/* ==========================================================================
   Steel City Chemistry — ACS Pittsburgh Local Section
   Palette derived from the event poster.
   ========================================================================== */

:root {
  --navy:      #12305e;
  --navy-deep: #0a1f40;
  --navy-soft: #1d4585;
  --gold:      #d9a520;
  --gold-deep: #b8860a;
  --sky:       #a9d3ef;
  --sky-pale:  #eaf4fb;
  --green:     #2f6b3f;
  --ink:       #16202e;
  --ink-soft:  #4a5768;
  --line:      #d3e2ee;
  --white:     #ffffff;

  --wrap: 1140px;
  --r: 10px;
  --shadow: 0 1px 2px rgba(18,48,94,.06), 0 8px 24px rgba(18,48,94,.07);
  --shadow-lg: 0 2px 6px rgba(18,48,94,.08), 0 18px 44px rgba(18,48,94,.13);

  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-display: "Helvetica Neue", "Segoe UI", Roboto, Arial, sans-serif;

  --header-h: 74px;
}

/* ---------- reset-ish ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .001ms !important; transition-duration: .001ms !important; }
}
body {
  margin: 0;
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.65;
  color: var(--ink);
  background: var(--white);
  -webkit-font-smoothing: antialiased;
}
img, picture, svg { max-width: 100%; }
img { height: auto; display: block; }
h1, h2, h3, h4 { margin: 0 0 .4em; line-height: 1.18; }
p { margin: 0 0 1em; }
ul, ol { margin: 0; padding: 0; list-style: none; }
a { color: var(--navy-soft); }

.wrap { width: min(100% - 2.5rem, var(--wrap)); margin-inline: auto; }

/* ---------- focus & skip ---------- */
:focus-visible {
  outline: 3px solid var(--gold);
  outline-offset: 3px;
  border-radius: 3px;
}
.skip-link {
  position: absolute; left: -9999px; top: 0; z-index: 200;
  background: var(--navy); color: #fff; padding: .8rem 1.2rem;
  font-weight: 700; text-decoration: none;
}
.skip-link:focus { left: .5rem; top: .5rem; }

/* ==========================================================================
   Header
   ========================================================================== */
.announce {
  background: var(--navy-deep);
  color: #cfe2f5;
  font-size: .8rem;
  letter-spacing: .06em;
  text-transform: uppercase;
  text-align: center;
  padding: .5rem 1rem;
}
.announce__mark {
  color: var(--gold);
  font-weight: 800;
  letter-spacing: .1em;
  margin-right: .5rem;
}

/* Simple header nav on the form pages — no sticky CTA, no scroll-spy. */
.nav--simple { position: static; display: flex; }
.nav--simple .nav__list { display: flex; gap: 1.4rem; }

.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,.94);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
  transition: box-shadow .2s ease;
}
.site-header.is-stuck { box-shadow: 0 4px 20px rgba(18,48,94,.11); }
.site-header__inner {
  display: flex; align-items: center; gap: 1.5rem;
  min-height: var(--header-h);
}

/* Two separate destinations: the ACS mark goes to acs.org, the section
   wordmark to pittsburghacs.org. Kept visually as one lockup. */
.brand { display: flex; align-items: center; gap: .85rem; flex-shrink: 0; }
.brand__acs, .brand__section {
  text-decoration: none;
  border-radius: 4px;
  transition: opacity .15s ease, color .15s ease;
}
.brand__acs { display: block; }
.brand__acs:hover { opacity: .72; }
.brand__logo { height: 34px; width: auto; display: block; }
.brand__section {
  font-size: .68rem; line-height: 1.25; font-weight: 700;
  text-transform: uppercase; letter-spacing: .07em;
  color: var(--navy); padding-left: .85rem;
  border-left: 2px solid var(--gold);
}
.brand__section:hover { color: var(--gold-deep); }

.nav { display: flex; align-items: center; gap: 1.4rem; margin-left: auto; }
.nav__list { display: flex; gap: 1.35rem; }
.nav__list a {
  text-decoration: none; color: var(--navy);
  font-size: .93rem; font-weight: 600;
  padding: .35rem 0; display: block; position: relative;
}
.nav__list a::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: -2px;
  height: 3px; background: var(--gold); border-radius: 2px;
  transform: scaleX(0); transition: transform .18s ease;
}
.nav__list a:hover::after, .nav__list a.is-current::after { transform: scaleX(1); }

.nav-toggle {
  display: none; margin-left: auto; gap: .6rem; align-items: center;
  background: none; border: 1px solid var(--line); border-radius: var(--r);
  padding: .5rem .8rem; font: inherit; font-size: .85rem; font-weight: 700;
  color: var(--navy); cursor: pointer;
}
.nav-toggle__bars { display: grid; gap: 4px; }
.nav-toggle__bars span { display: block; width: 18px; height: 2px; background: var(--navy); border-radius: 2px; }

/* ==========================================================================
   Buttons
   ========================================================================== */
.btn {
  display: inline-flex; flex-direction: column; align-items: center;
  padding: .85rem 1.7rem;
  border-radius: var(--r);
  font-weight: 800; font-size: .95rem;
  letter-spacing: .04em; text-transform: uppercase;
  text-decoration: none; text-align: center;
  border: 2px solid transparent;
  transition: transform .12s ease, background-color .15s ease, box-shadow .15s ease;
}
.btn:hover { transform: translateY(-2px); }
/* .btn stacks its children so .btn__note can sit under the label; a button with
   a leading icon needs the row axis back. */
.btn--cal { flex-direction: row; gap: .55rem; }
.venue__cal { margin-top: 1.4rem; }

/* Contact addresses are shown as text as well as linked: mailto: silently does
   nothing for people on webmail with no mail-client handler, and a visible
   address can still be copied. */
.contact-line { margin-top: 1rem; font-size: .95rem; color: var(--ink-soft); }
.site-footer__contact {
  margin: 1.6rem 0 0; font-size: .92rem; line-height: 1.7; color: #c6d8ea;
}
.site-footer__contact--center { text-align: center; }
.site-footer__contact a { color: var(--gold); text-decoration: none; border-bottom: 1px solid rgba(217,165,32,.45); }
.site-footer__contact a:hover { color: #e8b32c; }
.btn--cal svg { width: 1.15em; height: 1.15em; flex: none; }
.btn--gold  { background: var(--gold); color: var(--navy-deep); box-shadow: 0 4px 14px rgba(217,165,32,.32); }
.btn--gold:hover { background: #e8b32c; }
.btn--navy  { background: var(--navy); color: #fff; }
.btn--navy:hover { background: var(--navy-soft); }
.btn--ghost { background: rgba(255,255,255,.08); color: #fff; border-color: rgba(255,255,255,.55); }
.btn--ghost:hover { background: rgba(255,255,255,.18); }
.btn--sm { padding: .55rem 1.1rem; font-size: .82rem; }

.btn__note {
  display: block; font-style: normal; font-weight: 600;
  font-size: .68rem; letter-spacing: .03em; text-transform: none;
  opacity: .82; margin-top: .15rem;
}
/* Pending links: visibly present, not yet actionable. */
.btn.is-pending { cursor: not-allowed; opacity: .92; }
.btn.is-pending:hover { transform: none; }
.btn--sm.is-pending .btn__note { display: none; }

/* ==========================================================================
   Hero
   ========================================================================== */
.hero {
  position: relative;
  background: linear-gradient(180deg, var(--navy-deep) 0%, var(--navy) 42%, #1b4a86 100%);
  color: #fff;
  overflow: hidden;
  padding-top: 3.2rem;
}
.hero__art {
  position: absolute; left: 0; right: 0; bottom: 2.35rem;
  z-index: 0; pointer-events: none;
}
.hero__art img { width: 100%; object-fit: cover; }
/* Scrim so display type stays legible over the skyline. */
.hero__art::after {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(180deg, var(--navy) 0%, rgba(18,48,94,.72) 26%, rgba(18,48,94,.12) 62%, rgba(18,48,94,0) 100%);
}
.hero__inner { position: relative; z-index: 2; text-align: center; padding-bottom: 15rem; }

/* The link carries the centring and spacing so it shrink-wraps the logo —
   a block-level anchor would make the whole hero width clickable. */
.hero__acs150-link {
  display: inline-block; margin: 0 auto 1.8rem;
  border-radius: 8px; transition: transform .15s ease, box-shadow .15s ease;
}
.hero__acs150-link:hover, .hero__acs150-link:focus-visible {
  transform: translateY(-2px);
  box-shadow: 0 8px 22px rgba(0, 0, 0, .3);
}
.hero__acs150 { height: 118px; width: auto; display: block; border-radius: 8px; }

.hero__title {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 7.2vw, 5.1rem);
  font-weight: 800; letter-spacing: -.015em;
  text-transform: uppercase;
  margin-bottom: .12em;
  text-shadow: 0 2px 18px rgba(6,20,44,.5);
}
.hero__sub {
  font-family: var(--font-display);
  font-size: clamp(1.05rem, 2.7vw, 1.7rem);
  font-weight: 700; letter-spacing: .13em; text-transform: uppercase;
  color: var(--gold);
  margin-bottom: .5em;
}
.hero__sub::before, .hero__sub::after {
  content: ""; display: inline-block; width: clamp(20px, 5vw, 56px); height: 2px;
  background: var(--gold); vertical-align: middle; margin: 0 .8em;
}
.hero__tag {
  font-size: clamp(.9rem, 2vw, 1.08rem);
  letter-spacing: .08em; text-transform: uppercase; font-weight: 600;
  color: #dbe9f8;
  margin-bottom: 2.2rem;
}

.hero__meta {
  display: flex; flex-wrap: wrap; justify-content: center; gap: 0;
  margin: 0 0 2.4rem;
}
.hero__meta > div {
  padding: 0 clamp(1rem, 4vw, 2.6rem);
  border-left: 1px solid rgba(255,255,255,.24);
}
.hero__meta > div:first-child { border-left: 0; }
.hero__meta dt {
  font-size: .68rem; font-weight: 800; letter-spacing: .16em;
  text-transform: uppercase; color: var(--gold); margin-bottom: .3rem;
}
.hero__meta dd { margin: 0; font-size: 1.02rem; font-weight: 700; line-height: 1.4; }
.hero__meta dd span { font-weight: 500; color: #cfe0f2; font-size: .92rem; }

.hero__cta { display: flex; flex-wrap: wrap; gap: 1rem; justify-content: center; }

.hero__open {
  margin: 1.5rem 0 0; display: flex; flex-direction: column; gap: .3rem;
  align-items: center; line-height: 1.4;
}
.hero__open strong {
  font-size: 1.05rem; letter-spacing: .01em; color: var(--gold);
}
.hero__open span { font-size: .92rem; color: #cfe0f2; }

/* Sits over the bottom of the skyline band, right-aligned the way a print
   credit would be. Small and low-contrast: present if looked for, not
   competing with the display type above it. */
.hero__credit {
  position: absolute; right: 1.2rem; bottom: 2.7rem; z-index: 2;
  margin: 0; font-size: .68rem; letter-spacing: .04em;
  color: rgba(255, 255, 255, .62);
  text-shadow: 0 1px 3px rgba(0, 0, 0, .6);
}

.hero__rule {
  position: relative; z-index: 2; margin: 0;
  background: var(--gold);
  color: var(--navy-deep);
  text-align: center;
  font-size: clamp(.7rem, 1.7vw, .85rem);
  font-weight: 800; font-style: italic;
  letter-spacing: .07em; text-transform: uppercase;
  padding: .7rem 1rem;
}

/* ==========================================================================
   Sections
   ========================================================================== */
.section { padding: clamp(3.5rem, 7vw, 6rem) 0; }
/* Anchor targets must clear the sticky header, or headings land underneath it. */
.section, .hero { scroll-margin-top: calc(var(--header-h) + 12px); }
.section--tint { background: var(--sky-pale); border-block: 1px solid var(--line); }

.eyebrow {
  font-size: .74rem; font-weight: 800; letter-spacing: .18em;
  text-transform: uppercase; color: var(--gold-deep);
  margin-bottom: .7rem;
}
.eyebrow::after {
  content: ""; display: block; width: 46px; height: 3px;
  background: var(--gold); border-radius: 2px; margin-top: .55rem;
}
.eyebrow--sm { font-size: .68rem; }
.eyebrow--sm::after { display: none; }
.eyebrow--light { color: var(--gold); }
.eyebrow--light::after { margin-inline: auto; }

.section__title {
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 2.6vw, 1.85rem);
  font-weight: 800; letter-spacing: -.01em;
  color: var(--navy);
  max-width: 30ch;
  margin-bottom: .5em;
}
.lede { font-size: 1.02rem; color: var(--ink-soft); max-width: 68ch; }
.lede--sm { font-size: .95rem; }
.h-sub {
  font-family: var(--font-display);
  font-size: 1.05rem; font-weight: 800; color: var(--navy);
  letter-spacing: -.005em;
}
.h-sub--center { text-align: center; margin-top: 3.5rem; margin-bottom: 1.6rem; }
.center { text-align: center; }
.note {
  font-size: .92rem; color: var(--ink-soft);
  border-left: 3px solid var(--sky);
  padding-left: .9rem; margin-bottom: 1rem;
}
/* Deadlines are the one thing a visitor must not miss, so this note reads as a
   flag rather than fine print. */
.note--deadline {
  border-left-color: var(--gold); color: var(--ink);
  font-size: 1rem; background: #fdf6e3;
  padding: .7rem .9rem; border-radius: 0 6px 6px 0;
}

/* ---------- pillars ---------- */
.pillars {
  display: grid; gap: 1.5rem; margin: 3rem 0 3.5rem;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}
.pillar { text-align: center; }
.pillar__icon {
  display: grid; place-items: center;
  width: 92px; height: 92px; margin: 0 auto 1.1rem;
  border-radius: 50%;
  background: var(--navy);
  box-shadow: 0 6px 20px rgba(18,48,94,.22);
}
.pillar--community .pillar__icon { background: var(--green); }
.pillar__icon svg { width: 46px; height: 46px; fill: #fff; stroke: #fff; }
.pillar__icon svg [fill="none"] { fill: none; }
.pillar h3 {
  font-family: var(--font-display);
  font-size: 1.15rem; font-weight: 800;
  text-transform: uppercase; letter-spacing: .1em;
  color: var(--navy);
}
.pillar p { color: var(--ink-soft); max-width: 30ch; margin-inline: auto; }

/* ---------- split ---------- */
.split { display: grid; gap: 2.2rem; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.split__col { background: var(--white); border: 1px solid var(--line); border-radius: var(--r); padding: 1.7rem; }
.section--tint .split__col { background: var(--white); }

/* ==========================================================================
   People (organizers + speakers)
   ========================================================================== */
.people {
  display: grid; gap: 1.4rem;
  grid-template-columns: repeat(auto-fill, minmax(232px, 1fr));
  margin-top: 2.6rem;
}
.person {
  background: var(--white);
  border: 1px solid var(--sky);
  border-radius: var(--r);
  padding: 1.6rem 1.2rem;
  text-align: center;
  box-shadow: var(--shadow);
  transition: transform .16s ease, box-shadow .16s ease;
}
.person:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); }

.avatar {
  display: grid; place-items: center;
  width: 112px; height: 112px; margin: 0 auto 1rem;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--gold);
  background: var(--sky-pale);
}
/* Monogram stand-in until approved headshots arrive. */
.avatar--mono {
  font-family: var(--font-display);
  font-size: 2.15rem; font-weight: 800; letter-spacing: .04em;
  color: var(--navy);
  background: linear-gradient(150deg, var(--sky) 0%, var(--sky-pale) 100%);
}
.avatar--tba {
  font-size: 2.4rem; font-weight: 800; color: var(--ink-soft);
  background: repeating-linear-gradient(-45deg, #eef4f9 0 8px, #e3ecf4 8px 16px);
  border-color: var(--line);
}

.person__tag {
  font-size: .64rem; font-weight: 800; letter-spacing: .13em;
  text-transform: uppercase; color: var(--gold-deep);
  margin-bottom: .5rem;
}
.person__name {
  font-family: var(--font-display);
  font-size: 1.05rem; font-weight: 800; color: var(--navy);
  margin-bottom: .3rem;
}
.person__role { font-size: .92rem; font-weight: 600; margin-bottom: .1rem; }
.person__org  { font-size: .88rem; color: var(--ink-soft); margin: 0; }

.person--featured {
  grid-column: span 2;
  border-color: var(--gold);
  border-width: 2px;
  background: linear-gradient(180deg, #fffdf6 0%, var(--white) 55%);
}
.person--featured .avatar { width: 136px; height: 136px; }
.person--featured .avatar--mono { font-size: 2.6rem; }
.person--featured .person__name { font-size: 1.28rem; }
.person--tba { border-style: dashed; border-color: var(--line); box-shadow: none; }
.person--tba:hover { transform: none; box-shadow: none; }

.people--organizers { grid-template-columns: repeat(auto-fill, minmax(226px, 1fr)); }

/* Speaker cards are shown in one grid; the category filter was removed. */

/* ==========================================================================
   Program
   ========================================================================== */
.agenda { margin-top: 2.6rem; border-top: 2px solid var(--navy); }
.agenda__row {
  display: grid;
  grid-template-columns: 210px 1fr 190px;
  gap: 1.4rem; align-items: center;
  padding: 1.05rem .6rem;
  border-bottom: 1px solid var(--line);
}
.agenda__row--session { background: var(--sky-pale); }
.section--tint .agenda__row--session { background: #dfeef9; }
.agenda__row p { margin: 0; }
.agenda__time { font-weight: 800; color: var(--navy); font-variant-numeric: tabular-nums; font-size: .95rem; }
.agenda__what { font-size: 1.02rem; }
.agenda__what strong { color: var(--navy); }
.agenda__focus { text-align: right; }
.chip {
  display: inline-block; font-size: .72rem; font-weight: 800;
  letter-spacing: .08em; text-transform: uppercase;
  padding: .3rem .75rem; border-radius: 999px;
  background: #e6edf4; color: var(--ink-soft);
}
.chip--navy { background: var(--navy); color: #fff; }

.highlights {
  display: grid; gap: 1.3rem;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}
.highlight {
  border: 1px solid var(--line); border-top: 4px solid var(--gold);
  border-radius: var(--r); padding: 1.5rem 1.3rem;
  background: var(--white);
}
.highlight__time {
  font-size: .74rem; font-weight: 800; letter-spacing: .1em;
  text-transform: uppercase; color: var(--gold-deep); margin-bottom: .4rem;
}
.highlight h4 { font-family: var(--font-display); font-size: 1.08rem; font-weight: 800; color: var(--navy); }
.highlight p:last-child { margin: 0; color: var(--ink-soft); font-size: .95rem; }

/* ==========================================================================
   Take part / awards
   ========================================================================== */
.takepart {
  display: grid; gap: 1.6rem; margin-top: 2.6rem;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}
.card {
  background: var(--white); border: 1px solid var(--sky);
  border-radius: var(--r); padding: 1.9rem;
  box-shadow: var(--shadow);
  display: flex; flex-direction: column;
}
.card--cta .btn { align-self: flex-start; margin-top: auto; }

.ticks { margin: 0 0 1.4rem; display: grid; gap: .5rem; }
.ticks li { position: relative; padding-left: 1.6rem; font-size: .95rem; color: var(--ink-soft); }
.ticks li::before {
  content: ""; position: absolute; left: 0; top: .52em;
  width: 8px; height: 8px; border-radius: 50%; background: var(--gold);
}

.awards {
  margin-top: 2.6rem; padding: 2rem;
  background: var(--navy); color: #fff; border-radius: var(--r);
}
.awards .h-sub { color: #fff; }
.awards__lede { color: #d5e4f4; max-width: 70ch; }
.awards__lede strong { color: var(--gold); }
.awards__grid {
  display: grid; gap: 1.2rem; margin: 1.8rem 0 1.4rem;
  grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
}
.award-cat {
  background: rgba(255,255,255,.07);
  border: 1px solid rgba(255,255,255,.16);
  border-radius: var(--r); padding: 1.2rem;
}
.award-cat h4 {
  font-size: .78rem; font-weight: 800; letter-spacing: .13em;
  text-transform: uppercase; color: var(--gold); margin-bottom: .8rem;
}
.award-cat ul { display: grid; gap: .4rem; }
.award-cat li { display: flex; gap: .7rem; font-size: .95rem; font-variant-numeric: tabular-nums; }
.award-cat li span { font-weight: 800; color: var(--sky); min-width: 2.4em; }
.awards .note { color: #c6d8ea; border-left-color: var(--gold); margin: 0; }
/* The deadline callout keeps its own light background inside the navy panel, so
   it must not inherit the light-on-dark text colour above. */
.awards .note--deadline { color: var(--ink); margin: 0 0 1rem; }

/* ==========================================================================
   Registration form
   ========================================================================== */
.wrap--narrow { width: min(100% - 2.5rem, 720px); }
.section--form { background: var(--sky-pale); border-block: 1px solid var(--line); }
.req { color: var(--gold-deep); font-weight: 800; }
.req-key { color: var(--gold-deep); font-weight: 800; }

.form {
  margin-top: 2.4rem;
  background: var(--white);
  border: 1px solid var(--sky);
  border-radius: var(--r);
  padding: clamp(1.4rem, 4vw, 2.4rem);
  box-shadow: var(--shadow);
}
.hp { position: absolute; left: -9999px; }

/* "We filled this in for you" bar. Must be dismissible: shared and lab
   machines mean the details on screen may belong to someone else. */
.prefill {
  display: flex; flex-wrap: wrap; align-items: center; gap: .8rem;
  background: var(--sky-pale); border: 1px solid var(--sky);
  border-radius: var(--r); padding: .8rem 1rem; margin-bottom: 1.6rem;
  font-size: .9rem; color: var(--navy);
}
.prefill__text { flex: 1; min-width: 12rem; }
.prefill__clear {
  font: inherit; font-size: .8rem; font-weight: 700;
  color: var(--navy); background: var(--white);
  border: 1.5px solid var(--sky); border-radius: 999px;
  padding: .35rem .9rem; cursor: pointer;
}
.prefill__clear:hover { border-color: var(--navy); }

.form__grid { display: grid; gap: 1.3rem; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }

.field { margin: 0 0 1.5rem; }
.form__grid .field { margin-bottom: 0; }
.field label, .field legend {
  display: block; margin-bottom: .4rem;
  font-weight: 700; font-size: .95rem; color: var(--navy);
}
.field__hint {
  display: block; font-size: .85rem; color: var(--ink-soft);
  margin: -.15rem 0 .5rem;
}

.field input[type="text"],
.field input[type="email"],
.field input[type="tel"],
.field select,
.field textarea {
  width: 100%;
  font: inherit; font-size: 1rem;
  color: var(--ink);
  padding: .7rem .85rem;
  border: 1.5px solid var(--line);
  border-radius: 8px;
  background: var(--white);
  transition: border-color .15s ease, box-shadow .15s ease;
}
.field textarea { resize: vertical; min-height: 3.2em; }
.field input:hover, .field select:hover, .field textarea:hover { border-color: var(--sky); }
.field input:focus, .field select:focus, .field textarea:focus {
  border-color: var(--navy-soft);
  box-shadow: 0 0 0 3px rgba(29,69,133,.14);
}
/* Only flag a field once the user has actually interacted with it or tried to
   submit. :user-invalid does this natively — plain :invalid would paint every
   empty required field red on page load. */
.field input:user-invalid,
.field select:user-invalid,
.field textarea:user-invalid {
  border-color: #b4342a;
  box-shadow: 0 0 0 3px rgba(180,52,42,.12);
}

.field--group { border: 0; padding: 0; margin: 0 0 1.5rem; }
.field--group legend { padding: 0; }
.choices { display: flex; flex-wrap: wrap; gap: .6rem; }
.choice {
  display: inline-flex; align-items: center; gap: .5rem;
  padding: .55rem 1.1rem;
  border: 1.5px solid var(--line); border-radius: 999px;
  font-weight: 600; font-size: .95rem; color: var(--ink);
  cursor: pointer;
  transition: border-color .15s ease, background-color .15s ease;
  margin-bottom: 0;
}
.choice:hover { border-color: var(--sky); background: var(--sky-pale); }
.choice input { accent-color: var(--navy); margin: 0; }
.choice:has(input:checked) { border-color: var(--navy); background: var(--sky-pale); }

.form__privacy {
  font-size: .87rem; color: var(--ink-soft);
  background: var(--sky-pale);
  border-left: 3px solid var(--sky);
  padding: .8rem 1rem;
  border-radius: 0 6px 6px 0;
  margin-bottom: 1.6rem;
}
.btn--submit { width: 100%; font-size: 1.02rem; padding: 1rem 1.7rem; border: 0; cursor: pointer; font-family: inherit; }
.btn--submit:disabled { opacity: .65; cursor: progress; transform: none; }

.form__status {
  margin: 1rem 0 0; padding: .8rem 1rem;
  border-radius: 8px; font-size: .95rem; font-weight: 600;
  border-left: 3px solid;
}
.form__status--pending { background: var(--sky-pale); border-color: var(--sky); color: var(--navy); }
.form__status--error   { background: #fdf0ef; border-color: #b4342a; color: #8c2820; }

/* ---------- multi-attendee blocks ---------- */
.attendee {
  border: 1.5px solid var(--line);
  border-radius: var(--r);
  padding: 1.3rem;
  margin: 0 0 1.2rem;
}
.attendee:first-child { border-color: var(--sky); background: #fbfdff; }
.attendee__legend {
  display: flex; align-items: center; gap: 1rem;
  width: 100%; padding: 0 .4rem;
  font-family: var(--font-display);
  font-size: .78rem; font-weight: 800;
  letter-spacing: .13em; text-transform: uppercase;
  color: var(--gold-deep);
}
.attendee__title { flex: 1; }
.attendee__remove {
  font: inherit; font-size: .72rem; font-weight: 700;
  letter-spacing: .06em; text-transform: uppercase;
  color: #8c2820; background: none;
  border: 1.5px solid #e6c4c0; border-radius: 999px;
  padding: .25rem .8rem; cursor: pointer;
}
.attendee__remove:hover { background: #fdf0ef; border-color: #b4342a; }
/* Nested fieldsets inside an attendee block shouldn't add another frame. */
.attendee .field--group { margin-bottom: 1.2rem; }

.addmore { margin: 0 0 1.6rem; }
.btn--outline {
  display: inline-block;
  background: none; color: var(--navy);
  border: 2px dashed var(--sky);
  padding: .7rem 1.3rem; border-radius: var(--r);
  font: inherit; font-weight: 800; font-size: .9rem;
  letter-spacing: .04em; text-transform: uppercase;
  cursor: pointer; width: 100%;
}
.btn--outline:hover:not(:disabled) { border-color: var(--navy); background: var(--sky-pale); }
.btn--outline:disabled { opacity: .45; cursor: not-allowed; }
.addmore .field__hint { margin-top: .5rem; }

.choice--block { display: flex; width: 100%; border-radius: var(--r); }

/* A volunteer opt-in, not a pill among pills: full width, aligned to the top so
   the hint can sit under the label without dragging the box off-centre. */
.field--optin .choice {
  align-items: flex-start; gap: .7rem;
  padding: .85rem 1.1rem; border-radius: var(--r);
  font-weight: 500;
}
.field--optin .choice input { margin-top: .18rem; width: 1.05rem; height: 1.05rem; flex: none; }
.field--optin .choice strong { font-weight: 800; }
.field--optin .field__hint { display: block; margin-top: .2rem; }

.form__total {
  margin: 0 0 1rem;
  font-family: var(--font-display);
  font-size: 1.05rem; font-weight: 800; color: var(--navy);
  text-align: center;
}

/* ---------- confirmation page: reference + payment ---------- */
.refbox {
  margin: 2rem auto; max-width: 30rem; padding: 1.4rem;
  background: var(--sky-pale); border: 1px solid var(--sky);
  border-radius: var(--r);
}
.refbox__label {
  font-size: .68rem; font-weight: 800; letter-spacing: .16em;
  text-transform: uppercase; color: var(--gold-deep); margin-bottom: .4rem;
}
.refbox__code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 1.6rem; font-weight: 700; letter-spacing: .04em;
  color: var(--navy); margin-bottom: .5rem;
}
.refbox__note { font-size: .87rem; color: var(--ink-soft); margin-bottom: .4rem; }
.refbox__note:last-child { margin-bottom: 0; }

.paybox {
  margin: 2rem auto; max-width: 34rem; padding: 1.8rem;
  background: var(--white); border: 2px solid var(--gold);
  border-radius: var(--r); box-shadow: var(--shadow);
}
.paybox__head {
  font-family: var(--font-display);
  font-size: 1.25rem; font-weight: 800; color: var(--navy);
  margin-bottom: .6rem;
}
.paybox__amount { font-size: 1.1rem; color: var(--ink-soft); margin-bottom: .8rem; }
.paybox__amount strong { color: var(--navy); font-size: 1.3rem; }
.paybox__qty {
  background: var(--sky-pale); border-left: 3px solid var(--gold);
  padding: .8rem 1rem; border-radius: 0 6px 6px 0;
  font-size: .95rem; color: var(--ink); margin-bottom: 1.2rem;
}
.paybox__form { margin-bottom: 0; }
.paybox__note { font-size: .85rem; color: var(--ink-soft); margin: 1rem 0 0; }
.paybox__note--refund { font-weight: 600; color: var(--navy); }
/* Shown when the PayPal SDK fails to load and the page drops back to the
   plain payment link — the payer still has a route through. */
.paybox__note--warn {
  color: #8a4b0a; background: #fdf0dc; border-left: 3px solid var(--gold);
  padding: .6rem .8rem; border-radius: 0 5px 5px 0; font-weight: 600;
}
.paybox__buttons { margin-top: 1.2rem; min-height: 50px; }
.paybox__pending {
  background: var(--sky-pale); border-left: 3px solid var(--sky);
  padding: .9rem 1.1rem; border-radius: 0 6px 6px 0;
  font-size: .95rem; color: var(--ink-soft); text-align: left;
}

/* ==========================================================================
   Thank-you page
   ========================================================================== */
.thanks {
  padding: clamp(3rem, 8vw, 6rem) 0;
  text-align: center;
}
.thanks__check {
  display: grid; place-items: center;
  width: 88px; height: 88px; margin: 0 auto 1.6rem;
  border-radius: 50%;
  background: var(--navy); color: var(--gold);
  box-shadow: 0 8px 24px rgba(18,48,94,.24);
}
.thanks__check svg { width: 48px; height: 48px; }
.thanks h1 {
  font-family: var(--font-display);
  font-size: clamp(1.9rem, 5vw, 3rem); font-weight: 800;
  text-transform: uppercase; letter-spacing: -.01em;
  color: var(--navy);
}
.thanks__lede { font-size: 1.12rem; color: var(--ink-soft); max-width: 54ch; margin-inline: auto; }
.thanks__meta {
  display: flex; flex-wrap: wrap; justify-content: center; gap: 1.4rem;
  margin: 2.2rem 0; padding: 1.6rem 1rem;
  background: var(--sky-pale); border: 1px solid var(--line); border-radius: var(--r);
  text-align: left;
}
.thanks__meta dt {
  font-size: .68rem; font-weight: 800; letter-spacing: .16em;
  text-transform: uppercase; color: var(--gold-deep); margin-bottom: .25rem;
}
.thanks__meta dd { margin: 0; font-weight: 600; color: var(--navy); line-height: 1.5; }
.thanks__btns { display: flex; flex-wrap: wrap; gap: 1rem; justify-content: center; margin-top: 2rem; }
.btn--ghost-dark { color: var(--navy); border-color: var(--navy); background: transparent; }
.btn--ghost-dark:hover { background: var(--sky-pale); }

/* ==========================================================================
   Sponsors
   ========================================================================== */
.opps {
  display: grid; gap: 1.4rem; margin: 2.6rem 0 2.2rem;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}
.opp {
  background: var(--white); border: 1px solid var(--sky);
  border-radius: var(--r); padding: 1.7rem;
}
.opp--feature { border-color: var(--gold); border-width: 2px; }

/* Four sponsorship tiers. They share the gold border so the group reads as one
   offer; the label colour alone carries the tier. */
.opps--tiers { grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); }
.opps--tiers .opp { border-color: var(--gold); border-width: 2px; }
.opp--platinum { background: linear-gradient(180deg, #f6f9fc 0%, var(--white) 60%); }
.opp--platinum .opp__label { color: var(--navy); }
.opp--gold .opp__label     { color: var(--gold-deep); }
.opp--silver .opp__label   { color: #6b7885; }
.opp--bronze .opp__label   { color: #9a6b3f; }
.opp__label {
  font-family: var(--font-display);
  font-size: .8rem; font-weight: 800;
  letter-spacing: .16em; text-transform: uppercase;
}

.tier__label--silver { color: #6b7885; }
.tier__label--bronze { color: #9a6b3f; }
.logos--silver .logo { min-width: 175px; min-height: 92px; }
.logos--bronze .logo { min-width: 150px; min-height: 76px; }
.logos--bronze .logo span { font-size: .92rem; }
.logo--empty {
  border-style: dashed; box-shadow: none; background: transparent;
}
.logo--empty span { color: var(--ink-soft); font-weight: 600; }

.ticks--wide li { font-size: 1rem; }
.note--center { max-width: 46ch; margin-inline: auto; text-align: left; }
.opp__label {
  font-size: .66rem; font-weight: 800; letter-spacing: .13em;
  text-transform: uppercase; color: var(--gold-deep); margin-bottom: .5rem;
}
.opp h3 { font-family: var(--font-display); font-size: 1.2rem; font-weight: 800; color: var(--navy); }
.opp__price {
  font-family: var(--font-display);
  font-size: 1.85rem; font-weight: 800; color: var(--navy);
  margin-bottom: .4rem;
}
.opp p:last-child { margin: 0; font-size: .95rem; color: var(--ink-soft); }

.tier { margin-top: 2.2rem; }
.tier__label {
  font-size: .76rem; font-weight: 800; letter-spacing: .18em;
  text-transform: uppercase; text-align: center;
  margin-bottom: 1rem; color: var(--ink-soft);
  display: flex; align-items: center; gap: 1rem; justify-content: center;
}
.tier__label::before, .tier__label::after {
  content: ""; height: 1px; flex: 1; max-width: 120px; background: var(--line);
}
.tier__label--platinum { color: var(--navy); }
.tier__label--gold { color: var(--gold-deep); }

.logos { display: flex; flex-wrap: wrap; gap: 1.2rem; justify-content: center; }
.logo {
  display: grid; place-items: center; text-align: center;
  background: var(--white); border: 1px solid var(--line);
  border-radius: var(--r); box-shadow: var(--shadow);
  padding: 1.2rem 1.6rem;
}
.logo span {
  font-family: var(--font-display);
  font-weight: 800; color: var(--navy);
  letter-spacing: .02em; line-height: 1.25;
}
/* Logos arrive at wildly different aspect ratios (a square CMU wordmark next to
   a 4:1 Duquesne lockup). Constraining height and letting width follow keeps
   them optically comparable instead of sizing them by area. */
.logo picture { display: block; }
/* The tile is the visual object, so the link fills it and the tile itself
   carries the hover state — a hover on just the image would look detached. */
.logo a { display: block; }
.logo:has(a) { transition: transform .15s ease, box-shadow .15s ease, border-color .15s ease; }
.logo:has(a:hover), .logo:has(a:focus-visible) {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(18, 48, 94, .16);
  border-color: var(--gold);
}
.logo img { width: auto; object-fit: contain; }
.logos--platinum .logo img { max-height: 84px; max-width: 210px; }
.logos--gold .logo img     { max-height: 68px; max-width: 170px; }
.logos--silver .logo img   { max-height: 56px; max-width: 145px; }
.logos--bronze .logo img   { max-height: 46px; max-width: 125px; }
/* The LSAC lockup is roughly 11:1, so it is width-constrained rather than
   height-constrained like the sponsor marks above. */
.logos--thanks .logo img   { max-height: 56px; max-width: min(380px, 78vw); }

/* Not a sponsorship tier — an acknowledgement, so it sits below the tiers with a
   rule separating it rather than a tier label. */
.thanks-to { margin-top: 3rem; padding-top: 2.2rem; border-top: 1px solid var(--line); }
.thanks-to__label {
  text-align: center; margin: 0 0 1.1rem;
  font-size: .76rem; font-weight: 800; letter-spacing: .18em;
  text-transform: uppercase; color: var(--ink-soft);
}
.logos--platinum .logo { min-width: 260px; min-height: 128px; border-width: 2px; border-color: var(--navy); }
.logos--platinum .logo span { font-size: 1.5rem; }
.logos--gold .logo { min-width: 210px; min-height: 104px; border-color: var(--gold); }
.logos--gold .logo span { font-size: 1.15rem; }
.logos--silver .logo { min-width: 176px; min-height: 88px; }
.logos--silver .logo span { font-size: 1rem; }

/* ==========================================================================
   Venue
   ========================================================================== */
.venue { display: grid; gap: 2.2rem; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); margin-top: 2.2rem; }
.venue address {
  font-style: normal; font-size: 1.12rem; line-height: 1.75;
  font-weight: 600; color: var(--navy); margin-bottom: 1rem;
}
.link-arrow { font-weight: 700; text-decoration: none; border-bottom: 2px solid var(--gold); padding-bottom: 1px; }
.link-arrow::after { content: " →"; }
.link-arrow:hover { color: var(--navy); }

/* ==========================================================================
   Final CTA + footer
   ========================================================================== */
.finalcta {
  background: linear-gradient(160deg, var(--navy) 0%, var(--navy-deep) 100%);
  color: #fff; text-align: center;
  padding: clamp(3.2rem, 6vw, 5rem) 0;
}
.finalcta h2 {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4.4vw, 3rem); font-weight: 800;
  text-transform: uppercase; letter-spacing: -.01em;
}
.finalcta__meta { color: #cfe0f2; font-size: 1.05rem; margin-bottom: 2rem; }
.finalcta__btns { display: flex; flex-wrap: wrap; gap: 1rem; justify-content: center; }

.site-footer { background: var(--navy-deep); color: #b9cde3; border-top: 4px solid var(--gold); padding: 2.8rem 0 1.6rem; }
.site-footer__inner { display: grid; gap: 2rem; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.site-footer__title {
  font-family: var(--font-display);
  font-size: 1.3rem; font-weight: 800; color: #fff;
  text-transform: uppercase; letter-spacing: .04em; margin-bottom: .3rem;
}
.site-footer__sub { font-size: .92rem; margin-bottom: .5rem; }
.site-footer__org { font-size: .92rem; color: var(--gold); font-weight: 600; margin: 0; }
.site-footer__nav ul { display: flex; flex-wrap: wrap; gap: .5rem 1.4rem; }
.site-footer__nav a { color: #d7e5f3; text-decoration: none; font-size: .93rem; font-weight: 600; }
.site-footer__nav a:hover { color: var(--gold); }
.site-footer__tags {
  text-align: center; margin: 2.2rem 0 0; padding-top: 1.4rem;
  border-top: 1px solid rgba(255,255,255,.12);
  font-size: .8rem; letter-spacing: .1em; text-transform: uppercase;
}

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width: 980px) {
  .nav-toggle { display: flex; }

  /* Let the header wrap rather than push the menu button off-screen. */
  .site-header__inner { flex-wrap: wrap; row-gap: .4rem; }

  /* The form pages (register, posters) use .nav--simple and have NO menu
     toggle, so the collapsing rules below must not apply to them — otherwise
     their links are display:none with nothing to reveal them, stranding phone
     visitors with no way back to the event page. Keep it inline, wrapping to
     its own row when space runs out. */
  .nav.nav--simple {
    position: static;
    display: flex;
    width: 100%;
    margin-left: 0;
    padding: 0 0 .3rem;
    background: none;
    border: 0;
    box-shadow: none;
  }
  .nav--simple .nav__list { flex-direction: row; gap: 1.3rem; }
  .nav--simple .nav__list a { padding: .2rem 0; border-bottom: 0; }
  .nav--simple .nav__list a::after { display: block; }
  .nav {
    position: absolute; top: 100%; left: 0; right: 0;
    flex-direction: column; align-items: stretch; gap: .4rem;
    background: #fff; border-bottom: 1px solid var(--line);
    box-shadow: 0 14px 28px rgba(18,48,94,.14);
    padding: 1rem 1.25rem 1.4rem;
    display: none;
  }
  .nav.is-open { display: flex; }
  .nav__list { flex-direction: column; gap: 0; }
  .nav__list a { padding: .7rem 0; border-bottom: 1px solid var(--line); }
  .nav__list a::after { display: none; }
  .nav .btn { margin-top: .8rem; }

  .agenda__row { grid-template-columns: 1fr; gap: .45rem; padding: 1.1rem .3rem; }
  .agenda__focus { text-align: left; }

  .person--featured { grid-column: span 1; }
}

@media (max-width: 620px) {
  body { font-size: 16px; }

  /* Stacked, the pillars should read in the same order as the tagline above
     them — "Academia, Industry, and Community". Side by side the original
     order balances better, so this only applies once they are in one column.
     Visual order only: the DOM sequence, and so the reading order for
     assistive tech, is unchanged. These are three static cards with nothing
     focusable, so nothing can get out of step. */
  .pillar--industry  { order: 2; }
  .pillar--community { order: 3; }

  /* Two-part brand plus a menu button is tight at 390px; shrink the lockup so
     the toggle stays on screen instead of forcing horizontal scroll. */
  .site-header__inner { gap: .6rem; }
  .brand { gap: .55rem; }
  .brand__logo { height: 26px; }
  .brand__section {
    font-size: .55rem; letter-spacing: .05em;
    padding-left: .55rem; border-left-width: 2px;
  }
  /* Icon alone is enough at this width, but keep a 44px hit area — anything
     smaller is genuinely hard to tap accurately. */
  .nav-toggle {
    padding: .45rem .75rem; font-size: .78rem;
    min-height: 44px; min-width: 44px;
    justify-content: center;
  }
  .nav-toggle__label { display: none; }

  /* Comfortable hit area for removing an attendee on a touch screen. */
  .attendee__remove { min-height: 40px; padding: .4rem 1rem; }
  .attendee { padding: 1rem .8rem; }
  .attendee__legend { gap: .5rem; }
  .hero { padding-top: 2rem; }
  .hero__inner { padding-bottom: 9rem; }
  .hero__acs150 { height: 84px; }
  .hero__acs150-link { margin-bottom: 1.3rem; }
  .hero__art { bottom: 2.1rem; }
  .hero__meta { gap: 1.2rem; }
  .hero__meta > div { border-left: 0; padding: 0; flex: 1 1 100%; }
  .hero__cta .btn, .finalcta__btns .btn { width: 100%; }
  .people { grid-template-columns: 1fr 1fr; gap: .9rem; }
  .person { padding: 1.2rem .7rem; }
  .avatar, .person--featured .avatar { width: 84px; height: 84px; }
  .avatar--mono, .person--featured .avatar--mono { font-size: 1.7rem; }
  .person__name, .person--featured .person__name { font-size: .95rem; }
  .awards { padding: 1.4rem; }
  .logos--platinum .logo { min-width: 100%; }
}

/* ==========================================================================
   Print
   ========================================================================== */
@media print {
  .site-header, .announce, .nav-toggle, .filters, .finalcta__btns, .hero__cta { display: none !important; }
  body { font-size: 11pt; }
  .hero, .finalcta, .awards, .site-footer { background: none !important; color: #000 !important; }
  .hero__title, .finalcta h2, .awards .h-sub { color: #000 !important; }
  .person, .card, .opp, .highlight { break-inside: avoid; }
}