/*
 * Flikt site — production stylesheet for the cryptographic-vault aesthetic.
 *
 * This file IS the production version of design-tokens.css (NAS-143 / NAS-145).
 * The styleguide.html spike loads design-tokens.css directly; the three
 * production pages (index, privacy, terms) load this file. They are kept
 * in sync — diff one against the other when changing tokens.
 *
 * The bottom half of this file adds backwards-compatible shims for the
 * legacy class names (.btn, .step, header.site, .legal, .cta-row) so the
 * index/privacy/terms rebuilds can drop in vault-* classes without forcing
 * a full HTML rename pass.
 */

/* ============================================================
 * @font-face — self-hosted WOFF2 subsets (NAS-144, latin only)
 * ============================================================ */
@font-face {
  font-family: "Fraunces";
  src: url("/fonts/Fraunces-Variable.woff2") format("woff2-variations");
  font-weight: 100 900;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "IBM Plex Sans";
  src: url("/fonts/IBMPlexSans-Regular.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "IBM Plex Sans";
  src: url("/fonts/IBMPlexSans-SemiBold.woff2") format("woff2");
  font-weight: 600;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "IBM Plex Mono";
  src: url("/fonts/IBMPlexMono-Regular.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

/* ============================================================
 * Tokens — single accent, three blacks, three papers
 * ============================================================ */
:root {
  color-scheme: dark;

  --vault-ink:        #07070a;
  --vault-ink-2:      #0d0d12;
  --vault-ink-3:      #14141b;
  --vault-paper:      #f3efe6;
  --vault-paper-2:    #c9c2b3;
  --vault-paper-dim:  #8b8576;
  --vault-rule:       #2a2820;
  --vault-rule-soft:  #1a1814;
  --vault-accent:     #c19a4e;
  --vault-accent-dim: #8c6f37;
  --vault-warning:    #d97757;

  --vault-display: "Fraunces", "Cormorant Garamond", "Times New Roman", serif;
  --vault-body:    "IBM Plex Sans", "Helvetica Neue", system-ui, sans-serif;
  --vault-mono:    "IBM Plex Mono", "JetBrains Mono", ui-monospace, Menlo, monospace;

  --vault-step--1: 0.8125rem;
  --vault-step-0:  1rem;
  --vault-step-1:  1.125rem;
  --vault-step-2:  1.5rem;
  --vault-step-3:  2.25rem;
  --vault-step-4:  3.5rem;
  --vault-step-5:  6rem;
  --vault-step-6:  10rem;

  --vault-s-1: 0.25rem;
  --vault-s-2: 0.5rem;
  --vault-s-3: 0.75rem;
  --vault-s-4: 1rem;
  --vault-s-5: 1.5rem;
  --vault-s-6: 2rem;
  --vault-s-7: 3rem;
  --vault-s-8: 4rem;
  --vault-s-9: 6rem;
  --vault-s-10: 8rem;

  --vault-rail:   1.25rem;
  --vault-max:    1280px;
  --vault-prose:  640px;

  --vault-ease-out: cubic-bezier(0.2, 0.7, 0.2, 1);
  --vault-tx-fast:  140ms;
  --vault-tx-mid:   320ms;
  --vault-tx-slow:  640ms;
}

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

html, body {
  margin: 0;
  padding: 0;
  background: var(--vault-ink);
  color: var(--vault-paper);
  font-family: var(--vault-body);
  font-size: var(--vault-step-0);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* Ciphertext-grid background motif. */
body {
  background-image:
    linear-gradient(to right,  rgba(193,154,78,0.04) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(193,154,78,0.04) 1px, transparent 1px);
  background-size: 32px 32px;
}

a {
  color: var(--vault-accent);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--vault-tx-fast) var(--vault-ease-out),
              border-color var(--vault-tx-fast) var(--vault-ease-out);
}
a:hover { border-bottom-color: var(--vault-accent); }
a:focus-visible {
  outline: 2px solid var(--vault-accent);
  outline-offset: 3px;
  border-radius: 2px;
}

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

/* ============================================================
 * Type
 * ============================================================ */
h1, h2, h3 {
  font-family: var(--vault-display);
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--vault-paper);
  margin: 0 0 var(--vault-s-4);
  line-height: 1.05;
  font-variation-settings: "opsz" 144;
}
h1 { font-size: var(--vault-step-4); }
h2 { font-size: var(--vault-step-3); margin-top: var(--vault-s-8); }
h3 { font-size: var(--vault-step-2); margin-top: var(--vault-s-6); }
h4, h5, h6 {
  font-family: var(--vault-body);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-size: var(--vault-step--1);
  color: var(--vault-paper-2);
  margin: var(--vault-s-6) 0 var(--vault-s-2);
}

p {
  margin: 0 0 var(--vault-s-4);
  color: var(--vault-paper-2);
  max-width: 62ch;
}
p strong { color: var(--vault-paper); font-weight: 600; }
em { font-style: italic; color: var(--vault-paper); }

ul, ol {
  color: var(--vault-paper-2);
  padding-left: var(--vault-s-5);
  max-width: 62ch;
}
li { margin-bottom: var(--vault-s-2); }

code, kbd, samp {
  font-family: var(--vault-mono);
  font-size: 0.92em;
  color: var(--vault-accent);
  background: transparent;
  padding: 0;
}
pre {
  font-family: var(--vault-mono);
  font-size: var(--vault-step--1);
  color: var(--vault-paper-2);
  overflow-x: auto;
  padding: var(--vault-s-4);
  border: 1px solid var(--vault-rule);
}

hr {
  border: 0;
  border-top: 1px solid var(--vault-rule);
  margin: var(--vault-s-7) 0;
}

/* ============================================================
 * Vault primitives (preferred for rebuilds)
 * ============================================================ */
.vault-eyebrow {
  font-family: var(--vault-mono);
  font-size: var(--vault-step--1);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--vault-accent);
  margin: 0 0 var(--vault-s-3);
}
.vault-caption {
  font-family: var(--vault-mono);
  font-size: var(--vault-step--1);
  letter-spacing: 0.04em;
  color: var(--vault-paper-dim);
}

.vault-wordmark {
  font-family: var(--vault-display);
  font-weight: 700;
  text-transform: lowercase;
  letter-spacing: -0.04em;
  line-height: 0.85;
  color: var(--vault-paper);
  font-variation-settings: "opsz" 144;
}
.vault-wordmark--sm { font-size: var(--vault-step-3); }
.vault-wordmark--md { font-size: var(--vault-step-4); }
.vault-wordmark--lg { font-size: var(--vault-step-5); }
.vault-wordmark--xl { font-size: var(--vault-step-6); }
.vault-wordmark .dot { color: var(--vault-accent); }

.vault-shell {
  max-width: var(--vault-max);
  margin: 0 auto;
  padding: 0 var(--vault-rail);
}
.vault-shell--prose {
  max-width: calc(var(--vault-prose) + (var(--vault-rail) * 2));
}

.vault-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  padding: var(--vault-s-5) 0;
  border-bottom: 1px solid var(--vault-rule);
}
.vault-header__brand {
  font-family: var(--vault-display);
  font-weight: 700;
  text-transform: lowercase;
  letter-spacing: -0.04em;
  font-size: var(--vault-step-2);
  color: var(--vault-paper);
}
.vault-header__brand .dot { color: var(--vault-accent); }
.vault-nav {
  display: flex;
  gap: var(--vault-s-5);
  font-family: var(--vault-mono);
  font-size: var(--vault-step--1);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  flex-wrap: wrap;
}
.vault-nav a {
  color: var(--vault-paper-2);
  border-bottom: 0;
}
.vault-nav a:hover { color: var(--vault-paper); }

.vault-footer {
  border-top: 1px solid var(--vault-rule);
  padding: var(--vault-s-6) 0;
  margin-top: var(--vault-s-9);
  display: flex;
  flex-wrap: wrap;
  gap: var(--vault-s-4);
  align-items: baseline;
  justify-content: space-between;
  color: var(--vault-paper-dim);
  font-family: var(--vault-mono);
  font-size: var(--vault-step--1);
  letter-spacing: 0.06em;
}
.vault-footer a { color: var(--vault-paper-dim); }
.vault-footer a:hover { color: var(--vault-paper); }

/* ---- Buttons (preferred .vault-btn; legacy .btn shimmed below) -------- */
.vault-btn,
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--vault-s-2);
  padding: 0.875rem 1.5rem;
  font-family: var(--vault-mono);
  font-size: var(--vault-step--1);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--vault-paper);
  background: transparent;
  border: 1px solid var(--vault-paper);
  border-radius: 0;
  cursor: pointer;
  text-decoration: none;
  font-weight: 400;
  transition: background var(--vault-tx-fast) var(--vault-ease-out),
              color var(--vault-tx-fast) var(--vault-ease-out),
              border-color var(--vault-tx-fast) var(--vault-ease-out);
}
.vault-btn:hover,
.btn:hover {
  background: var(--vault-paper);
  color: var(--vault-ink);
  border-color: var(--vault-paper);
  text-decoration: none;
}
.vault-btn:focus-visible,
.btn:focus-visible {
  outline: 2px solid var(--vault-accent);
  outline-offset: 3px;
}
.vault-btn--primary,
.btn:not(.secondary) {
  border-color: var(--vault-accent);
  color: var(--vault-accent);
}
.vault-btn--primary:hover,
.btn:not(.secondary):hover {
  background: var(--vault-accent);
  color: var(--vault-ink);
  border-color: var(--vault-accent);
}
.vault-btn--ghost {
  border-color: var(--vault-rule);
  color: var(--vault-paper-2);
}
.vault-btn--ghost:hover {
  background: transparent;
  color: var(--vault-paper);
  border-color: var(--vault-paper);
}
.vault-btn--small {
  padding: 0.5rem 0.875rem;
  font-size: 0.75rem;
}

/* ---- Hairline block (replaces filled .step card) ---------------------- */
.vault-block {
  border: 1px solid var(--vault-rule);
  padding: var(--vault-s-6);
  position: relative;
  background: transparent;
}
.vault-block__num {
  font-family: var(--vault-mono);
  font-size: var(--vault-step--1);
  letter-spacing: 0.2em;
  color: var(--vault-accent);
  margin: 0 0 var(--vault-s-4);
}
.vault-block__title {
  font-family: var(--vault-display);
  font-size: var(--vault-step-2);
  margin: 0 0 var(--vault-s-2);
  color: var(--vault-paper);
}
.vault-block__body {
  color: var(--vault-paper-2);
  margin: 0;
  font-size: var(--vault-step-0);
}

.vault-hairline {
  border: 0;
  border-top: 1px solid var(--vault-rule);
  margin: 0;
}

/* ---- Ciphertext feed motif ------------------------------------------ */
.vault-feed {
  font-family: var(--vault-mono);
  font-size: var(--vault-step--1);
  line-height: 1.7;
  color: var(--vault-paper-dim);
  overflow: hidden;
  position: relative;
  mask-image: linear-gradient(to bottom, transparent 0, #000 8%, #000 92%, transparent 100%);
  -webkit-mask-image: linear-gradient(to bottom, transparent 0, #000 8%, #000 92%, transparent 100%);
}
.vault-feed__inner {
  animation: vault-feed-crawl 60s linear infinite;
  white-space: nowrap;
}
.vault-feed__line {
  display: block;
  padding: 0;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: clip;
  transition: color var(--vault-tx-mid) var(--vault-ease-out);
}
.vault-feed__line .prefix {
  color: var(--vault-accent);
  padding-right: var(--vault-s-2);
}
.vault-feed__line:hover {
  color: var(--vault-paper);
}
.vault-feed__line:hover .prefix {
  color: var(--vault-paper);
}

@keyframes vault-feed-crawl {
  from { transform: translateY(0); }
  to   { transform: translateY(-50%); }
}

/* ---- Tables ----------------------------------------------------------- */
.vault-table,
.legal table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--vault-mono);
  font-size: var(--vault-step--1);
  margin: var(--vault-s-6) 0;
}
.vault-table th, .vault-table td,
.legal table th, .legal table td {
  text-align: left;
  padding: var(--vault-s-3) var(--vault-s-4);
  border-top: 1px solid var(--vault-rule);
  border-bottom: 1px solid var(--vault-rule);
  vertical-align: top;
}
.vault-table th,
.legal table th {
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--vault-accent);
  font-size: 0.75rem;
}
.vault-table td,
.legal table td { color: var(--vault-paper-2); }
.vault-table tbody tr + tr td,
.vault-table tbody tr + tr th,
.legal table tbody tr + tr td,
.legal table tbody tr + tr th { border-top: 0; }

/* ---- Drop caps for editorial sections -------------------------------- */
.vault-essay > p:first-of-type::first-letter,
.vault-section__body > p:first-of-type::first-letter {
  font-family: var(--vault-display);
  font-weight: 700;
  float: left;
  font-size: 4.5rem;
  line-height: 0.85;
  padding-right: 0.5rem;
  padding-top: 0.4rem;
  color: var(--vault-paper);
  font-variation-settings: "opsz" 144;
}

/* ---- Two-column essay sections (NAS-147/148) ------------------------- */
.vault-section {
  margin: var(--vault-s-8) 0;
}
.vault-section__head {
  margin-bottom: var(--vault-s-4);
}
.vault-section__title {
  font-family: var(--vault-display);
  font-size: var(--vault-step-3);
  color: var(--vault-paper);
  margin: 0 0 var(--vault-s-2);
  letter-spacing: -0.02em;
}
.vault-section__num {
  font-family: var(--vault-mono);
  font-size: var(--vault-step--1);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--vault-accent);
  margin: 0 0 var(--vault-s-2);
}
.vault-section__quote {
  font-family: var(--vault-display);
  font-style: italic;
  font-size: var(--vault-step-1);
  color: var(--vault-paper);
  border-left: 1px solid var(--vault-accent);
  padding-left: var(--vault-s-4);
  margin: var(--vault-s-4) 0;
  max-width: 28ch;
}

@media (min-width: 900px) {
  .vault-section--two-col {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--vault-s-8);
  }
  .vault-section--two-col .vault-section__head {
    margin-bottom: 0;
    position: sticky;
    top: var(--vault-s-6);
    align-self: start;
  }
}

/* ============================================================
 * Legacy shims — keep existing HTML rendering passably until each
 * page is rebuilt (NAS-146/147/148). They look "close to vault" without
 * matching it pixel for pixel. The full layout work happens in those PRs.
 * ============================================================ */

header.site {
  border-bottom: 1px solid var(--vault-rule);
  padding: var(--vault-s-3) 0;
}
header.site .inner {
  max-width: var(--vault-max);
  margin: 0 auto;
  padding: 0 var(--vault-rail);
  display: flex;
  gap: var(--vault-s-5);
  align-items: baseline;
  justify-content: space-between;
}
header.site .brand {
  font-family: var(--vault-display);
  font-weight: 700;
  text-transform: lowercase;
  font-size: var(--vault-step-2);
  letter-spacing: -0.04em;
  color: var(--vault-paper);
}
header.site nav {
  display: flex;
  gap: var(--vault-s-4);
  flex-wrap: wrap;
}
header.site nav a {
  margin-left: 0;
  color: var(--vault-paper-2);
  font-family: var(--vault-mono);
  font-size: var(--vault-step--1);
  letter-spacing: 0.12em;
  text-transform: uppercase;
}
header.site nav a:hover { color: var(--vault-paper); }

main {
  max-width: var(--vault-prose);
  margin: 0 auto;
  padding: var(--vault-s-8) var(--vault-rail);
}

.cta-row {
  display: flex;
  gap: var(--vault-s-3);
  flex-wrap: wrap;
  margin: var(--vault-s-5) 0 var(--vault-s-6);
}

.steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--vault-s-4);
  margin: var(--vault-s-5) 0;
}

.step {
  background: transparent;
  border: 1px solid var(--vault-rule);
  border-radius: 0;
  padding: var(--vault-s-5);
}
.step .n {
  display: block;
  background: transparent;
  color: var(--vault-accent);
  width: auto;
  height: auto;
  text-align: left;
  line-height: 1;
  font-family: var(--vault-mono);
  font-size: var(--vault-step--1);
  letter-spacing: 0.2em;
  font-weight: 400;
  margin: 0 0 var(--vault-s-3);
  border-radius: 0;
}
.step h3 {
  margin: 0 0 var(--vault-s-2);
  color: var(--vault-paper);
  font-family: var(--vault-display);
  font-size: var(--vault-step-2);
}
.step p {
  font-size: var(--vault-step-0);
  margin: 0;
  color: var(--vault-paper-2);
}

.tagline {
  font-size: var(--vault-step-1);
  color: var(--vault-paper);
  margin-bottom: var(--vault-s-6);
  font-family: var(--vault-display);
  font-style: italic;
  max-width: 28ch;
}

footer {
  border-top: 1px solid var(--vault-rule);
  padding: var(--vault-s-6) var(--vault-rail);
  margin-top: var(--vault-s-9);
  color: var(--vault-paper-dim);
  font-family: var(--vault-mono);
  font-size: var(--vault-step--1);
  letter-spacing: 0.06em;
  text-align: center;
}
footer a { color: var(--vault-paper-dim); }
footer a:hover { color: var(--vault-paper); }

/* Legal-essay legacy styles */
.legal h1 { font-size: var(--vault-step-4); }
.legal h2 {
  font-family: var(--vault-display);
  font-size: var(--vault-step-3);
  border-bottom: 0;
  padding-bottom: 0;
  margin-top: var(--vault-s-8);
}
.legal-meta {
  color: var(--vault-paper-dim);
  font-family: var(--vault-mono);
  font-size: var(--vault-step--1);
  letter-spacing: 0.08em;
  margin-bottom: var(--vault-s-6);
  text-transform: uppercase;
}

/* ============================================================
 * Page-load reveal (NAS-152). Total runtime <= 1.0s. Disabled
 * automatically under prefers-reduced-motion (see below).
 * ============================================================ */
@keyframes vault-fade-up {
  from { opacity: 0; transform: translateY(10px); }
  to   { opacity: 1; transform: translateY(0); }
}
.vault-reveal {
  animation: vault-fade-up 560ms var(--vault-ease-out) both;
}
.vault-reveal--d1 { animation-delay: 60ms; }
.vault-reveal--d2 { animation-delay: 180ms; }
.vault-reveal--d3 { animation-delay: 300ms; }
.vault-reveal--d4 { animation-delay: 420ms; }
.vault-reveal--d5 { animation-delay: 540ms; }
.vault-reveal--d6 { animation-delay: 660ms; }

/* Guard against horizontal overflow from the ciphertext feed motif. */
html, body { overflow-x: hidden; }

/* Make the threat-model table horizontally scrollable on phones rather than
 * forcing the page to grow. The wrapper is added in the rebuilt index.html
 * and (for the long-form essay table) inside privacy.html if needed. */
.vault-table-scroll {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  margin: var(--vault-s-6) 0;
}
.vault-table-scroll > .vault-table {
  margin: 0;
  min-width: 480px;
}

/* ============================================================
 * Responsive
 * ============================================================ */
@media (max-width: 720px) {
  :root {
    --vault-step-4: 2.5rem;
    --vault-step-5: 4rem;
    --vault-step-6: 5rem;
  }
  .vault-section--two-col {
    grid-template-columns: 1fr;
    gap: var(--vault-s-5);
  }
}

@media (max-width: 420px) {
  :root {
    --vault-step-4: 2.125rem;
    --vault-step-5: 3rem;
    --vault-step-6: 3.5rem;
    --vault-rail: 1rem;
  }
  .vault-nav { gap: var(--vault-s-3); }
  .vault-footer { flex-direction: column; align-items: flex-start; }
}

/* ============================================================
 * Reduced motion
 * ============================================================ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
  .vault-feed__inner { animation: none !important; }
}