/* ───────────────────────────────────────────────────────────
   Stim — landing
   Design system mirrors the iOS app: deep navy gradient,
   water cyan accent, glass surfaces, continuous radii,
   tracked caps for section labels.
   Mobile-first; desktop layers in at >= 760px.
   ─────────────────────────────────────────────────────────── */

:root {
  --bg-top:        #0E2447;
  --bg-bottom:     #061633;
  --bg-deep:       #04102A;
  --water:         #5BB8E8;
  --water-dim:     rgba(91, 184, 232, 0.85);
  --accent:        #5EE9C0;

  --ink:           rgba(255, 255, 255, 1.00);
  --ink-2:         rgba(255, 255, 255, 0.78);
  --ink-3:         rgba(255, 255, 255, 0.55);
  --ink-4:         rgba(255, 255, 255, 0.38);
  --ink-5:         rgba(255, 255, 255, 0.22);

  --line:          rgba(255, 255, 255, 0.10);
  --line-strong:   rgba(255, 255, 255, 0.18);
  --surface:       rgba(255, 255, 255, 0.05);
  --surface-2:     rgba(255, 255, 255, 0.08);

  --r-sm: 10px;
  --r-md: 14px;
  --r-lg: 20px;
  --r-xl: 32px;

  --shadow-card:
    0 1px 0 rgba(255, 255, 255, 0.04) inset,
    0 1px 0 rgba(0, 0, 0, 0.18),
    0 24px 48px -16px rgba(0, 0, 0, 0.55);
  --shadow-glow:
    0 0 0 1px rgba(255, 255, 255, 0.08) inset,
    0 6px 16px rgba(91, 184, 232, 0.32),
    0 18px 38px rgba(0, 0, 0, 0.30);

  --font: -apple-system, BlinkMacSystemFont, "SF Pro Text", "SF Pro Display",
          "Inter", "Helvetica Neue", system-ui, sans-serif;

  --maxw: 1120px;
  --pad-x: 22px;
}

/* ── reset ─────────────────────────────────────────────── */

*, *::before, *::after { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.5;
  color: var(--ink);
  background: var(--bg-bottom);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
  min-height: 100dvh;
}

img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; }

/* Selection */
::selection { background: var(--water); color: var(--bg-deep); }

/* ── background ────────────────────────────────────────── */

.bg {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  overflow: hidden;
}
.bg__gradient {
  position: absolute; inset: 0;
  background: linear-gradient(180deg, var(--bg-top) 0%, var(--bg-bottom) 60%, var(--bg-deep) 100%);
}
.bg__glow {
  position: absolute;
  width: 720px; height: 720px;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.35;
  pointer-events: none;
}
.bg__glow--top {
  top: -260px; left: 50%;
  transform: translateX(-50%);
  background: radial-gradient(closest-side, var(--water) 0%, rgba(91,184,232,0) 70%);
}
.bg__glow--bottom {
  bottom: -360px; right: -160px;
  width: 520px; height: 520px;
  background: radial-gradient(closest-side, var(--accent) 0%, rgba(94,233,192,0) 70%);
  opacity: 0.18;
}
.bg__grain {
  position: absolute; inset: 0;
  background-image:
    radial-gradient(rgba(255,255,255,0.025) 1px, transparent 1px);
  background-size: 3px 3px;
  mix-blend-mode: overlay;
  opacity: 0.6;
}

/* ── topbar ────────────────────────────────────────────── */

.topbar {
  position: sticky;
  top: 0;
  z-index: 30;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px var(--pad-x);
  backdrop-filter: saturate(140%) blur(16px);
  -webkit-backdrop-filter: saturate(140%) blur(16px);
  background: linear-gradient(180deg, rgba(6,22,51,0.82) 0%, rgba(6,22,51,0.45) 100%);
  border-bottom: 1px solid var(--line);
}
.topbar__brand {
  display: inline-flex; align-items: center; gap: 12px;
  font-weight: 600; letter-spacing: 0.4px;
  font-size: 17px;
}
.topbar__brand img {
  width: 34px; height: 34px;
  border-radius: 9px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.4);
}
.topbar__cta {
  display: inline-flex;
  align-items: center;
  height: 40px;
  padding: 0 16px;
  border-radius: 999px;
  background: var(--surface);
  border: 1px solid var(--line-strong);
  font-size: 14px;
  font-weight: 500;
  color: var(--ink-2);
  transition: background 0.18s ease, color 0.18s ease;
}
.topbar__cta:hover {
  background: var(--surface-2);
  color: var(--ink);
}

/* ── shared ────────────────────────────────────────────── */

main {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--pad-x);
}

.eyebrow {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 1.8px;
  text-transform: uppercase;
  color: var(--ink-3);
  margin: 0 0 16px;
}

.section {
  padding: 72px 0;
}
.section__title {
  font-size: clamp(34px, 6.5vw, 60px);
  line-height: 1.08;
  letter-spacing: -0.6px;
  font-weight: 600;
  margin: 0 0 22px;
  color: var(--ink);
}
.section__lede {
  font-size: 18px;
  line-height: 1.55;
  color: var(--ink-2);
  margin: 0 0 40px;
  max-width: 60ch;
}

/* ── status pill ───────────────────────────────────────── */

.status {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  height: 32px;
  padding: 0 14px;
  border-radius: 999px;
  background: rgba(91, 184, 232, 0.10);
  border: 1px solid rgba(91, 184, 232, 0.25);
  color: var(--ink-2);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.4px;
}
.status__dot {
  width: 7px; height: 7px;
  border-radius: 50%;
  background: var(--water);
  box-shadow: 0 0 0 4px rgba(91,184,232,0.18);
  animation: pulse 2.4s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 4px rgba(91,184,232,0.18); }
  50%      { box-shadow: 0 0 0 7px rgba(91,184,232,0.04); }
}

/* ── hero ──────────────────────────────────────────────── */

.hero {
  display: grid;
  grid-template-columns: 1fr;
  gap: 48px;
  padding: 56px 0 96px;
  align-items: center;
}
.hero__inner {
  display: flex;
  flex-direction: column;
  gap: 26px;
  max-width: 620px;
}
.hero__title {
  font-size: clamp(40px, 7.6vw, 76px);
  line-height: 1.04;
  letter-spacing: -1.4px;
  font-weight: 600;
  margin: 8px 0 0;
  max-width: 16ch;
  text-wrap: balance;
  background: linear-gradient(180deg, #FFFFFF 0%, rgba(255,255,255,0.78) 100%);
  -webkit-background-clip: text;
          background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}
.hero__sub {
  font-size: 20px;
  line-height: 1.5;
  color: var(--ink-2);
  margin: 0;
  max-width: 50ch;
}
.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 6px;
}
.hero__meta {
  font-size: 14px;
  color: var(--ink-4);
  letter-spacing: 0.3px;
  margin: 8px 0 0;
}

/* ── buttons ───────────────────────────────────────────── */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  height: 58px;
  padding: 0 26px;
  border-radius: var(--r-md);
  font-size: 16.5px;
  font-weight: 600;
  letter-spacing: 0.2px;
  cursor: pointer;
  border: 1px solid transparent;
  transition: transform 0.12s ease, box-shadow 0.18s ease, background 0.18s ease, opacity 0.18s ease;
  user-select: none;
  -webkit-user-select: none;
}
.btn:active { transform: translateY(1px) scale(0.995); }

.btn--primary {
  color: #FFFFFF;
  background: linear-gradient(180deg, var(--water) 0%, var(--water-dim) 100%);
  border-color: rgba(255,255,255,0.22);
  box-shadow:
    0 1px 0 rgba(255,255,255,0.18) inset,
    0 6px 16px rgba(91,184,232,0.32),
    0 14px 28px rgba(0,0,0,0.30);
}
.btn--primary:hover {
  box-shadow:
    0 1px 0 rgba(255,255,255,0.20) inset,
    0 8px 22px rgba(91,184,232,0.42),
    0 18px 36px rgba(0,0,0,0.36);
}

.btn--ghost {
  color: var(--ink-2);
  background: var(--surface);
  border-color: var(--line-strong);
}
.btn--ghost:hover { background: var(--surface-2); color: var(--ink); }

.btn--block { width: 100%; }

.btn[disabled] { opacity: 0.5; cursor: progress; pointer-events: none; }

/* ── hero device mockup ────────────────────────────────── */

.hero__device {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
  perspective: 1600px;
  margin: 0 auto;
  width: 100%;
  max-width: 440px;
}
.device {
  position: relative;
  width: 100%;
  border-radius: 48px;
  padding: 10px;
  background:
    linear-gradient(160deg, #1A2D55 0%, #0A1B3D 55%, #050E25 100%);
  box-shadow:
    0 0 0 1px rgba(255,255,255,0.10) inset,
    0 1px 0 rgba(255,255,255,0.12) inset,
    0 40px 80px -24px rgba(0,0,0,0.75),
    0 100px 120px -50px rgba(91,184,232,0.22);
  transform: rotate3d(0.5, 1, 0.05, -7deg) rotateZ(1.5deg);
  transform-origin: 50% 60%;
  animation: float 9s ease-in-out infinite;
}
.device__shot {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 38px;
  background: #050E25;
}
.device__glow {
  position: absolute;
  inset: -10% -20% -20% -20%;
  z-index: -1;
  background: radial-gradient(closest-side, rgba(91,184,232,0.28) 0%, rgba(91,184,232,0) 70%);
  filter: blur(40px);
  pointer-events: none;
}
@keyframes float {
  0%,100% { transform: rotate3d(0.5,1,0.05,-7deg) rotateZ(1.5deg) translateY(0); }
  50%     { transform: rotate3d(0.5,1,0.05,-7deg) rotateZ(1.5deg) translateY(-10px); }
}

/* ── steps ─────────────────────────────────────────────── */

.steps {
  list-style: none;
  margin: 0; padding: 0;
  display: grid;
  gap: 16px;
}
.step {
  position: relative;
  padding: 28px 26px 30px;
  border-radius: var(--r-lg);
  background: var(--surface);
  border: 1px solid var(--line);
  box-shadow: var(--shadow-card);
}
.step__num {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 1.8px;
  color: var(--water);
  margin-bottom: 14px;
}
.step__title {
  margin: 0 0 10px;
  font-size: 23px;
  font-weight: 600;
  letter-spacing: -0.3px;
  color: var(--ink);
}
.step__body {
  margin: 0;
  font-size: 16.5px;
  line-height: 1.55;
  color: var(--ink-2);
}

/* ── perks ─────────────────────────────────────────────── */

.section--why .section__lede { margin-bottom: 32px; }

.perks {
  list-style: none;
  padding: 0; margin: 0;
  display: grid;
  gap: 14px;
}
.perk {
  display: grid;
  grid-template-columns: 44px 1fr;
  gap: 16px;
  padding: 22px 24px;
  border-radius: var(--r-md);
  background: var(--surface);
  border: 1px solid var(--line);
}
.perk h3 {
  margin: 0 0 6px;
  font-size: 17.5px;
  font-weight: 600;
  letter-spacing: -0.1px;
  color: var(--ink);
}
.perk p {
  margin: 0;
  font-size: 15.5px;
  color: var(--ink-2);
  line-height: 1.5;
}
.perk__icon {
  width: 36px; height: 36px;
  padding: 7px;
  border-radius: 10px;
  background: rgba(94,233,192,0.14);
  color: var(--accent);
  align-self: start;
}

/* ── signup form ───────────────────────────────────────── */

.section--form { padding-top: 24px; padding-bottom: 72px; }

.signup {
  position: relative;
  margin: 0 auto;
  max-width: 600px;
  padding: 38px 26px 32px;
  border-radius: var(--r-xl);
  background:
    linear-gradient(180deg, rgba(14,36,71,0.78) 0%, rgba(6,22,51,0.94) 100%);
  border: 1px solid var(--line);
  box-shadow:
    0 1px 0 rgba(255,255,255,0.10) inset,
    0 30px 60px -20px rgba(0,0,0,0.65),
    0 80px 100px -40px rgba(91,184,232,0.18);
}
.signup::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(180deg, rgba(255,255,255,0.20), rgba(255,255,255,0.02) 60%, transparent);
  -webkit-mask:
    linear-gradient(#000 0 0) content-box,
    linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
          mask-composite: exclude;
  pointer-events: none;
}

.form {
  display: flex;
  flex-direction: column;
  gap: 22px;
  margin-top: 10px;
}
.field {
  display: flex; flex-direction: column;
  gap: 10px;
}
.field label,
.field__label {
  font-size: 12.5px;
  font-weight: 600;
  letter-spacing: 1.8px;
  text-transform: uppercase;
  color: var(--ink-3);
}
.field__hint {
  font-weight: 500; letter-spacing: 0.4px;
  text-transform: none;
  color: var(--ink-4);
  margin-left: 6px;
}
.field__note {
  margin: 4px 0 0;
  font-size: 13px;
  line-height: 1.5;
  color: var(--ink-4);
  letter-spacing: 0.1px;
  text-transform: none;
  font-weight: 400;
}

.field input[type="email"],
.field input[type="text"],
.select select {
  width: 100%;
  height: 54px;
  padding: 0 18px;
  border-radius: var(--r-md);
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.10);
  color: var(--ink);
  font-size: 17px;            /* ≥ 16px to stop iOS zoom-in on focus */
  font-family: inherit;
  appearance: none;
  -webkit-appearance: none;
  transition: background 0.18s ease, border-color 0.18s ease, box-shadow 0.18s ease;
}
.field input::placeholder {
  color: var(--ink-4);
}
.field input:focus,
.select select:focus {
  outline: none;
  background: rgba(255,255,255,0.07);
  border-color: rgba(91,184,232,0.55);
  box-shadow: 0 0 0 3px rgba(91,184,232,0.18);
}

.select {
  position: relative;
}
.select select {
  padding-right: 40px;
  cursor: pointer;
}
.select__chev {
  position: absolute;
  right: 14px; top: 50%;
  transform: translateY(-50%);
  color: var(--ink-3);
  pointer-events: none;
}

/* chips */
.chips {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}
.chips input { position: absolute; opacity: 0; pointer-events: none; }
.chip {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 50px;
  padding: 0 22px;
  border-radius: 14px;
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.10);
  font-size: 15.5px;
  font-weight: 500;
  color: var(--ink-2);
  cursor: pointer;
  user-select: none;
  -webkit-user-select: none;
  transition: background 0.18s ease, color 0.18s ease, border-color 0.18s ease, box-shadow 0.18s ease, transform 0.12s ease;
  flex: 1 1 0;
  min-width: 100px;
  letter-spacing: 0;
  text-transform: none;
}
.chips input:checked + .chip {
  background: linear-gradient(180deg, var(--water) 0%, var(--water-dim) 100%);
  border-color: rgba(255,255,255,0.22);
  color: #FFFFFF;
  font-weight: 600;
  box-shadow: 0 6px 16px rgba(91,184,232,0.30);
}
.chips input:focus-visible + .chip {
  box-shadow: 0 0 0 3px rgba(91,184,232,0.30);
}

/* honeypot */
.hp {
  position: absolute;
  left: -10000px; top: auto;
  width: 1px; height: 1px;
  overflow: hidden;
}

/* submit button + spinner */
.btn--primary .btn__spinner { display: none; }
.btn--primary[data-loading="true"] .btn__label { opacity: 0.6; }
.btn--primary[data-loading="true"] .btn__spinner {
  display: inline-block;
  width: 16px; height: 16px;
  border: 2px solid rgba(255,255,255,0.45);
  border-top-color: #FFFFFF;
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

.form__error {
  margin: 0;
  font-size: 14px;
  color: #FFA8A8;
  letter-spacing: 0.2px;
  text-align: center;
}
.form__fineprint {
  font-size: 13.5px;
  line-height: 1.55;
  color: var(--ink-4);
  margin: 6px 0 0;
}
.form__fineprint a {
  color: var(--ink-3);
  border-bottom: 1px solid var(--line-strong);
}
.form__fineprint a:hover { color: var(--ink-2); }

/* success state */
.success {
  text-align: center;
  padding: 16px 8px 8px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
}
.success__check {
  width: 56px; height: 56px;
  display: grid; place-items: center;
  border-radius: 50%;
  background: rgba(94,233,192,0.18);
  color: var(--accent);
  border: 1px solid rgba(94,233,192,0.30);
  animation: pop 0.45s cubic-bezier(0.2, 0.8, 0.2, 1.2);
}
@keyframes pop {
  0%   { transform: scale(0.7); opacity: 0; }
  100% { transform: scale(1);   opacity: 1; }
}
.success h3 {
  margin: 0;
  font-size: 28px;
  font-weight: 600;
  letter-spacing: -0.4px;
}
.success p {
  margin: 0;
  font-size: 17px;
  color: var(--ink-2);
  max-width: 38ch;
  line-height: 1.5;
}

/* ── faq ───────────────────────────────────────────────── */

.faq {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 40px var(--pad-x) 96px;
}
.faq .eyebrow { margin-bottom: 22px; }

.qa {
  border-bottom: 1px solid var(--line);
  padding: 22px 2px;
}
.qa:first-of-type { border-top: 1px solid var(--line); }
.qa summary {
  list-style: none;
  cursor: pointer;
  display: flex; align-items: center; justify-content: space-between;
  gap: 16px;
  font-size: 18px;
  font-weight: 500;
  color: var(--ink);
  padding-right: 4px;
}
.qa summary::-webkit-details-marker { display: none; }
.qa summary::after {
  content: "";
  width: 12px; height: 12px;
  border-right: 1.5px solid var(--ink-3);
  border-bottom: 1.5px solid var(--ink-3);
  transform: rotate(45deg);
  margin-right: 4px;
  margin-top: -4px;
  transition: transform 0.2s ease, border-color 0.2s ease;
}
.qa[open] summary::after {
  transform: rotate(-135deg);
  margin-top: 2px;
  border-color: var(--water);
}
.qa p {
  margin: 14px 0 0;
  font-size: 16px;
  line-height: 1.6;
  color: var(--ink-2);
  max-width: 64ch;
}

/* ── footer ────────────────────────────────────────────── */

.footer {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 28px var(--pad-x) 44px;
  border-top: 1px solid var(--line);
}
.footer__row {
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; gap: 14px;
}
.footer__brand {
  display: inline-flex; align-items: center; gap: 12px;
  font-weight: 600; letter-spacing: 0.4px;
  font-size: 15px;
}
.footer__brand img {
  width: 26px; height: 26px;
  border-radius: 7px;
}
.footer__links {
  display: inline-flex; align-items: center; gap: 14px;
  font-size: 14px;
  color: var(--ink-3);
}
.footer__links a:hover { color: var(--ink); }
.footer__meta {
  margin: 16px 0 0;
  font-size: 13px;
  color: var(--ink-4);
  letter-spacing: 0.3px;
}

/* ── reduce motion ─────────────────────────────────────── */

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ── tablet ≥ 640 ──────────────────────────────────────── */

@media (min-width: 640px) {
  :root { --pad-x: 36px; }

  .section { padding: 104px 0; }

  .steps { grid-template-columns: repeat(3, 1fr); gap: 16px; }
  .perks { grid-template-columns: repeat(2, 1fr); gap: 16px; }

  .chip { flex: 0 0 auto; min-width: 120px; }
}

/* ── desktop ≥ 880 ─────────────────────────────────────── */

@media (min-width: 880px) {
  .topbar { padding-left: 40px; padding-right: 40px; }

  .hero {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    gap: 56px;
    padding: 88px 0 120px;
  }
  .hero__device { max-width: 420px; }

  .signup { padding: 44px 40px 40px; }
}

/* ── desktop ≥ 1080 ────────────────────────────────────── */

@media (min-width: 1080px) {
  :root { --pad-x: 56px; }
  .hero { gap: 88px; padding: 112px 0 140px; }
  .hero__device { max-width: 460px; }
}