/* =========================================================================
   IMPACT — Center for Innovation in Mathematics, Physics, and Computational Theory
   Clean academic. Spectral serif + IBM Plex Mono. Northeastern red used sparingly.
   ========================================================================= */

:root {
  --paper:  #FCFCFA;   /* cool near-white (deliberately not cream)         */
  --paper-2:#F5F5F1;   /* faint panel wash                                  */
  --ink:    #1A1D24;   /* near-black ink, slightly blue                     */
  --slate:  #565E6C;   /* secondary / body-dim                              */
  --rule:   #E4E5E1;   /* hairlines                                         */
  --red:    #C8102E;   /* Northeastern red — accent, restrained             */
  --red-ink:#9C0C24;   /* darker red for text-on-hover contrast             */

  --serif: "Spectral", Charter, "Sitka Text", Cambria, Georgia, serif;
  --mono:  "IBM Plex Mono", ui-monospace, "SF Mono", Menlo, monospace;

  --wrap: 1120px;
  --pad: clamp(1.25rem, 5vw, 3rem);
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 1.0625rem;
  line-height: 1.7;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--pad);
}

a { color: var(--red-ink); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: var(--red); }

.skip-link {
  position: absolute; left: -9999px; top: 0;
  background: var(--ink); color: var(--paper);
  padding: .6rem 1rem; z-index: 100; border-radius: 0 0 4px 0;
}
.skip-link:focus { left: 0; }

:focus-visible { outline: 2px solid var(--red); outline-offset: 3px; }

/* ---- Shared type devices ------------------------------------------------ */

.eyebrow {
  font-family: var(--mono);
  font-size: .72rem;
  font-weight: 500;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--red);
  margin: 0 0 1.1rem;
}

h1, h2 { font-weight: 600; letter-spacing: -.015em; line-height: 1.12; }

h2 {
  font-size: clamp(1.6rem, 3.2vw, 2.3rem);
  margin: 0 0 1.4rem;
}

/* ---- Header ------------------------------------------------------------- */

.site-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: saturate(150%) blur(10px);
  border-bottom: 1px solid var(--rule);
}
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.wordmark {
  font-family: var(--serif);
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: .14em;
  color: var(--ink);
  text-decoration: none;
  display: inline-flex; align-items: baseline; gap: .3em;
}
.wordmark:hover { color: var(--ink); }
.wordmark-mark {
  color: var(--red);
  font-weight: 700;
  font-size: 1.34em;          /* scale cap to match letter cap-height */
  position: relative;
  top: -0.01em;               /* flush mark baseline to the letters */
}

.site-nav { display: flex; gap: clamp(1rem, 3vw, 2.2rem); }
.site-nav a {
  font-family: var(--mono);
  font-size: .78rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--slate);
  text-decoration: none;
  padding: .25rem 0;
  border-bottom: 1px solid transparent;
  transition: color .15s ease, border-color .15s ease;
}
.site-nav a:hover { color: var(--ink); border-color: var(--red); }

/* ---- Hero --------------------------------------------------------------- */

.hero {
  position: relative;
  padding-block: clamp(4rem, 12vw, 8.5rem) clamp(3rem, 8vw, 5.5rem);
  overflow: hidden;
}
/* Ambient coordinate dot-field — faint, static, subject-appropriate. */
.hero::before {
  content: "";
  position: absolute; inset: 0;
  background-image: radial-gradient(var(--rule) 1px, transparent 1.4px);
  background-size: 26px 26px;
  -webkit-mask-image: radial-gradient(120% 90% at 82% 8%, #000 0%, transparent 62%);
          mask-image: radial-gradient(120% 90% at 82% 8%, #000 0%, transparent 62%);
  opacity: .9;
  pointer-events: none;
}
.hero .wrap { position: relative; }

.hero-title {
  font-size: clamp(2.3rem, 6.2vw, 4.4rem);
  font-weight: 500;
  max-width: 16ch;
  margin: 0 0 1.6rem;
  color: var(--ink);
}
.hero-title .acr {
  color: var(--red);
  font-weight: 700;
}

.hero-lead {
  max-width: 60ch;
  font-size: clamp(1.05rem, 1.6vw, 1.3rem);
  line-height: 1.6;
  color: var(--slate);
  margin: 0 0 2.4rem;
  font-weight: 300;
}

.hero-tag {
  font-family: var(--mono);
  font-size: .8rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--ink);
  margin: 0;
  padding-top: 1.4rem;
  border-top: 1px solid var(--rule);
  display: inline-block;
}

/* ---- Section base ------------------------------------------------------- */

.section { padding-block: clamp(3.5rem, 8vw, 6rem); }
.about { border-top: 1px solid var(--rule); }

/* ---- About -------------------------------------------------------------- */

.about-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
  gap: clamp(2rem, 6vw, 5rem);
  align-items: start;
}
.about-main p { max-width: 62ch; margin: 0 0 1.2rem; }
.about-main p:last-child { margin-bottom: 0; }

.about-side {
  display: grid;
  gap: 2rem;
  padding: 1.75rem;
  background: var(--paper-2);
  border: 1px solid var(--rule);
}
.side-block { }
.side-label {
  font-family: var(--mono);
  font-size: .7rem;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--red);
  margin: 0 0 .8rem;
}
.side-list { list-style: none; margin: 0; padding: 0; }
.side-list li {
  font-size: .95rem;
  line-height: 1.5;
  color: var(--ink);
  padding: .55rem 0;
  border-top: 1px solid var(--rule);
}
.side-list li:first-child { border-top: 0; padding-top: 0; }

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

.people { border-top: 1px solid var(--rule); }

.group-label {
  font-family: var(--mono);
  font-size: .7rem;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--red);
  margin: 0 0 1.5rem;
}
.group-label + .member-grid { margin-top: 0; }

.member-grid {
  list-style: none; margin: 0 0 2.75rem; padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(168px, 1fr));
  gap: clamp(1.5rem, 3vw, 2.25rem) clamp(1.25rem, 2.5vw, 1.75rem);
}
.member { display: flex; flex-direction: column; }

.avatar {
  aspect-ratio: 1 / 1;
  overflow: hidden;
  background: var(--paper-2);
  border: 1px solid var(--rule);
  margin-bottom: .85rem;
}
.avatar img {
  width: 100%; height: 100%;
  object-fit: cover;
  object-position: center top;
  display: block;
  transition: transform .4s ease;
}
.member:hover .avatar { border-color: var(--slate); }
.member:hover .avatar img { transform: scale(1.035); }

.member-name {
  font-size: 1.08rem;
  font-weight: 500;
  line-height: 1.25;
  margin-bottom: .2rem;
}
.member-field {
  font-family: var(--mono);
  font-size: .68rem;
  letter-spacing: .05em;
  text-transform: uppercase;
  color: var(--slate);
  line-height: 1.4;
}
.role-tag { color: var(--red); font-weight: 500; }

.junior-note {
  max-width: 66ch;
  color: var(--slate);
  font-size: .98rem;
  margin: 0;
  padding-top: 1.5rem;
  border-top: 1px solid var(--rule);
}

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

.site-footer {
  background: var(--ink);
  color: #C9CDD6;
  margin-top: clamp(3rem, 8vw, 5rem);
  padding-block: clamp(3rem, 7vw, 4.5rem) 1.5rem;
}
.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.7fr) repeat(2, minmax(0, 1fr));
  gap: 2.5rem;
  padding-bottom: 2.5rem;
}
.footer-brand { max-width: 34ch; }
.footer-mark {
  font-family: var(--serif);
  font-size: 1.3rem; font-weight: 700; letter-spacing: .14em;
  color: #fff; margin: 0 0 .6rem;
}
.footer-mark span { color: var(--red); }
.footer-full { margin: 0; color: #9aa1ad; font-size: .95rem; line-height: 1.5; }
.footer-col p { margin: 0; font-size: .95rem; line-height: 1.6; color: #C9CDD6; }
.site-footer .side-label { color: #fff; }
.site-footer a { color: #fff; }
.site-footer a:hover { color: var(--red); }
.site-footer .side-label { opacity: .95; }

.footer-base {
  border-top: 1px solid rgba(255,255,255,.12);
  padding-top: 1.5rem;
}
.footer-base p {
  margin: 0;
  font-family: var(--mono);
  font-size: .72rem;
  letter-spacing: .05em;
  color: #7c828d;
}

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

@media (max-width: 820px) {
  .about-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-brand { grid-column: 1 / -1; }
}

@media (max-width: 560px) {
  .site-nav { gap: 1.1rem; }
  .site-nav a { font-size: .72rem; }
  .footer-grid { grid-template-columns: 1fr; gap: 1.75rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}