/* Swells LLC - static marketing site
   Black, white and grey only. No dependencies. */

:root {
  --black: #000000;
  --white: #ffffff;
  --grey-900: #0a0a0a;
  --grey-700: #3d3d3d;
  --grey-500: #6f6f6f;
  --grey-300: #b5b5b5;
  --grey-150: #e2e2e2;
  --grey-100: #ededed;

  --shell: 1180px;
  --gutter: 20px;

  --sans: "Space Grotesk", "Helvetica Neue", Arial, sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, monospace;

  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  margin: 0;
  background-color: var(--white);
  background-image: radial-gradient(var(--grey-150) 1px, transparent 1px);
  background-size: 28px 28px;
  background-position: -1px -1px;
  color: var(--black);
  font-family: var(--sans);
  font-weight: 300;
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

a { color: inherit; }

.shell {
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding-inline: var(--gutter);
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--black);
  color: var(--white);
  padding: 10px 16px;
  z-index: 100;
  font-family: var(--mono);
  font-size: 12px;
}
.skip-link:focus { left: 8px; top: 8px; }

:focus-visible {
  outline: 2px solid var(--black);
  outline-offset: 3px;
}

/* ---------- Nav ---------- */

.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 1px solid var(--grey-150);
  background: rgba(255, 255, 255, 0.82);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  height: 64px;
}

.wordmark {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  text-decoration: none;
  font-weight: 500;
  font-size: 18px;
  letter-spacing: -0.02em;
}

.wordmark__mark { width: 20px; height: 20px; flex: none; }

.nav__links {
  display: flex;
  align-items: center;
  gap: clamp(16px, 4vw, 34px);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.nav__links a {
  position: relative;
  text-decoration: none;
  color: var(--grey-700);
  padding-block: 4px;
  transition: color 0.25s var(--ease);
}

.nav__links a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 1px;
  background: var(--black);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s var(--ease);
}

.nav__links a:hover { color: var(--black); }
.nav__links a:hover::after { transform: scaleX(1); }

/* ---------- Type helpers ---------- */

.eyebrow {
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--grey-500);
  margin: 0 0 22px;
}

.section__title {
  font-size: clamp(30px, 5vw, 46px);
  font-weight: 400;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin: 0;
}

.section__sub {
  max-width: 52ch;
  margin: 18px 0 0;
  color: var(--grey-700);
}

/* ---------- Hero ---------- */

.hero {
  padding: clamp(72px, 14vw, 150px) 0 clamp(60px, 10vw, 110px);
  border-bottom: 1px solid var(--grey-150);
}

.hero__title {
  font-size: clamp(38px, 8.4vw, 82px);
  font-weight: 400;
  line-height: 1.02;
  letter-spacing: -0.045em;
  margin: 0;
  max-width: 17ch;
}

.hero__lede {
  margin: 28px 0 0;
  max-width: 58ch;
  font-size: clamp(16px, 2vw, 19px);
  color: var(--grey-700);
}

.hero__cta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 22px;
  margin-top: 44px;
}

.hero__meta {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--grey-500);
}

/* ---------- Button ---------- */

.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 15px 30px;
  border: 1px solid var(--black);
  background: var(--black);
  color: var(--white);
  font-family: var(--mono);
  font-size: 12.5px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  text-decoration: none;
  cursor: pointer;
  overflow: hidden;
  transition: color 0.3s var(--ease), background-color 0.3s var(--ease);
}

.btn::before {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--white);
  transform: translateY(100%);
  transition: transform 0.35s var(--ease);
  z-index: 0;
}

.btn > * { position: relative; z-index: 1; }

.btn:hover { color: var(--black); }
.btn:hover::before { transform: translateY(0); }
.btn:active { transform: translateY(1px); }

/* ---------- Sections ---------- */

.section { padding: clamp(64px, 10vw, 118px) 0; }
.section--rule { border-top: 1px solid var(--grey-150); }

.section__head { margin-bottom: clamp(38px, 6vw, 62px); }

/* ---------- Service cards ---------- */

.cards {
  display: grid;
  grid-template-columns: 1fr;
  border-top: 1px solid var(--grey-150);
  border-left: 1px solid var(--grey-150);
  background: rgba(255, 255, 255, 0.6);
}

.card {
  position: relative;
  padding: 34px 28px 38px;
  border-right: 1px solid var(--grey-150);
  border-bottom: 1px solid var(--grey-150);
  transition: background-color 0.35s var(--ease), color 0.35s var(--ease);
}

.card__num {
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.14em;
  color: var(--grey-300);
  transition: color 0.35s var(--ease);
}

.card h3 {
  margin: 26px 0 12px;
  font-size: 21px;
  font-weight: 500;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.card p {
  margin: 0;
  color: var(--grey-700);
  font-size: 15.5px;
  max-width: 34ch;
  transition: color 0.35s var(--ease);
}

.card:hover { background: var(--black); color: var(--white); }
.card:hover p { color: var(--grey-300); }
.card:hover .card__num { color: var(--grey-500); }

/* ---------- Approach ---------- */

.split { display: grid; gap: clamp(34px, 6vw, 64px); }

.split__lede {
  margin: 0;
  font-size: clamp(19px, 2.6vw, 25px);
  line-height: 1.38;
  letter-spacing: -0.02em;
  max-width: 30ch;
}

.props { list-style: none; margin: 0; padding: 0; }

.props li {
  padding: 24px 0;
  border-top: 1px solid var(--grey-150);
}
.props li:last-child { border-bottom: 1px solid var(--grey-150); }

.props h3 {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 500;
  letter-spacing: -0.01em;
}

.props p {
  margin: 0;
  color: var(--grey-700);
  font-size: 15.5px;
  max-width: 62ch;
}

/* ---------- Credibility strip ---------- */

.strip {
  border-top: 1px solid var(--black);
  border-bottom: 1px solid var(--black);
  background: var(--black);
  color: var(--white);
  overflow: hidden;
}

.strip__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px clamp(18px, 5vw, 54px);
  padding-block: 22px;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--grey-300);
}

.strip__inner span { white-space: nowrap; }

/* ---------- Form ---------- */

.form { max-width: 720px; }

.form__row { display: grid; gap: 0; }

.field { display: flex; flex-direction: column; margin-bottom: 26px; }

.field label {
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--grey-500);
  margin-bottom: 10px;
}

.field input,
.field textarea {
  font-family: var(--sans);
  font-size: 16px;
  font-weight: 300;
  color: var(--black);
  background: transparent;
  border: 0;
  border-bottom: 1px solid var(--grey-300);
  padding: 10px 2px;
  border-radius: 0;
  transition: border-color 0.3s var(--ease);
}

.field textarea { resize: vertical; line-height: 1.55; }

.field input::placeholder,
.field textarea::placeholder { color: var(--grey-300); }

.field input:hover,
.field textarea:hover { border-color: var(--grey-500); }

.field input:focus,
.field textarea:focus {
  outline: none;
  border-color: var(--black);
}

.field.is-invalid input,
.field.is-invalid textarea { border-color: var(--black); }

.field__error {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--grey-700);
  margin: 8px 0 0;
}

.form__foot {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 18px 24px;
  margin-top: 12px;
}

.form__status {
  margin: 0;
  font-family: var(--mono);
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--black);
  opacity: 0;
  transform: translateY(6px);
  transition: opacity 0.4s var(--ease), transform 0.4s var(--ease);
}

.form__status.is-visible { opacity: 1; transform: translateY(0); }

/* ---------- Footer ---------- */

.footer {
  border-top: 1px solid var(--grey-150);
  padding-block: 30px;
  background: var(--white);
}

.footer__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--grey-500);
}

.footer__brand { color: var(--black); }

.footer__mail {
  text-decoration: none;
  border-bottom: 1px solid var(--grey-300);
  padding-bottom: 2px;
  transition: color 0.25s var(--ease), border-color 0.25s var(--ease);
}
.footer__mail:hover { color: var(--black); border-color: var(--black); }

/* ---------- Reveal on scroll ---------- */

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
  will-change: opacity, transform;
}

.reveal.is-in { opacity: 1; transform: none; }

/* ---------- Breakpoints ---------- */

@media (min-width: 640px) {
  :root { --gutter: 32px; }
  .form__row { grid-template-columns: 1fr 1fr; gap: 0 28px; }
  .cards { grid-template-columns: repeat(2, 1fr); }
  .card { padding: 40px 34px 46px; }
}

@media (min-width: 960px) {
  :root { --gutter: 48px; }
  body { font-size: 17px; }
  .cards { grid-template-columns: repeat(4, 1fr); }
  .split { grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr); }
  .props li { padding: 26px 0; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .form__status { transition: none; }
  * { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}