/* ==========================================================================
   SePAL — Security and Privacy Analytics Laboratory, Drexel University
   Design language: the logo leads — white masthead crowned by a shield-gold
   line, deep brand-blue banners, calm light content. Quiet confidence.
   Type: Source Serif 4 (display) · Source Sans 3 (text)
   ========================================================================== */

:root {
  /* From the logo */
  --blue: #2c5aa0;          /* wordmark blue — links & accents on light */
  --blue-ink: #163a68;      /* banner background */
  --blue-glow: #1e4a80;     /* banner gradient highlight */
  --blue-night: #0f2949;    /* footer */
  --gold-bright: #f0b429;   /* shield gold — the guarding line */
  --gold: #c28f0e;          /* shield gold, darkened for light backgrounds */

  --bg: #fbfbf8;
  --text: #1f2833;
  --muted: #5b6572;
  --line: #e6e5de;
  --line-strong: #cfcec6;
  --line-dark: rgba(244, 242, 236, 0.14);

  --on-dark: #f2f3f0;
  --on-dark-muted: #aebdd1;

  --font-serif: "Source Serif 4", "Iowan Old Style", Georgia, serif;
  --font-sans: "Source Sans 3", "Helvetica Neue", Arial, sans-serif;

  --w-wide: 70rem;
  --w-text: 46rem;
}

/* ---------- Reset ---------- */

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

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 1.03rem;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

a {
  color: var(--blue);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-decoration-color: color-mix(in srgb, var(--blue) 32%, transparent);
  text-underline-offset: 3px;
  transition: color 0.18s, text-decoration-color 0.18s;
}

a:hover {
  color: var(--blue-ink);
  text-decoration-color: var(--blue-ink);
}

::selection {
  background: color-mix(in srgb, var(--blue) 16%, transparent);
}

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

h1,
h2,
h3 {
  font-family: var(--font-serif);
  font-weight: 560;
  line-height: 1.2;
  letter-spacing: -0.008em;
  text-wrap: balance;
}

p {
  text-wrap: pretty;
}

/* ---------- Utilities ---------- */

.wrap {
  max-width: var(--w-wide);
  margin-inline: auto;
  padding-inline: clamp(1.4rem, 4.5vw, 3rem);
}

.label {
  font-size: 0.76rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
  display: flex;
  align-items: center;
  gap: 0.7rem;
}

.label::before {
  content: "";
  width: 1.7rem;
  height: 2px;
  background: var(--gold-bright);
  flex: none;
}

/* ---------- Masthead ----------
   White, so the blue-and-gold logo reads exactly as designed.
   The 3px gold line above is the shield's gold guarding every page. */

.site-head {
  position: sticky;
  top: 0;
  z-index: 50;
  background: #ffffff;
  border-top: 3px solid var(--gold-bright);
  border-bottom: 1px solid var(--line);
}

.site-head .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
  padding-block: 0.95rem;
}

.brand {
  display: block;
  line-height: 0;
}

.brand img {
  height: 2.8rem;
  width: auto;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: clamp(1.2rem, 2.6vw, 2.1rem);
}

.site-nav a {
  text-decoration: none;
  font-size: 0.97rem;
  font-weight: 500;
  color: var(--muted);
  padding-block: 0.35rem;
  border-bottom: 2px solid transparent;
  transition: color 0.18s;
}

.site-nav a:hover {
  color: var(--blue);
}

.site-nav a[aria-current="page"] {
  color: var(--text);
  font-weight: 600;
  border-bottom-color: var(--gold-bright);
}

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--line-strong);
  border-radius: 3px;
  font-family: var(--font-sans);
  font-size: 0.85rem;
  padding: 0.4rem 0.85rem;
  cursor: pointer;
  color: var(--text);
}

/* ---------- Banners (home hero + interior page heads) ---------- */

.hero,
.page-hero {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(70rem 40rem at 12% -20%, var(--blue-glow) 0%, transparent 55%),
    var(--blue-ink);
  color: var(--on-dark);
}

.hero .label,
.page-hero .label {
  color: var(--on-dark-muted);
}

.hero h1,
.page-hero h1 {
  color: #ffffff;
}

/* Home hero */

.hero .wrap {
  position: relative;
  z-index: 1;
  padding-block: clamp(4rem, 9vw, 7rem) clamp(3.6rem, 8vw, 6rem);
}

.hero-field {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
}

.hero h1 {
  font-size: clamp(2.3rem, 4.3vw, 3.4rem);
  font-weight: 560;
  line-height: 1.14;
  max-width: 21ch;
  margin-top: 1.2rem;
}

.hero .lede {
  margin-top: 1.7rem;
  max-width: 44rem;
  font-size: clamp(1.06rem, 1.3vw, 1.16rem);
  color: var(--on-dark-muted);
}

.hero .lede strong {
  color: var(--on-dark);
  font-weight: 600;
}

.hero-links {
  margin-top: 2.2rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.9rem 2.4rem;
}

.hero-links a {
  font-size: 1.05rem;
  font-weight: 600;
  color: #ffffff;
  text-decoration: none;
  border-bottom: 2px solid color-mix(in srgb, var(--gold-bright) 75%, transparent);
  padding-bottom: 0.25rem;
  transition: border-color 0.2s, color 0.2s;
}

.hero-links a:hover {
  color: var(--gold-bright);
  border-bottom-color: var(--gold-bright);
}




/* Interior page banner */

.page-hero .wrap {
  padding-block: clamp(2.8rem, 6vw, 4.4rem);
}

.page-hero h1 {
  font-size: clamp(2rem, 3.8vw, 2.8rem);
  margin-top: 1rem;
}

.page-hero .lede {
  margin-top: 1rem;
  max-width: var(--w-text);
  color: var(--on-dark-muted);
  font-size: 1.06rem;
}

/* ---------- Sections (light) ---------- */

.section {
  padding-block: clamp(3.2rem, 7.5vw, 5.5rem);
  scroll-margin-top: 5.5rem;
}

.section + .section {
  border-top: 1px solid var(--line);
}

.section-alt {
  background: #f4f4ee;
}

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem 2rem;
  margin-bottom: clamp(2rem, 4.5vw, 3rem);
}

.section-head h2 {
  font-size: clamp(1.6rem, 2.8vw, 2.1rem);
  margin-top: 0.8rem;
}

.section-head .more {
  font-size: 0.98rem;
  font-weight: 600;
}

.prose {
  max-width: var(--w-text);
  color: var(--muted);
  font-size: 1.05rem;
}

.prose strong {
  color: var(--text);
  font-weight: 600;
}

.prose p + p {
  margin-top: 1rem;
}

/* ---------- Quiet notice ---------- */

.notice {
  border: 1px solid var(--line);
  border-left: 3px solid var(--gold-bright);
  background: #ffffff;
  padding: 1.1rem 1.4rem;
  max-width: var(--w-text);
  font-size: 0.98rem;
  color: var(--muted);
  border-radius: 0 3px 3px 0;
}

.notice b {
  color: var(--text);
  font-weight: 600;
}

/* ---------- Research areas ---------- */

.areas {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(2.2rem, 5vw, 3.2rem) clamp(2.5rem, 6vw, 5rem);
}

.area {
  display: grid;
  grid-template-columns: 2.6rem 1fr;
  gap: 0 1rem;
  scroll-margin-top: 6rem;
}

.area .num {
  font-family: var(--font-serif);
  font-size: 0.95rem;
  font-weight: 460;
  color: var(--gold);
  padding-top: 0.35rem;
  font-variant-numeric: tabular-nums;
}

.area h3 {
  font-size: 1.22rem;
  margin-bottom: 0.45rem;
}

.area p {
  font-size: 0.96rem;
  color: var(--muted);
  grid-column: 2;
}


/* ---------- Publications ---------- */

.pub {
  padding-block: 1.35rem;
}

.pub + .pub {
  border-top: 1px solid var(--line);
}

.pub .venue {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--blue);
}

.pub .award {
  color: var(--gold);
  margin-left: 0.7rem;
}

.pub .award::before {
  content: "◆ ";
  font-size: 0.6rem;
}

.pub h3 {
  font-size: 1.18rem;
  font-weight: 560;
  line-height: 1.35;
  margin-top: 0.3rem;
  max-width: 52rem;
}

.pub h3 a {
  color: var(--text);
  text-decoration: none;
}

.pub h3 a:hover {
  color: var(--blue);
  text-decoration: underline;
  text-decoration-color: color-mix(in srgb, var(--blue) 35%, transparent);
}

.pub .authors {
  margin-top: 0.3rem;
  font-size: 0.91rem;
  color: var(--muted);
  max-width: 52rem;
}

.pub .authors b {
  color: var(--text);
  font-weight: 600;
}

.pub .links {
  margin-top: 0.4rem;
  font-size: 0.86rem;
  display: flex;
  gap: 1.1rem;
}

/* Year groups */

.year-group {
  padding-block: 0.5rem 1.8rem;
}

.year-group h2 {
  font-size: 1.4rem;
  padding-bottom: 0.6rem;
  border-bottom: 1px solid var(--line-strong);
}

.year-group .pub:first-of-type {
  border-top: none;
}

/* Filters */

.filters {
  display: flex;
  flex-wrap: wrap;
  gap: 0.2rem 1.5rem;
  margin-bottom: clamp(1.8rem, 4vw, 2.6rem);
  border-bottom: 1px solid var(--line);
}

.filter-btn {
  font-family: var(--font-sans);
  font-size: 0.94rem;
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--muted);
  padding: 0.5rem 0.1rem;
  cursor: pointer;
  transition: color 0.15s;
}

.filter-btn:hover {
  color: var(--text);
}

.filter-btn.is-active {
  color: var(--text);
  font-weight: 600;
  border-bottom-color: var(--gold-bright);
}

.pub.is-hidden,
.year-group.is-hidden {
  display: none;
}

/* ---------- People ---------- */

.group-label {
  margin-top: clamp(2.4rem, 5vw, 3.6rem);
  margin-bottom: 1.5rem;
  padding-bottom: 0.55rem;
  border-bottom: 1px solid var(--line-strong);
}

.group-label h2 {
  font-size: 1.4rem;
}

.people-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(12rem, 1fr));
  gap: 2rem 1.8rem;
}

.portrait {
  aspect-ratio: 1 / 1.08;
  overflow: hidden;
  border-radius: 4px;
  background: #f1f1ec;
  border: 1px solid var(--line);
  margin-bottom: 0.75rem;
}

.portrait img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 22%;
  transition: transform 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}

.person:hover .portrait img {
  transform: scale(1.025);
}

.portrait .ph {
  width: 100%;
  height: 100%;
  display: grid;
  place-items: center;
  font-family: var(--font-serif);
  font-size: 2.4rem;
  font-weight: 560;
  color: var(--line-strong);
}

.person h3 {
  font-size: 1.08rem;
  font-weight: 600;
}

.person .role {
  font-size: 0.86rem;
  color: var(--muted);
  margin-top: 0.1rem;
}

.person .plink {
  font-size: 0.86rem;
  margin-top: 0.25rem;
}

/* PI feature */

.pi-feature {
  display: grid;
  grid-template-columns: minmax(13rem, 17rem) 1fr;
  gap: clamp(2rem, 4.5vw, 3.6rem);
  align-items: start;
}

.pi-feature .portrait {
  aspect-ratio: 1 / 1.12;
  margin-bottom: 0;
}

.pi-feature h3 {
  font-size: clamp(1.6rem, 2.8vw, 2.1rem);
}

.pi-feature .role {
  font-size: 0.86rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  margin-top: 0.45rem;
}

.pi-feature .bio {
  margin-top: 1.1rem;
  color: var(--muted);
  max-width: 42rem;
}

.pi-feature .bio p + p {
  margin-top: 0.85rem;
}

.pi-meta {
  margin-top: 1.2rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.7rem;
  font-size: 0.94rem;
}

.pi-meta span {
  color: var(--muted);
}

/* Alumni */

.alumni {
  max-width: var(--w-text);
}

.alum {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.3rem 2rem;
  padding-block: 0.85rem;
  border-bottom: 1px solid var(--line);
}

.alum:first-of-type {
  border-top: 1px solid var(--line);
}

.alum .name {
  font-family: var(--font-serif);
  font-size: 1.08rem;
  font-weight: 600;
}

.alum .where {
  font-size: 0.91rem;
  color: var(--muted);
}

/* ---------- Join page ---------- */

.qual-cols {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(2rem, 4.5vw, 3.8rem);
  margin-top: 2rem;
}

.qual h3 {
  font-size: 1.2rem;
  padding-bottom: 0.55rem;
  border-bottom: 1px solid var(--line-strong);
  margin-bottom: 1rem;
}

.qual .sub {
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 0.5rem;
}

.qual ul {
  list-style: none;
}

.qual li {
  padding: 0.5rem 0 0.5rem 1.25rem;
  position: relative;
  color: var(--muted);
  font-size: 0.98rem;
}

.qual li strong {
  color: var(--text);
  font-weight: 600;
}

.qual li::before {
  content: "–";
  position: absolute;
  left: 0;
  color: var(--gold);
}

/* ---------- Contact page ---------- */

.contact-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: clamp(2.2rem, 5.5vw, 4.5rem);
  align-items: start;
}

.contact-line .row {
  display: grid;
  grid-template-columns: 8rem 1fr;
  gap: 1.5rem;
  padding-block: 1rem;
  border-bottom: 1px solid var(--line);
  align-items: baseline;
}

.contact-line .row:first-of-type {
  border-top: 1px solid var(--line);
}

.contact-line .row dt {
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}

.contact-line .row dd {
  font-size: 1.02rem;
}

.aside-card {
  position: relative;
  overflow: hidden;
  border-radius: 4px;
  background:
    radial-gradient(30rem 20rem at 100% 0%, var(--blue-glow) 0%, transparent 60%),
    var(--blue-ink);
  color: var(--on-dark);
  padding: 1.8rem 1.9rem;
}

.aside-card h3 {
  font-size: 1.2rem;
  color: #ffffff;
}

.aside-card p {
  margin-top: 0.6rem;
  font-size: 0.94rem;
  color: var(--on-dark-muted);
}

.aside-card .go {
  display: inline-block;
  margin-top: 1.1rem;
  font-size: 0.94rem;
  font-weight: 600;
  color: var(--gold-bright);
  text-decoration: none;
}

.aside-card .go:hover {
  color: #f6c95e;
  text-decoration: underline;
}

/* ---------- Footer ---------- */

.site-foot {
  background: var(--blue-night);
  color: var(--on-dark);
  font-size: 0.94rem;
}

.site-foot .top {
  display: grid;
  grid-template-columns: 2fr 1fr 1.3fr;
  gap: 2.5rem;
  padding-block: clamp(2.4rem, 5.5vw, 3.6rem);
}

.site-foot .brand-block b {
  font-family: var(--font-serif);
  font-size: 1.2rem;
  font-weight: 600;
  display: block;
  margin-bottom: 0.6rem;
  color: #ffffff;
}

.site-foot .brand-block p {
  color: var(--on-dark-muted);
  max-width: 26rem;
}

.site-foot h4 {
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--gold-bright);
  margin-bottom: 0.9rem;
}

.site-foot ul {
  list-style: none;
}

.site-foot li + li {
  margin-top: 0.45rem;
}

.site-foot a {
  color: var(--on-dark);
  text-decoration: none;
}

.site-foot a:hover {
  color: #ffffff;
  text-decoration: underline;
  text-decoration-color: var(--gold-bright);
}

.site-foot address {
  font-style: normal;
  color: var(--on-dark-muted);
  line-height: 1.8;
}

.site-foot .base {
  border-top: 1px solid var(--line-dark);
  padding-block: 1.1rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.5rem 2rem;
  font-size: 0.82rem;
  color: var(--on-dark-muted);
}

/* ---------- Responsive ---------- */

@media (max-width: 860px) {
  .areas {
    grid-template-columns: 1fr;
  }

  .pi-feature {
    grid-template-columns: 1fr;
  }

  .pi-feature .portrait {
    max-width: 15rem;
  }

  .qual-cols,
  .contact-grid {
    grid-template-columns: 1fr;
  }

  .site-foot .top {
    grid-template-columns: 1fr;
    gap: 1.8rem;
  }

}

@media (max-width: 720px) {
  .brand img {
    height: 2.05rem;
  }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: #ffffff;
    border-bottom: 1px solid var(--line);
    flex-direction: column;
    align-items: flex-start;
    padding: 1rem clamp(1.4rem, 4.5vw, 3rem) 1.3rem;
    gap: 0.7rem;
    display: none;
  }

  .site-nav.is-open {
    display: flex;
  }

  .nav-toggle {
    display: block;
  }
}

@media (max-width: 520px) {
  .people-grid {
    grid-template-columns: repeat(auto-fill, minmax(9.5rem, 1fr));
    gap: 1.5rem 1.1rem;
  }

  .area {
    grid-template-columns: 2.2rem 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
  }
}