/* SK6 Software — Public site
 * Editorial / engineering-journal aesthetic.
 * Serif display + Inter body + JetBrains Mono details.
 */

@import url('https://fonts.googleapis.com/css2?family=Fraunces:opsz,wght@9..144,400;9..144,500;9..144,600;9..144,700&family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500;600&display=swap');

:root {
  /* Editorial palette — paper, ink, single accent */
  --paper: #f6f4ee;          /* warm off-white */
  --paper-2: #efece3;        /* card alt */
  --ink: #14110e;            /* near-black with warmth */
  --ink-2: #3a352f;
  --muted: #6e655c;
  --faint: #a39a8e;
  --line: #d9d3c6;
  --line-strong: #b9b1a1;
  --accent: #c2410c;         /* burnt orange accent — restrained */
  --accent-soft: #f7e7d8;
  --good: #2f6f4d;

  --serif: 'Fraunces', 'Iowan Old Style', 'Times New Roman', serif;
  --sans: 'Inter', system-ui, -apple-system, sans-serif;
  --mono: 'JetBrains Mono', ui-monospace, Menlo, monospace;

  --maxw: 1180px;
  --maxw-text: 720px;
  --gutter: 32px;
}

* { box-sizing: border-box; }
html, body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  font-feature-settings: 'ss01','cv11';
}

body { min-height: 100vh; }

a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; }

/* ======= Typography ======= */
.display {
  font-family: var(--serif);
  font-weight: 500;
  font-variation-settings: "opsz" 144, "SOFT" 30;
  letter-spacing: -0.02em;
  line-height: 1.04;
  color: var(--ink);
}
.h1 { font-size: clamp(40px, 6vw, 72px); }
.h2 {
  font-family: var(--serif);
  font-weight: 500;
  font-size: clamp(28px, 3.4vw, 40px);
  letter-spacing: -0.015em;
  line-height: 1.1;
  color: var(--ink);
  margin: 0 0 16px;
}
.h3 {
  font-family: var(--serif);
  font-weight: 500;
  font-size: 22px;
  letter-spacing: -0.01em;
  line-height: 1.25;
  color: var(--ink);
  margin: 0 0 8px;
}
.eyebrow {
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--muted);
}
.body { font-size: 16px; color: var(--ink-2); }
.lead { font-size: 19px; line-height: 1.55; color: var(--ink-2); max-width: 60ch; }
.muted { color: var(--muted); }
.mono  { font-family: var(--mono); }
.serif-italic { font-family: var(--serif); font-style: italic; font-weight: 400; }

::selection { background: var(--accent); color: #fff; }

/* ======= Layout ======= */
.container {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--gutter);
}
.container-text { max-width: var(--maxw-text); margin: 0 auto; padding: 0 var(--gutter); }

.section { padding: 96px 0; border-top: 1px solid var(--line); }
.section.tight { padding: 64px 0; }
.section.first { border-top: 0; }

/* ======= Top Nav ======= */
.nav {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: blur(12px);
  background: color-mix(in oklab, var(--paper) 88%, transparent);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--gutter);
  height: 68px;
  display: flex; align-items: center; justify-content: space-between;
  gap: 24px;
}
.logo {
  display: inline-flex; align-items: center; gap: 10px;
  font-family: var(--serif);
  font-weight: 600;
  font-size: 19px;
  letter-spacing: -0.01em;
  color: var(--ink);
}
.logo-mark {
  width: 28px; height: 28px;
  border: 1.5px solid var(--ink);
  border-radius: 6px;
  display: grid; place-items: center;
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: -0.04em;
  background: var(--ink);
  color: var(--paper);
}
.nav-links {
  display: flex; align-items: center; gap: 4px;
  list-style: none; padding: 0; margin: 0;
}
.nav-link {
  padding: 8px 14px;
  font-size: 14px;
  color: var(--ink-2);
  border-radius: 6px;
  transition: background 0.15s, color 0.15s;
}
.nav-link:hover { background: var(--paper-2); color: var(--ink); }
.nav-link.active { color: var(--ink); font-weight: 500; }
.nav-link.active::after {
  content: '';
  display: block;
  height: 1.5px; background: var(--accent);
  margin-top: 4px;
}
.nav-right { display: flex; align-items: center; gap: 12px; }

/* Language switcher */
.lang-switch {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  padding-right: 8px;
  border-right: 1px solid var(--line);
  margin-right: 4px;
}
.lang-switch .lang-btn {
  background: transparent;
  border: 0;
  padding: 4px 6px;
  cursor: pointer;
  color: var(--muted);
  font-family: inherit;
  font-size: inherit;
  letter-spacing: inherit;
  font-weight: 500;
  transition: color .15s ease;
}
.lang-switch .lang-btn:hover { color: var(--ink); }
.lang-switch .lang-btn.active { color: var(--ink); }
.lang-switch .lang-btn.active::after {
  content: '';
  display: block;
  height: 1.5px;
  background: var(--accent);
  margin-top: 2px;
}
.lang-switch .lang-sep { color: var(--faint); }

.nav-mobile-toggle { display: none; }

/* ======= Buttons ======= */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 11px 18px;
  border-radius: 6px;
  border: 1px solid var(--ink);
  background: var(--ink);
  color: var(--paper);
  font-size: 14px;
  font-weight: 500;
  transition: transform 0.15s, background 0.15s, color 0.15s, border-color 0.15s;
}
.btn:hover { background: #000; transform: translateY(-1px); }
.btn.ghost {
  background: transparent;
  color: var(--ink);
}
.btn.ghost:hover { background: var(--ink); color: var(--paper); transform: translateY(-1px); }
.btn.link {
  border: 0; padding: 0; background: transparent; color: var(--ink);
  font-weight: 500;
  border-bottom: 1px solid var(--ink);
  border-radius: 0;
  padding-bottom: 1px;
}
.btn.link:hover { color: var(--accent); border-color: var(--accent); transform: none; }
.btn.sm { padding: 7px 12px; font-size: 13px; }

/* ======= Hero ======= */
.hero {
  padding: 120px 0 80px;
  position: relative;
}
.hero-eyebrow {
  display: inline-flex; align-items: center; gap: 10px;
  margin-bottom: 28px;
}
.hero-eyebrow .pulse {
  width: 7px; height: 7px; border-radius: 50%;
  background: var(--good);
  box-shadow: 0 0 0 0 color-mix(in oklab, var(--good) 60%, transparent);
  animation: pulse 2s infinite;
}
@keyframes pulse {
  0%   { box-shadow: 0 0 0 0 color-mix(in oklab, var(--good) 50%, transparent); }
  70%  { box-shadow: 0 0 0 8px transparent; }
  100% { box-shadow: 0 0 0 0 transparent; }
}
.hero h1 {
  margin: 0 0 28px;
  max-width: 18ch;
}
.hero h1 .accent { color: var(--accent); font-style: italic; font-weight: 400; }
.hero-sub {
  font-size: 20px;
  line-height: 1.55;
  color: var(--ink-2);
  max-width: 56ch;
  margin: 0 0 36px;
}
.hero-cta { display: flex; gap: 12px; flex-wrap: wrap; }

.hero-meta {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 80px;
  padding-top: 32px;
  border-top: 1px solid var(--line);
}
.hero-meta .item .k {
  font-family: var(--mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--muted);
  margin-bottom: 6px;
}
.hero-meta .item .v {
  font-family: var(--serif);
  font-size: 22px;
  font-weight: 500;
  color: var(--ink);
}
.hero-meta .item-link {
  display: block;
  text-decoration: none;
  padding: 20px 22px;
  border: 1px solid var(--line);
  background: var(--paper);
  border-radius: 2px;
  transition: border-color .18s ease, transform .18s ease, background .18s ease;
}
.hero-meta .item-link:hover {
  border-color: var(--ink);
  background: var(--paper-2);
}
.hero-meta .item-link .v .arrow {
  display: inline-block;
  margin-left: 4px;
  transition: transform .18s ease;
  color: var(--accent);
  font-style: normal;
}
.hero-meta .item-link:hover .v .arrow { transform: translateX(4px); }
.hero-meta .item-link .item-sub {
  margin-top: 10px;
  font-family: var(--sans, inherit);
  font-size: 14px;
  line-height: 1.55;
  color: var(--ink-2);
}

/* ======= Section header ======= */
.section-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  margin-bottom: 48px;
  gap: 32px;
}
.section-head .left { max-width: 48ch; }
.section-head .num {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--muted);
  margin-bottom: 12px;
}

/* ======= App cards ======= */
.app-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}
.app-grid .app-card {
  background: var(--paper);
  padding: 32px 28px;
  display: flex; flex-direction: column; gap: 16px;
  transition: background 0.2s;
  position: relative;
}
.app-grid .app-card:hover { background: var(--paper-2); }
.app-grid .app-card.is-clickable { cursor: pointer; }
.app-card-head {
  display: flex; align-items: flex-start; justify-content: space-between;
  gap: 12px;
}
.app-card-name {
  font-family: var(--serif);
  font-size: 26px;
  font-weight: 500;
  letter-spacing: -0.01em;
  color: var(--ink);
}
.app-card-num {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--faint);
  letter-spacing: 0.08em;
}
.app-card-desc {
  font-size: 15px;
  color: var(--ink-2);
  line-height: 1.55;
  flex: 1;
}
.app-card-meta {
  display: flex; align-items: center; justify-content: space-between;
  gap: 12px;
  font-size: 12px;
  color: var(--muted);
  font-family: var(--mono);
  letter-spacing: 0.04em;
  padding-top: 12px;
  border-top: 1px dashed var(--line-strong);
}
.app-card .arrow {
  display: inline-block;
  transition: transform 0.2s;
}
.app-card:hover .arrow { transform: translateX(4px); color: var(--accent); }

/* ======= Status badges ======= */
.badge {
  display: inline-flex; align-items: center; gap: 6px;
  font-family: var(--mono);
  font-size: 10px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  padding: 4px 10px;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  color: var(--ink-2);
  background: var(--paper);
  white-space: nowrap;
}
.badge::before {
  content: '';
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--faint);
}
.badge.live::before { background: var(--good); }
.badge.beta::before { background: var(--accent); }
.badge.alpha::before { background: #b07d2a; }
.badge.idea::before { background: var(--faint); }

/* ======= Filter chips ======= */
.chips { display: flex; gap: 8px; flex-wrap: wrap; }
.chip {
  padding: 7px 14px;
  border: 1px solid var(--line-strong);
  background: var(--paper);
  border-radius: 999px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--ink-2);
  cursor: pointer;
  transition: all 0.15s;
}
.chip:hover { border-color: var(--ink); }
.chip.active {
  background: var(--ink); color: var(--paper); border-color: var(--ink);
}

/* ======= Footer ======= */
.footer {
  border-top: 1px solid var(--line);
  background: var(--paper-2);
  padding: 64px 0 32px;
  margin-top: 80px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 48px;
}
.footer h4 {
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--muted);
  margin: 0 0 16px;
}
.footer ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 8px; }
.footer ul a { color: var(--ink-2); font-size: 14px; }
.footer ul a:hover { color: var(--accent); }
.footer-bottom {
  display: flex; justify-content: space-between; align-items: center;
  padding-top: 24px;
  border-top: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 11px;
  color: var(--muted);
  letter-spacing: 0.06em;
}
.footer-tagline {
  font-family: var(--serif);
  font-size: 16px;
  color: var(--ink-2);
  font-style: italic;
  max-width: 32ch;
  line-height: 1.4;
}

/* ======= Philosophy quote / pull ======= */
.pull-quote {
  font-family: var(--serif);
  font-size: clamp(28px, 3.8vw, 44px);
  font-weight: 400;
  font-style: italic;
  line-height: 1.2;
  letter-spacing: -0.015em;
  color: var(--ink);
  max-width: 24ch;
}
.pull-quote .accent { color: var(--accent); }

.principle {
  padding: 48px 0;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 64px;
  align-items: start;
}
.principle:first-child { border-top: 0; padding-top: 0; }
.principle .num {
  font-family: var(--serif);
  font-size: 44px;
  font-weight: 500;
  font-style: italic;
  color: var(--accent);
  line-height: 1;
}
.principle .title {
  font-family: var(--serif);
  font-size: 28px;
  font-weight: 500;
  letter-spacing: -0.015em;
  margin: 0 0 14px;
}
.principle .body p { font-size: 17px; line-height: 1.65; color: var(--ink-2); margin: 0 0 14px; }
.principle .body p:last-child { margin-bottom: 0; }

/* ======= App detail page ======= */
.detail-hero {
  padding: 80px 0 48px;
}
.crumbs {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--muted);
  letter-spacing: 0.06em;
  margin-bottom: 24px;
}
.crumbs a:hover { color: var(--accent); }
.crumbs .sep { margin: 0 8px; }

.detail-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 64px;
  align-items: start;
}

.kv-list {
  border-top: 1px solid var(--line);
}
.kv-list .row {
  display: grid;
  grid-template-columns: 1fr 1.4fr;
  gap: 16px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
  font-size: 14px;
}
.kv-list .row .k {
  font-family: var(--mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--muted);
  align-self: center;
}
.kv-list .row .v { color: var(--ink); }

.feature-list {
  list-style: none;
  padding: 0; margin: 0;
  display: grid; gap: 24px;
}
.feature-list li {
  display: grid;
  grid-template-columns: 36px 1fr;
  gap: 16px;
  align-items: start;
}
.feature-list .feat-num {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--accent);
  padding-top: 4px;
  border-top: 2px solid var(--accent);
  letter-spacing: 0.06em;
}
.feature-list .feat-title {
  font-family: var(--serif);
  font-size: 19px;
  font-weight: 500;
  margin: 0 0 4px;
  color: var(--ink);
}
.feature-list .feat-desc {
  font-size: 14px;
  color: var(--ink-2);
  margin: 0;
}

/* ======= Roadmap columns ======= */
.roadmap {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}
.road-col { background: var(--paper); padding: 20px; min-height: 200px; }
.road-col.now h4::before { content: '●'; color: var(--accent); margin-right: 8px; }
.road-col.next h4::before { content: '○'; color: var(--accent); margin-right: 8px; }
.road-col.later h4::before { content: '◇'; color: var(--muted); margin-right: 8px; }
.road-col h4 {
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--muted);
  margin: 0 0 16px;
}
.road-item {
  font-size: 14px;
  padding: 10px 0;
  border-bottom: 1px dashed var(--line);
  color: var(--ink);
}
.road-item:last-child { border-bottom: 0; }

/* ======= Contact form ======= */
.form-grid { display: grid; gap: 20px; }
.field label {
  display: block;
  font-family: var(--mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--muted);
  margin-bottom: 8px;
}
.field input, .field select, .field textarea {
  width: 100%;
  font: inherit;
  font-size: 15px;
  padding: 12px 14px;
  border: 1px solid var(--line-strong);
  border-radius: 6px;
  background: var(--paper);
  color: var(--ink);
  transition: border-color 0.15s, box-shadow 0.15s;
}
.field input:focus, .field select:focus, .field textarea:focus {
  outline: 0;
  border-color: var(--ink);
  box-shadow: 0 0 0 3px color-mix(in oklab, var(--accent) 18%, transparent);
}
.field textarea { min-height: 140px; resize: vertical; font-family: inherit; }

/* ======= Login ======= */
.auth-shell {
  min-height: calc(100vh - 68px);
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: stretch;
}
.auth-left {
  padding: 80px var(--gutter);
  display: flex; flex-direction: column; justify-content: center;
  border-right: 1px solid var(--line);
}
.auth-right {
  padding: 80px var(--gutter);
  background: var(--paper-2);
  display: flex; flex-direction: column; justify-content: center;
}
.auth-card {
  max-width: 380px;
  width: 100%;
}

/* ======= About ======= */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1.6fr;
  gap: 80px;
  align-items: start;
}
.about-grid .sticky { position: sticky; top: 100px; }

.tag-list { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 12px; }
.tag {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--ink-2);
  padding: 4px 10px;
  border: 1px solid var(--line-strong);
  border-radius: 4px;
  background: var(--paper);
}

/* ======= Cards inside text ======= */
.callout {
  border: 1px solid var(--line);
  background: var(--paper-2);
  padding: 24px 28px;
  border-left: 3px solid var(--accent);
  border-radius: 4px;
  margin: 24px 0;
}
.callout .eyebrow { margin-bottom: 8px; display: block; }

/* ======= Standalone app page ======= */
.app-standalone {
  background: var(--paper);
  min-height: 100vh;
}
.app-nav {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in oklab, var(--paper) 92%, transparent);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}
.app-nav-inner {
  height: 68px;
  display: flex; align-items: center; justify-content: space-between;
}
.app-logo {
  display: inline-flex; align-items: center; gap: 10px;
  font-family: var(--serif);
  font-weight: 600;
  font-size: 20px;
  letter-spacing: -0.01em;
  color: var(--ink);
}
.app-logo-mark {
  width: 30px; height: 30px;
  border-radius: 7px;
  display: grid; place-items: center;
  font-family: var(--mono);
  font-weight: 600;
  font-size: 13px;
  color: #fff;
  letter-spacing: -0.02em;
}
.app-nav-links {
  display: flex; align-items: center; gap: 22px;
  font-size: 14px;
  color: var(--ink-2);
}
.app-nav-links a:not(.btn):hover { color: var(--app-accent, var(--accent)); }
.app-nav-links .btn { color: #fff; }

.app-hero {
  padding: 120px 0 100px;
  border-bottom: 1px solid var(--line);
}

.app-footer {
  border-top: 1px solid var(--line);
  background: var(--paper-2);
  padding: 64px 0 32px;
  margin-top: 80px;
}
.app-footer-inner {
  display: flex; justify-content: space-between; align-items: flex-start;
  gap: 48px;
}
.sk6-attribution {
  display: inline-block;
  padding: 16px 20px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
  transition: border-color 0.15s, transform 0.15s;
}
.sk6-attribution:hover { border-color: var(--ink); transform: translateY(-1px); }

/* ======= Page transitions ======= */
/* ======= Page transitions ======= */
.page-fade {
  animation: fadeUp 0.45s cubic-bezier(0.2, 0.7, 0.2, 1) both;
}
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: none; }
}

/* ======= Responsive ======= */
@media (max-width: 900px) {
  :root { --gutter: 20px; }
  .nav-links { display: none; }
  .nav-mobile-toggle {
    display: inline-flex; align-items: center; justify-content: center;
    width: 40px; height: 40px;
    border: 1px solid var(--line-strong); border-radius: 6px;
    background: var(--paper); color: var(--ink);
  }
  .nav-mobile-panel {
    position: fixed; inset: 68px 0 0;
    background: var(--paper);
    padding: 32px var(--gutter);
    display: flex; flex-direction: column; gap: 4px;
    border-top: 1px solid var(--line);
    z-index: 40;
  }
  .nav-mobile-panel a {
    padding: 14px 0;
    border-bottom: 1px solid var(--line);
    font-family: var(--serif);
    font-size: 22px;
    color: var(--ink);
  }
  .section { padding: 64px 0; }
  .hero { padding: 64px 0 48px; }
  .hero-meta { grid-template-columns: 1fr; gap: 16px; margin-top: 48px; }
  .app-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
  .principle { grid-template-columns: 1fr; gap: 16px; }
  .detail-grid { grid-template-columns: 1fr; gap: 32px; }
  .roadmap { grid-template-columns: 1fr; }
  .auth-shell { grid-template-columns: 1fr; }
  .auth-left { display: none; }
  .auth-right { padding: 48px var(--gutter); min-height: calc(100vh - 68px); }
  .about-grid { grid-template-columns: 1fr; gap: 32px; }
  .about-grid .sticky { position: static; }
  .section-head { flex-direction: column; align-items: flex-start; }
}