/* StackPrep — site styles */

@font-face {
  font-family: "Sora";
  src: url("/assets/fonts/Sora-Variable.woff2") format("woff2");
  font-weight: 100 800;
  font-display: swap;
}

/* Colour themes: light by default, dark from the system setting or the header toggle */

:root {
  color-scheme: light;
  --bg: #F7F8FC;
  --glow: rgba(46, 91, 255, 0.12);
  --card: #FFFFFF;
  --card-top: #FFFFFF;
  --card-border: #E3E7F2;
  --inset: #F2F4FA;
  --inset-border: #E3E7F2;
  --text: #0E1433;
  --muted: #4A5480;
  --accent: #2E5BFF;
  --action: #2E5BFF;
  --action-hover: #1F47E0;
  --on-action: #FFFFFF;
  --light-pill: #0E1433;
  --on-light-pill: #FFFFFF;
  --ok: #1F47E0;
  --mid: #6B7499;
  --wrong: #C8102E;
  --wrong-soft: #FFEDF0;
  --track: #E3E7F2;
  --focus: #2E5BFF;
  --verified: #1A7F37;
  --shadow: 0 1px 2px rgba(14, 20, 51, 0.04), 0 12px 32px -12px rgba(14, 20, 51, 0.12);

  --font-sans: "Sora", ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;

  --gutter: clamp(1rem, 0.5rem + 2.5vw, 2.5rem);
  --radius-card: 22px;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --bg: #05070F;
    --glow: rgba(61, 107, 255, 0.22);
    --card: rgba(255, 255, 255, 0.025);
    --card-top: rgba(255, 255, 255, 0.06);
    --card-border: rgba(255, 255, 255, 0.09);
    --inset: rgba(255, 255, 255, 0.04);
    --inset-border: rgba(255, 255, 255, 0.08);
    --text: #F2F4FA;
    --muted: #9AA3BF;
    --accent: #9DB2FF;
    --action-hover: #4D74FF;
    --light-pill: #F2F4FA;
    --on-light-pill: #05070F;
    --ok: #9DB2FF;
    --mid: #9AA3BF;
    --wrong: #FF8A9A;
    --wrong-soft: rgba(255, 61, 87, 0.16);
    --track: rgba(255, 255, 255, 0.08);
    --focus: #9DB2FF;
    --verified: #3FB950;
    --shadow: 0 1px 0 rgba(255, 255, 255, 0.04) inset, 0 24px 48px -24px rgba(0, 0, 0, 0.6);
  }
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #05070F;
  --glow: rgba(61, 107, 255, 0.22);
  --card: rgba(255, 255, 255, 0.025);
  --card-top: rgba(255, 255, 255, 0.06);
  --card-border: rgba(255, 255, 255, 0.09);
  --inset: rgba(255, 255, 255, 0.04);
  --inset-border: rgba(255, 255, 255, 0.08);
  --text: #F2F4FA;
  --muted: #9AA3BF;
  --accent: #9DB2FF;
  --action-hover: #4D74FF;
  --light-pill: #F2F4FA;
  --on-light-pill: #05070F;
  --ok: #9DB2FF;
  --mid: #9AA3BF;
  --wrong: #FF8A9A;
  --wrong-soft: rgba(255, 61, 87, 0.16);
  --track: rgba(255, 255, 255, 0.08);
  --focus: #9DB2FF;
  --verified: #3FB950;
  --shadow: 0 1px 0 rgba(255, 255, 255, 0.04) inset, 0 24px 48px -24px rgba(0, 0, 0, 0.6);
}

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

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

body {
  margin: 0;
  background:
    radial-gradient(70rem 40rem at 15% -10%, var(--glow), transparent 65%),
    radial-gradient(50rem 30rem at 95% 5%, var(--glow), transparent 70%),
    var(--bg);
  background-repeat: no-repeat;
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 1.0625rem;
  line-height: 1.6;
}

h1,
h2,
h3,
p {
  margin: 0;
}

a {
  color: inherit;
}

img {
  display: block;
}

:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 3px;
  border-radius: 6px;
}

.container {
  width: 100%;
  max-width: 74rem;
  margin-inline: auto;
  padding-inline: var(--gutter);
}

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

.nowrap {
  white-space: nowrap;
}

.accent {
  color: var(--accent);
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: -4rem;
  z-index: 20;
  padding: 0.75rem 1rem;
  background: var(--text);
  color: var(--bg);
  border-radius: 10px;
}

.skip-link:focus {
  top: 1rem;
}

/* Pill buttons */

.pill-button {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  min-height: 3rem;
  padding: 0.375rem 0.375rem 0.375rem 1.375rem;
  border: 0;
  border-radius: 999px;
  background: var(--action);
  color: var(--on-action);
  font: inherit;
  font-size: 0.9375rem;
  font-weight: 600;
  white-space: nowrap;
  text-decoration: none;
  cursor: pointer;
  box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.12) inset, 0 8px 24px -8px rgba(46, 91, 255, 0.6);
  transition: background-color 150ms ease;
}

.pill-button:hover {
  background: var(--action-hover);
}

.pill-button:disabled {
  opacity: 0.6;
  cursor: progress;
}

.pill-button__arrow {
  display: inline-grid;
  place-items: center;
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.18);
}

.pill-button__arrow svg {
  width: 1rem;
  height: 1rem;
}

.pill-button--light {
  min-height: 2.75rem;
  background: var(--light-pill);
  color: var(--on-light-pill);
  box-shadow: none;
}

.pill-button--light:hover {
  background: var(--light-pill);
  opacity: 0.9;
}

.pill-button--light .pill-button__arrow {
  width: 2rem;
  height: 2rem;
  background: var(--action);
  color: #FFFFFF;
}

/* Header */

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  background: color-mix(in srgb, var(--bg) 72%, transparent);
  border-bottom: 1px solid var(--card-border);
}

.site-header__inner {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  min-height: 4.5rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.625rem;
  margin-right: auto;
  text-decoration: none;
}

.brand__mark {
  width: 2.125rem;
  height: 2.125rem;
  border-radius: 8px;
  outline: 1px solid var(--card-border);
  outline-offset: -1px;
}

.brand__word {
  font-size: 1.3125rem;
  letter-spacing: -0.045em;
  line-height: 1;
}

.brand__stack {
  font-weight: 700;
}

.brand__prep {
  font-weight: 300;
}

.site-nav {
  display: flex;
  gap: 1.75rem;
}

.site-nav a {
  color: var(--muted);
  font-size: 0.9375rem;
  text-decoration: none;
}

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

.site-header__actions {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  margin-left: auto;
}

.theme-toggle {
  display: inline-grid;
  place-items: center;
  width: 2.75rem;
  height: 2.75rem;
  padding: 0;
  border: 1px solid var(--card-border);
  border-radius: 50%;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
}

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

.theme-toggle:hover {
  color: var(--text);
}

.theme-toggle svg {
  width: 1.125rem;
  height: 1.125rem;
}

.theme-toggle[aria-pressed="true"] .icon-moon,
.theme-toggle[aria-pressed="false"] .icon-sun {
  display: none;
}

/* Hero */

.hero {
  padding-block: clamp(4rem, 2rem + 8vw, 9rem) clamp(3rem, 2rem + 4vw, 6rem);
}

.hero__copy {
  display: flex;
  flex-direction: column;
  align-items: center;
  max-width: 50rem;
  margin-inline: auto;
  text-align: center;
}

.hero h1 {
  font-size: clamp(2.5rem, 1.2rem + 4.6vw, 4.75rem);
  font-weight: 500;
  letter-spacing: -0.05em;
  line-height: 1.04;
  text-wrap: balance;
}

.hero h1 .accent {
  display: block;
}

.hero__lead {
  margin-top: 1.5rem;
  max-width: 36rem;
  color: var(--muted);
  font-size: 1.1875rem;
}

.hero__actions {
  margin-top: 2.25rem;
}

.proof {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 0.875rem;
  margin-top: 2rem;
  color: var(--muted);
  font-size: 0.9375rem;
}

.proof strong {
  color: var(--text);
  font-weight: 600;
}

.proof__avatars {
  display: flex;
  margin: 0;
  padding: 0;
  list-style: none;
}

.proof__avatars li {
  display: grid;
  place-items: center;
  width: 2.5rem;
  height: 2.5rem;
  margin-left: -0.5rem;
  border: 2px solid var(--bg);
  border-radius: 50%;
  background: linear-gradient(145deg, #3D6BFF, #2440B8);
  color: #FFFFFF;
  font-size: 0.625rem;
  font-weight: 700;
  letter-spacing: 0.01em;
}

.proof__avatars li:first-child {
  margin-left: 0;
}

.proof__avatars li:nth-child(2) { background: linear-gradient(145deg, #5B7CFF, #3048C8); }
.proof__avatars li:nth-child(3) { background: linear-gradient(145deg, #7A93FF, #3D5AD6); }
.proof__avatars li:nth-child(4) { background: linear-gradient(145deg, #4B5BD0, #1E2F8F); }
.proof__avatars li:nth-child(5) { background: linear-gradient(145deg, #FF5C73, #C8102E); }

/* Product mockups */

.mock {
  margin: 0;
  border: 1px solid var(--card-border);
  border-radius: 18px;
  background: linear-gradient(180deg, var(--card-top), var(--card));
  box-shadow: var(--shadow);
  overflow: hidden;
}

.mock__bar {
  display: flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--inset-border);
}

.mock__bar span {
  width: 0.625rem;
  height: 0.625rem;
  border-radius: 50%;
  background: var(--track);
}

.mock__bar span:nth-child(1) { background: #FF5F57; }
.mock__bar span:nth-child(2) { background: #FEBC2E; }
.mock__bar span:nth-child(3) { background: #28C840; }

.mock__bar p {
  flex: 1;
  margin-right: 2.25rem;
  color: var(--muted);
  font-size: 0.8125rem;
  text-align: center;
}

.topics {
  display: grid;
  gap: 0.625rem;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 0.875rem;
}

.topics li {
  display: grid;
  grid-template-columns: minmax(0, 10rem) minmax(0, 1fr) 4.25rem;
  align-items: center;
  gap: 0.875rem;
}

.topics li > span:first-child {
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}

.topics--small {
  padding: 1rem;
  font-size: 0.8125rem;
}

.topics--small li {
  grid-template-columns: 5.5rem minmax(0, 1fr);
}

.bar {
  position: relative;
  height: 0.4375rem;
  border-radius: 99px;
  background: var(--track);
  overflow: hidden;
}

.bar__fill {
  position: absolute;
  inset: 0 auto 0 0;
  border-radius: inherit;
  background: linear-gradient(90deg, #2E5BFF, #7A93FF);
}

.bar__fill--90 { width: 90%; }
.bar__fill--80 { width: 80%; }
.bar__fill--55 { width: 55%; }
.bar__fill--30 { width: 30%; }
.bar__fill--mid { background: var(--mid); }
.bar__fill--open { background: #FF3D57; }

.files,
.plan {
  display: grid;
  gap: 0.5rem;
  margin: 0;
  padding: 1rem;
  list-style: none;
  font-size: 0.8125rem;
}

.files li,
.plan li {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  padding: 0.5rem 0.625rem;
  border: 1px solid var(--inset-border);
  border-radius: 10px;
  background: var(--inset);
  min-width: 0;
}

.files__type {
  flex: none;
  padding: 0.125rem 0.375rem;
  border-radius: 5px;
  background: var(--action);
  color: #FFFFFF;
  font-size: 0.625rem;
  font-weight: 700;
}

.files__ok {
  margin-left: auto;
  color: var(--ok);
  font-weight: 700;
}

.plan li {
  justify-content: space-between;
}

.plan li span {
  flex: none;
  color: var(--muted);
}

/* Sections */

.section {
  padding-block: clamp(4rem, 3rem + 4vw, 7rem);
}

.section__title {
  max-width: 22ch;
  margin-inline: auto;
  font-size: clamp(2rem, 1.3rem + 2.6vw, 3.25rem);
  font-weight: 500;
  letter-spacing: -0.045em;
  line-height: 1.1;
  text-align: center;
  text-wrap: balance;
}

.section__lead {
  max-width: 36rem;
  margin: 1rem auto 0;
  color: var(--muted);
  font-size: 1.125rem;
  text-align: center;
}

.grid {
  display: grid;
  gap: 1.25rem;
  margin: clamp(2.5rem, 2rem + 2vw, 4rem) 0 0;
  padding: 0;
  list-style: none;
}

.grid--2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.grid--3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

/* Cards */

.card {
  position: relative;
  padding: clamp(1.5rem, 1rem + 2vw, 2.5rem);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-card);
  background: linear-gradient(180deg, var(--card-top), var(--card) 40%);
  box-shadow: var(--shadow);
}

.card h3 {
  font-size: clamp(1.25rem, 1.1rem + 0.5vw, 1.5rem);
  font-weight: 500;
  letter-spacing: -0.03em;
  line-height: 1.2;
}

.card p {
  margin-top: 0.75rem;
  color: var(--muted);
}

.card__icon {
  width: 2.25rem;
  height: 2.25rem;
  margin-bottom: 1.5rem;
  padding: 0.5rem;
  border-radius: 50%;
}

.card__icon--problem {
  background: var(--wrong-soft);
  color: var(--wrong);
}

/* Steps — a real sequence, so the order is numbered */

.steps {
  counter-reset: step;
}

.card--step {
  counter-increment: step;
  padding: 0.75rem 0.75rem clamp(1.5rem, 1rem + 1.5vw, 2rem);
}

.card--step .mock {
  margin-bottom: 1.5rem;
  box-shadow: none;
}

.card--step h3,
.card--step p {
  padding-inline: 0.75rem;
}

.card--step h3::before {
  content: counter(step) ". ";
}

/* GitHub materials */

.files__type--github {
  display: inline-grid;
  place-items: center;
  width: 1.75rem;
  padding: 0.1875rem 0;
  background: var(--text);
  color: var(--bg);
}

.files__type--github svg {
  width: 0.75rem;
  height: 0.75rem;
}

.files__verified {
  margin-left: auto;
  padding: 0.0625rem 0.5rem;
  border-radius: 999px;
  background: color-mix(in srgb, #28C840 18%, transparent);
  color: var(--verified);
  font-size: 0.6875rem;
  font-weight: 700;
}

.practice {
  display: grid;
  gap: 0.625rem;
  padding: 1rem;
}

.practice .plan {
  padding: 0;
}

.practice__source {
  display: flex;
  align-items: center;
  gap: 0.4375rem;
  font-size: 0.8125rem;
  font-weight: 600;
}

.practice__source svg {
  width: 0.875rem;
  height: 0.875rem;
}

.practice__source span {
  color: var(--muted);
  font-weight: 400;
}

.practice__note {
  color: var(--verified);
  font-size: 0.75rem;
  font-weight: 600;
}

.repo {
  display: grid;
  grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
  gap: clamp(1.5rem, 1rem + 3vw, 3.5rem);
  margin-top: 1.25rem;
  background:
    radial-gradient(28rem 14rem at 0% 0%, var(--glow), transparent 70%),
    linear-gradient(180deg, var(--card-top), var(--card) 40%);
}

.repo__head {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.repo__logo {
  flex: none;
  width: 3rem;
  height: 3rem;
  padding: 0.625rem;
  border: 1px solid var(--inset-border);
  border-radius: 14px;
  background: var(--inset);
}

.card .repo__path {
  margin-top: 0.25rem;
  font-size: 0.875rem;
}

.card .repo__text {
  margin-top: 1.25rem;
  max-width: 36rem;
}

.repo__badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 1.5rem 0 0;
  padding: 0;
  list-style: none;
}

.repo__badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4375rem 0.875rem 0.4375rem 0.625rem;
  border: 1px solid var(--inset-border);
  border-radius: 999px;
  background: var(--inset);
  font-size: 0.875rem;
  font-weight: 500;
}

.repo__badge svg {
  width: 1.125rem;
  height: 1.125rem;
  color: var(--accent);
}

.repo__badge--verified {
  border-color: color-mix(in srgb, #28C840 40%, transparent);
  background: color-mix(in srgb, #28C840 12%, transparent);
}

.repo__badge--verified svg {
  color: var(--verified);
}

.repo__side {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 1.5rem;
}

.repo__stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.75rem;
  margin: 0;
}

.repo__stats > div {
  padding: 1rem 1.125rem;
  border: 1px solid var(--inset-border);
  border-radius: 16px;
  background: var(--inset);
}

.repo__stats dt {
  display: flex;
  align-items: center;
  gap: 0.4375rem;
  color: var(--muted);
  font-size: 0.8125rem;
}

.repo__stats dt svg {
  width: 0.9375rem;
  height: 0.9375rem;
}

.repo__stats dt .repo__star {
  color: #E3B341;
}

.repo__stats dd {
  margin: 0.375rem 0 0;
  font-size: 2rem;
  font-weight: 500;
  letter-spacing: -0.04em;
  line-height: 1;
}

.repo__actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem 1.25rem;
}

.repo__button {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  min-height: 2.75rem;
  padding: 0.5rem 1.125rem;
  border: 1px solid var(--card-border);
  border-radius: 999px;
  background: var(--light-pill);
  color: var(--on-light-pill);
  font-size: 0.9375rem;
  font-weight: 600;
  text-decoration: none;
}

.repo__button:hover {
  opacity: 0.9;
}

.repo__button svg {
  width: 1rem;
  height: 1rem;
  color: #E3B341;
}

.repo__link {
  color: var(--muted);
  font-size: 0.9375rem;
  text-underline-offset: 0.25em;
}

.repo__link:hover {
  color: var(--text);
}

/* Waitlist */

.signup {
  max-width: 44rem;
  margin-inline: auto;
  padding: clamp(2rem, 1rem + 4vw, 4rem) clamp(1.25rem, 0.5rem + 4vw, 4rem);
  border: 1px solid var(--card-border);
  border-radius: 28px;
  background:
    radial-gradient(30rem 16rem at 50% 0%, var(--glow), transparent 70%),
    linear-gradient(180deg, var(--card-top), var(--card) 50%);
  box-shadow: var(--shadow);
}

.waitlist {
  display: grid;
  gap: 0.875rem;
  max-width: 32rem;
  margin: 2rem auto 0;
}

.waitlist__field {
  display: flex;
  gap: 0.5rem;
  padding: 0.375rem;
  border: 1px solid var(--card-border);
  border-radius: 999px;
  background: var(--inset);
}

.waitlist__field:focus-within {
  border-color: var(--focus);
}

.waitlist input[type="email"] {
  flex: 1;
  min-width: 0;
  min-height: 3rem;
  padding: 0 1rem;
  border: 0;
  border-radius: 999px;
  background: transparent;
  color: var(--text);
  font: inherit;
}

.waitlist input[type="email"]::placeholder {
  color: var(--muted);
}

.waitlist input[type="email"]:focus-visible {
  outline: none;
}

.waitlist__field:has([aria-invalid="true"]) {
  border-color: var(--wrong);
}

.check {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.625rem;
  align-items: start;
  color: var(--muted);
  font-size: 0.875rem;
  line-height: 1.5;
  cursor: pointer;
}

.check input {
  width: 1.125rem;
  height: 1.125rem;
  margin: 0.1rem 0 0;
  accent-color: var(--action);
}

.check:has([aria-invalid="true"]) {
  color: var(--wrong);
}

.hp {
  position: absolute;
  left: -10000px;
  width: 1px;
  height: 1px;
  overflow: hidden;
}

.form-status {
  min-height: 1.5em;
  font-size: 0.875rem;
  font-weight: 500;
}

.form-status[data-state="success"] { color: var(--ok); }
.form-status[data-state="error"],
.form-status[data-state="invalid"] { color: var(--wrong); }
.form-status[data-state="pending"] { color: var(--muted); }

/* Footer */

.site-footer {
  padding-block: 2rem;
  border-top: 1px solid var(--card-border);
  color: var(--muted);
  font-size: 0.875rem;
}

.site-footer__inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 1rem;
}

.site-footer ul {
  display: flex;
  gap: 1.5rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

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

/* Legal pages */

.legal {
  padding-block: clamp(3rem, 2rem + 4vw, 6rem);
}

.legal h1 {
  margin-bottom: 2rem;
  font-size: clamp(2rem, 1.4rem + 2.4vw, 3.25rem);
  font-weight: 500;
  letter-spacing: -0.045em;
  line-height: 1.05;
}

.legal h2 {
  margin: 2.5rem 0 0.75rem;
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.legal p {
  max-width: 42rem;
  color: var(--muted);
}

.legal p + p {
  margin-top: 0.75rem;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .pill-button { transition: none; }
}

/* Responsive */

@media (max-width: 960px) {
  .repo,
  .grid--3 {
    grid-template-columns: minmax(0, 1fr);
  }

  .site-nav {
    display: none;
  }
}

@media (max-width: 760px) {
  .grid--2 {
    grid-template-columns: minmax(0, 1fr);
  }
}

@media (max-width: 520px) {
  .site-header__inner {
    gap: 0.75rem;
  }

  .site-header .pill-button--light {
    padding-right: 1.125rem;
  }

  .site-header .pill-button--light .pill-button__arrow {
    display: none;
  }

  .waitlist__field {
    flex-direction: column;
    border-radius: 20px;
  }

  .waitlist__field .pill-button {
    justify-content: space-between;
  }

  .topics--small li {
    grid-template-columns: 5rem minmax(0, 1fr);
  }
}