/* ============================================================
   z:kv marketing site styles
   A small, self-contained stylesheet using the zkv design
   tokens (paper/ink/amber/oxford). No build step, no webfonts:
   system stacks chosen to echo IBM Plex Sans/Mono.
   ============================================================ */

:root {
  /* Paper: warm neutrals */
  --paper-50:  #FAF8F3;
  --paper-100: #F4F1EA;
  --paper-200: #ECE7DC;
  --paper-300: #D9D2C2;
  /* Ink */
  --ink-50:  #6E6F73;
  --ink-100: #4A4B50;
  --ink-200: #2C2E33;
  --ink-300: #15171B;
  --ink-400: #0A0B0E;
  /* Slate: dark chrome */
  --slate-100: #B8BEC8;
  --slate-300: #3F4651;
  --slate-500: #1A1D22;
  --slate-600: #131519;
  --slate-700: #0D0F12;
  /* Accents */
  --amber-300: #D69E37;
  --amber-400: #A8771E;
  --oxford-300: #2C4E80;
  --green-300: #4A7A3A;

  --fg-1: var(--ink-300);
  --fg-2: var(--ink-100);
  --fg-3: var(--ink-50);
  --fg-link: var(--oxford-300);
  --border-1: var(--paper-200);
  --border-2: var(--paper-300);

  --font-sans: "IBM Plex Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, "Menlo", "Consolas", monospace;

  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --wrap: 1040px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.55;
  color: var(--fg-1);
  background: var(--paper-50);
  -webkit-font-smoothing: antialiased;
}

a { color: var(--fg-link); text-decoration: none; }
a:hover { text-decoration: underline; }

code, pre { font-family: var(--font-mono); }
code {
  font-size: 0.88em;
  background: var(--paper-100);
  border: 1px solid var(--border-1);
  border-radius: var(--radius-sm);
  padding: 0.06em 0.34em;
}

.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 24px; }

/* ---------- Brand wordmark ---------- */
.wordmark {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 18px;
  letter-spacing: -0.01em;
  color: var(--ink-300);
}
.wordmark .colon { color: var(--amber-400); }

/* ============================ TOP BAR ============================ */
.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  gap: 24px;
  height: 56px;
  padding: 0 24px;
  background: rgba(250, 248, 243, 0.85);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border-1);
}
.brand { display: inline-flex; align-items: center; gap: 9px; }
.brand:hover { text-decoration: none; }
.topnav { display: flex; align-items: center; gap: 22px; margin-left: auto; }
.topnav a {
  font-size: 13px;
  color: var(--fg-2);
  text-decoration: none;
}
.topnav a:hover { color: var(--fg-1); }
.topnav a.ext { color: var(--fg-3); }

/* ============================ HERO ============================ */
.hero {
  background: var(--slate-600);
  color: var(--paper-50);
  border-bottom: 1px solid var(--slate-500);
  padding: 72px 24px 80px;
}
.hero-grid {
  max-width: var(--wrap);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.05fr 1fr;
  gap: 56px;
  align-items: center;
}
.eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--amber-300);
  border: 1px solid var(--slate-300);
  border-radius: var(--radius-sm);
  padding: 3px 9px;
  margin-bottom: 22px;
}
.hero-title {
  font-size: 46px;
  line-height: 1.08;
  letter-spacing: -0.02em;
  font-weight: 600;
  margin: 0 0 18px;
  color: #fff;
}
.hero-lede {
  font-size: 16px;
  line-height: 1.6;
  color: var(--slate-100);
  margin: 0 0 28px;
  max-width: 38em;
}
.hero-lede strong { color: #fff; font-weight: 600; }
.hero-lede code {
  background: var(--slate-500);
  border-color: var(--slate-300);
  color: var(--amber-300);
}
.hero-cta { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 26px; }
.hero-foot {
  font-size: 12px;
  color: var(--fg-3);
  margin: 0;
}
.hero-foot code { background: var(--slate-500); border-color: var(--slate-300); color: var(--slate-100); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  font-size: 14px;
  font-weight: 500;
  padding: 9px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 0.12s, border-color 0.12s;
}
.btn:hover { text-decoration: none; }
.btn.primary { background: var(--amber-300); color: var(--ink-400); }
.btn.primary:hover { background: var(--amber-400); color: #fff; }
.btn.secondary {
  background: transparent;
  color: var(--paper-50);
  border-color: var(--slate-300);
}
.btn.secondary:hover { background: var(--slate-500); }
.btn.ghost { background: transparent; color: var(--slate-100); }
.btn.ghost:hover { color: #fff; }

/* ---------- Terminal ---------- */
.terminal {
  background: var(--slate-700);
  border: 1px solid var(--slate-300);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 24px 64px rgba(10, 11, 14, 0.4);
}
.terminal-bar {
  display: flex;
  align-items: center;
  gap: 7px;
  padding: 10px 14px;
  background: var(--slate-500);
  border-bottom: 1px solid var(--slate-300);
}
.tl-dot { width: 11px; height: 11px; border-radius: 50%; background: var(--slate-300); }
.tl-title {
  margin-left: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--ink-50);
}
.terminal-body {
  padding: 16px 18px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  line-height: 1.65;
  color: var(--slate-100);
  white-space: pre-wrap;
}
.terminal-body .prompt { color: var(--amber-300); }
.terminal-body .cmd { color: #fff; }
.terminal-body .out { color: var(--slate-100); }
.terminal-body .dim { color: var(--ink-50); }
.terminal-body .ok { color: var(--green-300); }
/* CLI example: real-terminal line spacing. The shared .terminal-body uses
   white-space: pre-wrap, which renders the newlines *between* the source
   <div>s as extra blank lines. Switch to normal so each <div> is one line
   and let the long address wrap. */
#cli .terminal-body {
  line-height: 1.45;
  white-space: normal;
  overflow-wrap: anywhere;
}

/* ============================ SECTIONS ============================ */
.section { padding: 72px 0; border-bottom: 1px solid var(--border-1); }
.section.alt { background: var(--paper-100); }
.sec-h {
  font-size: 28px;
  letter-spacing: -0.02em;
  font-weight: 600;
  margin: 0 0 12px;
  color: var(--fg-1);
}
.sec-lede {
  font-size: 16px;
  color: var(--fg-2);
  max-width: 44em;
  margin: 0 0 36px;
}
.sec-note {
  font-size: 13px;
  color: var(--fg-3);
  margin-top: 24px;
  max-width: 44em;
}

/* ---------- Download cards ---------- */
.dl-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}
.dl-card {
  display: block;
  background: #fff;
  border: 1px solid var(--border-2);
  border-radius: var(--radius-md);
  padding: 22px 20px;
  color: var(--fg-1);
  transition: border-color 0.12s, box-shadow 0.12s, transform 0.12s;
}
.dl-card:hover {
  text-decoration: none;
  border-color: var(--ink-300);
  box-shadow: 0 4px 12px rgba(20, 22, 27, 0.08);
  transform: translateY(-2px);
}
.dl-os { font-size: 18px; font-weight: 600; margin-bottom: 4px; }
.dl-sub { font-size: 13px; color: var(--fg-2); margin-bottom: 12px; }
.dl-note { font-size: 12px; color: var(--fg-3); }
.dl-note code { font-size: 11.5px; }

/* ---------- Docs ---------- */
.doc {
  background: #fff;
  border: 1px solid var(--border-2);
  border-radius: var(--radius-md);
  padding: 28px 32px;
  margin-bottom: 20px;
}
.section.alt .doc { background: var(--paper-50); }
.doc-h { font-size: 20px; font-weight: 600; margin: 0 0 14px; letter-spacing: -0.01em; }
.doc-sub { font-size: 15px; font-weight: 600; color: var(--fg-1); margin: 22px 0 6px; }
.doc p { margin: 0 0 12px; color: var(--fg-2); max-width: 52em; }
.steps { margin: 0; padding-left: 22px; color: var(--fg-2); }
.steps li { margin-bottom: 10px; max-width: 52em; }
.callout {
  background: var(--paper-100);
  border-left: 3px solid var(--amber-300);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 12px 16px;
  font-size: 14px;
}
.idlist { margin: 0; }
.idlist dt { font-weight: 600; margin-top: 16px; }
.idlist dt:first-child { margin-top: 0; }
.idlist dd { margin: 4px 0 0; color: var(--fg-2); max-width: 52em; }

/* ---------- Wire format blocks ---------- */
.wire {
  background: var(--slate-700);
  color: var(--slate-100);
  font-size: 12px;
  line-height: 1.55;
  padding: 12px 14px;
  border-radius: var(--radius-sm);
  overflow-x: auto;
  margin: 10px 0;
  white-space: pre;
}

/* ---------- Opcode grid ---------- */
.op-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}
.op {
  background: #fff;
  border: 1px solid var(--border-2);
  border-radius: var(--radius-md);
  padding: 18px 20px;
}
.op-head { display: flex; align-items: center; gap: 10px; margin-bottom: 8px; }
.op-name { font-family: var(--font-mono); font-size: 15px; font-weight: 600; color: var(--fg-1); }
.op p { margin: 0 0 8px; font-size: 13.5px; color: var(--fg-2); }
.op-auth { font-size: 12px; color: var(--fg-3); margin: 0 !important; }
.op .wire { font-size: 11px; }
.tag {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 2px 7px;
  border-radius: var(--radius-pill, 999px);
  border: 1px solid var(--border-2);
  color: var(--fg-3);
}
.tag.data { color: var(--oxford-300); border-color: #C7D4E8; background: #EEF3FA; }
.tag.life { color: var(--amber-400); border-color: #ECD9A8; background: #FBF3E0; }
.tag.mgmt { color: var(--green-300); border-color: #C9DCC2; background: #EEF4EA; }
.tag.ver  { color: var(--ink-100); border-color: var(--border-2); background: var(--paper-100); }

/* ---------- FAQ (always expanded) ---------- */
.faq {
  background: var(--paper-50);
  border: 1px solid var(--border-2);
  border-radius: var(--radius-md);
  padding: 16px 18px;
  margin-bottom: 10px;
}
.section.alt .faq { background: #fff; }
.faq-q {
  font-weight: 600;
  font-size: 15px;
  color: var(--fg-1);
  margin-bottom: 6px;
}
.faq p { margin: 0; color: var(--fg-2); font-size: 14px; max-width: 56em; }

/* ---------- Terminal typing cursor ---------- */
.cursor {
  display: inline-block;
  width: 7px;
  height: 14px;
  margin-left: 1px;
  vertical-align: text-bottom;
  background: var(--amber-300);
  animation: blink 1s steps(1) infinite;
}
@keyframes blink { 50% { opacity: 0; } }

/* ---------- Screenshot gallery ---------- */
.shot-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}
.shot {
  position: relative;
  display: block;
  padding: 0;
  aspect-ratio: 16 / 10;
  background: var(--paper-100);
  border: 1px solid var(--border-2);
  border-radius: var(--radius-md);
  overflow: hidden;
  cursor: pointer;
  font: inherit;
  transition: border-color 0.12s, box-shadow 0.12s, transform 0.12s;
}
.shot:hover {
  border-color: var(--ink-300);
  box-shadow: 0 4px 12px rgba(20, 22, 27, 0.08);
  transform: translateY(-2px);
}
.shot img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
/* Placeholder shown until an image is dropped in (img has .empty on its .shot) */
.shot-ph {
  position: absolute;
  inset: 0;
  display: none;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--fg-3);
}
.shot.empty { cursor: default; }
.shot.empty:hover { transform: none; box-shadow: none; border-color: var(--border-2); }
.shot.empty img { display: none; }
.shot.empty .shot-ph { display: flex; }

/* ---------- Lightbox modal ---------- */
.modal {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 40px;
  background: rgba(10, 11, 14, 0.82);
  backdrop-filter: blur(2px);
}
.modal[hidden] { display: none; }
.modal-img {
  max-width: 92vw;
  max-height: 88vh;
  border-radius: var(--radius-md);
  box-shadow: 0 24px 64px rgba(0, 0, 0, 0.5);
}
.modal-close {
  position: absolute;
  top: 18px;
  right: 24px;
  width: 40px;
  height: 40px;
  font-size: 28px;
  line-height: 1;
  color: var(--paper-50);
  background: transparent;
  border: none;
  cursor: pointer;
}
.modal-close:hover { color: #fff; }

/* ============================ FOOTER ============================ */
.footer { padding: 28px 0; background: var(--slate-600); color: var(--slate-100); }
.foot-row { display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.foot-brand { display: inline-flex; align-items: center; gap: 9px; font-size: 13px; }
.foot-links { display: flex; gap: 20px; font-size: 13px; }
.foot-links a { color: var(--slate-100); }
.foot-links a:hover { color: #fff; }
.foot-built { margin-top: 14px; font-size: 12px; color: var(--slate-100); opacity: 0.75; }
.foot-built a { color: var(--slate-100); text-decoration: underline; }
.foot-built a:hover { color: #fff; }

/* ============================ RESPONSIVE ============================ */
@media (max-width: 860px) {
  .hero-grid { grid-template-columns: 1fr; gap: 36px; }
  .hero-title { font-size: 36px; }
  .dl-grid { grid-template-columns: 1fr; }
  .op-grid { grid-template-columns: 1fr; }
  .shot-grid { grid-template-columns: repeat(2, 1fr); }
  .topnav { display: none; }
  .doc { padding: 22px 20px; }
}