/* ============================================================
   ARVENZA.ai — v4 "twilight" theme
   Brand-coherent: indigo-ink canvas · brand cyan → periwinkle
   gradient (the monogram's own purple) · warm copper counterpoint
   Display: Sora · Body: Inter
   ============================================================ */

:root {
  --abyss: #0A0C12;
  --panel: #0C0E14;
  --panel-2: #10131C;
  --line: rgba(147, 160, 188, 0.22);
  --text: #D3DCEF;
  --muted: #93A0BC;
  --faint: #64718D;
  --white: #F5F8FE;
  --teal: #14B8C4;
  --peri: #8F9DF2;
  --peri-deep: #6E7DE0;
  --copper: #E0A868;
  --radius: 16px;
  --display: 'Sora', 'Segoe UI', sans-serif;
  --sans: 'Inter', 'Segoe UI', system-ui, sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--sans);
  background: var(--abyss);
  color: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

.container { max-width: 1140px; margin: 0 auto; padding: 0 26px; }

h1, h2, h3 {
  font-family: var(--display);
  font-weight: 600;
  color: var(--white);
  line-height: 1.12;
  letter-spacing: -0.02em;
}
h1 { font-size: clamp(2.2rem, 4.6vw, 3.4rem); font-weight: 700; }
h2 { font-size: clamp(1.75rem, 3.3vw, 2.5rem); margin-bottom: 18px; }
h3 { font-size: 1.16rem; }

a { color: var(--teal); text-decoration: none; }

.grad {
  background: linear-gradient(94deg, var(--teal) 10%, var(--peri) 90%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.eyebrow {
  font-family: var(--display);
  font-size: 0.74rem;
  font-weight: 600;
  letter-spacing: 0.26em;
  text-transform: uppercase;
  color: var(--copper);
  margin-bottom: 16px;
}

.section__lead {
  max-width: 700px;
  color: var(--muted);
  font-size: 0.98rem;
  margin-bottom: 28px;
}

/* ---------- buttons ---------- */
.btn {
  display: inline-block;
  padding: 13px 28px;
  border-radius: 12px;
  font-family: var(--display);
  font-weight: 600;
  font-size: 0.93rem;
  transition: transform 0.15s ease, box-shadow 0.15s ease, border-color 0.15s ease, filter 0.15s ease;
}
.btn--sm { padding: 9px 18px; font-size: 0.84rem; }
.btn--primary {
  background: linear-gradient(94deg, var(--teal), var(--peri-deep));
  color: var(--white);
  box-shadow: 0 6px 26px rgba(110, 125, 224, 0.32);
}
.btn--primary:hover { transform: translateY(-2px); filter: brightness(1.08); box-shadow: 0 10px 34px rgba(110, 125, 224, 0.45); }
.btn--outline {
  border: 1px solid var(--line);
  color: var(--white);
  background: rgba(245, 248, 254, 0.02);
}
.btn--outline:hover { border-color: var(--peri); color: var(--peri); }

/* ---------- nav ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(6, 7, 9, 0.86);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s ease;
}
.nav.scrolled { border-bottom-color: var(--line); }
.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}
.nav__logo img { display: block; }
.nav__links { display: flex; align-items: center; gap: 28px; }
.nav__links a { color: var(--text); font-size: 0.92rem; font-weight: 500; }
.nav__links a:hover { color: var(--peri); }
.nav__links a.btn { color: var(--white); }
.nav__burger { display: none; background: none; border: 0; cursor: pointer; padding: 8px; }
.nav__burger span { display: block; width: 22px; height: 2px; background: var(--white); margin: 5px 0; border-radius: 2px; }

/* ---------- hero ---------- */
.hero {
  position: relative;
  overflow: hidden;
  padding: 44px 0 64px;
  background:
    radial-gradient(900px 480px at 82% -10%, rgba(110, 125, 224, 0.12), transparent 65%),
    radial-gradient(700px 420px at 8% 110%, rgba(20, 184, 196, 0.07), transparent 60%),
    var(--abyss);
}
.hero__grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(147, 160, 188, 0.10) 1px, transparent 1px),
    linear-gradient(90deg, rgba(147, 160, 188, 0.10) 1px, transparent 1px);
  background-size: 46px 46px;
  mask-image: radial-gradient(860px 500px at 60% 10%, #000 25%, transparent 76%);
  -webkit-mask-image: radial-gradient(860px 500px at 60% 10%, #000 25%, transparent 76%);
  pointer-events: none;
}
.hero__inner {
  position: relative;
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 56px;
  align-items: center;
}
.hero__sub {
  max-width: 520px;
  margin: 16px 0 24px;
  color: var(--muted);
  font-size: 1.05rem;
}
.hero__cta { display: flex; gap: 14px; flex-wrap: wrap; }
.hero__note { margin-top: 20px; font-size: 0.83rem; color: var(--faint); }

/* ---------- hero diagram ---------- */
.hero__diagram svg { width: 100%; height: auto; display: block; }
.dg-node rect {
  fill: var(--panel-2);
  stroke: var(--line);
  stroke-width: 1;
}
.dg-out rect {
  fill: var(--panel-2);
  stroke: rgba(224, 168, 104, 0.5);
  stroke-width: 1;
}
.dg-node text, .dg-out text {
  fill: var(--text);
  font-family: var(--sans);
  font-size: 12.5px;
  text-anchor: middle;
}
.dg-core rect {
  fill: var(--panel-2);
  stroke: url(#flow);
  stroke-width: 1.8;
}
.dg-core__label {
  fill: var(--white);
  font-family: var(--display);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-anchor: middle;
}
.dg-flow {
  stroke: url(#flow);
  stroke-width: 1.6;
  fill: none;
  opacity: 0.75;
  stroke-dasharray: 6 7;
  animation: flowdash 2.4s linear infinite;
}
@keyframes flowdash {
  to { stroke-dashoffset: -26; }
}

/* ---------- sections ---------- */
.section { padding: 92px 0; scroll-margin-top: 72px; }
.section--panel {
  background: var(--panel);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

/* ---------- feature cards ---------- */
#platform { padding: 60px 0; }
#platform h2 { margin-bottom: 14px; }
.grid { display: grid; gap: 20px; margin-top: 30px; }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
.grid--4 { grid-template-columns: repeat(4, 1fr); }

.fcard {
  background: var(--panel-2);
  border: 1px solid rgba(224, 168, 104, 0.7);
  border-radius: var(--radius);
  padding: 24px 24px;
  transition: transform 0.2s ease, border-color 0.2s ease;
}
.fcard:hover { transform: translateY(-4px); border-color: var(--copper); }
.fcard__tag {
  display: inline-block;
  font-family: var(--display);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  padding: 4px 12px;
  border-radius: 999px;
  margin-bottom: 12px;
}
.fcard__tag--blue   { color: var(--teal);   background: rgba(20, 184, 196, 0.12); }
.fcard__tag--mid    { color: var(--peri);   background: rgba(143, 157, 242, 0.13); }
.fcard__tag--violet { color: var(--copper); background: rgba(224, 168, 104, 0.13); }
.fcard h3 { margin-bottom: 8px; }
.fcard p { color: var(--muted); font-size: 0.9rem; }

/* ---------- steps ---------- */
#how { padding: 60px 0; }
#how h2 { margin-bottom: 14px; }
.steps {
  margin-top: 28px;
  display: flex;
  flex-direction: column;
}
.stepline {
  display: flex;
  gap: 24px;
  align-items: flex-start;
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
}
.stepline:last-child { border-bottom: 0; }
.stepline__num {
  flex: 0 0 46px;
  height: 46px;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-family: var(--display);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--abyss);
  background: linear-gradient(135deg, var(--teal), var(--peri));
}
.stepline h3 { margin-bottom: 6px; }
.stepline p { color: var(--muted); font-size: 0.9rem; max-width: 640px; }

/* ---------- trust cards ---------- */
.tcard {
  background: var(--panel-2);
  border: 1px solid rgba(224, 168, 104, 0.7);
  border-radius: var(--radius);
  padding: 28px 24px;
  position: relative;
  overflow: hidden;
}
.tcard::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(94deg, var(--teal), var(--peri));
  opacity: 0.9;
}
.tcard:nth-child(4)::before { background: linear-gradient(94deg, var(--copper), #C88F4E); }
.tcard h3 { font-size: 1.04rem; margin-bottom: 10px; }
.tcard p { color: var(--muted); font-size: 0.88rem; }

/* ---------- outcomes ---------- */
#outcomes { padding: 60px 0; }
.outcomes {
  margin-top: 32px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
}
.orow {
  background: var(--panel-2);
  border: 1px solid rgba(224, 168, 104, 0.7);
  border-radius: var(--radius);
  padding: 24px 26px;
}
.orow__big {
  display: block;
  font-family: var(--display);
  font-size: clamp(1.2rem, 1.9vw, 1.55rem);
  font-weight: 700;
  line-height: 1.18;
  letter-spacing: -0.02em;
  margin-bottom: 10px;
}
.orow p { color: var(--muted); font-size: 0.89rem; }

/* ---------- trial ---------- */
.trial {
  background:
    radial-gradient(700px 400px at 8% 10%, rgba(110, 125, 224, 0.11), transparent 60%),
    radial-gradient(700px 400px at 95% 90%, rgba(224, 168, 104, 0.08), transparent 60%),
    var(--abyss);
}
.trial__inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}
.trial__lead { color: var(--muted); margin-bottom: 24px; max-width: 460px; }

.soft-checks { list-style: none; }
.soft-checks li {
  padding: 8px 0 8px 32px;
  position: relative;
  font-size: 0.96rem;
}
.soft-checks li::before {
  content: '✓';
  position: absolute;
  left: 0; top: 8px;
  width: 21px; height: 21px;
  border-radius: 50%;
  background: rgba(143, 157, 242, 0.15);
  color: var(--peri);
  font-size: 0.72rem;
  font-weight: 700;
  display: flex; align-items: center; justify-content: center;
}

.trial__card {
  background: var(--panel-2);
  border: 1px solid rgba(224, 168, 104, 0.7);
  border-radius: 18px;
  padding: 36px 32px;
  box-shadow: 0 24px 70px rgba(0, 0, 0, 0.4);
}
.trial__card > p { color: var(--muted); font-size: 0.92rem; margin: 10px 0 22px; }
.cform { display: flex; flex-direction: column; gap: 12px; }
.cform input, .cform textarea {
  background: var(--abyss);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 13px 16px;
  color: var(--white);
  font-family: var(--sans);
  font-size: 0.93rem;
  resize: vertical;
}
.cform input:focus, .cform textarea:focus { outline: none; border-color: var(--peri); }
.cform input::placeholder, .cform textarea::placeholder { color: var(--faint); }
.cform .btn { border: 0; cursor: pointer; margin-top: 8px; }
.trial__alt { margin-top: 18px; font-size: 0.85rem; color: var(--muted); text-align: center; }

/* ---------- footer ---------- */
.footer {
  border-top: 1px solid var(--line);
  padding: 34px 0;
  background: var(--panel);
}
.footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  flex-wrap: wrap;
}
.footer p { color: var(--faint); font-size: 0.82rem; }
.footer nav { display: flex; gap: 22px; }
.footer nav a { color: var(--muted); font-size: 0.85rem; }
.footer nav a:hover { color: var(--peri); }

/* ---------- reveal ---------- */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  .dg-flow { animation: none; }
  html { scroll-behavior: auto; }
}

/* ---------- responsive ---------- */
@media (max-width: 980px) {
  .hero__inner { grid-template-columns: 1fr; gap: 48px; }
  .hero__diagram { max-width: 520px; margin: 0 auto; }
  .grid--4 { grid-template-columns: repeat(2, 1fr); }
  .grid--3 { grid-template-columns: 1fr; }
  .outcomes { grid-template-columns: 1fr; }
  .trial__inner { grid-template-columns: 1fr; gap: 44px; }
}

@media (max-width: 640px) {
  .grid--4 { grid-template-columns: 1fr; }
  .section { padding: 60px 0; }
  .hero { padding: 64px 0 56px; }

  .nav__links {
    position: absolute;
    top: 70px; left: 0; right: 0;
    flex-direction: column;
    align-items: stretch;
    background: var(--abyss);
    border-bottom: 1px solid var(--line);
    padding: 18px 26px;
    gap: 16px;
    display: none;
  }
  .nav__links.open { display: flex; }
  .nav__burger { display: block; }
}