/* ============================================================
   FolderVault — "Cold storage / append-only ledger" design system
   ============================================================ */

:root {
  /* palette */
  --ink:        #0F1518;   /* deep slate, primary dark ground */
  --ink-2:      #161E22;   /* raised panel on dark */
  --ink-3:      #1F292E;   /* hairline / border on dark */
  --paper:      #F1EDE6;   /* warm archival paper */
  --paper-2:    #E6E0D5;   /* dimmer paper panel */
  --paper-line: #D8D1C2;   /* hairline on paper */
  --brass:      #C89B53;   /* vault-brass key accent */
  --brass-deep: #A87C36;
  --patina:     #5E9A8E;   /* verdigris — "encrypted / secure" */
  --patina-dim: #3C5C56;

  --ink-text:   #EDEAE2;   /* text on dark */
  --ink-muted:  #93A0A0;   /* muted text on dark */
  --pap-text:   #1A2226;   /* text on paper */
  --pap-muted:  #5C6166;   /* muted text on paper */

  --maxw: 1140px;
  --gutter: clamp(20px, 5vw, 64px);

  --font-display: "Archivo", "Helvetica Neue", sans-serif;
  --font-body: "IBM Plex Sans", system-ui, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0;
  background: var(--ink);
  color: var(--ink-text);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img { max-width: 100%; display: block; }

a { color: inherit; }

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

/* ---------- typography ---------- */
h1, h2, h3 {
  font-family: var(--font-display);
  font-weight: 800;
  font-stretch: 125%;   /* Archivo expanded axis */
  line-height: 1.02;
  letter-spacing: -0.01em;
  margin: 0;
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  font-weight: 500;
  color: var(--brass);
  margin: 0 0 18px;
}
.eyebrow.on-dark { color: var(--brass); }

p { margin: 0 0 1em; }

.lead { font-size: clamp(18px, 2.1vw, 21px); line-height: 1.55; }

/* ---------- layout primitives ---------- */
.wrap { max-width: var(--maxw); margin: 0 auto; padding-inline: var(--gutter); }

section { padding-block: clamp(72px, 11vw, 132px); }

.band-paper { background: var(--paper); color: var(--pap-text); }
.band-ink   { background: var(--ink);   color: var(--ink-text); }
.band-ink2  { background: var(--ink-2); color: var(--ink-text); }

.band-paper .eyebrow { color: var(--brass-deep); }
.band-paper .muted { color: var(--pap-muted); }
.muted { color: var(--ink-muted); }

.section-head { max-width: 760px; margin-bottom: 56px; }
.section-head h2 { font-size: clamp(30px, 5vw, 52px); }
.section-head p { margin-top: 20px; }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 10px;
  font-family: var(--font-mono);
  font-size: 14px; letter-spacing: 0.02em;
  padding: 13px 22px;
  border-radius: 2px;
  text-decoration: none;
  border: 1px solid transparent;
  transition: transform .15s ease, background .15s ease, border-color .15s ease;
}
.btn-primary { background: var(--brass); color: var(--ink); }
.btn-primary:hover { background: #d9aa61; transform: translateY(-2px); }
.btn-ghost { border-color: var(--ink-3); color: var(--ink-text); background: transparent; }
.band-paper .btn-ghost { border-color: var(--paper-line); color: var(--pap-text); }
.btn-ghost:hover { border-color: var(--brass); color: var(--brass); transform: translateY(-2px); }
.band-paper .btn-ghost:hover { color: var(--brass-deep); }

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

/* ============================================================
   NAV
   ============================================================ */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--ink) 86%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--ink-3);
}
.nav-inner {
  max-width: var(--maxw); margin: 0 auto;
  padding: 14px var(--gutter);
  display: flex; align-items: center; justify-content: space-between; gap: 24px;
}
.brand {
  font-family: var(--font-mono); font-weight: 600; font-size: 15px;
  letter-spacing: 0.04em; text-decoration: none; color: var(--ink-text);
  display: inline-flex; align-items: center; gap: 10px;
}
.brand .mark {
  width: 22px; height: 22px; flex: none;
}
.nav-links { display: flex; gap: 28px; align-items: center; }
.nav-links a {
  font-family: var(--font-mono); font-size: 13px; letter-spacing: 0.03em;
  text-decoration: none; color: var(--ink-muted);
  transition: color .15s ease;
}
.nav-links a:hover { color: var(--ink-text); }
.nav-links a.cta { color: var(--brass); }
@media (max-width: 720px) {
  .nav-links .hide-sm { display: none; }
}

/* ============================================================
   HERO
   ============================================================ */
.hero { padding-block: clamp(56px, 9vw, 104px); overflow: hidden; }
.hero-grid {
  display: grid; grid-template-columns: 1.05fr 1fr; gap: clamp(36px, 6vw, 80px);
  align-items: center;
}
@media (max-width: 940px) { .hero-grid { grid-template-columns: 1fr; } }

.hero h1 {
  font-size: clamp(40px, 7.2vw, 84px);
  margin-bottom: 24px;
}
.hero h1 .accent { color: var(--brass); }
.hero-sub { font-size: clamp(17px, 2.2vw, 20px); color: var(--ink-muted); max-width: 30ch; margin-bottom: 32px; }
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 28px; }
.hero-foot {
  font-family: var(--font-mono); font-size: 12.5px; color: var(--ink-muted);
  letter-spacing: 0.02em; display: flex; gap: 10px; align-items: center;
}
.hero-foot .dot { color: var(--patina); }

/* ---- the ledger signature ---- */
.ledger {
  background: var(--ink-2);
  border: 1px solid var(--ink-3);
  border-radius: 6px;
  font-family: var(--font-mono);
  font-size: 13px;
  box-shadow: 0 28px 60px -28px rgba(0,0,0,.7);
  overflow: hidden;
}
.ledger-bar {
  display: flex; align-items: center; gap: 10px;
  padding: 12px 16px;
  border-bottom: 1px solid var(--ink-3);
  color: var(--ink-muted);
  font-size: 12px;
}
.ledger-bar .run { color: var(--ink-text); }
.ledger-bar .status { margin-left: auto; color: var(--patina); display: inline-flex; gap: 7px; align-items: center; }
.ledger-bar .blip {
  width: 7px; height: 7px; border-radius: 50%; background: var(--patina);
  animation: blip 1.6s ease-in-out infinite;
}
@keyframes blip { 0%,100% { opacity: .35; } 50% { opacity: 1; } }

.ledger-body { padding: 8px 0 10px; }
.row {
  display: grid; grid-template-columns: 1fr auto;
  gap: 10px; align-items: center;
  padding: 6px 16px;
  opacity: 0;
  transform: translateY(6px);
  animation: rowin .5s ease forwards;
}
.row .path { color: var(--ink-text); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.row .path .dir { color: var(--ink-muted); }
.row .path .crypt { color: var(--patina); }
.tag {
  font-size: 11px; letter-spacing: 0.04em; text-transform: uppercase;
  padding: 2px 8px; border-radius: 999px; white-space: nowrap;
}
.tag.new   { color: var(--ink); background: var(--brass); }
.tag.skip  { color: var(--ink-muted); border: 1px solid var(--ink-3); }
.tag.dup   { color: var(--patina); border: 1px solid var(--patina-dim); }
@keyframes rowin { to { opacity: 1; transform: none; } }
@media (prefers-reduced-motion: reduce) {
  .row { opacity: 1; transform: none; animation: none; }
  .ledger-bar .blip { animation: none; }
}
.ledger-foot {
  border-top: 1px solid var(--ink-3);
  padding: 12px 16px;
  display: flex; gap: 16px; flex-wrap: wrap;
  font-size: 12px; color: var(--ink-muted);
}
.ledger-foot b { color: var(--ink-text); font-weight: 600; }
.ledger-foot .safe { color: var(--patina); margin-left: auto; }

/* ============================================================
   STAT STRIP
   ============================================================ */
.strip {
  border-top: 1px solid var(--ink-3); border-bottom: 1px solid var(--ink-3);
  background: var(--ink-2);
}
.strip-inner {
  max-width: var(--maxw); margin: 0 auto; padding: 0 var(--gutter);
  display: grid; grid-template-columns: repeat(4, 1fr);
}
.strip-cell { padding: 28px 8px; border-left: 1px solid var(--ink-3); }
.strip-cell:first-child { border-left: 0; padding-left: 0; }
.strip-cell .k { font-family: var(--font-display); font-weight: 800; font-stretch: 125%; font-size: clamp(22px, 3vw, 30px); }
.strip-cell .v { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.04em; color: var(--ink-muted); text-transform: uppercase; margin-top: 6px; }
.strip-cell .k.brass { color: var(--brass); }
.strip-cell .k.patina { color: var(--patina); }
@media (max-width: 720px) {
  .strip-inner { grid-template-columns: repeat(2, 1fr); }
  .strip-cell:nth-child(odd) { border-left: 0; padding-left: 0; }
  .strip-cell { border-top: 1px solid var(--ink-3); }
  .strip-cell:nth-child(-n+2) { border-top: 0; }
}

/* ============================================================
   CARDS GRID (strengths)
   ============================================================ */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; background: var(--paper-line); border: 1px solid var(--paper-line); border-radius: 6px; overflow: hidden; }
@media (max-width: 860px) { .cards { grid-template-columns: 1fr 1fr; } }
@media (max-width: 560px) { .cards { grid-template-columns: 1fr; } }
.card { background: var(--paper); padding: 30px 28px; }
.card .ix { font-family: var(--font-mono); font-size: 12px; color: var(--brass-deep); letter-spacing: 0.06em; }
.card h3 { font-size: 21px; margin: 14px 0 10px; font-stretch: 110%; }
.card p { margin: 0; color: var(--pap-muted); font-size: 15.5px; }

/* ============================================================
   STEPS (how incremental works) — numbered sequence
   ============================================================ */
.steps { display: grid; gap: 0; }
.step {
  display: grid; grid-template-columns: 96px 1fr; gap: clamp(20px, 4vw, 48px);
  padding: 34px 0;
  border-top: 1px solid var(--ink-3);
}
.step:last-child { border-bottom: 1px solid var(--ink-3); }
.step .num { font-family: var(--font-display); font-weight: 800; font-stretch: 125%; font-size: clamp(34px, 5vw, 54px); color: var(--brass); line-height: 1; }
.step h3 { font-size: clamp(20px, 2.6vw, 26px); margin-bottom: 10px; }
.step p { margin: 0; color: var(--ink-muted); max-width: 60ch; }
.step code { font-family: var(--font-mono); font-size: .92em; color: var(--patina); background: var(--ink-2); padding: 1px 6px; border-radius: 3px; }
@media (max-width: 560px) { .step { grid-template-columns: 1fr; gap: 10px; } }

/* ============================================================
   ENCRYPTION transform
   ============================================================ */
.enc-grid { display: grid; grid-template-columns: 1.1fr .9fr; gap: clamp(36px, 6vw, 72px); align-items: center; }
@media (max-width: 880px) { .enc-grid { grid-template-columns: 1fr; } }

.transform {
  font-family: var(--font-mono);
  background: var(--ink-2); border: 1px solid var(--ink-3); border-radius: 6px;
  padding: 26px;
}
.t-row { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; }
.t-name { font-size: 14px; }
.t-name .crypt { color: var(--patina); }
.t-arrow { color: var(--brass); }
.t-bytes {
  margin-top: 18px; font-size: 12px; line-height: 1.7;
  color: var(--patina); word-break: break-all; letter-spacing: 0.04em;
  background: var(--ink); padding: 14px; border-radius: 4px; border: 1px solid var(--ink-3);
}
.t-note { margin-top: 16px; font-size: 12.5px; color: var(--ink-muted); }

.enc-list { list-style: none; padding: 0; margin: 0; }
.enc-list li { padding: 14px 0; border-top: 1px solid var(--ink-3); display: grid; grid-template-columns: auto 1fr; gap: 14px; }
.enc-list li:first-child { border-top: 0; }
.enc-list .ic { color: var(--patina); font-family: var(--font-mono); font-size: 13px; padding-top: 2px; }
.enc-list b { font-weight: 600; }
.enc-list span.d { color: var(--ink-muted); display: block; font-size: 15px; }

/* ============================================================
   LIMITATIONS — the candor section
   ============================================================ */
.limits { display: grid; grid-template-columns: 1fr 1fr; gap: 1px; background: var(--paper-line); border: 1px solid var(--paper-line); border-radius: 6px; overflow: hidden; }
@media (max-width: 720px) { .limits { grid-template-columns: 1fr; } }
.limit { background: var(--paper); padding: 28px; }
.limit .h { display: flex; align-items: baseline; gap: 12px; margin-bottom: 8px; }
.limit .h .tagline { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.08em; text-transform: uppercase; color: var(--brass-deep); }
.limit h3 { font-size: 18px; font-stretch: 110%; }
.limit p { margin: 0; color: var(--pap-muted); font-size: 15px; }

.honest-note {
  margin-top: 40px; padding: 22px 26px;
  border-left: 3px solid var(--brass-deep);
  background: var(--paper-2); border-radius: 0 4px 4px 0;
  font-size: 15.5px; color: var(--pap-text);
}

/* ============================================================
   RESTORE
   ============================================================ */
.restore-grid { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(28px, 5vw, 56px); align-items: start; }
@media (max-width: 820px) { .restore-grid { grid-template-columns: 1fr; } }
.restore-steps { counter-reset: r; list-style: none; padding: 0; margin: 0; }
.restore-steps li { position: relative; padding: 0 0 22px 44px; }
.restore-steps li::before {
  counter-increment: r; content: counter(r);
  position: absolute; left: 0; top: -2px;
  width: 28px; height: 28px; border-radius: 50%;
  display: grid; place-items: center;
  font-family: var(--font-mono); font-size: 13px;
  color: var(--ink); background: var(--brass);
}
.restore-steps li::after {
  content: ""; position: absolute; left: 13px; top: 30px; bottom: 4px; width: 1px; background: var(--paper-line);
}
.restore-steps li:last-child::after { display: none; }
.restore-steps b { font-weight: 600; }
.restore-steps p { margin: 4px 0 0; color: var(--pap-muted); font-size: 15px; }

.callout {
  background: var(--paper-2); border-radius: 6px; padding: 28px;
  border: 1px solid var(--paper-line);
}
.callout h3 { font-size: 19px; font-stretch: 110%; margin-bottom: 10px; }
.callout p { margin: 0 0 .8em; color: var(--pap-muted); font-size: 15px; }
.callout .mono { font-family: var(--font-mono); font-size: 13px; color: var(--patina-dim); }

/* ============================================================
   FOOTER
   ============================================================ */
.foot {
  background: var(--ink); border-top: 1px solid var(--ink-3);
  padding-block: 64px 40px;
}
.foot-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 36px; }
@media (max-width: 720px) { .foot-grid { grid-template-columns: 1fr; gap: 28px; } }
.foot h4 { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-muted); margin: 0 0 16px; font-weight: 500; }
.foot a { display: block; color: var(--ink-text); text-decoration: none; font-size: 15px; padding: 5px 0; }
.foot a:hover { color: var(--brass); }
.foot .blurb { color: var(--ink-muted); font-size: 14.5px; max-width: 36ch; }
.foot-bottom { margin-top: 48px; padding-top: 22px; border-top: 1px solid var(--ink-3); display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; font-family: var(--font-mono); font-size: 12px; color: var(--ink-muted); }
.foot-bottom .safe { color: var(--patina); }

/* ============================================================
   REVEAL ON SCROLL
   ============================================================ */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) { .reveal { opacity: 1; transform: none; transition: none; } }

/* ============================================================
   PRIVACY PAGE
   ============================================================ */
.doc { background: var(--paper); color: var(--pap-text); }
.doc-hero { background: var(--ink); color: var(--ink-text); padding-block: clamp(64px, 10vw, 104px) clamp(44px, 7vw, 72px); }
.doc-hero h1 { font-size: clamp(34px, 6vw, 64px); margin-bottom: 18px; }
.doc-hero .meta { font-family: var(--font-mono); font-size: 13px; color: var(--ink-muted); letter-spacing: 0.03em; }
.doc-hero .meta b { color: var(--patina); font-weight: 500; }

.doc-body { padding-block: clamp(48px, 8vw, 84px); }
.doc-layout { display: grid; grid-template-columns: 220px 1fr; gap: clamp(32px, 6vw, 72px); align-items: start; }
@media (max-width: 880px) { .doc-layout { grid-template-columns: 1fr; } }

.toc { position: sticky; top: 86px; font-family: var(--font-mono); font-size: 13px; }
.toc .lbl { letter-spacing: 0.12em; text-transform: uppercase; color: var(--pap-muted); margin-bottom: 14px; font-size: 11px; }
.toc a { display: block; color: var(--pap-text); text-decoration: none; padding: 6px 0 6px 14px; border-left: 1px solid var(--paper-line); transition: border-color .15s, color .15s; }
.toc a:hover { color: var(--brass-deep); border-color: var(--brass); }
@media (max-width: 880px) { .toc { position: static; margin-bottom: 28px; } }

.prose { max-width: 70ch; }
.prose h2 { font-size: clamp(22px, 3vw, 30px); margin: 48px 0 14px; scroll-margin-top: 86px; font-stretch: 110%; }
.prose h2:first-child { margin-top: 0; }
.prose h3 { font-size: 18px; margin: 26px 0 8px; font-stretch: 105%; }
.prose p { color: #353c41; margin: 0 0 1em; }
.prose ul { margin: 0 0 1.2em; padding-left: 0; list-style: none; }
.prose li { position: relative; padding: 4px 0 4px 24px; color: #353c41; }
.prose li::before { content: "—"; position: absolute; left: 0; color: var(--brass-deep); font-family: var(--font-mono); }
.prose strong { color: var(--pap-text); }
.prose code { font-family: var(--font-mono); font-size: .9em; background: var(--paper-2); padding: 1px 6px; border-radius: 3px; color: var(--patina-dim); }
.prose .key {
  border-left: 3px solid var(--patina); background: var(--paper-2);
  padding: 16px 20px; border-radius: 0 4px 4px 0; margin: 0 0 1.4em;
}
.prose .key p { margin: 0; }
.back-home { font-family: var(--font-mono); font-size: 13px; text-decoration: none; color: var(--ink-muted); display: inline-flex; gap: 8px; }
.back-home:hover { color: var(--brass); }