135deg, #E2DED6 0%, #C8A96E33 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.sidebar-photo-placeholder svg {
  width: 60px;
  height: 60px;
  max-width: 100%;
  max-height: 100%;
}

.sidebar-name {
  font-family: 'DM Serif Display', serif;
  font-size: 1.15rem;
  font-weight: 400;
  text-align: center;
  line-height: 1.25;
  margin-bottom: 0.3rem;
}

.sidebar-title {
  font-size: 0.75rem;
  color: var(--ink-muted);
  text-align: center;
  line-height: 1.5;
  margin-bottom: 0.2rem;
}

.sidebar-dept {
  font-size: 0.72rem;
  color: var(--accent);
  text-align: center;
  letter-spacing: 0.05em;
  margin-bottom: 1.75rem;
}

.sidebar-divider {
  width: 100%;
  height: 1px;
  background: var(--border);
  margin-bottom: 1.25rem;
}

.sidebar-section-label {
  font-size: 0.65rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-muted);
  align-self: flex-start;
  margin-bottom: 0.85rem;
}

.sidebar-contact-list {
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
  margin-bottom: 1.75rem;
}

.sidebar-contact-item {
  display: flex;
  align-items: flex-start;
  gap: 0.65rem;
  font-size: 0.8rem;
  color: var(--ink);
  text-decoration: none;
  line-height: 1.4;
  transition: color 0.2s;
}
.sidebar-contact-item:hover { color: var(--accent); }

.ci-icon {
  width: 15px; height: 15px;
  flex-shrink: 0;
  margin-top: 2px;
  color: var(--ink-muted);
}

.ci-label {
  font-size: 0.62rem;
  color: var(--ink-muted);
  display: block;
  margin-bottom: 0.1rem;
  letter-spacing: 0.07em;
  text-transform: uppercase;
}

.sidebar-socials {
  width: 100%;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem;
  margin-top: auto;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}

.social-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  padding: 0.5rem 0.6rem;
  border: 1px solid var(--border);
  border-radius: 2px;
  font-size: 0.7rem;
  letter-spacing: 0.04em;
  text-decoration: none;
  color: var(--ink-muted);
  transition: all 0.2s;
}
.social-btn:hover { border-color: var(--accent); color: var(--accent); }
.social-btn svg { width: 12px; height: 12px; flex-shrink: 0; }

/* ── MAIN WRAPPER ── */
#main {
  margin-left: var(--sidebar-w);
  flex: 1;
  min-height: 100vh;
}

/* ── NAV ── */
nav {
  position: sticky;
  top: 0; z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.4rem 3.5rem;
  background: rgba(248,246,241,0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s;
}
nav.scrolled { border-bottom-color: var(--border); }

.nav-logo {
  font-family: 'DM Serif Display', serif;
  font-size: 1.1rem;
  text-decoration: none;
  color: var(--ink);
}

.nav-links { display: flex; gap: 2.5rem; list-style: none; }

/* Nav item wrapper for dropdown positioning */
.nav-links li {
  position: relative;
}

.nav-links a {
  text-decoration: none;
  color: var(--ink-muted);
  font-size: 0.82rem;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  transition: color 0.2s;
  position: relative;
  padding-bottom: 2px;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}
.nav-links a::after {
  content: '';
  position: absolute; left: 0; bottom: 0;
  width: 0; height: 1px;
  background: var(--accent);
  transition: width 0.25s;
}
.nav-links a:hover { color: var(--ink); }
.nav-links a:hover::after,
.nav-links a.active::after { width: 100%; }
.nav-links a.active { color: var(--ink); }

/* Dropdown chevron */
.nav-chevron {
  display: inline-block;
  width: 8px; height: 8px;
  position: relative;
  flex-shrink: 0;
  margin-bottom: 1px;
}
.nav-chevron::before,
.nav-chevron::after {
  content: '';
  position: absolute;
  top: 3px;
  width: 5px; height: 1px;
  background: currentColor;
  transition: transform 0.2s;
}
.nav-chevron::before { left: 0; transform: rotate(35deg); }
.nav-chevron::after  { right: 0; transform: rotate(-35deg); }

/* Dropdown panel */
.nav-dropdown {
  position: absolute;
  top: 100%;
  left: 50%;
  min-width: 210px;
  background: var(--white);
  border: 1px solid var(--border);
  box-shadow: 0 8px 32px rgba(26,25,22,0.08);
  opacity: 0;
  pointer-events: none;
  transform: translateX(-50%) translateY(8px);
  transition: opacity 0.2s ease, transform 0.2s ease;
  z-index: 300;
  /* Invisible top padding acts as a bridge over the gap */
  padding-top: 18px;
  margin-top: 0;
}

/* Arrow notch sits inside the padding bridge */
.nav-dropdown::before {
  content: '';
  position: absolute;
  top: 13px;
  left: 50%;
  transform: translateX(-50%) rotate(45deg);
  width: 8px; height: 8px;
  background: var(--white);
  border-left: 1px solid var(--border);
  border-top: 1px solid var(--border);
}

.nav-dropdown a {
  display: block;
  padding: 0.7rem 1.25rem;
  font-size: 0.75rem;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: var(--ink-muted);
  text-decoration: none;
  border-bottom: 1px solid var(--border);
  transition: background 0.15s, color 0.15s;
  white-space: nowrap;
}
.nav-dropdown a:last-child { border-bottom: none; }
.nav-dropdown a::after { display: none; } /* suppress underline pseudo */
.nav-dropdown a:hover {
  background: var(--bg);
  color: var(--accent);
}

/* Show on hover */
.nav-links li:hover .nav-dropdown,
.nav-links li:focus-within .nav-dropdown {
  opacity: 1;
  pointer-events: auto;
  transform: translateX(-50%) translateY(0);
}

/* Rotate chevron on hover */
.nav-links li:hover .nav-chevron::before,
.nav-links li:focus-within .nav-chevron::before { transform: rotate(-35deg); }
.nav-links li:hover .nav-chevron::after,
.nav-links li:focus-within .nav-chevron::after  { transform: rotate(35deg); }

/* ── SHARED PAGE HEADER (research & teaching) ── */
.page-header {
  padding: 4rem 3.5rem 2.5rem;
  border-bottom: 1px solid var(--border);
  opacity: 0;
  transform: translateY(20px);
  animation: fadeUp 0.8s ease forwards 0.1s;
}

.section-label {
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.75rem;
}

h1 {
  font-family: 'DM Serif Display', serif;
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 400;
  line-height: 1.1;
  letter-spacing: -0.01em;
  margin-bottom: 0.75rem;
}

h2 {
  font-family: 'DM Serif Display', serif;
  font-size: 1.4rem;
  font-weight: 400;
  margin-bottom: 0.75rem;
  margin-top: 0.75rem;
  padding-bottom: 0.25rem;
  /*border-bottom: 1px solid var(--border);*/
}


h3 {
  font-family: 'DM Serif Display', serif;
  font-size: 1.2rem;
  font-weight: 400;
  margin-bottom: 0.75rem;
  margin-top: 0.75rem;
  padding-bottom: 0.25rem;
  /*border-bottom: 1px solid var(--border);*/
}

h4 {
  font-family: 'DM Serif Display', serif;
  font-size: 1rem;
  font-weight: 400;
  margin-bottom: 0.75rem;
  margin-top: 0.75rem;
  padding-bottom: 0.25rem;
  /*border-bottom: 1px solid var(--border);*/
}


.page-intro {
  max-width: 800px;
  color: var(--ink-muted);
  line-height: 1.8;
  font-size: 0.97rem;
}

.page-course {
  max-width: 900px;
  color: black;
  line-height: 1.8;
  font-size: 1.2rem;
}

/* ── SHARED SECTION CHROME ── */
section { padding: 4rem 3.5rem; }
section + section { border-top: 1px solid var(--border); padding-top: 3.5rem; }

ol {
  margin: .5em 0 1.25em;
  padding-left: 2em;          /* room for the numbers (your * reset zeroes padding) */
  list-style: decimal;
  font-size: 1.2rem;
}

ol li {
  margin: 4px 0 2px;
  padding-left: .25em;
}

/* Nested ordered lists: a, b, c... then i, ii, iii... */
ol ol {
  list-style: lower-alpha;
  margin: .25em 0;
}
ol ol ol {
  list-style: lower-roman;
}


/*ol {
  margin:.5em 0 1.25em;
  padding:0 0px;
  list-style:none;
  font-size: 1.2rem;
  }

ol li li
{
  background:url("https://hqahtan.github.io/img/icon_star_sm.jpg") no-repeat 1px .2em;
  margin:0;
  padding:0 0 0px 16px;
  margin-top: 4px;
  margin-bottom: 2px;
  font-size: 1.2rem;
  margin-left:30px;
}

ol li
{
  background:url("https://hqahtan.github.io/img/icon_arrow_bk.jpg") no-repeat 1px .2em;
  margin:0;
  margin-top: 4px;
  padding:0 0 0px 16px;
  margin-bottom: 2px;
  font-size: 1.2rem;
  margin-left:10px
}

ol li span {
  position: relative;
  left: +100px;
}
*/
ul {
  margin: .5em 0 1.25em;
  padding: 0;
  list-style: none;
  font-size: 1.2rem;
}

/* Direct children only — prevents this rule bleeding into nested levels */
ul > li {
  position: relative;
  padding: 0 0 0 1.25em;
  margin-top: 4px;
  margin-bottom: 2px;
  margin-left: 1em;
  font-size: 1.2rem;
}

ul > li::before {
  content: '–';
  position: absolute;
  left: 0;
  color: var(--ink-muted);
}

/* Level 2 */
ul ul {
  margin: .25em 0 .25em;
  padding: 0;
}

ul ul > li {
  position: relative;
  padding: 0 0 0 1.25em;
  margin-left: 1.75em;
  margin-top: 3px;
  margin-bottom: 2px;
  font-size: 1.2rem;
}

ul ul > li::before {
  content: '·';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-size: 1.2rem;
  line-height: 1.4;
}

/* Level 3 */
ul ul ul > li {
  margin-left: 1.75em;
  font-size: 1.1rem;
}

ul ul ul > li::before {
  content: '○';
  font-size: .8em;
  padding: 10px;
  margin-left: 20px
  color: var(--ink-muted);
}


/* ── SHARED BUTTONS ── */
.btn {
  display: inline-block;
  text-decoration: none;
  padding: 0.8rem 1.75rem;
  font-size: 0.82rem;
  letter-spacing: 0.06em;
  border-radius: 2px;
  transition: all 0.22s ease;
  font-family: 'DM Sans', sans-serif;
  font-weight: 500;
}
.btn-primary { background: var(--ink); color: var(--white); border: 1px solid var(--ink); }
.btn-primary:hover { background: transparent; color: var(--ink); }
.btn-ghost { background: transparent; color: var(--ink); border: 1px solid var(--border); }
.btn-ghost:hover { border-color: var(--ink); }

.btn-group { display: flex; gap: 1rem; flex-wrap: wrap; }

/* ── FOOTER ── */
footer {
  border-top: 1px solid var(--border);
  padding: 2rem 3.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.75rem;
  color: var(--ink-muted);
}

/* ── ANIMATIONS ── */
@keyframes fadeUp { to { opacity: 1; transform: translateY(0); } }

.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.65s ease, transform 0.65s ease;
}
.reveal.visible { opacity: 1; transform: translateY(0); }

/* ── RESPONSIVE ── */
@media (max-width: 900px) {
  body { flex-direction: column; }

  #sidebar {
    position: relative;
    width: 100%;
    flex-direction: column;
    align-items: center;
    padding: 1.75rem 1.5rem 1.25rem;
    border-right: none;
    border-bottom: 1px solid var(--border);
  }

  #main { margin-left: 0; }

  nav { padding: 1.1rem 1.5rem; }

  .page-header,
  section { padding-left: 1.5rem; padding-right: 1.5rem; }

  footer { flex-direction: column; gap: 0.75rem; text-align: center; }
}


table table-ask {
      font-family: Arial, Helvetica, sans-serif;
      border-collapse: collapse;
      width: 500px;
    }

table table-schedule {
      font-family: Arial, Helvetica, sans-serif;
      border-collapse: collapse;
      max-width: 800px;
    }
    td, th {
      border: 1px solid #ddd;
      padding: 8px;
    }

    tr:nth-child(even){background-color: #f2f2f2;}

    tr:hover {background-color: #ddd;}

    th {
      padding-top: 12px;
      padding-bottom: 12px;
      text-align: left;
      background-color: #008080;
      color: white;
    }
    td {
      padding-top: 12px;
      padding-bottom: 12px;
      text-align: left;
      color: black;
    }




#to_top {
  display: none;
  position: fixed;
  bottom: 20px;
  right: 30px;
  z-index: 99;
  font-size: 18px;
  border: none;
  outline: none;
  background-color: transparent;
  color: white;
  cursor: pointer;
  padding: 15px;
  border-radius: 4px;
}

/*#to_top:hover {
  background-color: teal;
}
*/





  /* ── Code blocks ── */
  pre {
    background: var(--surface2);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 1rem 1.2rem;
    overflow-x: auto;
    margin: 1rem 0;
    position: relative;
  }
  .copy-btn {
      position: absolute;
      top: 8px;
      right: 8px;
      padding: 4px 10px;
      font-size: 12px;
      font-family: inherit;
      line-height: 1;
      background: var(--accent);
      color: #fff;
      border: 1px solid var(--accent); 
      border-radius: 4px;
      cursor: pointer;
      opacity: 0.75;
      transition: opacity 0.2s ease, background 0.2s ease;
    }
    pre:hover .copy-btn { opacity: 1; }
    .copy-btn:hover { background: var(--text-muted); color: #111;}
    .copy-btn.copied {
      background: #2ecc71;
      border: 1px solid var(--text-muted);
      border-color: #2ecc71;
      color: #111;
      opacity: 1;
    }
  pre .lang-label {
    position: absolute;
    top: .45rem; right: .7rem;
    font-family: 'IBM Plex Mono', monospace;
    font-size: .65rem;
    letter-spacing: .08em;
    text-transform: uppercase;
    color: rosybrown;
    opacity: .7;
  }
  code {
    font-family: 'IBM Plex Mono', monospace;
    font-size: .84rem;
    line-height: 1.65;
    color: brown;
  }
  /* Inline code */
  p code, li code {
    background: var(--surface2);
    border: 1px solid var(--border);
    border-radius: 3px;
    padding: .1em .4em;
    font-size: .82rem;
    color: brown;
  }

  /* Syntax highlight classes */
  .kw  { color: #a45af0; }
  .wd  { color: SaddleBrown; font-size: 120%; font-weight:bold;}
  .str { color: var(--accent); }
  .cm  { color: var(--text-muted); font-style: italic; }
  .fn  { color: #008000; }
  .op  { color: #f05a8a; }
  .nb  { color: #5a9ef0; }
  .ct  { color: #555; }
  .sh  { color: #800080; font-weight:bold; }   /* shell prompt */
  .tx  { color: brown; }

/* ── Table list (table names) ── */
  .table-list {
    display: flex;
    flex-wrap: wrap;
    gap: .4rem;
    margin: .5rem 0 1rem;
  }
  .table-list span {
    font-family: 'IBM Plex Mono', monospace;
    font-size: .76rem;
    background: var(--surface2);
    border: 1px solid var(--border);
    border-radius: 3px;
    padding: .15em .55em;
    /*color: var(--accent);*/
    color: navy;
  }

/* ── Note ── */
  .note {
    border-left: 3px solid var(--accent2);
    background: rgba(240,164,90,.05);
    padding: .75rem 1rem;
    border-radius: 0 4px 4px 0;
    margin: .75rem 0;
    font-size: .88rem;
    color: var(--text-muted);
  }
  .note strong { color: var(--accent2); }

  
/* ── Quarto layout classes ── */
  .page-columns {
    display: flex;
    flex-direction: row;
    gap: 2rem;
    width: 100%;
  }

  .page-rows-contents {
    display: flex;
    flex-direction: column;
    width: 100%;
  }

  .page-layout-article {
    max-width: 900px;
  }

  .margin-sidebar {
    width: 0;
    flex-shrink: 0;
    overflow: hidden;
  }

  main.content {
    flex: 1;
    min-width: 0;
  }

  /* ── Section levels (Quarto heading structure) ── */
  section.level2 {
    padding: 0;
    border-top: none;
  }

  section.level2 + section.level2 {
    border-top: 1px solid var(--border);
    padding-top: 1.5rem;
    margin-top: 1.5rem;
  }

  h2.anchored {
    scroll-margin-top: 5rem; /* account for sticky nav */
  }

  /* ── Figures ── */
  .quarto-figure {
    margin: 1.5rem 0;
  }

  .quarto-figure-center {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

  figure.figure {
    margin: 0;
    display: inline-block;
    max-width: 100%;
  }

  figure.figure img {
    max-width: 100%;
    height: auto;
    border: 1px solid var(--border);
    border-radius: 3px;
  }

  .figure-caption {
    margin-top: 0.5rem;
    font-size: 0.82rem;
    color: var(--ink-muted);
    font-style: italic;
    text-align: center;
  }

  /* ── Code blocks with copy button ── */
  .sourceCode {
    position: relative;
    margin: 1rem 0;
  }

  .code-with-copy {
    padding-right: 3rem; /* room for the copy button */
  }

  .code-copy-button {
    position: absolute;
    top: 0.45rem;
    right: 0.5rem;
    background: transparent;
    border: 1px solid var(--border);
    border-radius: 3px;
    padding: 0.2rem 0.45rem;
    cursor: pointer;
    color: var(--ink-muted);
    font-size: 0.75rem;
    line-height: 1;
    transition: color 0.2s, border-color 0.2s, background 0.2s;
  }

  .code-copy-button:hover {
    color: var(--accent);
    border-color: var(--accent);
    background: rgba(200, 169, 110, 0.07);
  }

  /* Bootstrap icon fallback — renders a clipboard symbol via CSS */
  .bi::before {
    content: '⧉';
    font-style: normal;
  }

/* ── Callout cards ── */
  .callout {
    margin: 2rem 0;
    border-radius: 6px;
    border: 1px solid var(--border);
    background: var(--surface);
    overflow: hidden;
  }
  .callout-header {
    display: flex;
    align-items: center;
    gap: .6rem;
    padding: .75rem 1.2rem;
    font-family: 'IBM Plex Mono', monospace;
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: .06em;
    text-transform: uppercase;
    border-bottom: 1px solid var(--border);
    color:black;
    background: rgba(90,240,196,.07);
  }
  .callout-header .icon { font-size: 1rem; }
  .callout-body { padding: 1.25rem 1.4rem; }
  .callout-body p { font-size: .93rem; }

  /* Callout type variants — set the accent color used by header + left border */
  .callout-note      { --callout-color: var(--accent); }
  .callout-tip        { --callout-color: #4CAF7D; }
  .callout-warning    { --callout-color: var(--accent2, #E0A458); }
  .callout-important  { --callout-color: #D1554A; }

  .callout {
    border-left: 3px solid var(--callout-color, var(--accent));
  }
  .callout-header {
    background: color-mix(in srgb, var(--callout-color, var(--accent)) 10%, transparent);
  }
  .callout-header .icon { color: var(--callout-color, var(--accent)); }

  /* ── Nested callouts ── */
  /* A callout dropped inside another callout's body loses its own outer
     margin/radius so it reads as "inside" the parent, and its border
     narrows slightly so nesting depth is legible at a glance. */
  .callout .callout {
    margin: 1rem 0;
    border-left-width: 2px;
  }
  .callout .callout .callout {
    border-left-width: 1px;
  }
  .callout .callout .callout-header {
    font-size: .82rem;
    padding: .6rem 1rem;
  }
  .callout .callout .callout-body {
    padding: 1rem 1.1rem;
  }
  .callout .callout .callout .callout-header { font-size: .74rem; }


.code2 {
    font-family: "Verdana", "Helvetica", "Arial", sans-serif;
    font-size: .84rem;
    line-height: 1.65;
    color: seagreen;
  }