/* ==========================================================================
   Azim Akhtarshenas — academic site
   Design tokens
   ========================================================================== */

:root {
  /* -- palette (light) — dusty plum, rose, sage -- */
  --bg: #ffffff;
  --bg-raised: #ffffff;
  --bg-sunken: #f6f6f6;
  --ink: #241f28;
  --ink-soft: #5c5560;
  --ink-faint: #928a94;
  --hairline: #e8e0e6;
  --blue: #5e4060;
  --blue-deep: #40293f;
  --blue-soft: #8a6b8c;
  --blue-wash: #f1e6f0;
  --accent-line: #5e4060;
  --rose: #8c4a58;
  --rose-deep: #6b3540;
  --rose-wash: #f7e7ea;
  --sage: #47654a;
  --sage-deep: #324a34;
  --sage-wash: #e9efe6;
  --shadow: 0 1px 2px rgba(64, 41, 63, 0.07), 0 8px 24px rgba(64, 41, 63, 0.07);

  /* -- type -- */
  --font-display: "Source Serif 4", "Iowan Old Style", Georgia, serif;
  --font-body: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", "SF Mono", Menlo, monospace;

  --radius: 3px;
  --max-w: 1080px;
}

html[data-theme="dark"] {
  --bg: #17131a;
  --bg-raised: #1f1922;
  --bg-sunken: #120e15;
  --ink: #f1eaf0;
  --ink-soft: #cabec8;
  --ink-faint: #8c7f8a;
  --hairline: #362e37;
  --blue: #d3a8d6;
  --blue-deep: #e6cae8;
  --blue-soft: #ab84ac;
  --blue-wash: #2c2130;
  --accent-line: #d3a8d6;
  --rose: #d99aa5;
  --rose-deep: #e8bcc4;
  --rose-wash: #302127;
  --sage: #9dc2a0;
  --sage-deep: #c1ddc3;
  --sage-wash: #1b2a1e;
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 8px 24px rgba(0, 0, 0, 0.35);
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; }
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: background 0.2s ease, color 0.2s ease;
}

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

:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 2px;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  color: var(--ink);
  font-weight: 600;
  line-height: 1.2;
  margin: 0 0 0.5em;
}

p { margin: 0 0 1em; color: var(--ink-soft); }

.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- Signature motif: waveform divider ----------
   A thin sine/pulse trace, standing in for an RF signal —
   used as a section divider instead of a generic <hr>. */
.waveform-divider {
  display: block;
  width: 100%;
  height: 28px;
  margin: 0 auto;
}
.waveform-divider path {
  fill: none;
  stroke: url(#waveform-gradient);
  stroke-width: 1.4;
  opacity: 0.7;
}

/* ---------- Header / nav ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.86);
  backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--hairline);
}
html[data-theme="dark"] .site-header {
  background: rgba(15, 22, 33, 0.86);
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 14px 24px;
}
.nav-brand {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--ink);
  letter-spacing: 0.01em;
}
.nav-brand:hover { text-decoration: none; color: var(--blue); }
.nav-links {
  display: flex;
  gap: 2px;
  list-style: none;
  margin: 0;
  padding: 0;
  align-items: center;
}
.nav-links a {
  display: inline-block;
  color: var(--ink-soft);
  font-size: 0.92rem;
  padding: 8px 12px;
  border-radius: var(--radius);
  position: relative;
}
.nav-links a:hover { color: var(--blue); text-decoration: none; background: var(--blue-wash); }
.nav-links a.active { color: var(--blue); font-weight: 600; }
.nav-links a.active::after {
  content: "";
  position: absolute;
  left: 12px; right: 12px; bottom: 3px;
  height: 2px;
  background: var(--accent-line);
  border-radius: 2px;
}
.nav-toggle {
  display: none;
  background: none; border: none; cursor: pointer;
  color: var(--ink); padding: 8px;
}
.theme-toggle {
  background: none;
  border: 1px solid var(--hairline);
  border-radius: 999px;
  width: 34px; height: 34px;
  display: inline-flex; align-items: center; justify-content: center;
  cursor: pointer;
  color: var(--ink-soft);
  margin-left: 8px;
}
.theme-toggle:hover { border-color: var(--blue); color: var(--blue); }
.theme-toggle svg { width: 16px; height: 16px; }
.theme-toggle .icon-moon { display: none; }
html[data-theme="dark"] .theme-toggle .icon-sun { display: none; }
html[data-theme="dark"] .theme-toggle .icon-moon { display: inline-block; }

@media (max-width: 820px) {
  .nav-toggle { display: inline-flex; align-items: center; }
  .nav-links {
    position: fixed;
    top: 61px; left: 0; right: 0;
    flex-direction: column;
    align-items: stretch;
    background: var(--bg);
    border-bottom: 1px solid var(--hairline);
    padding: 8px 24px 16px;
    display: none;
    box-shadow: var(--shadow);
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 12px 8px; }
}

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--hairline);
  margin-top: 96px;
  padding: 36px 0 48px;
}
.footer-inner {
  display: flex; flex-wrap: wrap; gap: 12px 28px;
  justify-content: space-between; align-items: center;
  font-size: 0.85rem; color: var(--ink-faint);
}
.footer-links { display: flex; gap: 18px; flex-wrap: wrap; }
.footer-links a { color: var(--ink-faint); }
.footer-links a:hover { color: var(--blue); }

/* ---------- Hero (home) ---------- */
.hero {
  padding: 72px 0 40px;
  position: relative;
  overflow: hidden;
}
.hero-art {
  position: absolute;
  top: 50%;
  right: -40px;
  transform: translateY(-50%);
  width: min(58vw, 760px);
  height: auto;
  color: var(--blue);
  opacity: 0.1;
  pointer-events: none;
  z-index: 0;
}
html[data-theme="dark"] .hero-art { opacity: 0.16; }
.hero-grid {
  position: relative;
  z-index: 1;
}

/* ---------- Ambient flying drones (hero background) ---------- */
.drone-fly {
  opacity: 0;
  transform-box: fill-box;
  transform-origin: center;
}
.drone-fly-a {
  color: var(--rose);
  animation: drone-fly-a 26s linear infinite;
}
.drone-fly-b {
  color: var(--sage);
  animation: drone-fly-b 34s linear infinite -9s;
}
@keyframes drone-fly-a {
  0%   { transform: translate(-60px, 380px) scale(0.6) rotate(-4deg); opacity: 0; }
  8%   { opacity: 0.22; }
  50%  { transform: translate(420px, 70px) scale(0.85) rotate(3deg); }
  92%  { opacity: 0.22; }
  100% { transform: translate(880px, -50px) scale(1) rotate(-2deg); opacity: 0; }
}
@keyframes drone-fly-b {
  0%   { transform: translate(860px, 130px) scale(0.7) rotate(4deg); opacity: 0; }
  8%   { opacity: 0.18; }
  50%  { transform: translate(380px, 350px) scale(0.9) rotate(-3deg); }
  92%  { opacity: 0.18; }
  100% { transform: translate(-80px, 410px) scale(0.6) rotate(2deg); opacity: 0; }
}
.hero-grid {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 44px;
  align-items: center;
}
.hero-photo {
  width: 220px; height: 220px;
  border-radius: 6px;
  object-fit: cover;
  background: var(--bg-sunken);
  border: 1px solid var(--hairline);
  box-shadow: var(--shadow);
}
.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--blue);
  margin-bottom: 10px;
  display: block;
}
.hero h1 {
  font-size: 2.5rem;
  margin-bottom: 6px;
}
.hero .role {
  font-size: 1.05rem;
  color: var(--ink-soft);
  margin-bottom: 4px;
}
.hero .affil {
  font-size: 0.98rem;
  color: var(--ink-faint);
  margin-bottom: 14px;
}
.hero .affil a { color: var(--ink-faint); text-decoration: underline; }
.tag-row {
  display: flex; flex-wrap: wrap; gap: 8px;
  margin-top: 12px;
}
.tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--blue-deep);
  background: var(--blue-wash);
  border: 1px solid var(--hairline);
  padding: 4px 10px;
  border-radius: 999px;
}
.tag-row .tag:nth-child(3n+2) { color: var(--rose-deep); background: var(--rose-wash); }
.tag-row .tag:nth-child(3n+3) { color: var(--sage-deep); background: var(--sage-wash); }

@media (max-width: 700px) {
  .hero-grid { grid-template-columns: 1fr; text-align: center; }
  .hero-photo { width: 160px; height: 160px; margin: 0 auto; }
  .tag-row, .btn-row { justify-content: center; }
  .hero h1 { font-size: 2rem; }
  .hero-art { display: none; }
}

/* ---------- Buttons ---------- */
.btn-row { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 0.88rem; font-weight: 500;
  padding: 9px 16px;
  border-radius: var(--radius);
  border: 1px solid var(--hairline);
  color: var(--ink);
  background: var(--bg-raised);
}
.btn:hover { text-decoration: none; border-color: var(--blue); color: var(--blue); }
.btn-primary {
  background: var(--blue);
  border-color: var(--blue);
  color: #fff;
}
.btn-primary:hover { background: var(--blue-deep); border-color: var(--blue-deep); color: #fff; }
.btn svg { width: 15px; height: 15px; }

/* ---------- Sections ---------- */
.section { padding: 44px 0; }
.section-head { margin-bottom: 28px; }
.section-head .eyebrow { margin-bottom: 4px; }
.section-head h2 { font-size: 1.6rem; }
.section-head p.lede { max-width: 640px; }

/* ---------- Bio ---------- */
.bio { max-width: 720px; font-size: 1rem; }
.bio p { color: var(--ink); }

/* ---------- Research cards ---------- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}
@media (max-width: 700px) { .card-grid { grid-template-columns: 1fr; } }

.card {
  border: 1px solid var(--hairline);
  border-radius: 6px;
  background: var(--bg-raised);
  padding: 26px 26px 22px;
  transition: box-shadow 0.15s ease, transform 0.15s ease;
}
.card:hover { box-shadow: var(--shadow); transform: translateY(-2px); }
.card h3 {
  font-size: 1.1rem;
  display: flex; align-items: center; gap: 10px;
}
.card-icon {
  width: 20px; height: 20px;
  color: var(--blue);
  flex: none;
}
.card ul {
  margin: 12px 0 0;
  padding: 0;
  list-style: none;
  display: flex; flex-wrap: wrap; gap: 8px;
}
.card ul li {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--blue-deep);
  background: var(--blue-wash);
  border: 1px solid var(--hairline);
  padding: 4px 9px;
  border-radius: 4px;
}
.card ul li:nth-child(3n+2) { color: var(--rose-deep); background: var(--rose-wash); }
.card ul li:nth-child(3n+3) { color: var(--sage-deep); background: var(--sage-wash); }

/* ---------- Publications ---------- */
.pub-filter {
  display: flex; flex-wrap: wrap; gap: 8px;
  margin-bottom: 26px;
}
.pub-filter button {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  padding: 6px 13px;
  border-radius: 999px;
  border: 1px solid var(--hairline);
  background: var(--bg-raised);
  color: var(--ink-soft);
  cursor: pointer;
}
.pub-filter button:hover { border-color: var(--blue); color: var(--blue); }
.pub-filter button.active { background: var(--blue); border-color: var(--blue); color: #fff; }

.pub-list { display: flex; flex-direction: column; gap: 0; }
.pub-item {
  padding: 22px 0;
  border-bottom: 1px solid var(--hairline);
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 18px;
}
.pub-item:first-child { padding-top: 0; }
.pub-year {
  font-family: var(--font-mono);
  color: var(--ink-faint);
  font-size: 0.85rem;
  padding-top: 3px;
}
.pub-title { font-size: 1.05rem; margin-bottom: 4px; color: var(--ink); font-weight: 600; }
.pub-authors { font-size: 0.9rem; color: var(--ink-soft); margin-bottom: 3px; }
.pub-venue { font-size: 0.87rem; color: var(--ink-faint); font-style: italic; margin-bottom: 10px; }
.pub-links { display: flex; gap: 14px; flex-wrap: wrap; }
.pub-links a {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--blue);
  border-bottom: 1px solid transparent;
}
.pub-links a:hover { border-bottom-color: var(--blue); text-decoration: none; }
@media (max-width: 600px) {
  .pub-item { grid-template-columns: 1fr; gap: 4px; }
}

/* ---------- Projects ---------- */
.project-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 26px;
}
@media (max-width: 760px) { .project-grid { grid-template-columns: 1fr; } }
.project-card {
  border: 1px solid var(--hairline);
  border-radius: 6px;
  overflow: hidden;
  background: var(--bg-raised);
}
.project-media {
  width: 100%; aspect-ratio: 4/5;
  background: var(--bg-sunken);
  display: flex; align-items: center; justify-content: center;
  color: var(--ink-faint);
  font-family: var(--font-mono); font-size: 0.78rem;
  border-bottom: 1px solid var(--hairline);
  overflow: hidden;
}
.project-media img { width: 100%; height: 100%; object-fit: cover; }
.project-body { padding: 20px 22px 22px; }
.project-body h3 { font-size: 1.08rem; margin-bottom: 8px; }
.project-body p { font-size: 0.92rem; margin-bottom: 12px; }
.project-card--wide { grid-column: 1 / -1; }
.gif-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin: 4px 0 4px;
}
@media (max-width: 760px) { .gif-grid { grid-template-columns: repeat(2, 1fr); } }
.gif-grid figure {
  margin: 0;
  border: 1px solid var(--hairline);
  border-radius: 6px;
  overflow: hidden;
  background: var(--bg-sunken);
}
.gif-grid img {
  display: block;
  width: 100%;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  background: var(--bg-sunken);
}
.gif-grid figcaption {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--ink-soft);
  text-align: center;
  padding: 6px 4px;
  border-top: 1px solid var(--hairline);
}
.chip-row { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 12px; }

/* ---------- Scroll-reveal animation ---------- */
.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- Image hover zoom ---------- */
.project-media img,
.hero-photo {
  transition: transform 0.45s ease;
}
.project-card:hover .project-media img {
  transform: scale(1.06);
}
.hero-photo:hover {
  transform: scale(1.03);
}

/* ---------- GIF gallery page ---------- */
.gif-pair { margin-bottom: 40px; }
.gif-pair h2 { font-size: 1.15rem; margin-bottom: 12px; }
.gif-pair-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}
@media (max-width: 640px) { .gif-pair-row { grid-template-columns: 1fr; } }
.gif-pair-row figure {
  margin: 0;
  border: 1px solid var(--hairline);
  border-radius: 6px;
  overflow: hidden;
  background: var(--bg-sunken);
}
.gif-pair-row img {
  display: block;
  width: 100%;
  height: auto;
  background: var(--bg-sunken);
}
.gif-pair-row figcaption {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--ink-soft);
  text-align: center;
  padding: 8px 4px;
  border-top: 1px solid var(--hairline);
}
.chip {
  font-family: var(--font-mono); font-size: 0.72rem;
  color: var(--blue-deep); background: var(--blue-wash);
  border: 1px solid var(--hairline);
  padding: 3px 8px; border-radius: 4px;
}
.chip-row .chip:nth-child(3n+2) { color: var(--rose-deep); background: var(--rose-wash); }
.chip-row .chip:nth-child(3n+3) { color: var(--sage-deep); background: var(--sage-wash); }

/* ---------- News ---------- */
.news-list { position: relative; }
.news-year {
  font-family: var(--font-mono);
  color: var(--blue);
  font-size: 0.9rem;
  margin: 30px 0 10px;
  letter-spacing: 0.04em;
}
.news-year:first-child { margin-top: 0; }
.news-item {
  display: grid;
  grid-template-columns: 96px 1fr;
  gap: 16px;
  padding: 12px 0;
  border-bottom: 1px solid var(--hairline);
}
.news-item:last-child { border-bottom: none; }
.news-date { font-family: var(--font-mono); font-size: 0.78rem; color: var(--ink-faint); padding-top: 2px; }
.news-text { color: var(--ink); font-size: 0.95rem; }
.news-text a { font-weight: 500; }

/* ---------- Teaching ---------- */
.teach-item {
  border-bottom: 1px solid var(--hairline);
  padding: 20px 0;
}
.teach-item:first-child { padding-top: 0; }
.teach-item h3 { font-size: 1.05rem; margin-bottom: 4px; }
.teach-meta { font-family: var(--font-mono); font-size: 0.78rem; color: var(--ink-faint); margin-bottom: 8px; }

/* ---------- CV ---------- */
.cv-embed {
  width: 100%;
  height: 900px;
  border: 1px solid var(--hairline);
  border-radius: 6px;
  background: var(--bg-sunken);
}
@media (max-width: 700px) { .cv-embed { height: 560px; } }
.cv-fallback {
  padding: 18px;
  font-size: 0.9rem;
  color: var(--ink-soft);
}

/* ---------- Contact ---------- */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
}
@media (max-width: 700px) { .contact-grid { grid-template-columns: 1fr; } }
.contact-list { list-style: none; padding: 0; margin: 0; }
.contact-list li {
  display: flex; gap: 12px; align-items: flex-start;
  padding: 10px 0;
  border-bottom: 1px solid var(--hairline);
  font-size: 0.95rem;
}
.contact-list li svg { width: 17px; height: 17px; color: var(--blue); flex: none; margin-top: 2px; }
.map-frame {
  width: 100%; height: 260px; border: 1px solid var(--hairline);
  border-radius: 6px; filter: grayscale(0.15);
}

/* ---------- Contact form card ---------- */
.contact-form-card {
  border-radius: 10px;
  padding: 28px;
  color: #fff;
  background: linear-gradient(150deg, var(--blue-deep) 0%, var(--blue) 45%, var(--rose) 100%);
  box-shadow: var(--shadow);
}
.contact-form-card h3 {
  color: #fff;
  font-size: 1.2rem;
  margin-bottom: 6px;
}
.contact-form-card > p {
  color: rgba(255, 255, 255, 0.82);
  font-size: 0.9rem;
  margin-bottom: 20px;
}
.contact-form-card form {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.contact-form-card label {
  font-size: 0.85rem;
  font-weight: 600;
  margin: 10px 0 6px;
}
.contact-form-card label:first-of-type { margin-top: 0; }
.contact-form-card .req { color: #ffe3ea; }
.contact-form-card input[type="text"],
.contact-form-card input[type="email"],
.contact-form-card input[type="tel"],
.contact-form-card textarea {
  width: 100%;
  border: 1px solid rgba(255, 255, 255, 0.5);
  border-radius: 6px;
  padding: 10px 12px;
  font-family: var(--font-body);
  font-size: 0.92rem;
  background: #fff;
  color: var(--ink);
  box-sizing: border-box;
}
.contact-form-card textarea { resize: vertical; }
.contact-form-card input[type="file"] {
  font-size: 0.82rem;
  color: rgba(255, 255, 255, 0.9);
}
.contact-form-card input:focus,
.contact-form-card textarea:focus {
  outline: 2px solid #fff;
  outline-offset: 1px;
}
.contact-form-card .btn-primary {
  background: rgba(0, 0, 0, 0.28);
  border-color: transparent;
  backdrop-filter: blur(2px);
}
.contact-form-card .btn-primary:hover { background: rgba(0, 0, 0, 0.4); }

/* ---------- Page header (non-home pages) ---------- */
.page-head { padding: 56px 0 8px; }
.page-head h1 { font-size: 2rem; }
.page-head p.lede { color: var(--ink-soft); max-width: 640px; }

/* ---------- Misc ---------- */
.note {
  font-size: 0.82rem;
  color: var(--ink-faint);
  border-left: 2px solid var(--hairline);
  padding-left: 12px;
  margin-top: 8px;
}