/* =============================================================
   Mahdi Esmailoghli — personal website
   Plain HTML + CSS. No build step, no JavaScript, no frameworks.

   Almost everything you'd want to tweak is in the variables just
   below: change a color or the content width in ONE place here.
   ============================================================= */

:root {
  --bg:          #ffffff;   /* page background            */
  --text:        #1b1b1b;   /* main text                  */
  --muted:       #5c636b;   /* secondary text: authors, dates, venues */
  --accent:      #1a5fb4;   /* links                      */
  --accent-2:    #134a8e;   /* link hover                 */
  --accent-tint: #eaf1fb;   /* background of resource tags */
  --accent-fg:   #ffffff;   /* text on a filled accent background */
  --rule:        #e6e8eb;   /* hairlines under headings   */

  --maxw:        46rem;     /* content column width       */
  --font:        -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

/* Honors the reader's system dark mode automatically.
   Don't want a dark version? Delete this whole block. */
@media (prefers-color-scheme: dark) {
  :root {
    --bg:          #14171a;
    --text:        #e6e7e9;
    --muted:       #9aa1a9;
    --accent:      #7fb0ef;
    --accent-2:    #a7c8f5;
    --accent-tint: #1e2a38;
    --accent-fg:   #14171a;
    --rule:        #2a2f36;
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-2); text-decoration: underline; }

strong { font-weight: 650; }

/* ---------------- top navigation (sticky) ---------------- */
.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--bg);
  border-bottom: 1px solid var(--rule);
}
.topbar-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0.85rem 1.25rem;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 1rem;
}
.brand { color: var(--text); font-weight: 600; }
.topbar nav a { color: var(--muted); margin-left: 1.15rem; font-size: 0.92rem; }
.topbar nav a:hover { color: var(--accent); text-decoration: none; }

/* ---------------- layout ---------------- */
main {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 2rem 1.25rem;
}
section { margin: 2.5rem 0; }
section:first-child { margin-top: 0.5rem; }

h1 {
  font-size: 2rem;
  font-weight: 600;
  letter-spacing: -0.015em;
  margin: 0 0 0.3rem;
}
h2 {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  color: var(--muted);
  font-weight: 600;
  margin: 0 0 1.1rem;
  padding-bottom: 0.45rem;
  border-bottom: 1px solid var(--rule);
}
p { margin: 0 0 0.95rem; }

/* ---------------- intro ---------------- */
.intro .role { color: var(--muted); margin: 0 0 0.7rem; }
.intro .links { margin: 0; }
.interests { color: var(--muted); font-size: 0.95rem; }

/* optional profile photo (see commented markup in index.html) */
.photo {
  float: right;
  width: 150px;
  height: 150px;
  object-fit: cover;          /* square photo shows whole, no cropping */
  border-radius: 8px;
  margin: 0.3rem 0 1rem 1.5rem;
}

/* ---------------- news ---------------- */
ul.news { list-style: none; padding: 0; margin: 0; }
ul.news li { display: flex; gap: 1rem; margin-bottom: 0.6rem; }
ul.news .date {
  flex: 0 0 5.5rem;
  color: var(--muted);
  font-size: 0.92rem;
  font-variant-numeric: tabular-nums;
}

/* ---------------- publications ---------------- */
ul.pubs { list-style: none; padding: 0; margin: 0; }
.pub { margin: 0 0 1.3rem; }
.pub-title { font-weight: 700; color: var(--text); }
.pub-authors { color: var(--muted); font-size: 0.95rem; }
.pub-venue { color: var(--muted); font-size: 0.86rem; margin-top: 0.05rem; }
.pub-venue .note { font-style: italic; }

/* resource links under a paper: PDF / Slides / Video / Code / arXiv … */
.pub-links { margin-top: 0.45rem; }
.pub-links a {
  display: inline-block;
  font-size: 0.76rem;
  font-weight: 500;
  color: var(--accent);
  background: var(--accent-tint);
  border-radius: 5px;
  padding: 0.1rem 0.5rem;
  margin: 0 0.3rem 0.3rem 0;
  text-decoration: none;
  transition: background 0.12s ease, color 0.12s ease;
}
.pub-links a:hover { background: var(--accent); color: var(--accent-fg); text-decoration: none; }

/* ---------------- plain lists (talks, teaching, awards, service) ---------------- */
ul.list { list-style: none; padding: 0; margin: 0; }
ul.list li { margin: 0 0 0.75rem; }
ul.list .sub { display: block; color: var(--muted); font-size: 0.92rem; }
.label { color: var(--muted); font-weight: 600; }
.note-block { color: var(--muted); font-size: 0.95rem; margin-top: 1rem; }

/* ---------------- footer ---------------- */
footer {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 1.5rem 1.25rem 3rem;
  border-top: 1px solid var(--rule);
  color: var(--muted);
  font-size: 0.85rem;
}

/* ---------------- small screens ---------------- */
@media (max-width: 540px) {
  body { font-size: 16px; }
  .topbar-inner { flex-direction: column; align-items: flex-start; gap: 0.35rem; }
  .topbar nav a { margin: 0 1rem 0 0; }
  ul.news li { flex-direction: column; gap: 0.1rem; }
  .photo { float: none; display: block; margin: 0 0 1rem; }
}