/* ============================================================
   HYPERLOOP OPEN — brand tokens sampled from logo
   teal #109C9C · navy #44546A · ink #18222E
   ring gradient #4EADB7 → #C7D5ED
   type: Archivo (display) · IBM Plex Sans (body) · IBM Plex Mono (spec)
   ============================================================ */

:root {
  --teal: #109C9C;
  --teal-deep: #0B7E7E;
  --navy: #44546A;
  --ink: #18222E;
  --ink-soft: #3c4a5c;
  --peri: #C7D5ED;
  --peri-mid: #9FBEDE;
  --paper: #FFFFFF;
  --tint: #F2F7F7;
  --line: #DCE5E8;
  --line-dark: rgba(199, 213, 237, 0.18);

  --display: "Righteous", "Trebuchet MS", sans-serif;
  --ui: "IBM Plex Sans", sans-serif;
  --body: "IBM Plex Sans", sans-serif;
  --mono: "IBM Plex Mono", monospace;

  --max: 1140px;
  --radius: 14px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 90px; }

body {
  font-family: var(--body);
  color: var(--ink);
  background: var(--paper);
  line-height: 1.65;
  font-size: 1.0625rem;
  -webkit-font-smoothing: antialiased;
}

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

h1, h2 { font-family: var(--display); font-weight: 400; line-height: 1.12; letter-spacing: 0.005em; }
h1 { font-size: clamp(2.2rem, 5vw, 3.7rem); }
h2 { font-size: clamp(1.7rem, 3.3vw, 2.45rem); margin-bottom: 0.5em; }
h3 { font-family: var(--ui); font-weight: 600; line-height: 1.2; font-size: 1.28rem; margin-bottom: 0.45em; }

a { color: var(--teal-deep); text-decoration: none; }
a:focus-visible, button:focus-visible, input:focus-visible, textarea:focus-visible {
  outline: 3px solid var(--teal);
  outline-offset: 2px;
}

.eyebrow {
  font-family: var(--mono);
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--teal-deep);
  margin-bottom: 1.1rem;
}
.eyebrow-light { color: #7FD6D0; }
.accent { color: var(--teal); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-block;
  font-family: var(--ui);
  font-weight: 600;
  font-size: 0.98rem;
  letter-spacing: 0.01em;
  padding: 0.85rem 1.7rem;
  border-radius: 999px;
  border: 2px solid transparent;
  cursor: pointer;
  transition: transform 0.15s ease, background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}
.btn:hover { transform: translateY(-2px); }
.btn-solid { background: var(--teal); color: #fff; }
.btn-solid:hover { background: var(--teal-deep); }
.btn-ghost { border-color: var(--line); color: var(--ink); background: transparent; }
.btn-ghost:hover { border-color: var(--teal); color: var(--teal-deep); }
.btn-on-dark { background: var(--teal); color: #fff; }
.btn-on-dark:hover { background: #14b6b6; }
.btn-wide { width: 100%; padding: 1rem; font-size: 1.05rem; }
.btn:disabled { opacity: 0.6; cursor: wait; transform: none; }

/* ---------- Nav ---------- */
.nav {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 50;
  display: flex;
  align-items: center;
  gap: 2rem;
  padding: 0.8rem clamp(1.2rem, 4vw, 3rem);
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}
.nav-brand { display: flex; align-items: center; gap: 0.6rem; color: var(--ink); }
.nav-ring { width: 30px; height: 30px; }
.nav-word { font-family: var(--display); font-weight: 400; font-size: 1.05rem; letter-spacing: 0.03em; text-transform: uppercase; }
.nav-word b { font-weight: 400; color: var(--teal-deep); }
.nav-links { display: flex; gap: 1.6rem; margin-left: auto; }
.nav-links a {
  font-family: var(--mono);
  font-size: 0.8rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-soft);
}
.nav-links a:hover { color: var(--teal-deep); }
.nav-cta { padding: 0.55rem 1.3rem; font-size: 0.88rem; }
.nav-toggle { display: none; }
.nav-drawer { display: none; }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  padding: clamp(8.5rem, 16vh, 12rem) clamp(1.2rem, 4vw, 3rem) 0;
  overflow: hidden;
  background:
    radial-gradient(1100px 520px at 85% -10%, rgba(16, 156, 156, 0.08), transparent 65%),
    radial-gradient(900px 500px at -10% 110%, rgba(199, 213, 237, 0.35), transparent 60%),
    var(--paper);
}
.hero-ring {
  position: absolute;
  right: -12vw;
  top: 6rem;
  width: clamp(380px, 44vw, 660px);
  opacity: 0.16;
  pointer-events: none;
  animation: ringDrift 14s ease-in-out infinite alternate;
}
@keyframes ringDrift {
  from { transform: translateY(0) rotate(0deg); }
  to   { transform: translateY(-26px) rotate(8deg); }
}
.hero-inner { max-width: var(--max); margin: 0 auto; position: relative; }
.hero h1 { max-width: 15ch; }
.hero-sub {
  max-width: 56ch;
  margin-top: 1.4rem;
  font-size: 1.13rem;
  color: var(--ink-soft);
}
.hero-actions { display: flex; gap: 1rem; flex-wrap: wrap; margin-top: 2.2rem; }

/* Signature: telemetry rail */
.telemetry { max-width: var(--max); margin: clamp(3.5rem, 7vh, 5.5rem) auto 0; padding-bottom: 2.6rem; position: relative; }
.telemetry-track {
  height: 3px;
  background: linear-gradient(90deg, var(--teal), var(--peri-mid) 70%, var(--peri));
  border-radius: 2px;
  position: relative;
  overflow: visible;
}
.telemetry-pod {
  position: absolute;
  top: 50%;
  left: 0;
  width: 46px;
  height: 9px;
  border-radius: 5px;
  background: var(--navy);
  transform: translateY(-50%);
  animation: podRun 9s cubic-bezier(0.45, 0, 0.2, 1) infinite;
  box-shadow: 0 0 14px rgba(16, 156, 156, 0.55);
}
@keyframes podRun {
  0%   { left: -5%; }
  55%  { left: 101%; }
  100% { left: 101%; }
}
.telemetry-readouts {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  margin-top: 1.4rem;
}
.readout { display: flex; flex-direction: column; gap: 0.15rem; }
.r-label {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--navy);
  opacity: 0.75;
}
.r-value { font-family: var(--mono); font-size: 1.05rem; font-weight: 500; color: var(--ink); }

/* ---------- Sections ---------- */
.section { padding: clamp(4.5rem, 10vh, 7.5rem) clamp(1.2rem, 4vw, 3rem); }
.section-tint { background: var(--tint); }
.section-inner { max-width: var(--max); margin: 0 auto; }
.section-inner.narrow { max-width: 760px; }

.split { display: grid; grid-template-columns: 5fr 7fr; gap: clamp(2rem, 5vw, 4.5rem); }
.split-head h2 { position: sticky; top: 110px; }
.split-body p + p { margin-top: 1.1rem; }
.split-body { color: var(--ink-soft); }
.split-body b { color: var(--ink); }

.callout {
  margin-top: 1.4rem !important;
  padding: 1.1rem 1.3rem;
  border-left: 3px solid var(--teal);
  background: var(--tint);
  border-radius: 0 var(--radius) var(--radius) 0;
  color: var(--ink);
}

.center-head { text-align: center; max-width: 720px; margin: 0 auto 3.2rem; }
.lede { color: var(--ink-soft); font-size: 1.1rem; }
.draft-note {
  display: inline-block;
  margin-top: 1.2rem;
  padding: 0.6rem 1rem;
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--navy);
  border: 1px dashed var(--peri-mid);
  border-radius: 8px;
  background: rgba(199, 213, 237, 0.18);
}
.lede-light { color: #B9C6D8; }

/* ---------- Sled cards ---------- */
.sled-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.4rem;
}
.sled {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.8rem 1.6rem;
  display: flex;
  flex-direction: column;
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}
.sled:hover {
  transform: translateY(-5px);
  border-color: var(--teal);
  box-shadow: 0 16px 40px rgba(16, 156, 156, 0.12);
}
.sled-no {
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  color: var(--teal-deep);
  margin-bottom: 0.9rem;
}
.sled p { color: var(--ink-soft); font-size: 0.97rem; flex: 1; }
.spec { list-style: none; margin-top: 1.3rem; border-top: 1px solid var(--line); }
.spec li {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.55rem 0;
  border-bottom: 1px solid var(--line);
  font-size: 0.84rem;
}
.spec span { font-family: var(--mono); text-transform: uppercase; letter-spacing: 0.08em; font-size: 0.7rem; color: var(--navy); white-space: nowrap; padding-top: 2px; }
.spec b { font-weight: 600; text-align: right; }

/* ---------- Facilities ---------- */
.facility + .facility { margin-top: 2.2rem; }
.facility-tag {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--teal-deep);
  margin-bottom: 0.5rem;
}
.facility p { color: var(--ink-soft); }

/* ---------- Dark sponsor section ---------- */
.section-dark {
  background:
    radial-gradient(900px 480px at 90% 0%, rgba(16, 156, 156, 0.16), transparent 60%),
    var(--ink);
  color: #E8EEF5;
}
.section-dark h2 { color: #fff; }
.h2-sm { font-size: clamp(1.5rem, 2.6vw, 2rem); }

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.2rem;
  max-width: 1080px;
  margin: 0 auto 4rem;
}
.feature {
  border: 1px solid var(--line-dark);
  border-radius: var(--radius);
  padding: 1.5rem 1.4rem;
  background: rgba(255, 255, 255, 0.03);
  transition: border-color 0.2s ease, background 0.2s ease;
}
.feature:hover { border-color: rgba(16, 156, 156, 0.6); background: rgba(16, 156, 156, 0.06); }
.feature-tag {
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.18em;
  color: var(--teal);
  margin-bottom: 0.7rem;
}
.feature h3 { color: #fff; font-size: 1.08rem; }
.feature p { color: #ADBBCB; font-size: 0.93rem; }

.dual-title {
  text-align: center;
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #7FD6D0;
  margin-bottom: 1.4rem;
}
.dual-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.9rem;
  max-width: 920px;
  margin: 0 auto 1.6rem;
}
.dual {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  padding: 1rem 1.2rem;
  border: 1px solid var(--line-dark);
  border-radius: 10px;
  font-family: var(--mono);
  font-size: 0.88rem;
  background: rgba(255, 255, 255, 0.03);
}
.dual-from { color: #fff; }
.dual-arrow { color: var(--teal); font-weight: 700; }
.dual-to { color: var(--peri); margin-left: auto; text-align: right; }

.sector-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  max-width: 980px;
  margin: 0 auto 4.5rem;
}
.sector {
  border: 1px solid rgba(16, 156, 156, 0.45);
  border-radius: 10px;
  padding: 1.1rem 1.2rem;
  text-align: center;
}
.sector h3 { color: #7FD6D0; font-size: 0.92rem; margin-bottom: 0.4rem; }
.sector p { font-family: var(--mono); font-size: 0.76rem; color: #ADBBCB; line-height: 1.6; }

.tiers-head { margin-bottom: 2.4rem; }
.tier-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.2rem;
  max-width: 1080px;
  margin: 0 auto 4rem;
  align-items: stretch;
}
.tier-grid-4 { grid-template-columns: repeat(4, 1fr); max-width: 1140px; gap: 1rem; }
.tier {
  border: 1px solid var(--line-dark);
  border-radius: var(--radius);
  padding: 1.7rem 1.5rem;
  background: rgba(255, 255, 255, 0.03);
  display: flex;
  flex-direction: column;
}
.tier-mid { border-color: rgba(159, 190, 222, 0.45); }
.tier-top {
  border-color: var(--teal);
  background: linear-gradient(180deg, rgba(16, 156, 156, 0.12), rgba(16, 156, 156, 0.04));
  box-shadow: 0 0 40px rgba(16, 156, 156, 0.15);
}
.tier-label {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--peri);
  margin-bottom: 0.6rem;
}
.tier-top .tier-label { color: var(--teal); }
.tier h3 { color: #fff; font-size: 1.15rem; margin-bottom: 0.9rem; }
.tier ul { list-style: none; }
.tier li {
  font-size: 0.88rem;
  color: #ADBBCB;
  padding: 0.42rem 0 0.42rem 1.3rem;
  position: relative;
}
.tier li::before {
  content: "→";
  position: absolute;
  left: 0;
  color: var(--teal);
  font-family: var(--mono);
}

.btn-ghost-dark { border-color: rgba(199, 213, 237, 0.35); color: #E8EEF5; }
.btn-ghost-dark:hover { border-color: var(--teal); color: #7FD6D0; }
.cta-pair { display: flex; justify-content: center; gap: 1rem; flex-wrap: wrap; }
.sponsor-points {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  max-width: 1040px;
  margin: 0 auto;
}
.point h3 { color: #fff; font-size: 1.08rem; }
.point p { color: #ADBBCB; font-size: 0.95rem; }
.center-cta { text-align: center; margin-top: 3.2rem; }

/* ---------- Teams list ---------- */
.team-list { list-style: none; margin-top: 1.4rem; }
.team-list li { padding: 0.85rem 0 0.85rem 1.4rem; border-left: 3px solid var(--peri-mid); margin-bottom: 0.7rem; border-radius: 2px; }
.team-list b { color: var(--ink); }

/* ---------- Form ---------- */
.form {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: clamp(1.4rem, 4vw, 2.4rem);
  box-shadow: 0 20px 50px rgba(24, 34, 46, 0.06);
}
.role-select {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.6rem;
  margin-bottom: 1.6rem;
}
.role input { position: absolute; opacity: 0; pointer-events: none; }
.role span {
  display: block;
  text-align: center;
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  padding: 0.7rem 0.4rem;
  border: 1.5px solid var(--line);
  border-radius: 9px;
  cursor: pointer;
  transition: all 0.15s ease;
  color: var(--ink-soft);
}
.role input:checked + span {
  background: var(--teal);
  border-color: var(--teal);
  color: #fff;
  font-weight: 500;
}
.role input:focus-visible + span { outline: 3px solid var(--teal); outline-offset: 2px; }
.role span:hover { border-color: var(--teal); color: var(--teal-deep); }
.role input:checked + span:hover { color: #fff; }

.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.field { margin-bottom: 1.1rem; }
.field label {
  display: block;
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--navy);
  margin-bottom: 0.4rem;
}
.opt { opacity: 0.55; text-transform: none; letter-spacing: 0; }
.field input, .field textarea {
  width: 100%;
  font-family: var(--body);
  font-size: 1rem;
  padding: 0.75rem 0.9rem;
  border: 1.5px solid var(--line);
  border-radius: 9px;
  background: #fff;
  color: var(--ink);
  transition: border-color 0.15s ease;
}
.field input:focus, .field textarea:focus { border-color: var(--teal); outline: none; }
.field textarea { resize: vertical; }
.form-status { margin-top: 1rem; font-family: var(--mono); font-size: 0.85rem; text-align: center; min-height: 1.4em; }
.form-status.ok { color: var(--teal-deep); }
.form-status.err { color: #B4452F; }

/* ---------- Footer ---------- */
.footer {
  background: var(--ink);
  color: #ADBBCB;
  padding: 4rem clamp(1.2rem, 4vw, 3rem) 2rem;
}
.footer-inner {
  max-width: var(--max);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2.2fr 1fr 1fr 1.4fr;
  gap: 2.5rem;
}
.footer-logo {
  width: 190px;
  background: #fff;
  border-radius: 10px;
  padding: 0.4rem 0.9rem;
  margin-bottom: 1rem;
}
.footer-mission { font-size: 0.92rem; max-width: 34ch; }
.footer-head {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: #fff;
  margin-bottom: 0.9rem;
}
.footer-col a { display: block; color: #ADBBCB; font-size: 0.93rem; padding: 0.22rem 0; }
.footer-col a:hover { color: var(--teal); }
.footer-legal {
  max-width: var(--max);
  margin: 3rem auto 0;
  padding-top: 1.4rem;
  border-top: 1px solid var(--line-dark);
  display: flex;
  justify-content: space-between;
  gap: 2rem;
  font-size: 0.8rem;
  flex-wrap: wrap;
}
.footer-coords { font-family: var(--mono); white-space: nowrap; }

/* ---------- Reveal animation ---------- */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity 0.7s ease, transform 0.7s ease; }
.reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .telemetry-pod, .hero-ring { animation: none; }
  .btn:hover, .sled:hover { transform: none; }
}

/* ---------- Responsive ---------- */
@media (max-width: 1100px) {
  .tier-grid-4 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 960px) {
  .split { grid-template-columns: 1fr; }
  .split-head h2 { position: static; }
  .sled-grid, .sponsor-points, .feature-grid, .sector-grid { grid-template-columns: 1fr; }
  .dual-grid { grid-template-columns: 1fr; }
  .telemetry-readouts { grid-template-columns: repeat(2, 1fr); row-gap: 1.2rem; }
  .footer-inner { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 720px) {
  .tier-grid, .tier-grid-4 { grid-template-columns: 1fr; }
  .nav-links, .nav-cta { display: none; }
  .nav-toggle {
    display: flex;
    flex-direction: column;
    gap: 5px;
    margin-left: auto;
    background: none;
    border: none;
    padding: 8px;
    cursor: pointer;
  }
  .nav-toggle span { width: 22px; height: 2px; background: var(--ink); border-radius: 2px; }
  .nav-drawer {
    position: fixed;
    top: 56px;
    left: 0;
    right: 0;
    z-index: 49;
    background: #fff;
    border-bottom: 1px solid var(--line);
    display: flex;
    flex-direction: column;
    padding: 0.6rem 1.4rem 1.2rem;
    transform: translateY(-110%);
    transition: transform 0.25s ease;
  }
  .nav-drawer.open { transform: none; }
  .nav-drawer a {
    font-family: var(--mono);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--ink);
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--line);
  }
  .nav-drawer .drawer-cta { color: var(--teal-deep); font-weight: 600; border-bottom: none; }
  .form-row { grid-template-columns: 1fr; }
  .role-select { grid-template-columns: 1fr 1fr; }
  .footer-inner { grid-template-columns: 1fr; gap: 1.8rem; }
  .hero-ring { right: -40vw; opacity: 0.1; }
}

/* ---------- Research symposium card & domain labels ---------- */
.domain-label {
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--navy);
  margin: 2.6rem 0 1rem;
  text-align: center;
}
.domain-label:first-of-type { margin-top: 0; }
.research-card {
  display: grid;
  grid-template-columns: 7fr 5fr;
  gap: 2rem;
  background: linear-gradient(135deg, rgba(16, 156, 156, 0.07), rgba(199, 213, 237, 0.18));
  border: 1px solid var(--teal);
  border-radius: var(--radius);
  padding: 1.9rem 1.8rem;
  max-width: 980px;
  margin: 0 auto;
}
.research-card p { color: var(--ink-soft); font-size: 0.98rem; }
.research-spec { margin-top: 0; border-top: 1px solid var(--line); align-self: center; }
.sector-grid-4 { grid-template-columns: repeat(4, 1fr); }
@media (max-width: 960px) {
  .research-card { grid-template-columns: 1fr; }
  .sector-grid-4 { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 720px) {
  .sector-grid-4 { grid-template-columns: 1fr; }
}