/* ============================================================
   Sajjad Habibi Ehsani — minimal academic single-page site
   ============================================================ */

:root {
  --bg: #fbfaf6;
  --bg-alt: #f4f1ea;
  --surface: #ffffff;
  --ink: #1c1917;
  --ink-2: #44403c;
  --ink-muted: #78716c;
  --ink-faint: #a8a29e;
  --rule: #e7e2d6;
  --rule-strong: #d6cfbf;
  --accent: #7c2d12;
  --accent-hover: #5c1f0c;
  --accent-soft: #fef3ec;

  --serif: "Source Serif 4", Charter, "Iowan Old Style", Georgia, "Times New Roman", serif;
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;

  --measure: 64ch;
  --content-w: 1080px;
  --gutter: clamp(1.25rem, 4vw, 2.5rem);
  --radius: 4px;

  --shadow-soft: 0 1px 0 var(--rule);
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: 72px;
  -webkit-text-size-adjust: 100%;
  text-rendering: optimizeLegibility;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 18px;
  line-height: 1.7;
  font-feature-settings: "kern" 1, "liga" 1, "onum" 1;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

@media (max-width: 640px) {
  body { font-size: 17px; line-height: 1.65; }
}

img, svg { display: block; max-width: 100%; }

a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid rgba(124, 45, 18, 0.25);
  transition: border-color 120ms ease, color 120ms ease;
}
a:hover { color: var(--accent-hover); border-bottom-color: var(--accent-hover); }
a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 2px;
}

strong { font-weight: 600; color: var(--ink); }
em { font-style: italic; }

.sup {
  font-size: 0.65em;
  vertical-align: super;
  margin-left: 0.05em;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--ink);
  color: var(--bg);
  padding: 0.5rem 1rem;
  z-index: 1000;
  border: 0;
}
.skip-link:focus { left: 1rem; top: 1rem; }

.wrap {
  width: 100%;
  max-width: var(--content-w);
  margin: 0 auto;
  padding-left: var(--gutter);
  padding-right: var(--gutter);
}

/* =================== HEADER =================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(251, 250, 246, 0.92);
  backdrop-filter: saturate(140%) blur(10px);
  -webkit-backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--rule);
}

.header-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  height: 64px;
}

.monogram {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  color: var(--ink);
  border-bottom: 0;
  font-family: var(--serif);
}

.monogram-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border: 1px solid var(--accent);
  color: var(--accent);
  font-family: var(--serif);
  font-weight: 600;
  font-size: 13px;
  letter-spacing: 0.04em;
  border-radius: 2px;
}

.monogram-name {
  font-size: 15px;
  font-weight: 500;
  letter-spacing: 0.01em;
}

@media (max-width: 540px) {
  .monogram-name { display: none; }
}

.site-nav {
  display: flex;
  gap: 1.5rem;
  font-family: var(--sans);
  font-size: 14px;
  letter-spacing: 0.01em;
}
.site-nav a {
  color: var(--ink-2);
  border-bottom: 0;
  padding: 0.25rem 0;
  position: relative;
}
.site-nav a::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: -2px;
  height: 1px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 180ms ease;
}
.site-nav a:hover { color: var(--ink); }
.site-nav a:hover::after,
.site-nav a.is-active::after { transform: scaleX(1); }
.site-nav a.is-active { color: var(--ink); }

@media (max-width: 720px) {
  .site-nav { gap: 1rem; font-size: 13px; }
}
@media (max-width: 540px) {
  .site-nav a:nth-child(4),
  .site-nav a:nth-child(5) { display: none; }
}

.nav-ig {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  border: 0;
  border-radius: 6px;
  line-height: 0;
  transition: transform 140ms ease, filter 140ms ease;
}
.nav-ig::after { display: none; }
.nav-ig:hover {
  transform: translateY(-1px);
  filter: brightness(1.06);
}

/* =================== HERO =================== */

.hero {
  padding-top: 0;
  padding-bottom: clamp(3rem, 7vw, 5.5rem);
  border-bottom: 1px solid var(--rule);
}

.hero-banner {
  position: relative;
  width: 100%;
  height: clamp(200px, 32vw, 380px);
  overflow: hidden;
  background: var(--bg-alt);
}
.hero-banner img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 35%;
  display: block;
}
.hero-banner::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 60px;
  background: linear-gradient(to bottom, rgba(251,250,246,0) 0%, var(--bg) 100%);
  pointer-events: none;
}

.hero-wrap { max-width: 880px; }

.hero-identity {
  display: flex;
  align-items: flex-end;
  gap: 1.5rem;
  margin-top: -70px;
  margin-bottom: 2rem;
  position: relative;
  z-index: 2;
}
.hero-avatar {
  width: 140px;
  height: 140px;
  border-radius: 50%;
  object-fit: cover;
  object-position: center 22%;
  background: var(--bg-alt);
  border: 5px solid var(--bg);
  box-shadow: 0 8px 24px rgba(28, 25, 23, 0.12);
  flex-shrink: 0;
}
.hero-identity-text { padding-bottom: 0.5rem; }
.hero-identity-text .eyebrow { margin-bottom: 0.75rem; }
.hero-identity-text .display { margin-bottom: 0; }

@media (max-width: 640px) {
  .hero-identity {
    flex-direction: column;
    align-items: flex-start;
    gap: 1rem;
    margin-top: -60px;
  }
  .hero-avatar { width: 110px; height: 110px; border-width: 4px; }
  .hero-identity-text { padding-bottom: 0; }
}

.eyebrow {
  font-family: var(--sans);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-muted);
  margin: 0 0 1.5rem;
}

.display {
  font-family: var(--serif);
  font-weight: 600;
  font-size: clamp(2.4rem, 6.5vw, 4.5rem);
  line-height: 1.05;
  letter-spacing: -0.012em;
  margin: 0 0 1.5rem;
  color: var(--ink);
}

.lede {
  font-size: clamp(1.05rem, 1.8vw, 1.25rem);
  line-height: 1.65;
  color: var(--ink-2);
  max-width: var(--measure);
  margin: 0 0 2rem;
}
.lede em {
  font-style: italic;
  color: var(--ink);
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 3rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--sans);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.01em;
  padding: 0.65rem 1.1rem;
  border-radius: var(--radius);
  border: 1px solid transparent;
  transition: background 140ms ease, border-color 140ms ease, color 140ms ease, transform 140ms ease;
  cursor: pointer;
}
.btn:hover { transform: translateY(-1px); }
.btn-primary {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}
.btn-primary:hover {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
  color: #fff;
}
.btn-ghost {
  background: transparent;
  color: var(--ink);
  border-color: var(--rule-strong);
}
.btn-ghost:hover {
  background: var(--surface);
  border-color: var(--ink-muted);
}

.hero-meta {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(1rem, 3vw, 2.5rem);
  padding: 0;
  margin: 0;
  border-top: 1px solid var(--rule);
  padding-top: 2rem;
}
.hero-meta li {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}
.meta-num {
  font-family: var(--serif);
  font-weight: 500;
  font-size: clamp(1.7rem, 3.5vw, 2.4rem);
  line-height: 1;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}
.meta-num-sm {
  font-size: 0.55em;
  color: var(--ink-muted);
  margin-left: 0.1em;
}
.meta-lbl {
  font-family: var(--sans);
  font-size: 13px;
  line-height: 1.45;
  color: var(--ink-muted);
}

@media (max-width: 640px) {
  .hero-meta { grid-template-columns: 1fr; gap: 1.25rem; }
}

/* =================== SECTIONS =================== */

.section {
  padding-top: clamp(3.5rem, 7vw, 5.5rem);
  padding-bottom: clamp(3.5rem, 7vw, 5.5rem);
  border-bottom: 1px solid var(--rule);
}
.section-alt { background: var(--bg-alt); }

.section-head {
  display: flex;
  align-items: baseline;
  gap: 1rem;
  margin-bottom: 2rem;
  padding-bottom: 0.85rem;
  border-bottom: 1px solid var(--rule-strong);
}
.section-num {
  font-family: var(--sans);
  font-size: 12px;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
  font-weight: 500;
}
.section-head h2 {
  font-family: var(--serif);
  font-weight: 600;
  font-size: clamp(1.4rem, 2.5vw, 1.85rem);
  line-height: 1.2;
  letter-spacing: -0.005em;
  margin: 0;
  color: var(--ink);
}

.prose { max-width: var(--measure); color: var(--ink-2); }
.prose.lead {
  font-size: clamp(1rem, 1.4vw, 1.12rem);
  color: var(--ink-2);
  margin-bottom: 2.5rem;
}
.prose em { color: var(--ink); }

/* =================== PILLARS =================== */

.pillars {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(1.25rem, 2.5vw, 2.5rem);
  margin-bottom: 3rem;
}
.pillar {
  padding-top: 1.25rem;
  border-top: 2px solid var(--accent);
}
.pillar h3 {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 1.15rem;
  margin: 0 0 0.6rem;
  color: var(--ink);
}
.pillar p {
  margin: 0;
  font-size: 0.98rem;
  line-height: 1.6;
  color: var(--ink-2);
}
@media (max-width: 820px) {
  .pillars { grid-template-columns: 1fr; }
}

.pullquote {
  font-family: var(--serif);
  font-style: italic;
  font-size: clamp(1.15rem, 2.2vw, 1.5rem);
  line-height: 1.45;
  color: var(--ink);
  max-width: var(--measure);
  margin: 0;
  padding: 0.25rem 0 0.25rem 1.5rem;
  border-left: 3px solid var(--accent);
}

/* =================== PROJECT CARD =================== */

.project-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}
@media (min-width: 960px) {
  .project-list { grid-template-columns: 1fr 1fr; gap: 1.75rem; }
  .project-list .project-card { display: flex; flex-direction: column; }
  .project-list .project-card .project-card-tag { flex: 1 1 auto; }
}

.project-card {
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  padding: clamp(1.5rem, 3vw, 2.25rem);
  position: relative;
  overflow: hidden;
}
.project-card::before {
  content: "";
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 4px;
  background: var(--accent);
}
.project-card-eyebrow {
  font-family: var(--sans);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 0.5rem;
  font-weight: 600;
}
.project-card h3 {
  font-family: var(--serif);
  font-weight: 600;
  font-size: clamp(1.3rem, 2.2vw, 1.55rem);
  margin: 0 0 0.65rem;
  color: var(--ink);
  letter-spacing: -0.005em;
}
.project-card-tag {
  color: var(--ink-2);
  line-height: 1.65;
  margin: 0 0 1.4rem;
  max-width: 60ch;
}
.project-card-stats {
  list-style: none;
  padding: 0;
  margin: 0 0 1.6rem;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(0.75rem, 2.5vw, 2rem);
  padding-top: 1.1rem;
  border-top: 1px solid var(--rule);
}
.project-card-stats li {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}
.project-card-stats .num {
  font-family: var(--serif);
  font-weight: 500;
  font-size: clamp(1.4rem, 2.5vw, 1.8rem);
  line-height: 1;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}
.project-card-stats .lbl {
  font-family: var(--sans);
  font-size: 12px;
  color: var(--ink-muted);
  line-height: 1.4;
}
@media (max-width: 560px) {
  .project-card-stats { grid-template-columns: 1fr; gap: 0.85rem; }
}

/* =================== RESEARCH LIST =================== */

.research-list {
  list-style: none;
  counter-reset: research;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 1.5rem;
}
.research-list li {
  counter-increment: research;
  position: relative;
  padding: 1.5rem 1.5rem 1.5rem 4.5rem;
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
}
.research-list li::before {
  content: counter(research, decimal-leading-zero);
  position: absolute;
  left: 1.5rem;
  top: 1.55rem;
  font-family: var(--serif);
  font-weight: 500;
  font-size: 1.5rem;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}
.research-list h3 {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 1.15rem;
  margin: 0 0 0.4rem;
  color: var(--ink);
}
.research-list p {
  margin: 0;
  color: var(--ink-2);
  font-size: 0.98rem;
  line-height: 1.6;
}

@media (max-width: 560px) {
  .research-list li { padding: 1.25rem 1.1rem 1.25rem 3.5rem; }
  .research-list li::before { left: 1.1rem; top: 1.3rem; font-size: 1.25rem; }
}

/* =================== TIMELINE =================== */

.timeline {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 2.5rem;
}

.tl-item {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 2rem;
  position: relative;
  padding-left: 1.25rem;
  border-left: 1px solid var(--rule-strong);
}
.tl-item::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 0.55rem;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--accent);
}

.tl-when {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
  font-family: var(--sans);
  font-size: 13px;
  color: var(--ink-muted);
  padding-top: 0.15rem;
}
.tl-year {
  font-weight: 500;
  color: var(--ink-2);
  font-variant-numeric: tabular-nums;
}
.tl-meta {
  font-size: 12px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

.tl-body h3 {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 1.2rem;
  margin: 0 0 0.75rem;
  color: var(--ink);
  line-height: 1.3;
}
.tl-org {
  font-weight: 400;
  font-style: italic;
  color: var(--ink-muted);
}
.tl-body ul {
  margin: 0;
  padding: 0 0 0 1.1rem;
  color: var(--ink-2);
}
.tl-body li {
  margin-bottom: 0.5rem;
  line-height: 1.6;
}
.tl-body li::marker { color: var(--ink-faint); }

@media (max-width: 720px) {
  .tl-item { grid-template-columns: 1fr; gap: 0.5rem; }
}

/* =================== COACHING CARDS =================== */

.coach-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.5rem;
}
.coach-card {
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  padding: 1.5rem 1.6rem;
}
.coach-card h3 {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 1.15rem;
  margin: 0 0 0.35rem;
  color: var(--ink);
}
.coach-when {
  font-family: var(--sans);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 0.5rem;
}
.coach-org {
  font-style: italic;
  color: var(--ink-muted);
  margin: 0 0 0.85rem;
  font-size: 0.95rem;
}
.coach-card ul {
  margin: 0;
  padding-left: 1.1rem;
  color: var(--ink-2);
  font-size: 0.97rem;
}
.coach-card li { margin-bottom: 0.4rem; line-height: 1.55; }
.coach-card li::marker { color: var(--ink-faint); }

@media (max-width: 760px) {
  .coach-grid { grid-template-columns: 1fr; }
}

/* =================== TWO-COLUMN =================== */

.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(2rem, 5vw, 4rem);
}
@media (max-width: 820px) {
  .two-col { grid-template-columns: 1fr; gap: 3rem; }
}

.achievements {
  list-style: none;
  padding: 0;
  margin: 0 0 1.5rem;
}
.achievements li {
  padding: 0.75rem 0;
  border-bottom: 1px dotted var(--rule-strong);
  color: var(--ink-2);
}
.achievements li:last-child { border-bottom: 0; }

.footnote {
  font-style: italic;
  color: var(--ink-muted);
  font-size: 0.95rem;
  line-height: 1.55;
  padding-left: 1rem;
  border-left: 2px solid var(--rule-strong);
  margin: 0;
}

.skills {
  margin: 0;
  display: grid;
  gap: 1.2rem;
}
.skills dt {
  font-family: var(--sans);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 0.25rem;
}
.skills dd {
  margin: 0;
  color: var(--ink-2);
  font-size: 0.98rem;
  line-height: 1.6;
}

/* =================== EDUCATION =================== */

.edu h3 {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 1.2rem;
  margin: 0 0 0.25rem;
  color: var(--ink);
}
.edu-meta {
  font-family: var(--sans);
  font-size: 13px;
  color: var(--ink-muted);
  margin: 0 0 0.65rem;
}
.edu p { color: var(--ink-2); margin: 0 0 0.8rem; }
.edu ul {
  margin: 0;
  padding-left: 1.1rem;
  color: var(--ink-2);
}
.edu li { margin-bottom: 0.4rem; }
.edu li::marker { color: var(--ink-faint); }

.certs {
  list-style: none;
  padding: 0;
  margin: 0 0 1.5rem;
}
.certs li {
  padding: 0.55rem 0;
  border-bottom: 1px dotted var(--rule-strong);
  color: var(--ink-2);
}
.certs li:last-child { border-bottom: 0; }
.muted { color: var(--ink-muted); }

.languages {
  margin: 0;
  padding-top: 1rem;
  border-top: 1px solid var(--rule);
  color: var(--ink-2);
  font-size: 0.97rem;
}

/* =================== GALLERY =================== */

.gallery {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(1.25rem, 2.5vw, 2rem);
}
.gallery-item {
  margin: 0;
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: transform 200ms ease, box-shadow 200ms ease;
}
.gallery-item:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 28px rgba(28, 25, 23, 0.08);
}
.gallery-item a {
  display: block;
  border-bottom: 0;
  background: var(--bg-alt);
  aspect-ratio: 4 / 3;
  overflow: hidden;
}
.gallery-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 400ms ease;
}
.gallery-item:hover img { transform: scale(1.02); }
.gallery-item figcaption {
  padding: 1rem 1.2rem 1.2rem;
  font-size: 0.95rem;
  line-height: 1.55;
  color: var(--ink-2);
}
.gallery-item figcaption strong {
  display: block;
  margin-bottom: 0.3rem;
  font-family: var(--serif);
  font-size: 1rem;
  font-weight: 600;
}
.gallery-item figcaption em {
  color: var(--ink-muted);
  font-size: 0.88rem;
}
@media (max-width: 720px) {
  .gallery { grid-template-columns: 1fr; }
}

/* =================== CONTACT =================== */

.section-contact {
  border-bottom: 0;
  padding-bottom: clamp(4rem, 8vw, 6rem);
}

.contact-list {
  list-style: none;
  padding: 0;
  margin: 0;
  max-width: 640px;
}
.contact-list li {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 1rem;
  padding: 0.95rem 0;
  border-bottom: 1px solid var(--rule);
  align-items: baseline;
}
.contact-list li:last-child { border-bottom: 0; }
.contact-lbl {
  font-family: var(--sans);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-muted);
}
.contact-list a { word-break: break-word; }
.contact-list a.ig-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}
.contact-list a.ig-link svg { flex-shrink: 0; }

@media (max-width: 560px) {
  .contact-list li { grid-template-columns: 1fr; gap: 0.15rem; padding: 0.7rem 0; }
}

/* =================== FOOTER =================== */

.site-footer {
  padding: 2rem 0 2.5rem;
  border-top: 1px solid var(--rule);
  background: var(--bg);
}
.footer-wrap {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  font-family: var(--sans);
  font-size: 13px;
  color: var(--ink-muted);
  flex-wrap: wrap;
}
.footer-wrap p { margin: 0; }
.footer-links {
  display: inline-flex;
  align-items: center;
  gap: 1.25rem;
}
.footer-links a {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--ink-muted);
  border-bottom: 0;
  transition: color 140ms ease;
}
.footer-links a:hover { color: var(--accent); }

/* =================== MOTION =================== */

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

/* =================== PRINT =================== */

@media print {
  .site-header, .site-footer, .cta-row, .site-nav { display: none; }
  body { background: #fff; color: #000; }
  .section { page-break-inside: avoid; border-color: #ccc; }
  a { color: #000; border-bottom: 0; }
}