/* ==========================================================================
   Acme landing page — layout & typography
   Single stylesheet, mobile-first, no external deps.
   ========================================================================== */

/* Design tokens ------------------------------------------------------- */
:root {
  /* Color */
  --color-bg: #ffffff;
  --color-bg-soft: #f6f8fb;
  --color-bg-dark: #0b1726;
  --color-text: #0b1726;
  --color-text-soft: #4a5b73;
  --color-text-on-dark: #f6f8fb;
  --color-border: #e2e8f0;
  --color-accent: #2563eb;
  --color-accent-hover: #1d4ed8;
  --color-accent-contrast: #ffffff;

  /* Type */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, "Noto Sans", sans-serif,
    "Apple Color Emoji", "Segoe UI Emoji";
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --fs-xs: 0.8125rem;
  --fs-sm: 0.9375rem;
  --fs-base: 1rem;
  --fs-md: 1.125rem;
  --fs-lg: 1.375rem;
  --fs-xl: 1.75rem;
  --fs-2xl: 2.25rem;
  --fs-3xl: 3rem;

  /* Spacing scale (4px base) */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.5rem;
  --space-6: 2rem;
  --space-7: 3rem;
  --space-8: 4rem;
  --space-9: 6rem;

  /* Layout */
  --container-max: 1120px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;

  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 6px 24px rgba(15, 23, 42, 0.08);
}

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

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

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

h1,
h2,
h3 {
  margin: 0 0 var(--space-4);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--color-text);
}

h1 {
  font-size: var(--fs-2xl);
}

h2 {
  font-size: var(--fs-xl);
}

h3 {
  font-size: var(--fs-lg);
}

p {
  margin: 0 0 var(--space-4);
}

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

a:hover,
a:focus-visible {
  text-decoration: underline;
}

ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

/* Accessibility -------------------------------------------------------- */
.skip-link {
  position: absolute;
  left: -9999px;
  top: var(--space-2);
  background: var(--color-accent);
  color: var(--color-accent-contrast);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-sm);
  z-index: 1000;
}

.skip-link:focus {
  left: var(--space-2);
  outline: 3px solid #ffd166;
  outline-offset: 2px;
}

:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 2px;
  border-radius: 2px;
}

/* Layout primitives --------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-5);
}

/* Site header --------------------------------------------------------- */
.site-header {
  background-color: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: saturate(180%) blur(8px);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding: var(--space-4) var(--space-5);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-weight: 700;
  font-size: var(--fs-md);
  color: var(--color-text);
  text-decoration: none;
}

.brand:hover,
.brand:focus-visible {
  text-decoration: none;
}

.brand__name {
  letter-spacing: -0.01em;
}

.site-nav ul {
  display: flex;
  gap: var(--space-5);
}

.site-nav a {
  color: var(--color-text-soft);
  font-size: var(--fs-sm);
  font-weight: 500;
}

.site-nav a:hover,
.site-nav a:focus-visible {
  color: var(--color-text);
  text-decoration: none;
}

/* Hero ---------------------------------------------------------------- */
.hero {
  background: linear-gradient(180deg, var(--color-bg-soft) 0%, var(--color-bg) 100%);
  padding: var(--space-9) 0 var(--space-8);
}

.hero__inner {
  max-width: 720px;
  text-align: center;
}

.hero__eyebrow {
  display: inline-block;
  font-size: var(--fs-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-accent);
  background: rgba(37, 99, 235, 0.08);
  padding: var(--space-1) var(--space-3);
  border-radius: 999px;
  margin: 0 0 var(--space-4);
}

.hero__title {
  font-size: var(--fs-2xl);
  margin-bottom: var(--space-4);
}

.hero__subhead {
  font-size: var(--fs-md);
  color: var(--color-text-soft);
  margin-bottom: var(--space-6);
  max-width: 56ch;
  margin-left: auto;
  margin-right: auto;
}

.hero__cta {
  display: flex;
  gap: var(--space-3);
  justify-content: center;
  flex-wrap: wrap;
}

/* Buttons ------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-5);
  border-radius: var(--radius-sm);
  font-size: var(--fs-sm);
  font-weight: 600;
  line-height: 1.2;
  text-decoration: none;
  cursor: pointer;
  border: 1px solid transparent;
  transition: background-color 120ms ease, color 120ms ease,
    border-color 120ms ease, transform 120ms ease;
}

.btn:hover,
.btn:focus-visible {
  text-decoration: none;
  transform: translateY(-1px);
}

.btn--primary {
  background-color: var(--color-accent);
  color: var(--color-accent-contrast);
}

.btn--primary:hover,
.btn--primary:focus-visible {
  background-color: var(--color-accent-hover);
  color: var(--color-accent-contrast);
}

.btn--ghost {
  background-color: transparent;
  color: var(--color-text);
  border-color: var(--color-border);
}

.btn--ghost:hover,
.btn--ghost:focus-visible {
  background-color: var(--color-bg-soft);
  color: var(--color-text);
}

/* Features ------------------------------------------------------------ */
.features {
  padding: var(--space-8) 0;
}

.features__header {
  max-width: 720px;
  margin: 0 auto var(--space-7);
  text-align: center;
}

.features__lede {
  font-size: var(--fs-md);
  color: var(--color-text-soft);
  margin-bottom: 0;
}

.feature-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-5);
}

.feature {
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-6);
  box-shadow: var(--shadow-sm);
  transition: box-shadow 200ms ease, transform 200ms ease,
    border-color 200ms ease;
}

.feature:hover {
  box-shadow: var(--shadow-md);
  border-color: #cbd5e1;
  transform: translateY(-2px);
}

.feature__icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  background: rgba(37, 99, 235, 0.08);
  margin-bottom: var(--space-4);
}

.feature__title {
  font-size: var(--fs-lg);
  margin-bottom: var(--space-2);
}

.feature__body {
  margin: 0;
  color: var(--color-text-soft);
  font-size: var(--fs-sm);
}

/* Contact section ---------------------------------------------------- */
.contact {
  padding: var(--space-8) 0;
  background-color: var(--color-bg-soft);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.contact__inner {
  max-width: 640px;
  margin-inline: auto;
  text-align: left;
}

.contact__inner > h2,
.contact__lede {
  text-align: center;
}

.contact__lede {
  color: var(--color-text-soft);
  margin: 0 0 var(--space-6);
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
  background-color: var(--color-bg);
  padding: var(--space-6);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
}

.contact-form__row {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.contact-form__actions {
  display: flex;
  justify-content: flex-end;
  margin-top: var(--space-2);
}

.contact-form__status {
  margin: 0;
  min-height: 1.4em;
  font-size: var(--fs-sm);
  color: var(--color-text-soft);
}

.contact-form__status[data-state="error"] {
  color: #b91c1c;
}

.contact-form__confirmation {
  margin-top: var(--space-5);
  padding: var(--space-5) var(--space-6);
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-accent);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  text-align: left;
}

.contact-form__confirmation[hidden] {
  display: none;
}

.contact-form__confirmation-title {
  margin: 0 0 var(--space-2);
  font-size: var(--fs-lg);
  color: var(--color-text);
}

.contact-form__confirmation-body {
  margin: 0;
  color: var(--color-text-soft);
}

/* Field (label + input + error) ------------------------------------- */
.field {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.field__label {
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--color-text);
}

.field__input {
  font: inherit;
  color: var(--color-text);
  background-color: var(--color-bg);
  padding: var(--space-3) var(--space-4);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  width: 100%;
  transition: border-color 120ms ease, box-shadow 120ms ease;
}

.field__input:hover {
  border-color: #cbd5e1;
}

.field__input:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.25);
}

.field__input--textarea {
  resize: vertical;
  min-height: 7rem;
  font-family: inherit;
}

.field[data-invalid="true"] .field__input {
  border-color: #b91c1c;
}

.field[data-invalid="true"] .field__input:focus {
  box-shadow: 0 0 0 3px rgba(185, 28, 28, 0.2);
}

.field__error {
  color: #b91c1c;
  font-size: var(--fs-sm);
}

.field__error[hidden] {
  display: none;
}

/* Footer -------------------------------------------------------------- */
.site-footer {
  padding: var(--space-6) 0;
  background-color: var(--color-bg-dark);
  color: var(--color-text-on-dark);
  font-size: var(--fs-sm);
}

.site-footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  flex-wrap: wrap;
}

.site-footer p {
  margin: 0;
  color: rgba(246, 248, 251, 0.8);
}

.site-footer__links {
  display: flex;
  gap: var(--space-5);
}

.site-footer__links a {
  color: rgba(246, 248, 251, 0.8);
}

.site-footer__links a:hover,
.site-footer__links a:focus-visible {
  color: var(--color-text-on-dark);
  text-decoration: underline;
}

/* Responsive: tablet --------------------------------------------------- */
@media (min-width: 768px) {
  h1 {
    font-size: var(--fs-3xl);
  }

  h2 {
    font-size: var(--fs-2xl);
  }

  .hero {
    padding: var(--space-9) 0;
  }

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

/* Responsive: desktop -------------------------------------------------- */
@media (min-width: 1024px) {
  .feature-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* Reduced motion ------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    transition-duration: 0.001ms !important;
    animation-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}