:root {
  color-scheme: light;
  --page: #ebf5ee;
  --hero: linear-gradient(180deg, #ebf5ee 0%, #d8ede6 100%);
  --text: #132820;
  --muted: #42675d;
  --accent: #2d7e6c;
  --accent-strong: #245f53;
  --bird-opacity: .68;
  --bird-filter: saturate(.92) brightness(1.02);
  --bird-blend: multiply;
  --wordmark-filter: none;
  --panel: rgba(255, 255, 255, .72);
  --panel-border: rgba(45, 126, 108, .20);
  --panel-shadow: 0 24px 80px rgba(19, 40, 32, .09);
  --input-placeholder: #5c776f;
  --button: #132820;
  --button-text: #f7fffb;
  --privacy: #d7eee6;
  --line: rgba(19, 40, 32, .18);
  --focus: #147f6a;
  --serif: Georgia, "Times New Roman", serif;
  --sans: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --page: #081610;
    --hero: radial-gradient(circle at 75% 40%, #234236 0%, #10271d 38%, #081610 78%);
    --text: #f1faf5;
    --muted: rgba(241, 250, 245, .70);
    --accent: #7ed9c1;
    --accent-strong: #9ce4d0;
    --bird-opacity: .50;
    --bird-filter: contrast(1.04) brightness(.78);
    --bird-blend: luminosity;
    --wordmark-filter: brightness(1.48) drop-shadow(0 0 20px rgba(110, 200, 212, .16));
    --panel: rgba(255, 255, 255, .07);
    --panel-border: rgba(255, 255, 255, .14);
    --panel-shadow: none;
    --input-placeholder: rgba(241, 250, 245, .55);
    --button: #82dcc4;
    --button-text: #081610;
    --privacy: #0d2018;
    --line: rgba(255, 255, 255, .14);
    --focus: #8ce2cb;
  }
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --page: #081610;
  --hero: radial-gradient(circle at 75% 40%, #234236 0%, #10271d 38%, #081610 78%);
  --text: #f1faf5;
  --muted: rgba(241, 250, 245, .70);
  --accent: #7ed9c1;
  --accent-strong: #9ce4d0;
  --bird-opacity: .50;
  --bird-filter: contrast(1.04) brightness(.78);
  --bird-blend: luminosity;
  --wordmark-filter: brightness(1.48) drop-shadow(0 0 20px rgba(110, 200, 212, .16));
  --panel: rgba(255, 255, 255, .07);
  --panel-border: rgba(255, 255, 255, .14);
  --panel-shadow: none;
  --input-placeholder: rgba(241, 250, 245, .55);
  --button: #82dcc4;
  --button-text: #081610;
  --privacy: #0d2018;
  --line: rgba(255, 255, 255, .14);
  --focus: #8ce2cb;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--page);
  color: var(--text);
  font-family: var(--sans);
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-underline-offset: .2em;
  text-decoration-thickness: 1px;
}

button,
input {
  font: inherit;
}

button,
a,
input {
  -webkit-tap-highlight-color: transparent;
}

:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 4px;
}

.skip-link {
  position: fixed;
  top: 1rem;
  left: 1rem;
  z-index: 20;
  padding: .75rem 1rem;
  border-radius: .5rem;
  background: var(--button);
  color: var(--button-text);
  transform: translateY(-200%);
}

.skip-link:focus {
  transform: translateY(0);
}

.hero {
  position: relative;
  isolation: isolate;
  min-height: 100svh;
  overflow: hidden;
  background: var(--hero);
}

.bird-photo {
  position: absolute;
  right: -5vw;
  bottom: -15vw;
  z-index: -1;
  width: min(67vw, 68rem);
  height: auto;
  opacity: var(--bird-opacity);
  filter: var(--bird-filter);
  mix-blend-mode: var(--bird-blend);
  mask-image: radial-gradient(ellipse 64% 63% at 56% 52%, #000 32%, rgba(0, 0, 0, .96) 51%, transparent 79%);
  transition: opacity .25s ease, filter .25s ease;
}

.site-header,
.hero-content,
.privacy-inner {
  width: min(92rem, calc(100% - 4rem));
  margin-inline: auto;
}

.site-header {
  display: flex;
  min-height: 7rem;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}

.brand {
  display: block;
  width: clamp(11rem, 17vw, 16rem);
  line-height: 0;
}

.brand img {
  width: 100%;
  height: auto;
  filter: var(--wordmark-filter);
  transition: filter .25s ease;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 1.4rem;
  color: var(--muted);
  font-size: .78rem;
}

.site-nav a {
  text-decoration: none;
}

.site-nav a:hover {
  color: var(--text);
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  gap: .55rem;
  padding: .62rem .85rem;
  border: 1px solid var(--panel-border);
  border-radius: 999px;
  background: var(--panel);
  color: var(--text);
  cursor: pointer;
  font-size: .74rem;
  font-weight: 700;
}

.theme-symbol {
  position: relative;
  width: .9rem;
  height: .9rem;
  border: 2px solid currentColor;
  border-radius: 50%;
}

.theme-symbol::after {
  position: absolute;
  top: -.2rem;
  right: -.2rem;
  width: .62rem;
  height: .62rem;
  border-radius: 50%;
  background: var(--panel);
  content: "";
}

.hero-content {
  padding: clamp(3.75rem, 9vh, 7.5rem) 0 clamp(7rem, 13vh, 11rem);
}

.section-label {
  margin: 0 0 1.4rem;
  color: var(--accent);
  font-size: .7rem;
  font-weight: 800;
  letter-spacing: .18em;
  text-transform: uppercase;
}

h1 {
  max-width: 9ch;
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(4.2rem, 8.5vw, 8.8rem);
  font-weight: 400;
  letter-spacing: -.06em;
  line-height: .89;
}

.introduction {
  max-width: 37rem;
  margin: 2rem 0 2.5rem;
  color: var(--muted);
  font-size: clamp(1rem, 1.3vw, 1.18rem);
  line-height: 1.75;
}

.signup-panel {
  width: min(38rem, 100%);
  padding: .6rem;
  border: 1px solid var(--panel-border);
  border-radius: 999px;
  background: var(--panel);
  box-shadow: var(--panel-shadow);
  backdrop-filter: blur(18px);
}

.signup {
  display: flex;
  gap: .6rem;
}

.signup input {
  min-width: 0;
  flex: 1;
  padding: .95rem 1.1rem;
  border: 0;
  border-radius: 999px;
  background: transparent;
  color: var(--text);
}

.signup input::placeholder {
  color: var(--input-placeholder);
  opacity: 1;
}

.signup button {
  padding: .95rem 1.3rem;
  border: 0;
  border-radius: 999px;
  background: var(--button);
  color: var(--button-text);
  cursor: pointer;
  font-weight: 750;
  white-space: nowrap;
}

.signup button:hover {
  filter: brightness(1.08);
}

.form-note,
.form-status {
  max-width: 37rem;
  margin: .8rem 0 0 1.4rem;
  color: var(--muted);
  font-size: .76rem;
  line-height: 1.55;
}

.form-status:empty {
  display: none;
}

.privacy {
  background: var(--privacy);
}

.privacy-inner {
  padding: clamp(6rem, 10vw, 10rem) 0 3rem;
}

.privacy-intro {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(18rem, .6fr);
  gap: 5rem;
  align-items: end;
  margin-bottom: clamp(4rem, 8vw, 7rem);
}

.privacy-intro h2 {
  max-width: 11ch;
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(3rem, 6vw, 6.8rem);
  font-weight: 400;
  letter-spacing: -.055em;
  line-height: .94;
}

.privacy-intro > p {
  margin: 0;
  color: var(--muted);
  line-height: 1.8;
}

.promise-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid var(--line);
}

.promise-card {
  padding: 2.5rem 2.2rem 1rem 0;
}

.promise-card + .promise-card {
  padding-left: 2.2rem;
  border-left: 1px solid var(--line);
}

.promise-card h3 {
  margin: 2rem 0 .8rem;
  font-family: var(--serif);
  font-size: 1.5rem;
  font-weight: 500;
  line-height: 1.15;
}

.promise-card p {
  margin: 0;
  color: var(--muted);
  font-size: .86rem;
  line-height: 1.7;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 2rem;
  padding-top: 6rem;
  color: var(--muted);
  font-size: .78rem;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (max-width: 900px) {
  .bird-photo {
    right: -13rem;
    bottom: 3rem;
    width: 52rem;
  }

  .privacy-intro {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .privacy-intro > p {
    max-width: 38rem;
  }

  .promise-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .promise-card:nth-child(3) {
    padding-left: 0;
    border-top: 1px solid var(--line);
    border-left: 0;
  }

  .promise-card:nth-child(4) {
    border-top: 1px solid var(--line);
  }
}

@media (max-width: 640px) {
  .site-header,
  .hero-content,
  .privacy-inner {
    width: min(100% - 2rem, 92rem);
  }

  .site-header {
    min-height: 5.5rem;
  }

  .brand {
    width: 10.5rem;
  }

  .site-nav > a {
    display: none;
  }

  .theme-toggle [data-theme-label] {
    display: none;
  }

  .theme-toggle {
    padding: .7rem;
  }

  .hero-content {
    padding: 4.5rem 0 7rem;
  }

  h1 {
    font-size: clamp(4rem, 19vw, 6rem);
  }

  .introduction {
    font-size: .98rem;
  }

  .signup-panel {
    padding: .7rem;
    border-radius: 1.4rem;
  }

  .signup {
    flex-direction: column;
  }

  .signup input,
  .signup button {
    width: 100%;
  }

  .form-note,
  .form-status {
    margin-left: .25rem;
  }

  .bird-photo {
    right: -17rem;
    /* Let the artwork run past the viewport edge instead of ending abruptly
       above the bottom of the hero on short, narrow screens. */
    bottom: -8rem;
    width: 47rem;
    opacity: calc(var(--bird-opacity) * .72);
  }

  .promise-grid {
    grid-template-columns: 1fr;
  }

  .promise-card,
  .promise-card + .promise-card,
  .promise-card:nth-child(3) {
    padding: 2rem 0;
    border-top: 1px solid var(--line);
    border-left: 0;
  }

  .promise-grid {
    border-top: 0;
  }

  .promise-card h3 {
    margin-top: 0;
  }

  .site-footer {
    flex-direction: column;
    padding-top: 4rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }
}