/* signalk.it v1 coming-soon page
 * --------------------------------
 * Single light theme. Restrained color (one warm-amber accent).
 * Editorial typography: Source Serif 4 display + Inter body, both
 * self-hosted under /fonts/ to honor the no-third-party-trackers promise.
 * No build step. No framework. One stylesheet.
 *
 * Pre-launch follow-ups still open: favicon, OG image, robots.txt,
 * sitemap.xml. Tracked in DESIGN.md.
 */

/* -------- 0. Self-hosted fonts (Latin subset only) --------
 *
 * Variable woff2 files for the Latin subset, served from the same origin
 * so the strict CSP (font-src 'self') admits them. Both files cover the
 * full weight axis of their family — separate font-weight @font-face
 * blocks are not needed.
 *
 * The unicode-range matches Google Fonts' "latin" subset so the browser
 * skips the request entirely if the page only contains glyphs outside
 * this range.
 */

@font-face {
  font-family: 'Inter';
  src: url('/fonts/inter-latin.woff2') format('woff2');
  font-weight: 100 900;
  font-style: normal;
  font-display: swap;
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6,
                 U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F,
                 U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF,
                 U+FFFD;
}

@font-face {
  font-family: 'Source Serif 4';
  src: url('/fonts/source-serif-4-latin.woff2') format('woff2');
  font-weight: 200 900;
  font-style: normal;
  font-display: swap;
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6,
                 U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F,
                 U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF,
                 U+FFFD;
}

/* -------- 1. Tokens -------- */

:root {
  /* Color (OKLCH, warm-tinted neutrals + amber accent). */
  --ink:           oklch(0.18  0.010  65);
  --ink-soft:      oklch(0.36  0.008  65);
  --ink-faint:     oklch(0.55  0.006  65);
  --surface:       oklch(0.985 0.005  70);
  --surface-sunk:  oklch(0.965 0.006  70);
  --rule:          oklch(0.90  0.010  65);
  --accent:        oklch(0.62  0.16   60);
  --accent-strong: oklch(0.50  0.18   55);
  --accent-faint:  oklch(0.94  0.04   70);

  /* Typography. */
  --font-display: "Source Serif 4", "Source Serif Pro", "Iowan Old Style",
                  Charter, Georgia, "Times New Roman", serif;
  --font-body:    "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI",
                  Roboto, "Helvetica Neue", Arial, system-ui, sans-serif;

  /* Modular scale, base 17px, ratio ≈ 1.25. */
  --text-xs:   0.75rem;
  --text-sm:   0.875rem;
  --text-base: 1rem;
  --text-lg:   1.25rem;
  --text-xl:   1.5rem;
  --text-2xl:  1.875rem;
  --text-3xl:  2.5rem;
  --text-hero: clamp(2.5rem, 1.6rem + 4.4vw, 3.75rem);

  /* Space, 8px base. */
  --space-2xs: 0.25rem;
  --space-xs:  0.5rem;
  --space-sm:  1rem;
  --space-md:  1.5rem;
  --space-lg:  2rem;
  --space-xl:  4rem;
  --space-2xl: 6rem;

  /* Motion. */
  --ease-out-quart: cubic-bezier(0.22, 1, 0.36, 1);
  --duration-quick: 150ms;
  --duration-fade:  240ms;
}

/* -------- 2. Reset / base -------- */

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

html {
  font-size: 17px;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  block-size: 100%;
}

body {
  margin: 0;
  min-block-size: 100vh;
  min-block-size: 100dvh;
  background: var(--surface);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: 1.6;
  font-feature-settings: "ss01", "cv11";
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  animation: fade-in var(--duration-fade) var(--ease-out-quart) backwards;
}

@keyframes fade-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  body { animation: none; }
  *, *::before, *::after {
    animation-duration: 1ms !important;
    transition-duration: 1ms !important;
  }
}

::selection {
  background: var(--accent-faint);
  color: var(--ink);
}

/* -------- 3. Skip link (visible only on focus) -------- */

.skip-link {
  position: absolute;
  inset-block-start: var(--space-xs);
  inset-inline-start: var(--space-xs);
  padding: var(--space-xs) var(--space-sm);
  background: var(--ink);
  color: var(--surface);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 500;
  text-decoration: none;
  border-radius: 0;
  transform: translateY(calc(-100% - var(--space-sm)));
  transition: transform var(--duration-quick) var(--ease-out-quart);
  z-index: 50;
}

.skip-link:focus {
  transform: translateY(0);
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* -------- 4. Page frame -------- */

.page {
  min-block-size: 100vh;
  min-block-size: 100dvh;
  display: grid;
  grid-template-rows: minmax(var(--space-2xl), 0.85fr) auto minmax(var(--space-md), 1fr);
  grid-template-columns:
    minmax(0, 1fr)
    min(640px, 100% - 2 * var(--space-md))
    minmax(0, 1fr);
  align-items: start;
  overflow-x: clip;
}

.page > * {
  grid-column: 2;
  min-inline-size: 0;
}

/* -------- 5. Hero block -------- */

.hero {
  grid-row: 2;
  display: grid;
}

.hero > * { margin: 0; }
.hero > * + * { margin-block-start: var(--space-md); }

.wordmark {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 500;
  line-height: 1;
  letter-spacing: -0.012em;
  color: var(--ink);
  font-feature-settings: "kern", "liga";
}

.wordmark a {
  color: inherit;
  text-decoration: none;
}

.wordmark a:hover,
.wordmark a:focus-visible {
  color: var(--accent-strong);
  outline: none;
}

.tag {
  margin-block-start: var(--space-xl) !important; /* 64px from wordmark */
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-soft);
  display: inline-flex;
  align-items: baseline;
  gap: 0.7em;
  line-height: 1.2;
}

.tag__mark {
  display: inline-block;
  inline-size: 0.5em;
  block-size: 0.5em;
  background: var(--ink);
  transform: translateY(-0.05em);
  flex: none;
}

.headline {
  margin-block-start: var(--space-sm) !important; /* 16px under tag */
  font-family: var(--font-display);
  font-size: var(--text-hero);
  font-weight: 600;
  line-height: 1.04;
  letter-spacing: -0.022em;
  color: var(--ink);
  text-wrap: balance;
  overflow-wrap: break-word;
  hyphens: manual;
  font-feature-settings: "kern", "liga", "ss01";
}

.lede {
  margin-block-start: var(--space-lg) !important; /* 32px under headline */
  font-family: var(--font-body);
  font-size: var(--text-lg);
  font-weight: 400;
  line-height: 1.5;
  color: var(--ink-soft);
  max-inline-size: 50ch;
  text-wrap: pretty;
}

/* -------- 6. Signup form -------- */

.signup {
  margin-block-start: var(--space-xl) !important; /* 48px under lede */
}

@media (min-width: 640px) {
  .signup {
    margin-block-start: 3rem !important;
  }
}

.signup__row {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
  align-items: stretch;
}

.signup__label {
  position: absolute;
  inline-size: 1px;
  block-size: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Honeypot — visible to bots, invisible to humans and assistive tech.
 * Off-screen positioning + zero opacity + pointer-events:none + tabindex
 * -1 (set in HTML) keeps it out of the human flow entirely. */
.signup__honeypot {
  position: absolute;
  left: -9999px;
  inline-size: 1px;
  block-size: 1px;
  opacity: 0;
  pointer-events: none;
}

.signup__input {
  flex: 1 1 auto;
  min-inline-size: 0;
  font-family: inherit;
  font-size: var(--text-base);
  font-weight: 400;
  line-height: 1.4;
  padding: 0.85rem 1rem;
  background: var(--surface);
  color: var(--ink);
  border: 1px solid var(--rule);
  border-radius: 0;
  appearance: none;
  transition: border-color var(--duration-quick) var(--ease-out-quart),
              box-shadow var(--duration-quick) var(--ease-out-quart);
}

.signup__input::placeholder {
  color: var(--ink-faint);
  opacity: 1;
}

.signup__input:hover {
  border-color: var(--ink-faint);
}

.signup__input:focus-visible {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-faint);
}

.signup__input[aria-invalid="true"] {
  border-color: var(--accent-strong);
}

.signup__submit {
  flex: 0 0 auto;
  font-family: inherit;
  font-size: var(--text-base);
  font-weight: 500;
  line-height: 1.4;
  padding: 0.85rem 1.6rem;
  background: var(--ink);
  color: var(--surface);
  border: 1px solid var(--ink);
  border-radius: 0;
  cursor: pointer;
  white-space: nowrap;
  transition: background-color var(--duration-quick) var(--ease-out-quart),
              border-color var(--duration-quick) var(--ease-out-quart),
              color var(--duration-quick) var(--ease-out-quart);
}

.signup__submit:hover {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--surface);
}

.signup__submit:focus-visible {
  outline: none;
  background: var(--accent);
  border-color: var(--accent);
  color: var(--surface);
  box-shadow: 0 0 0 3px var(--accent-faint);
}

.signup__submit:active {
  background: var(--accent-strong);
  border-color: var(--accent-strong);
}

.signup__submit:disabled {
  cursor: not-allowed;
}

.signup__submit-pending { display: none; }

.signup--submitting .signup__submit-label { display: none; }
.signup--submitting .signup__submit-pending {
  display: inline-block;
  letter-spacing: 0.05em;
}
.signup--submitting .signup__submit { background: var(--ink-soft); border-color: var(--ink-soft); }
.signup--submitting .signup__input { color: var(--ink-faint); }

.signup__helper {
  margin-block-start: var(--space-sm);
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 400;
  letter-spacing: 0.005em;
  color: var(--ink-soft);
}

.signup__helper--noscript {
  color: var(--accent-strong);
}

.signup__error {
  margin-block-start: var(--space-xs);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  color: var(--accent-strong);
}

.signup__confirmation {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 500;
  line-height: 1.4;
  color: var(--ink);
}

@media (min-width: 640px) {
  .signup__row {
    flex-direction: row;
    align-items: stretch;
    gap: 0;
  }

  .signup__input {
    border-inline-end: 0;
  }

  .signup__input:focus-visible {
    border-inline-end: 1px solid var(--accent);
  }
}

/* -------- 7. Colophon (footer) -------- */

.colophon {
  grid-row: 3;
  align-self: end;
  padding-block-end: var(--space-md);
  text-align: center;
  font-family: var(--font-body);
  font-size: var(--text-xs);
  color: var(--ink-faint);
}

.colophon__line {
  margin: 0;
  display: inline-flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: baseline;
  column-gap: 0.6em;
  row-gap: var(--space-2xs);
  letter-spacing: 0.005em;
}

.colophon__cell { white-space: nowrap; }

.colophon__sep {
  color: var(--ink-faint);
  user-select: none;
}

.colophon__link {
  color: var(--ink-faint);
  text-decoration: none;
  border-block-end: 1px solid transparent;
  transition: color var(--duration-quick) var(--ease-out-quart),
              border-color var(--duration-quick) var(--ease-out-quart);
}

.colophon__link:hover,
.colophon__link:focus-visible {
  color: var(--ink);
  border-block-end-color: var(--ink);
  outline: none;
}

/* -------- 8. Mobile compositional adjustments -------- */

@media (max-width: 480px) {
  :root {
    --text-hero: clamp(1.875rem, 1.1rem + 4.4vw, 2.375rem);
  }
  .page {
    grid-template-rows: minmax(var(--space-xl), 0.7fr) auto minmax(var(--space-sm), 0.7fr);
    grid-template-columns: var(--space-md) minmax(0, 1fr) var(--space-md);
  }
  .hero > .tag { margin-block-start: var(--space-lg) !important; }
  .signup { margin-block-start: var(--space-lg) !important; }
}

/* -------- 9. Forced-colors / high-contrast (Windows etc.) -------- */

@media (forced-colors: active) {
  .signup__input { border-color: CanvasText; }
  .signup__submit {
    background: ButtonFace;
    color: ButtonText;
    border-color: ButtonText;
  }
  .tag__mark { background: CanvasText; }
}