@font-face {
  font-family: 'Inter';
  font-weight: 300 800;
  font-display: swap;
  src: url('../assets/fonts/inter-variable.woff2') format('woff2');
}
@font-face {
  font-family: 'Playfair Display';
  font-weight: 400 900;
  font-display: swap;
  src: url('../assets/fonts/playfair-variable.woff2') format('woff2');
}

:root {
  --navy: #111827;
  --steel: #1E3A5F;
  --ice: #D9E4F1;
  --green: #3DDC97;
  --paper: #F7F8FA;
  --ink: #1A1F29;
  --muted: #6B7280;

  --serif: 'Playfair Display', Cambria, Georgia, serif;
  --sans: 'Inter', Calibri, -apple-system, BlinkMacSystemFont, sans-serif;

  --edge: clamp(1.25rem, 5vw, 3rem);
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  --header-h: 4.5rem;
}

@media (max-width: 699px) { :root { --header-h: 6.5rem; } }

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: var(--header-h); }
body, h2, h3, p, figure, ul, ol, dl, dd, blockquote { margin: 0; padding: 0; }
ul, ol { list-style: none; }
img { display: block; max-width: 100%; height: auto; }

body {
  font-family: var(--sans);
  line-height: 1.65;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  overflow-x: clip;
}

a { color: inherit; }
a:focus-visible, button:focus-visible, [tabindex]:focus-visible {
  outline: 2px solid var(--steel);
  outline-offset: 4px;
}
.section--dark a:focus-visible, .section--dark button:focus-visible { outline-color: var(--green); }

.skip-link {
  position: absolute; left: 1rem; top: -4rem; z-index: 30;
  background: var(--navy); color: #fff; padding: 0.6rem 1rem;
}
.skip-link:focus { top: 1rem; }

#sentinel { position: absolute; top: 0; left: 0; width: 1px; height: 80px; pointer-events: none; }

/* ---------- header ---------- */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.75rem 1.5rem;
  padding: 1.5rem var(--edge);
  border-bottom: 1px solid transparent;
  transition: background 0.4s var(--ease), padding 0.4s var(--ease), border-color 0.4s var(--ease);
}
.site-header.is-scrolled {
  padding-block: 0.9rem;
  background: rgba(247, 248, 250, 0.86);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  backdrop-filter: blur(14px) saturate(140%);
  border-color: rgba(30, 58, 95, 0.12);
}
.wordmark { color: var(--navy); display: block; }
.wordmark svg { width: clamp(140px, 20vw, 210px); height: auto; }
.site-header nav { display: flex; gap: clamp(0.85rem, 2.6vw, 1.75rem); }
.site-header nav a {
  text-decoration: none;
  font-size: 0.92rem;
  letter-spacing: 0.02em;
  color: var(--ink);
  padding-block: 0.25rem;
  background: linear-gradient(var(--steel), var(--steel)) 0 100% / 0 1px no-repeat;
  transition: background-size 0.35s var(--ease);
}
.site-header nav a { white-space: nowrap; }
@media (max-width: 420px) {
  .site-header nav { gap: 0.75rem; }
  .site-header nav a { font-size: 0.86rem; letter-spacing: 0.01em; }
}
.site-header nav a:hover,
.site-header nav a[aria-current="true"] { background-size: 100% 1px; }

/* ---------- hero ---------- */
.hero {
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}
.hero-figure {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 8rem var(--edge) 2rem;
}
.hero-figure img {
  width: min(100%, 880px);
  mix-blend-mode: multiply; /* image background is normalised to white */
  -webkit-mask-image: radial-gradient(ellipse 72% 72% at 50% 50%, #000 62%, transparent 100%);
  mask-image: radial-gradient(ellipse 72% 72% at 50% 50%, #000 62%, transparent 100%);
  animation: rise 1.2s var(--ease) both, hover 9s ease-in-out 1.2s infinite;
}
.banner {
  background: var(--navy);
  color: var(--ice);
  text-align: center;
  font-family: var(--serif);
  font-size: clamp(1.05rem, 2.3vw, 1.6rem);
  line-height: 1.4;
  padding: clamp(1.5rem, 3.5vw, 2.25rem) var(--edge);
}
@keyframes rise { from { opacity: 0; transform: translateY(14px); } to { opacity: 1; transform: none; } }
@keyframes hover { 50% { transform: translateY(-7px); } }

/* ---------- sections ---------- */
.section { padding: clamp(5rem, 11vw, 9rem) var(--edge); }
.section--dark { background: var(--navy); color: var(--ice); }
.wrap { max-width: 68rem; margin-inline: auto; }

h2 {
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(1.9rem, 4.4vw, 3.25rem);
  line-height: 1.2;
  letter-spacing: -0.01em;
  max-width: 22ch;
}
.section--dark h2 { color: #fff; }
h3 {
  font-family: var(--serif);
  font-weight: 400;
  font-size: 1.35rem;
  line-height: 1.3;
}
.lead {
  margin-top: 1.75rem;
  max-width: 34rem;
  font-size: clamp(1.02rem, 1.6vw, 1.15rem);
  color: var(--muted);
}
.section--dark .lead { color: #a9bcd6; }

#concept { border-top: 1px solid rgba(217, 228, 241, 0.14); }
#team { background: #E6EDF6; } /* soft tint of the brand ice */

/* ---------- use cases index ---------- */
.index { margin-top: clamp(2.5rem, 6vw, 4.5rem); display: grid; gap: 2.5rem; }
.index-tabs { display: flex; flex-direction: column; border-top: 1px solid rgba(30, 58, 95, 0.22); }
.index-tabs button {
  font: inherit;
  font-family: var(--serif);
  font-size: clamp(1.2rem, 2.4vw, 1.7rem);
  line-height: 1.25;
  text-align: left;
  color: rgba(26, 31, 41, 0.42);
  background: none;
  border: 0;
  border-bottom: 1px solid rgba(30, 58, 95, 0.22);
  padding: 0.95rem 0 0.95rem 1.25rem;
  position: relative;
  cursor: pointer;
  transition: color 0.3s var(--ease), padding 0.3s var(--ease);
}
.index-tabs button::before {
  content: "";
  position: absolute; left: 0; top: 50%;
  width: 3px; height: 0;
  background: var(--green);
  transform: translateY(-50%);
  transition: height 0.3s var(--ease);
}
.index-tabs button:hover { color: var(--ink); }
.index-tabs button[aria-selected="true"] { color: var(--ink); padding-left: 1.6rem; }
.index-tabs button[aria-selected="true"]::before { height: 60%; }

.panel { animation: fade 0.6s var(--ease) both; }
.panel[hidden] { display: none; }
.panel-title { margin-bottom: 1rem; }
.js .panel-title { display: none; }
.panel .problem {
  font-family: var(--serif);
  font-size: clamp(1.2rem, 2.2vw, 1.55rem);
  line-height: 1.5;
  max-width: 34rem;
}
.panel .helps {
  margin-top: 2rem;
  max-width: 32rem;
  color: var(--muted);
}
.panel .helps span {
  display: block;
  margin-bottom: 0.3rem;
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  font-weight: 600;
  color: var(--steel);
}
@keyframes fade { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }
@media (max-width: 899px) {
  .index-tabs {
    flex-direction: row;
    gap: 0.5rem;
    border-top: 0;
    overflow-x: auto;
    scroll-snap-type: x proximity;
    scrollbar-width: none;
    margin-inline: calc(var(--edge) * -1);
    padding: 0.25rem var(--edge);
  }
  .index-tabs::-webkit-scrollbar { display: none; }
  .index-tabs button {
    flex: none;
    scroll-snap-align: start;
    white-space: nowrap;
    font-size: 1.05rem;
    padding: 0.55rem 1.1rem;
    border: 1px solid rgba(30, 58, 95, 0.3);
    border-radius: 999px;
  }
  .index-tabs button::before { display: none; }
  .index-tabs button[aria-selected="true"] {
    padding-left: 1.1rem;
    background: var(--navy);
    border-color: var(--navy);
    color: #fff;
  }
}
html:not(.js) .index-tabs { display: none; }
html:not(.js) .panel + .panel { margin-top: 3rem; }

@media (min-width: 900px) {
  .index { grid-template-columns: 1fr 1fr; gap: 5rem; align-items: start; }
}
/* ---------- concept story ---------- */
.story { margin-top: clamp(2.5rem, 6vw, 4rem); display: grid; gap: 0; }
.stage {
  position: sticky;
  top: var(--header-h);
  z-index: 2;
  background: var(--navy);
  padding-block: 0.75rem;
}
.scene { width: 100%; height: auto; max-height: 38vh; }

.steps li {
  min-height: 46vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 1.5rem 0 1.5rem 1.4rem;
  border-left: 2px solid rgba(217, 228, 241, 0.16);
  opacity: 0.35;
  transition: opacity 0.5s var(--ease), border-color 0.5s var(--ease);
}
.steps li.is-active { opacity: 1; border-color: var(--green); }
.steps h3 { color: #fff; font-size: clamp(1.6rem, 3vw, 2.2rem); margin-bottom: 0.7rem; }
.steps p { color: #a9bcd6; max-width: 26rem; }
.steps li:last-child { min-height: 30vh; }
html:not(.js) .steps li { opacity: 1; min-height: 0; }

@media (min-width: 900px) {
  .story { grid-template-columns: 1.15fr 0.85fr; gap: 4rem; align-items: start; }
  .stage { top: 7rem; padding: 0; align-self: start; }
  .scene { max-height: none; }
  .steps li { min-height: 68vh; }
  .steps li:last-child { min-height: 50vh; }
}

/* scene states */
.scene .drone {
  offset-path: path("M172 202 C 210 90, 390 90, 428 236");
  offset-rotate: 0deg;
  offset-distance: 0%;
  transition: offset-distance 1.8s var(--ease);
}
.scene[data-step="2"] .drone { offset-distance: 50%; }
.scene[data-step="3"] .drone { offset-distance: 100%; }
.scene[data-step="4"] .drone { offset-distance: 0%; }
@supports not (offset-path: path("M0 0")) {
  .scene .drone { transform: translate(172px, 202px); transition: transform 1.8s var(--ease); }
  .scene[data-step="2"] .drone { transform: translate(300px, 130px); }
  .scene[data-step="3"] .drone { transform: translate(428px, 236px); }
}

.scene .route { stroke-dasharray: 1; stroke-dashoffset: 1; opacity: 0; transition: stroke-dashoffset 1.8s var(--ease), opacity 0.8s; }
.scene[data-step="2"] .route { stroke-dashoffset: 0.5; opacity: 0.8; }
.scene[data-step="3"] .route { stroke-dashoffset: 0; opacity: 0.8; }
.scene[data-step="4"] .route { stroke-dashoffset: 0; opacity: 0.2; }

.scene .focus, .scene .uplink { opacity: 0; transition: opacity 0.7s var(--ease); }
.scene[data-step="3"] .focus, .scene[data-step="4"] .uplink { opacity: 1; }

.scene .charge { transform-box: fill-box; transform-origin: left; }
.scene[data-step="1"] .charge, .scene[data-step="4"] .charge { animation: charge 3.2s ease-in-out infinite; }
.scene[data-step="2"] .charge, .scene[data-step="3"] .charge { transform: scaleX(0.15); }
.scene .ping { transform-box: fill-box; transform-origin: center; animation: ping 2.4s ease-out infinite; }
.scene .relay-ring { transform-box: fill-box; transform-origin: center; animation: ping 3s ease-out infinite; }
.scene .march { animation: march 1.6s linear infinite; }
@keyframes charge { 0% { transform: scaleX(0.2); } 80%, 100% { transform: scaleX(1); } }
@keyframes ping { 0% { transform: scale(0.6); opacity: 0.9; } 100% { transform: scale(1.35); opacity: 0; } }
@keyframes march { to { stroke-dashoffset: -20; } }

/* ---------- team ---------- */
.team-title { max-width: 34ch; text-wrap: balance; font-size: clamp(1.75rem, 3.6vw, 2.6rem); }
#team .kicker { color: var(--steel); }
.team {
  margin-top: clamp(2.5rem, 6vw, 4rem);
  border-top: 1px solid rgba(30, 58, 95, 0.25);
}
.member {
  display: grid;
  grid-template-columns: auto 1fr;
  grid-template-rows: auto auto;
  column-gap: 1.25rem;
  row-gap: 0.15rem;
  align-items: center;
  padding: 1.5rem 0;
  border-bottom: 1px solid rgba(30, 58, 95, 0.25);
}
.member img {
  grid-row: 1 / span 2;
  width: 4.75rem;
  aspect-ratio: 1;
  border-radius: 50%;
  object-fit: cover;
  box-shadow: 0 0 0 3px var(--paper), 0 0 0 4px rgba(30, 58, 95, 0.25);
}
.member h3 {
  align-self: end;
  font-size: clamp(1.4rem, 3.4vw, 2rem);
  line-height: 1.15;
}
.member p { align-self: start; color: var(--steel); font-size: 0.95rem; }
@media (min-width: 760px) {
  .member {
    grid-template-columns: auto minmax(0, 1fr) minmax(0, 20rem);
    grid-template-rows: auto;
    column-gap: 2rem;
    padding: 1.75rem 0;
  }
  .member img { grid-row: auto; width: 5.5rem; }
  .member h3 { align-self: center; }
  .member p { align-self: center; text-align: right; font-size: 1rem; }
}

/* ---------- investors form ---------- */
.section--dark#investors {
  background:
    radial-gradient(ellipse 55% 60% at 88% 8%, rgba(61, 220, 151, 0.11), transparent 70%),
    var(--navy);
}
.kicker {
  margin-bottom: 1.25rem;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--green);
}
.pitch h2 { max-width: none; font-size: clamp(1.75rem, 3.2vw, 2.5rem); }
.reasons { margin-top: 3rem; display: grid; }
.reasons li {
  padding: 1.5rem 0;
  border-top: 1px solid rgba(217, 228, 241, 0.16);
}
.reasons li:last-child { border-bottom: 1px solid rgba(217, 228, 241, 0.16); }
.reasons h3 { color: #fff; font-size: 1.25rem; margin-bottom: 0.4rem; }
.reasons p { color: #a9bcd6; max-width: 32rem; font-size: 0.98rem; }
.form-title { color: #fff; margin-bottom: 0.25rem; }
.investors { display: grid; gap: 3rem; grid-template-columns: 1fr; }
@media (min-width: 900px) {
  .investors { grid-template-columns: 1fr 1fr; align-items: start; gap: 5rem; }
}
.form { display: grid; gap: 1.25rem; }
.field { display: grid; gap: 0.4rem; }
.field label { font-size: 0.88rem; color: var(--ice); }
.field input, .field textarea {
  font: inherit;
  color: #fff;
  background: rgba(217, 228, 241, 0.06);
  border: 1px solid rgba(217, 228, 241, 0.4);
  padding: 0.75rem 0.9rem;
  width: 100%;
  resize: vertical;
}
.field input:focus, .field textarea:focus {
  outline: 2px solid var(--green);
  outline-offset: 2px;
  border-color: var(--green);
}
.hp { position: absolute; left: -9999px; }
.btn {
  justify-self: start;
  font: inherit;
  font-weight: 600;
  color: var(--navy);
  background: var(--green);
  border: 0;
  border-radius: 999px;
  padding: 0.85rem 1.9rem;
  cursor: pointer;
  transition: transform 0.15s var(--ease), background 0.2s var(--ease);
}
.btn:hover { background: #4fe6a5; }
.btn:active { transform: scale(0.97); }
.btn[disabled] { opacity: 0.6; cursor: default; }
.form-status { min-height: 1.5em; font-size: 0.95rem; color: var(--green); }
.form-status.is-error { color: #ffb4b4; }

/* ---------- contact + footer ---------- */
.site-footer {
  padding: clamp(4rem, 8vw, 6rem) var(--edge) 2rem;
  background: var(--paper);
  border-top: 1px solid rgba(30, 58, 95, 0.14);
  color: var(--muted);
}
.footer-top {
  display: grid;
  gap: 2.5rem;
  align-items: start;
}
.footer-tag {
  font-family: var(--serif);
  font-size: clamp(1.35rem, 2.6vw, 1.9rem);
  line-height: 1.35;
  color: var(--ink);
  max-width: 24ch;
}
.footer-nav { display: flex; flex-wrap: wrap; gap: 0.6rem 1.75rem; }
.site-footer a {
  color: var(--ink);
  text-decoration: none;
  font-size: 0.95rem;
  background: linear-gradient(var(--steel), var(--steel)) 0 100% / 0 1px no-repeat;
  transition: background-size 0.35s var(--ease);
}
.site-footer a:hover { background-size: 100% 1px; }
@media (min-width: 800px) {
  .footer-top { grid-template-columns: 1fr auto; gap: 4rem; }
  .footer-nav { flex-direction: column; gap: 0.6rem; text-align: right; }
}
.footer-mark {
  display: block;
  width: 100%;
  height: auto;
  margin-top: clamp(3rem, 7vw, 5rem);
  color: var(--steel);
  opacity: 0.85;
}
.footer-base {
  margin-top: 2rem;
  padding-top: 1.25rem;
  border-top: 1px solid rgba(30, 58, 95, 0.14);
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  font-size: 0.85rem;
}
.footer-base a { font-size: 0.85rem; color: var(--muted); }

/* ---------- reveal ---------- */
.reveal { opacity: 0; transform: translateY(16px); transition: opacity 0.9s var(--ease), transform 0.9s var(--ease); }
.reveal.is-visible { opacity: 1; transform: none; }
html:not(.js) .reveal { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .hero-figure img { animation: none; }
  .panel { animation: none; }
  .scene *, .scene .drone, .steps li { animation: none !important; transition: none !important; }
}