/* Layout: one narrow reading measure, left-aligned, sections divided by hairline rules.
   Mono labels and figure rows borrow the conventions of a terminal receipt. */

:root {
  --paper:   #F6F7F8;
  --surface: #FFFFFF;
  --ink:     #12171C;
  --muted:   #5C6670;
  --rule:    #DCE0E3;
  --accent:  #0E6B4F;
  --accent-soft: #E7F0EC;

  --display: 'Archivo', 'Helvetica Neue', Arial, sans-serif;
  --body: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --mono: 'IBM Plex Mono', ui-monospace, 'SF Mono', Menlo, monospace;

  --measure: 44rem;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper:   #0E1215;
    --surface: #151B20;
    --ink:     #E7EAEC;
    --muted:   #8F9BA3;
    --rule:    #242B31;
    --accent:  #58C197;
    --accent-soft: #15241E;
    color-scheme: dark;
  }
}

:root[data-theme="dark"] {
  --paper:   #0E1215;
  --surface: #151B20;
  --ink:     #E7EAEC;
  --muted:   #8F9BA3;
  --rule:    #242B31;
  --accent:  #58C197;
  --accent-soft: #15241E;
  color-scheme: dark;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--body);
  font-size: 1rem;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; }

a { color: var(--ink); text-decoration: none; border-bottom: 1px solid var(--rule); }
a:hover { border-bottom-color: var(--accent); color: var(--accent); }
a:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 2px; }

/* ---------- header ---------- */

.masthead {
  position: sticky;
  top: env(safe-area-inset-top, 0px);
  z-index: 10;
  background: color-mix(in srgb, var(--paper) 92%, transparent);
  backdrop-filter: saturate(140%) blur(8px);
  border-bottom: 1px solid var(--rule);
}

.masthead-in {
  max-width: var(--measure);
  margin: 0 auto;
  padding-block: 0.85rem;
  padding-inline: 1.25rem;
  display: flex;
  align-items: baseline;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.wordmark {
  font-family: var(--display);
  font-weight: 700;
  font-size: 1.0rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  border: 0;
  color: var(--ink);
  margin-right: auto;
}
.wordmark:hover { color: var(--ink); border: 0; }

nav { display: flex; gap: 1.15rem; flex-wrap: wrap; align-items: baseline; }

nav a {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  border: 0;
  padding-bottom: 2px;
  border-bottom: 1px solid transparent;
}
nav a:hover { color: var(--ink); border-bottom-color: var(--accent); }
nav a[aria-current="page"] { color: var(--ink); border-bottom-color: var(--ink); }

.lang {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--muted);
  border: 0;
  padding-left: 1.15rem;
  border-left: 1px solid var(--rule);
}
.lang:hover { color: var(--accent); border-bottom: 0; }

/* ---------- shell ---------- */

main {
  max-width: var(--measure);
  margin: 0 auto;
  padding-inline: 1.25rem;
  padding-block: 3.5rem 1rem;
}

section + section {
  margin-top: 3.25rem;
  padding-top: 3.25rem;
  border-top: 1px solid var(--rule);
}

/* ---------- type ---------- */

.eyebrow {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 1.1rem;
}

h1 {
  font-family: var(--display);
  font-weight: 700;
  font-size: clamp(1.85rem, 1.3rem + 2.4vw, 2.9rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
  text-wrap: balance;
  margin: 0 0 1.25rem;
}

h2 {
  font-family: var(--display);
  font-weight: 600;
  font-size: clamp(1.25rem, 1.05rem + 0.9vw, 1.6rem);
  line-height: 1.2;
  letter-spacing: -0.015em;
  text-wrap: balance;
  margin: 0 0 1.1rem;
}

h3 {
  font-family: var(--display);
  font-weight: 600;
  font-size: 1.0rem;
  letter-spacing: -0.005em;
  margin: 0 0 0.4rem;
}

p { margin: 0 0 1.1rem; max-width: 36rem; }
p:last-child { margin-bottom: 0; }

.lead {
  font-size: 1.1rem;
  line-height: 1.55;
  color: var(--ink);
  max-width: 34rem;
}

.note { color: var(--muted); font-size: 0.9rem; }

/* ---------- key points ---------- */

.points {
  display: grid;
  gap: 1.75rem;
  margin-top: 2.25rem;
}
@media (min-width: 46rem) {
  .points { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1.5rem; }
}

.point { min-width: 0; }
.point .k {
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  display: block;
  padding-bottom: 0.6rem;
  margin-bottom: 0.6rem;
  border-bottom: 1px solid var(--rule);
}
.point p { font-size: 0.93rem; line-height: 1.55; margin: 0; max-width: none; }

/* ---------- definition rows (receipt-like) ---------- */

.rows { margin: 1.75rem 0 0; display: grid; gap: 0; }
section > .rows:first-child { margin-top: 0; }

.row {
  display: grid;
  gap: 0.15rem 1.5rem;
  padding-block: 0.95rem;
  border-top: 1px solid var(--rule);
  min-width: 0;
}
.row:last-child { border-bottom: 1px solid var(--rule); }

@media (min-width: 40rem) {
  .row { grid-template-columns: 11rem minmax(0, 1fr); }
}

.row dt {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  padding-top: 0.25rem;
}
.row dd { margin: 0; min-width: 0; font-size: 0.95rem; line-height: 1.55; }
.row dd .when {
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--accent);
  display: block;
  margin-top: 0.2rem;
}

dl { margin: 0; }

/* ---------- terminal mock ---------- */

.terminal-wrap { margin-top: 2.5rem; }

.terminal {
  max-width: 19rem;
  background: #0B0F12;
  border: 1px solid #262E34;
  border-radius: 14px;
  padding: 1.1rem 1.1rem 0.9rem;
  color: #E9EDEF;
  font-size: 0.85rem;
  line-height: 1.45;
  box-shadow: 0 1px 2px rgba(10,16,20,.18), 0 10px 28px -14px rgba(10,16,20,.4);
}

.terminal .biz {
  font-family: var(--mono);
  font-size: 0.64rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #7E8C95;
  padding-bottom: 0.7rem;
  margin-bottom: 0.9rem;
  border-bottom: 1px solid #222A30;
}

.terminal .copy { margin: 0 0 0.9rem; max-width: none; color: #E9EDEF; }

.stamps { display: flex; gap: 0.4rem; align-items: center; margin-bottom: 0.95rem; }
.stamp {
  width: 1.45rem; height: 1.45rem; border-radius: 50%;
  border: 1px solid #39444C; display: grid; place-items: center;
  font-family: var(--mono); font-size: 0.68rem; color: #5E6B74;
}
.stamp.on { border-color: #58C197; color: #0B0F12; background: #58C197; }
.stamps .count {
  font-family: var(--mono); font-size: 0.68rem; color: #7E8C95;
  letter-spacing: 0.06em; margin-left: 0.3rem;
}

.keys { display: flex; gap: 0.5rem; }
.key {
  flex: 1; text-align: center; padding: 0.55rem 0.4rem; border-radius: 8px;
  font-family: var(--body); font-size: 0.82rem; font-weight: 500;
  border: 1px solid #39444C; color: #B9C3C9;
}
.key.primary { background: #58C197; border-color: #58C197; color: #08120D; }

.terminal .by {
  font-family: var(--mono); font-size: 0.6rem; letter-spacing: 0.1em;
  text-transform: uppercase; color: #5E6B74; text-align: center;
  margin: 0.85rem 0 0;
}

figcaption {
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.06em;
  color: var(--muted);
  margin-top: 0.85rem;
  max-width: 19rem;
  line-height: 1.5;
}

figure { margin: 0; }

/* ---------- contact block ---------- */

.addr { font-style: normal; }
.addr .mail {
  font-family: var(--mono);
  font-size: 0.95rem;
  word-break: break-word;
}

/* ---------- footer ---------- */

footer {
  max-width: var(--measure);
  margin: 3.25rem auto 0;
  padding-inline: 1.25rem;
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.06em;
  color: var(--muted);
  line-height: 1.8;
}
.footer-in {
  border-top: 1px solid var(--rule);
  padding-block: 2.5rem 3rem;
}
footer a { color: var(--muted); border-bottom-color: var(--rule); }

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
}