:root {
  --ink: #10202f;
  --muted: #5c6c78;
  --paper: #f7f5ef;
  --panel: #ffffff;
  --accent: #ff6b35;
  --accent-2: #0a7b83;
  --hero-accent: #8EDCFF;
  --line: #dbe2e7;
  --shadow: 0 24px 70px rgba(16, 32, 47, 0.12);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.65;
}

a { color: inherit; }
.skip-link {
  position: fixed;
  left: 1rem;
  top: -4rem;
  z-index: 100;
  background: #fff;
  padding: .75rem 1rem;
  border-radius: .5rem;
}
.skip-link:focus { top: 1rem; }

.hero {
  min-height: 78vh;
  display: grid;
  grid-template-rows: auto 1fr;
  background:
    radial-gradient(circle at 15% 20%, rgba(142,220,255,.18), transparent 27%),
    radial-gradient(circle at 85% 30%, rgba(10,123,131,.28), transparent 30%),
    #10202f;
  color: white;
}
.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.2rem clamp(1rem, 4vw, 4rem);
  border-bottom: 1px solid rgba(255,255,255,.15);
}
.brand { font-weight: 800; text-decoration: none; }
.nav-links { display: flex; gap: 1rem; flex-wrap: wrap; }
.nav-links a { text-decoration: none; opacity: .82; }
.nav-links a:hover { opacity: 1; }
.hero-copy {
  width: min(900px, calc(100% - 2rem));
  margin: auto;
  padding: 5rem 0 7rem;
}
.eyebrow, .section-kicker {
  text-transform: uppercase;
  letter-spacing: .15em;
  font-size: .78rem;
  font-weight: 800;
}
.section-kicker {
  color: #8b949d;
  opacity: .78;
}
.hero h1 {
  margin: .25rem 0 1rem;
  font-size: clamp(2.8rem, 7.2vw, 6.4rem);
  line-height: .92;
  max-width: 12ch;
}
.hero h1 span { display: block; }
.hero h1 span:nth-child(2) { color: var(--accent); }
.lede { max-width: 58ch; font-size: 1.25rem; color: rgba(255,255,255,.78); }
.button {
  display: inline-block;
  margin-top: 1rem;
  padding: .9rem 1.15rem;
  border-radius: 999px;
  background: var(--accent);
  color: white;
  text-decoration: none;
  font-weight: 800;
  border: 0;
  cursor: pointer;
}
.button.secondary { background: var(--ink); }

main {
  display: grid;
  grid-template-columns: minmax(320px, .8fr) minmax(0, 1.4fr);
  gap: clamp(2rem, 5vw, 6rem);
  width: min(1400px, calc(100% - 2rem));
  margin: 0 auto;
}
.protocol-stage { position: relative; }
.packet-panel {
  position: sticky;
  top: 1.5rem;
  min-height: calc(100vh - 3rem);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 2rem;
}
.layer-label {
  margin-bottom: 1rem;
  font-weight: 900;
  letter-spacing: .08em;
  text-transform: uppercase;
}
.packet {
  width: min(100%, 520px);
  background: white;
  border: 3px solid var(--ink);
  border-radius: 1rem;
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: transform .5s ease;
}
.header, .trailer, .payload {
  padding: 1rem;
  border-bottom: 2px solid var(--ink);
  font-weight: 800;
  transition: all .45s ease;
}
.ethernet { background: #f9c74f; }
.ip { background: #90be6d; }
.tcp { background: #4d9de0; color: white; }
.payload { background: white; display: grid; gap: .25rem; }
.payload span { color: var(--muted); font-weight: 500; }
.trailer { background: #f9844a; border-bottom: 0; }
.packet .header, .packet .trailer { max-height: 0; opacity: 0; padding-block: 0; border-width: 0; }
.packet.transport .tcp,
.packet.network .tcp, .packet.network .ip,
.packet.link .tcp, .packet.link .ip, .packet.link .ethernet, .packet.link .trailer,
.packet.physical .tcp, .packet.physical .ip, .packet.physical .ethernet, .packet.physical .trailer {
  max-height: 100px;
  opacity: 1;
  padding: 1rem;
  border-width: 2px;
}
.packet.physical { transform: scale(.93); }
.bits {
  margin-top: 1.5rem;
  font-family: "SFMono-Regular", Consolas, monospace;
  color: var(--accent-2);
  opacity: 0;
  transform: translateY(8px);
  transition: .4s ease;
  text-align: center;
}
.bits.visible { opacity: 1; transform: translateY(0); }
.packet-note { color: var(--muted); text-align: center; }

.content-column { padding: 8rem 0; }
.syllabus-section, .arrival {
  min-height: 88vh;
  padding: 4rem 0;
  border-bottom: 1px solid var(--line);
  scroll-margin-top: 2rem;
}
.syllabus-section h2, .arrival h2 {
  margin: .2rem 0 1rem;
  font-size: clamp(2.2rem, 5vw, 4.8rem);
  line-height: 1;
  max-width: 12ch;
}
.syllabus-section h3 { margin-top: 2rem; }
.syllabus-section p, .syllabus-section li, .arrival p { font-size: 1.05rem; }
.info-grid, .grade-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0,1fr));
  gap: 1rem;
  margin: 2rem 0;
}
.info-grid article, .grade-grid article, .protocol-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 1rem;
  padding: 1.25rem;
}
.info-grid h3, .grade-grid h3 { margin: 0 0 .3rem; }
.protocol-card { display: grid; gap: .8rem; }
.protocol-card div { display: flex; justify-content: space-between; gap: 2rem; border-bottom: 1px dashed var(--line); padding-bottom: .6rem; }
.protocol-card div:last-child { border-bottom: 0; }
.protocol-card span { color: var(--muted); }
.route-map { margin: 2rem 0; }
.route-stop {
  padding: 1rem 1.1rem;
  margin-bottom: .8rem;
  border-left: 4px solid var(--accent-2);
  border-radius: 0 .8rem .8rem 0;
  background: rgba(255,255,255,.72);
}
.route-stop small { display: block; color: var(--muted); }
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; background: white; }
th, td { text-align: left; padding: .9rem; border-bottom: 1px solid var(--line); }
th { background: #edf2f4; }
.grade-grid article span { font-size: 2rem; font-weight: 900; color: var(--accent-2); }
.policy-list details { background: white; border: 1px solid var(--line); border-radius: .8rem; padding: 1rem 1.1rem; margin-bottom: .8rem; }
.policy-list summary { cursor: pointer; font-weight: 900; }
.arrival { min-height: 65vh; }

footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  padding: 2rem clamp(1rem, 4vw, 4rem);
  background: var(--ink);
  color: white;
}
footer button { padding: .75rem 1rem; border-radius: 999px; border: 0; font-weight: 800; cursor: pointer; }

@media (max-width: 900px) {
  main { display: block; }
  .protocol-stage { height: 48vh; }
  .packet-panel { min-height: 48vh; top: 0; background: rgba(247,245,239,.96); z-index: 5; padding: 1rem; }
  .packet { width: min(92vw, 520px); }
  .content-column { padding-top: 1rem; }
  .info-grid, .grade-grid { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  .nav-links { display: none; }
  .hero { min-height: 68vh; }
  .hero-copy { padding: 4rem 0; }
  .protocol-card div { display: grid; gap: .1rem; }
  footer { display: grid; }
}

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

@media print {
  .hero, .protocol-stage, footer button, .nav-links { display: none !important; }
  body { background: white; font-size: 11pt; }
  main { display: block; width: 100%; }
  .content-column { padding: 0; }
  .syllabus-section, .arrival { min-height: auto; break-inside: avoid; padding: 1.2rem 0; }
  .syllabus-section h2, .arrival h2 { font-size: 24pt; }
  details { break-inside: avoid; }
  footer { display: block; background: white; color: black; padding: 1rem 0; }
}

/* End-to-end physical transmission */
.transmission {
  width: min(100%, 560px);
  display: grid;
  grid-template-columns: 72px minmax(120px, 1fr) 72px;
  align-items: end;
  gap: .65rem;
  margin-top: 1.5rem;
  opacity: 0;
  max-height: 0;
  overflow: hidden;
  transform: translateY(10px);
  transition: opacity .4s ease, transform .4s ease, max-height .4s ease;
}
.packet-panel.transmitting .transmission,
.packet-panel.arrived .transmission {
  opacity: 1;
  max-height: 190px;
  overflow: visible;
  transform: translateY(0);
}
.endpoint { text-align: center; color: var(--muted); font-weight: 800; }
.computer-screen {
  width: 62px;
  height: 48px;
  margin: 0 auto;
  border: 4px solid var(--ink);
  border-radius: .5rem;
  background: #e8f7f8;
  display: grid;
  place-items: center;
  box-shadow: inset 0 0 0 3px white;
}
.computer-screen span { font-size: .8rem; font-weight: 900; color: var(--accent-2); }
.computer-base {
  width: 42px;
  height: 8px;
  margin: 3px auto 5px;
  border-radius: 0 0 8px 8px;
  background: var(--ink);
}
.medium { position: relative; height: 82px; min-width: 0; }
.wire {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 25px;
  height: 7px;
  border-radius: 999px;
  background: repeating-linear-gradient(90deg, var(--accent-2) 0 18px, #84c9cd 18px 30px);
  box-shadow: 0 0 0 3px white, 0 0 0 4px var(--line);
}
.signal-bits {
  position: absolute;
  top: 0;
  left: 50%;
  width: max-content;
  max-width: 100%;
  transform: translateX(-50%);
  overflow: hidden;
  white-space: nowrap;
  font: 700 .67rem/1 "SFMono-Regular", Consolas, monospace;
  color: var(--accent-2);
  opacity: .75;
}
.mini-packet {
  position: absolute;
  left: -2px;
  bottom: 14px;
  z-index: 2;
  width: 43px;
  height: 29px;
  display: grid;
  grid-template-columns: 8px 8px 8px 1fr;
  border: 2px solid var(--ink);
  border-radius: .35rem;
  overflow: hidden;
  background: white;
  box-shadow: 0 5px 12px rgba(16,32,47,.25);
}
.mini-packet i:nth-child(1) { background: #f9c74f; }
.mini-packet i:nth-child(2) { background: #90be6d; }
.mini-packet i:nth-child(3) { background: #4d9de0; }
.mini-packet i:nth-child(4) { background: white; }
.packet-panel.transmitting .mini-packet,
.packet-panel.arrived .mini-packet {
  transition: opacity .25s ease;
}
.packet-panel.arrived .mini-packet {
  opacity: .35;
}
.packet-panel.transmitting #packet {
  transform: scale(.28) translateY(26px);
  opacity: 0;
  pointer-events: none;
  max-height: 0;
}
.packet-panel.arrived #packet {
  transform: scale(1);
  opacity: 1;
  max-height: 520px;
  transition: none;
  animation: received-packet .6s .18s cubic-bezier(.2,.8,.2,1) both;
}
/* At the receiver, reveal the complete frame as one object. Without this,
   each header's max-height transition runs after the outer scale animation,
   which looks like a second expansion. */
.packet-panel.arrived #packet .header,
.packet-panel.arrived #packet .trailer,
.packet-panel.arrived #packet .payload {
  transition: none;
}
.packet-panel.arrived .destination-endpoint .computer-screen {
  animation: destination-glow 1.3s ease-in-out infinite alternate;
}
@keyframes received-packet {
  from { transform: scale(.5) translateX(35%); opacity: 0; }
  to { transform: scale(1) translateX(0); opacity: 1; }
}
@keyframes destination-glow {
  to { background: #c9f3e8; box-shadow: inset 0 0 0 3px white, 0 0 22px rgba(10,123,131,.38); }
}
@media (max-width: 520px) {
  .hero h1 { font-size: clamp(2.65rem, 15vw, 4.4rem); max-width: 11ch; }
  .transmission { grid-template-columns: 54px minmax(90px, 1fr) 54px; gap: .35rem; }
  .computer-screen { width: 48px; height: 39px; }
  .computer-base { width: 33px; }
  .signal-bits { font-size: .52rem; }
}
@media print {
  .transmission { display: none !important; }
}

/* Collapsible semester schedule */
.week-list {
  display: grid;
  gap: .8rem;
  margin-top: 2rem;
}

.week-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 1rem;
  overflow: hidden;
  box-shadow: 0 8px 24px rgba(15, 23, 42, .05);
}

.week-card summary {
  display: grid;
  grid-template-columns: 7rem 1fr;
  gap: 1rem;
  align-items: center;
  cursor: pointer;
  list-style: none;
  padding: 1rem 1.15rem;
  font-weight: 750;
}

.week-card summary::-webkit-details-marker { display: none; }

.week-card summary::after {
  content: "+";
  grid-column: 3;
  font-size: 1.35rem;
  line-height: 1;
  transition: transform .2s ease;
}

.week-card[open] summary::after { transform: rotate(45deg); }
.week-card summary span { color: var(--ink); }
.week-card summary small { color: var(--muted); font-weight: 600; }

.week-body {
  border-top: 1px solid var(--line);
  padding: .45rem 1.15rem .9rem;
}

.week-body p {
  display: grid;
  grid-template-columns: 7rem 6.5rem 1fr;
  gap: .8rem;
  align-items: baseline;
  margin: 0;
  padding: .8rem 0;
  border-bottom: 1px dashed var(--line);
}

.week-body p:last-child { border-bottom: 0; }
.week-body time { color: var(--muted); font-variant-numeric: tabular-nums; }
.week-body strong { color: var(--ink); }
.week-body .special,
.week-body .calendar-note {
  grid-template-columns: 7rem minmax(0, 1fr);
  border-radius: .65rem;
  margin-top: .35rem;
  padding: .75rem .8rem;
  border-bottom: 0;
}

.week-body .special strong,
.week-body .calendar-note strong {
  white-space: nowrap;
}

.week-body .calendar-note:not(:has(time)) strong {
  grid-column: 1 / -1;
}
.week-body .exam { background: #fff4e8; }
.week-body .no-class { background: #eef6ff; }
.week-body .tba { background: #f5f2ff; }
.week-body .calendar-note { background: #f7f8fa; color: var(--muted); }

@media (max-width: 720px) {
  .week-card summary { grid-template-columns: 5.5rem 1fr; gap: .6rem; }
  .week-card summary::after { grid-column: 3; }
  .week-body p { grid-template-columns: 1fr; gap: .2rem; }
  .week-body .special,
  .week-body .calendar-note { grid-template-columns: auto minmax(0, 1fr); }
  .week-body .special strong,
  .week-body .calendar-note strong { white-space: normal; }
}

@media print {
  .week-card { break-inside: avoid; }
  .week-card > .week-body { display: block !important; }
  .week-card summary::after { display: none; }
}

/* v7 refinements */
.hero h1 span:nth-child(3) {
  white-space: nowrap;
  font-size: .78em;
  letter-spacing: -.035em;
}

/* During launch, the full frame shrinks first. The miniature frame then
   takes over and moves across the link according to scroll position. */
.packet-panel.transmitting #packet {
  transform: translateY(calc(26px * var(--shrink, 1))) scale(calc(1 - .72 * var(--shrink, 1)));
  opacity: calc(1 - var(--shrink, 1));
  max-height: calc(520px * (1 - var(--shrink, 1)));
  transition: none;
}
.packet-panel.transmitting .mini-packet {
  opacity: var(--mini-visible, 1);
  transition: none;
}

@media (max-width: 720px) {
  .hero h1 span:nth-child(3) {
    font-size: .58em;
    letter-spacing: -.045em;
  }
}

/* Course materials */
.materials-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
  margin: 1.25rem 0 2rem;
}
.materials-grid article {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 1rem;
  padding: 1.25rem;
}
.materials-grid h4 {
  margin: .15rem 0 .7rem;
  font-size: 1.15rem;
}
.materials-grid p {
  font-size: .98rem;
}
.material-icon {
  margin: 0;
  font-size: 1.65rem !important;
}
.materials-grid a {
  color: var(--accent-2);
  font-weight: 800;
}
@media (max-width: 900px) {
  .materials-grid { grid-template-columns: 1fr; }
}

/* v9 content and motion refinements */
.hero h1 {
  max-width: 15ch;
  font-size: clamp(2.55rem, 6.3vw, 5.8rem);
  line-height: .96;
}
.hero h1 span {
  display: block;
  font-size: 1em !important;
  letter-spacing: -.045em !important;
  white-space: nowrap;
}
.hero h1 span:nth-child(2) { color: var(--accent); }

.packet {
  transition: transform .65s cubic-bezier(.16,1,.3,1), opacity .45s ease;
}
.header, .trailer, .payload {
  transition: max-height .62s cubic-bezier(.16,1,.3,1), opacity .34s ease, padding .62s cubic-bezier(.16,1,.3,1), border-width .34s ease;
}
.packet-panel.transmitting .transmission,
.packet-panel.arrived .transmission {
  transition: opacity .58s ease, transform .7s cubic-bezier(.16,1,.3,1), max-height .5s ease;
}

.final-note {
  background: rgba(10,123,131,.08);
  border-left: 4px solid var(--accent-2);
  border-radius: 0 .9rem .9rem 0;
  padding: 1rem 1.15rem;
  margin-top: 1rem;
}

/* Router waypoints in the physical-layer journey */
.router {
  --router-glow: 0;
  position: absolute;
  bottom: 0;
  z-index: 1;
  width: 64px;
  transform: translateX(-50%);
  text-align: center;
  color: var(--muted);
  font-weight: 800;
  pointer-events: none;
}
.router-one { left: 33.333%; }
.router-two { left: 66.666%; }
.router-body {
  position: relative;
  width: 48px;
  height: 28px;
  margin: 0 auto 4px;
  border: 3px solid var(--ink);
  border-radius: .45rem;
  background: #e8f7f8;
  box-shadow:
    inset 0 0 0 2px white,
    0 0 calc(4px + 18px * var(--router-glow)) rgba(10,123,131,.38);
  transition: background .12s linear, box-shadow .12s linear, transform .12s linear;
  transform: translateY(calc(-2px * var(--router-glow))) scale(calc(1 + .05 * var(--router-glow)));
}
.router-body::before,
.router-body::after {
  content: "";
  position: absolute;
  top: 50%;
  width: 7px;
  height: 7px;
  margin-top: -3.5px;
  border-radius: 50%;
  background: var(--accent-2);
  opacity: calc(.35 + .65 * var(--router-glow));
}
.router-body::before { left: 7px; }
.router-body::after { right: 7px; }
.router-body i {
  position: absolute;
  bottom: 4px;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: #90be6d;
  opacity: calc(.35 + .65 * var(--router-glow));
}
.router-body i:nth-child(1) { left: 14px; }
.router-body i:nth-child(2) { left: 22px; }
.router-body i:nth-child(3) { left: 30px; }
.router small { font-size: .6rem; white-space: nowrap; }

@media (max-width: 520px) {
  .router { width: 48px; }
  .router-body { width: 38px; height: 24px; }
  .router-body i:nth-child(1) { left: 10px; }
  .router-body i:nth-child(2) { left: 17px; }
  .router-body i:nth-child(3) { left: 24px; }
  .router small { font-size: .5rem; }
}

/* v13: course staff ring topology */
.class-meeting-card {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: .25rem 1rem;
  align-items: baseline;
  margin: 1.5rem 0 2.5rem;
  padding: 1rem 1.15rem;
  border: 1px solid var(--line);
  border-left: 4px solid var(--accent-2);
  border-radius: .9rem;
  background: var(--panel);
}
.class-meeting-card span { color: var(--muted); font-weight: 800; }
.class-meeting-card strong { color: var(--ink); }
.class-meeting-card small { grid-column: 2; color: var(--muted); }

.staff-network { margin: 2.5rem 0 3rem; }
.staff-network-heading { max-width: 42rem; margin-bottom: 1rem; }
.staff-network-heading h3 { margin: .15rem 0 .35rem; }
.staff-network-heading p { margin: 0; }
.network-label {
  color: var(--accent-2);
  font: 800 .75rem/1.2 "SFMono-Regular", Consolas, monospace;
  letter-spacing: .1em;
  text-transform: uppercase;
}
.ring-topology {
  position: relative;
  width: min(100%, 650px);
  aspect-ratio: 1;
  margin: 1.5rem auto 0;
}
.ring-links { position: absolute; inset: 8%; width: 84%; height: 84%; overflow: visible; }
.ring-links path {
  fill: none;
  stroke: var(--accent-2);
  stroke-width: 5;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-dasharray: 10 11;
  opacity: .34;
}
.ring-pulse { fill: var(--accent); filter: drop-shadow(0 0 7px rgba(240,112,73,.48)); }
.staff-node {
  position: absolute;
  left: var(--x);
  top: var(--y);
  width: 9.5rem;
  transform: translate(-50%, -50%);
  text-align: center;
  z-index: 1;
}
.staff-photo {
  width: 78px;
  height: 78px;
  display: grid;
  place-items: center;
  margin: 0 auto .55rem;
  border: 4px solid white;
  outline: 3px solid var(--accent-2);
  border-radius: 50%;
  background: #e8f7f8;
  color: var(--accent-2);
  box-shadow: 0 8px 20px rgba(16,32,47,.14);
  font: 900 .88rem/1 "SFMono-Regular", Consolas, monospace;
  transition: transform .25s ease, box-shadow .25s ease, outline-color .25s ease;
}
.staff-photo.featured { width: 94px; height: 94px; background: #fff1e9; color: var(--accent); outline-color: var(--accent); }
.staff-node:hover .staff-photo,
.staff-node:focus-within .staff-photo { transform: translateY(-4px) scale(1.04); box-shadow: 0 13px 28px rgba(16,32,47,.2); }
.staff-node strong,
.staff-node span,
.staff-node small { display: block; }
.staff-node strong { font-size: .95rem; }
.staff-node span { color: var(--accent-2); font-size: .72rem; font-weight: 800; }
.staff-node small { color: var(--muted); font-size: .68rem; }

/* v13: brief arrival celebration */
.arrival { position: relative; overflow: hidden; text-align: center; }
.arrival > *:not(.celebration) { position: relative; z-index: 1; }
.arrival-badge {
  width: 66px;
  height: 66px;
  display: grid;
  place-items: center;
  margin: .5rem auto 1rem;
  border: 3px solid var(--accent-2);
  border-radius: 50%;
  color: var(--accent-2);
  background: #e8f7f8;
  font-size: 2rem;
  font-weight: 900;
}
.arrival.celebrate .arrival-badge { animation: arrival-pop .72s cubic-bezier(.2,1.5,.4,1) both; }
.arrival-cheer { color: var(--accent-2); font-weight: 850; }
.celebration { position: absolute; inset: 0; pointer-events: none; z-index: 0; }
.confetti-piece {
  position: absolute;
  left: 50%;
  top: 34%;
  width: 9px;
  height: 15px;
  border-radius: 2px;
  background: var(--confetti-color);
  opacity: 0;
}
.arrival.celebrate .confetti-piece {
  animation: confetti-burst 1.25s cubic-bezier(.1,.75,.3,1) var(--delay) both;
}
@keyframes arrival-pop {
  0% { transform: scale(.35) rotate(-18deg); opacity: 0; }
  65% { transform: scale(1.15) rotate(5deg); }
  100% { transform: scale(1) rotate(0); opacity: 1; }
}
@keyframes confetti-burst {
  0% { transform: translate(-50%, -50%) rotate(0) scale(.5); opacity: 0; }
  12% { opacity: 1; }
  100% { transform: translate(calc(-50% + var(--dx)), calc(-50% + var(--dy))) rotate(var(--rot)) scale(1); opacity: 0; }
}
@media (max-width: 700px) {
  .class-meeting-card { grid-template-columns: 1fr; }
  .class-meeting-card small { grid-column: 1; }
  .ring-topology { aspect-ratio: 1 / 1.18; }
  .staff-node { width: 7rem; }
  .staff-photo { width: 60px; height: 60px; }
  .staff-photo.featured { width: 72px; height: 72px; }
  .staff-node strong { font-size: .78rem; }
  .staff-node span, .staff-node small { font-size: .6rem; }
}
@media (prefers-reduced-motion: reduce) {
  .arrival.celebrate .confetti-piece { display: none; }
  .arrival.celebrate .arrival-badge { animation: none; }
  .staff-photo { transition: none; }
}
@media print {
  .celebration { display: none; }
  .ring-links path { stroke-dasharray: none; }
}

/* v14: scroll-reactive hero handoff */
.hero {
  --hero-progress: 0;
  position: relative;
  overflow: hidden;
  min-height: 92vh;
  isolation: isolate;
}
.hero::after {
  content: "";
  position: absolute;
  inset: auto 0 0;
  height: 24%;
  background: linear-gradient(to bottom, transparent, rgba(16,32,47,.7));
  pointer-events: none;
  z-index: -1;
}
.hero-network {
  position: absolute;
  inset: 0;
  z-index: -2;
  opacity: calc(.18 + var(--hero-progress) * .42);
  transform: scale(calc(1 + var(--hero-progress) * .08)) translateY(calc(var(--hero-progress) * -2.5rem));
  transition: opacity .12s linear;
}
.hero-network svg { width: 100%; height: 100%; }
.hero-links path {
  fill: none;
  stroke: rgba(255,255,255,.24);
  stroke-width: 2;
  stroke-dasharray: 9 13;
  stroke-dashoffset: calc(var(--hero-progress) * -180);
}
.hero-nodes circle {
  fill: rgba(255,255,255,.72);
  transform-box: fill-box;
  transform-origin: center;
  transform: scale(calc(.75 + var(--hero-progress) * .55));
}
.hero-copy {
  position: relative;
  z-index: 1;
  transform: translateY(calc(var(--hero-progress) * -3.2rem));
  opacity: calc(1 - var(--hero-progress) * .62);
}
.hero h1 span:nth-child(1) { transform: translateX(calc(var(--hero-progress) * -1.3rem)); }
.hero h1 span:nth-child(2) { transform: translateX(calc(var(--hero-progress) * .9rem)); }
.hero h1 span:nth-child(3) { transform: translateX(calc(var(--hero-progress) * -0.45rem)); }
.hero h1 span { transition: transform .08s linear; }
.hero-payload {
  position: absolute;
  left: 50%;
  bottom: 5.2rem;
  z-index: 2;
  width: 136px;
  height: 54px;
  border: 2px solid rgba(255,255,255,.88);
  border-radius: .75rem;
  background: rgba(255,255,255,.12);
  backdrop-filter: blur(8px);
  display: grid;
  place-items: center;
  color: #fff;
  font-family: "SFMono-Regular", Consolas, monospace;
  font-weight: 900;
  letter-spacing: .08em;
  transform: translate(-50%, calc((1 - var(--hero-progress)) * 5rem)) scale(calc(.7 + var(--hero-progress) * .3));
  opacity: clamp(0, calc((var(--hero-progress) - .18) * 2.5), 1);
  box-shadow: 0 18px 40px rgba(0,0,0,.22);
}
.hero-payload::after {
  content: "";
  position: absolute;
  inset: 6px;
  border: 1px dashed rgba(255,255,255,.35);
  border-radius: .45rem;
}
.payload-tag { position: relative; z-index: 2; font-size: .76rem; }
.payload-bit {
  position: absolute;
  font-size: .72rem;
  color: var(--accent);
  opacity: calc(.25 + var(--hero-progress) * .75);
}
.bit-a { left: -1.4rem; top: .2rem; transform: translateX(calc(var(--hero-progress) * 1.35rem)); }
.bit-b { right: -1.35rem; top: .45rem; transform: translateX(calc(var(--hero-progress) * -1.25rem)); }
.bit-c { left: -.8rem; bottom: -.5rem; transform: translate(calc(var(--hero-progress) * .75rem), calc(var(--hero-progress) * -.45rem)); }
.bit-d { right: -.8rem; bottom: -.4rem; transform: translate(calc(var(--hero-progress) * -.75rem), calc(var(--hero-progress) * -.45rem)); }
.scroll-cue {
  position: absolute;
  left: 50%;
  bottom: 1rem;
  transform: translateX(-50%);
  display: grid;
  justify-items: center;
  gap: .35rem;
  color: rgba(255,255,255,.62);
  opacity: calc(1 - var(--hero-progress) * 1.8);
}
.scroll-cue span {
  width: 1px;
  height: 28px;
  background: linear-gradient(to bottom, transparent, rgba(255,255,255,.9));
  animation: scrollCue 1.6s ease-in-out infinite;
}
.scroll-cue small { text-transform: uppercase; letter-spacing: .12em; font-size: .66rem; }
@keyframes scrollCue { 0%,100% { transform: scaleY(.55); opacity: .4; } 50% { transform: scaleY(1); opacity: 1; } }

@media (max-width: 640px) {
  .hero { min-height: 86vh; }
  .hero-payload { bottom: 4.6rem; width: 116px; height: 48px; }
}

@media (prefers-reduced-motion: reduce) {
  .hero-copy, .hero-network, .hero h1 span, .hero-payload { transform: none !important; opacity: 1 !important; }
  .scroll-cue { display: none; }
}

.schedule-note {
  margin: -.2rem 0 1.25rem;
  color: var(--muted);
  max-width: 50rem;
}

/* v18: network flow always moves; scroll still changes transparency */
.hero-network {
  opacity: 1;
  transform: none;
  transition: none;
}
.hero-links { opacity: calc(.18 + var(--hero-progress) * .34); }
.hero-nodes { opacity: calc(.28 + var(--hero-progress) * .52); }
.hero-links path {
  stroke-dashoffset: 0;
  animation: heroNetworkFlow 8s linear infinite;
}
.hero-links path:nth-child(2) { animation-duration: 10s; animation-direction: reverse; }
.hero-links path:nth-child(3) { animation-duration: 7s; }
.hero-links path:nth-child(4) { animation-duration: 9s; animation-direction: reverse; }
.hero-links path:nth-child(5) { animation-duration: 6.5s; }
@keyframes heroNetworkFlow {
  to { stroke-dashoffset: -220; }
}
.pronouns { color: var(--muted); font-size: .88em; font-weight: 500; }
.info-grid article p + p { margin-top: .8rem; padding-top: .8rem; border-top: 1px solid var(--border); }
@media (prefers-reduced-motion: reduce) {
  .hero-links path { animation: none !important; }
}

/* v18: center destination status heading */
.arrival h2 { text-align: center; margin-left: auto; margin-right: auto; }

/* v19: playful spider arrival in the hero */
.hero-spider {
  position: absolute;
  top: 0;
  right: clamp(1.25rem, 7vw, 7rem);
  z-index: 2;
  width: clamp(132px, 15.5vw, 215px);
  height: clamp(235px, 34vh, 360px);
  pointer-events: none;
  opacity: calc(1 - var(--hero-progress) * .78);
  transform-origin: 50% 0;
}
.spider-thread {
  position: absolute;
  top: 0;
  left: 50%;
  width: 2px;
  height: calc(100% - 80px);
  background: linear-gradient(to bottom, rgba(255,255,255,.12), rgba(255,255,255,.78));
  transform: translateX(-50%) scaleY(0);
  transform-origin: top;
  animation: spiderThreadDrop 2.1s cubic-bezier(.2,.8,.25,1) .35s forwards;
}
.hero-spider img {
  position: absolute;
  left: 50%;
  bottom: 0;
  width: 100%;
  height: auto;
  transform-origin: 50% 8%;
  opacity: 0;
  animation: spiderDropAndSettle 3.25s cubic-bezier(.2,.72,.22,1) .35s forwards;
  filter: drop-shadow(0 18px 22px rgba(0,0,0,.28));
}
@keyframes spiderThreadDrop {
  0% { transform: translateX(-50%) scaleY(0); }
  58%, 100% { transform: translateX(-50%) scaleY(1); }
}
@keyframes spiderDropAndSettle {
  0% { opacity: 0; transform: translate(-50%, -185px) rotate(0deg) scale(.82); }
  10% { opacity: 1; }
  46% { transform: translate(-50%, 10px) rotate(4deg) scale(1.02); }
  57% { transform: translate(-50%, -20px) rotate(-7deg) scale(.99); }
  67% { transform: translate(-50%, 4px) rotate(6deg) scale(1); }
  76% { transform: translate(-50%, -7px) rotate(-4deg) scale(1); }
  84% { transform: translate(-50%, 1px) rotate(2deg) scale(1); }
  91% { transform: translate(-50%, -2px) rotate(-1deg) scale(1); }
  100% { opacity: 1; transform: translate(-50%, 0) rotate(0deg) scale(1); }
}
@media (max-width: 900px) {
  .hero-spider { right: .5rem; width: clamp(104px, 20vw, 148px); opacity: calc(.72 - var(--hero-progress) * .55); }
}
@media (max-width: 640px) {
  .hero-spider { right: -.5rem; top: 2.5rem; width: 100px; height: 230px; }
}
@media (prefers-reduced-motion: reduce) {
  .hero-spider { opacity: .62; }
  .spider-thread { animation: none; transform: translateX(-50%) scaleY(1); }
  .hero-spider img { animation: none; opacity: 1; transform: translate(-50%, 0); }
}

/* v20: smoother spider entrance and clickable welcome */
.hero-spider {
  appearance: none;
  border: 0;
  padding: 0;
  background: transparent;
  cursor: pointer;
  pointer-events: auto;
  -webkit-tap-highlight-color: transparent;
}
.hero-spider:focus-visible {
  outline: 3px solid rgba(255,255,255,.9);
  outline-offset: 6px;
  border-radius: 45%;
}
.spider-thread {
  animation: spiderThreadSmooth 2.45s cubic-bezier(.22,.72,.18,1) .25s both;
  will-change: transform;
}
.hero-spider img {
  animation: spiderDropSmooth 2.8s cubic-bezier(.18,.72,.22,1) .25s both;
  will-change: transform, opacity;
  backface-visibility: hidden;
}
.spider-bubble {
  position: absolute;
  right: 72%;
  bottom: 24%;
  z-index: 3;
  padding: .55rem .8rem;
  border-radius: 999px 999px 999px .25rem;
  background: #fff;
  color: #24253e;
  font: 800 .9rem/1 system-ui, sans-serif;
  white-space: nowrap;
  box-shadow: 0 10px 30px rgba(0,0,0,.22);
  opacity: 0;
  transform: translate3d(8px,8px,0) scale(.72);
  transform-origin: 100% 100%;
  pointer-events: none;
}
.hero-spider.is-greeting img {
  animation: spiderHelloShake .72s cubic-bezier(.36,.07,.19,.97) both;
}
.hero-spider.is-greeting .spider-bubble {
  animation: spiderBubble 1.75s ease both;
}
@keyframes spiderThreadSmooth {
  0% { transform: translateX(-50%) scaleY(0); }
  72%, 100% { transform: translateX(-50%) scaleY(1); }
}
@keyframes spiderDropSmooth {
  0% { opacity: 0; transform: translate3d(-50%,-190px,0) rotate(0deg) scale(.88); }
  8% { opacity: 1; }
  62% { transform: translate3d(-50%,8px,0) rotate(2.5deg) scale(1.01); }
  76% { transform: translate3d(-50%,-7px,0) rotate(-2deg) scale(1); }
  88% { transform: translate3d(-50%,2px,0) rotate(.8deg) scale(1); }
  100% { opacity: 1; transform: translate3d(-50%,0,0) rotate(0deg) scale(1); }
}
@keyframes spiderHelloShake {
  0%,100% { transform: translate3d(-50%,0,0) rotate(0deg) scale(1); }
  18% { transform: translate3d(-50%,-3px,0) rotate(-7deg) scale(1.03); }
  36% { transform: translate3d(-50%,1px,0) rotate(6deg) scale(1.02); }
  54% { transform: translate3d(-50%,-2px,0) rotate(-4deg) scale(1.02); }
  72% { transform: translate3d(-50%,0,0) rotate(3deg) scale(1.01); }
  88% { transform: translate3d(-50%,0,0) rotate(-1deg) scale(1); }
}
@keyframes spiderBubble {
  0% { opacity: 0; transform: translate3d(8px,8px,0) scale(.72); }
  18%, 72% { opacity: 1; transform: translate3d(0,0,0) scale(1); }
  100% { opacity: 0; transform: translate3d(0,-7px,0) scale(.94); }
}
@media (prefers-reduced-motion: reduce) {
  .hero-spider.is-greeting img { animation: none !important; }
  .hero-spider.is-greeting .spider-bubble {
    animation: none !important;
    opacity: 1;
    transform: none;
  }
}

/* v21: separate one-time descent from repeatable pendulum swing */
.hero-spider .spider-swing {
  position: absolute;
  left: 50%;
  bottom: 0;
  width: 100%;
  transform: translateX(-50%);
  transform-origin: 50% calc(-1 * (100% - 8%));
  will-change: transform;
}
.hero-spider .spider-swing img {
  position: static;
  display: block;
  width: 100%;
  height: auto;
  opacity: 0;
  transform-origin: 50% 8%;
  animation: spiderDropThenRock 2.9s cubic-bezier(.22,.72,.2,1) .25s both;
  filter: drop-shadow(0 18px 22px rgba(0,0,0,.28));
  will-change: transform, opacity;
  backface-visibility: hidden;
}
.hero-spider.is-greeting .spider-swing {
  animation: spiderPendulum .9s cubic-bezier(.45,.05,.55,.95) both;
}
.hero-spider.is-greeting .spider-swing img {
  animation: none;
  opacity: 1;
  transform: translate3d(0,0,0) rotate(0deg) scale(1);
}
@keyframes spiderDropThenRock {
  0% { opacity: 0; transform: translate3d(0,-190px,0) rotate(0deg) scale(.9); }
  10% { opacity: 1; }
  58% { transform: translate3d(0,0,0) rotate(0deg) scale(1); }
  68% { transform: translate3d(0,0,0) rotate(-8deg) scale(1); }
  77% { transform: translate3d(0,0,0) rotate(7deg) scale(1); }
  85% { transform: translate3d(0,0,0) rotate(-4deg) scale(1); }
  92% { transform: translate3d(0,0,0) rotate(2deg) scale(1); }
  100% { opacity: 1; transform: translate3d(0,0,0) rotate(0deg) scale(1); }
}
@keyframes spiderPendulum {
  0%, 100% { transform: translateX(-50%) rotate(0deg); }
  18% { transform: translateX(-50%) rotate(-9deg); }
  36% { transform: translateX(-50%) rotate(8deg); }
  54% { transform: translateX(-50%) rotate(-6deg); }
  72% { transform: translateX(-50%) rotate(4deg); }
  88% { transform: translateX(-50%) rotate(-1.5deg); }
}
@media (prefers-reduced-motion: reduce) {
  .hero-spider .spider-swing img {
    animation: none !important;
    opacity: 1;
    transform: none;
  }
  .hero-spider.is-greeting .spider-swing { animation: none !important; }
}

/* v22: unified spider-and-web swing, stable click state, anchored bubble */
.hero-spider .spider-rig {
  position: absolute;
  inset: 0;
  transform-origin: 50% 0;
  will-change: transform;
}
.hero-spider .spider-thread {
  z-index: 0;
}
.hero-spider .spider-swing {
  z-index: 1;
}

/* The entrance remains on the inner pieces and runs only once. */
.hero-spider .spider-swing img {
  animation: spiderDropThenRock 2.9s cubic-bezier(.22,.72,.2,1) .25s both;
}

/* Clicking swings the complete rig, so the silk follows the spider. */
.hero-spider.is-greeting .spider-rig {
  animation: spiderRigPendulum .92s cubic-bezier(.45,.05,.55,.95) both;
}

/* Never replace the image's entrance animation on click. Doing so caused it
   to restart when the greeting class was removed. */
.hero-spider.is-greeting .spider-swing,
.hero-spider.is-greeting .spider-swing img {
  animation-name: revert-layer;
}
.hero-spider.is-greeting .spider-swing {
  animation: none !important;
}
.hero-spider.is-greeting .spider-swing img {
  opacity: 1;
}

.spider-bubble {
  left: -8%;
  right: auto;
  bottom: 14%;
  transform-origin: 100% 100%;
}

@keyframes spiderRigPendulum {
  0%, 100% { transform: rotate(0deg); }
  18% { transform: rotate(-8deg); }
  36% { transform: rotate(7deg); }
  54% { transform: rotate(-5deg); }
  72% { transform: rotate(3deg); }
  88% { transform: rotate(-1deg); }
}

@media (max-width: 640px) {
  .spider-bubble { left: -38%; bottom: 12%; }
}
@media (prefers-reduced-motion: reduce) {
  .hero-spider.is-greeting .spider-rig { animation: none !important; }
}

/* Keep the image on exactly the same animation declaration in both states. */
.hero-spider.is-greeting .spider-swing img {
  animation: spiderDropThenRock 2.9s cubic-bezier(.22,.72,.2,1) .25s both !important;
  opacity: 1;
}

/* v23: quiet spider interaction, no bubble or visible accessibility text */
.hero-spider {
  --spider-angle: 8deg;
  --spider-bounce: 0px;
  --spider-reaction-duration: 820ms;
  transition: opacity .25s ease;
}

.hero-spider .spider-rig {
  transition: none;
}

.hero-spider.is-reacting .spider-rig {
  animation: spiderRandomReaction var(--spider-reaction-duration) cubic-bezier(.42,.04,.3,1) both;
}

@keyframes spiderRandomReaction {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  16% { transform: translateY(calc(-1 * var(--spider-bounce))) rotate(calc(-1 * var(--spider-angle))); }
  34% { transform: translateY(var(--spider-bounce)) rotate(calc(var(--spider-angle) * .88)); }
  52% { transform: translateY(calc(-.55 * var(--spider-bounce))) rotate(calc(-.62 * var(--spider-angle))); }
  69% { transform: translateY(calc(.3 * var(--spider-bounce))) rotate(calc(.4 * var(--spider-angle))); }
  84% { transform: translateY(0) rotate(calc(-.16 * var(--spider-angle))); }
}

/* Retire the earlier greeting behavior completely. */
.spider-bubble { display: none !important; }
.hero-spider.is-greeting .spider-rig { animation: none !important; }

@media (prefers-reduced-motion: reduce) {
  .hero-spider .spider-rig { transition: none; }
  .hero-spider.is-reacting .spider-rig { animation: none !important; }
}

/* v26: one small, technically honest piece of the syllabus */
.accuracy-note {
  max-width: 38rem;
  margin: -.45rem auto 0;
  color: var(--muted);
  text-align: center;
  font-size: .76rem;
  line-height: 1.45;
}
.packet .payload strong { letter-spacing: .045em; }
.assembly-status {
  width: min(100%, 34rem);
  margin: 1rem auto 1.35rem;
  text-align: left;
}
.assembly-status span,
.assembly-status strong {
  display: block;
  text-align: center;
}
.assembly-status span {
  color: var(--muted);
  font-size: .92rem;
  font-weight: 700;
}
.assembly-track {
  height: 11px;
  margin: .65rem 0 .75rem;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #eef4f5;
}
.assembly-track i {
  display: block;
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--accent-2), #84c9cd);
}
.assembly-status strong {
  color: var(--accent-2);
  opacity: 0;
  transform: translateY(5px);
}
.arrival.celebrate .assembly-track i {
  animation: assemble-syllabus 3.6s .35s cubic-bezier(.22,.72,.18,1) both;
}
.arrival.celebrate .assembly-status strong {
  animation: assembly-complete .5s 3.95s ease-out both;
}
@keyframes assemble-syllabus {
  from { width: 0; }
  to { width: 100%; }
}
@keyframes assembly-complete {
  to { opacity: 1; transform: translateY(0); }
}
@media (prefers-reduced-motion: reduce) {
  .assembly-track i { width: 100%; }
  .assembly-status strong { opacity: 1; transform: none; }
  .arrival.celebrate .assembly-track i,
  .arrival.celebrate .assembly-status strong { animation: none; }
}


/* v27: make the overview scannable without changing its substance */
.overview-story {
  display: grid;
  gap: 1rem;
}
.overview-lead {
  margin: 0;
  max-width: 54rem;
  font-size: clamp(1.08rem, 1.7vw, 1.3rem);
  line-height: 1.65;
  color: var(--ink);
}
.overview-topics {
  display: flex;
  flex-wrap: wrap;
  gap: .55rem;
}
.overview-topics span {
  display: inline-flex;
  align-items: center;
  min-height: 2rem;
  padding: .34rem .7rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: color-mix(in srgb, var(--accent-soft) 72%, white);
  color: var(--ink);
  font-size: .82rem;
  font-weight: 700;
}
.overview-assessment {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: .75rem;
}
.overview-assessment div {
  min-width: 0;
  padding: .85rem .9rem;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: rgba(255,255,255,.72);
}
.overview-assessment strong,
.overview-assessment span { display: block; }
.overview-assessment strong {
  color: var(--accent-2);
  font-size: 1.05rem;
}
.overview-assessment span {
  margin-top: .18rem;
  color: var(--muted);
  font-size: .78rem;
  line-height: 1.35;
}
.overview-footnote {
  margin-top: -.25rem;
  color: var(--muted);
  font-size: .88rem;
}
.deadline-note {
  margin: 1rem 0 1.2rem;
  padding: .85rem 1rem;
  border-left: 4px solid var(--accent-2);
  border-radius: 0 12px 12px 0;
  background: var(--accent-soft);
}
@media (max-width: 720px) {
  .overview-assessment { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

/* v29: formatted plain-syllabus download and reliable print expansion */
.footer-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: .65rem;
}
.footer-button,
footer button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.75rem;
  padding: .75rem 1rem;
  border: 0;
  border-radius: 999px;
  background: white;
  color: var(--ink);
  font: 800 .9rem/1 system-ui, sans-serif;
  text-decoration: none;
  cursor: pointer;
}
.footer-button { background: transparent; color: white; box-shadow: inset 0 0 0 1px rgba(255,255,255,.55); }
.footer-button:hover,
.footer-button:focus-visible,
footer button:hover,
footer button:focus-visible { transform: translateY(-1px); }
@media (max-width: 640px) {
  .footer-actions { justify-content: flex-start; }
}
@media print {
  .footer-actions { display: none !important; }
}


/* v31 pastel hero accent */
.hero h1 span:nth-child(2) {
  color: var(--hero-accent);
  text-shadow: 0 0 24px rgba(142, 220, 255, .16);
}
.hero .button {
  color: var(--hero-accent);
  background: rgba(255,255,255,.065);
  border: 1px solid rgba(142,220,255,.72);
  box-shadow: 0 0 18px rgba(142,220,255,.12), inset 0 1px 0 rgba(255,255,255,.08);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: background .25s ease, border-color .25s ease, box-shadow .25s ease, transform .25s ease, color .25s ease;
}
.hero .button:hover,
.hero .button:focus-visible {
  color: #B5EAFF;
  background: rgba(142,220,255,.11);
  border-color: #B5EAFF;
  box-shadow: 0 0 24px rgba(142,220,255,.22), inset 0 1px 0 rgba(255,255,255,.12);
  transform: translateY(-2px);
}


/* v32: reveal the technical note in the sticky packet panel only at the destination */
.packet-accuracy-note {
  max-width: 28rem;
  margin: .85rem auto 0;
  color: var(--muted);
  text-align: center;
  font-size: .76rem;
  line-height: 1.45;
  opacity: 0;
  transform: translateY(5px);
  pointer-events: none;
  transition: opacity .45s ease, transform .45s ease;
}
.packet-panel.arrived .packet-accuracy-note {
  opacity: 1;
  transform: translateY(0);
  transition-delay: 4.25s;
}
@media (prefers-reduced-motion: reduce) {
  .packet-panel.arrived .packet-accuracy-note {
    transition-delay: 0s;
  }
}

/* Shared course assistant card. */
.assistants-card { grid-column: 1 / -1; }
.assistants-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem 1.5rem;
}
.assistants-grid p { margin: 0; overflow-wrap: anywhere; }
.assistant-role { color: var(--muted); font-size: .9em; }
@media screen and (max-width: 520px) {
  .assistants-grid { grid-template-columns: 1fr; }
}