/* СКАнгар — фирменные стили */
:root {
  --graphite: #1F2528;
  --graphite-2: #2a3134;
  --graphite-3: #3a4145;
  --concrete: #F5F3EE;
  --concrete-2: #ECE9E0;
  --steel: #D8D2C5;
  --steel-2: #C6BFAE;
  --orange: #F26A21;
  --orange-deep: #D85510;
  --green: #3D5A45;
  --muted: rgba(31, 37, 40, 0.58);
  --muted-2: rgba(31, 37, 40, 0.38);
  --border: rgba(31, 37, 40, 0.12);
  --border-strong: rgba(31, 37, 40, 0.22);
  --grid-line: rgba(31, 37, 40, 0.06);
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }

body {
  font-family: 'IBM Plex Sans', system-ui, -apple-system, sans-serif;
  background: var(--concrete);
  color: var(--graphite);
  font-size: 16px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  font-feature-settings: 'ss01', 'tnum';
}

/* Mono for numbers / technical labels */
.mono {
  font-family: 'IBM Plex Mono', 'JetBrains Mono', ui-monospace, monospace;
  font-feature-settings: 'tnum';
}

/* Layout */
.shell { width: 100%; max-width: 1360px; margin: 0 auto; padding: 0 32px; }
@media (max-width: 720px) { .shell { padding: 0 20px; } }

section { position: relative; }

/* Typography per brandbook */
h1, h2, h3, h4 { margin: 0; letter-spacing: -0.01em; color: var(--graphite); font-weight: 600; }
h1 { font-size: clamp(40px, 5.5vw, 76px); line-height: 1.02; letter-spacing: -0.025em; font-weight: 600; }
h2 { font-size: clamp(28px, 3vw, 44px); line-height: 1.08; letter-spacing: -0.018em; }
h3 { font-size: 20px; line-height: 1.25; font-weight: 600; }
p { margin: 0; }

/* Section header label (small technical tag) */
.tag {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  display: inline-flex;
  align-items: center;
  gap: 8px;
}
.tag::before {
  content: '';
  width: 18px; height: 1px;
  background: var(--graphite);
  opacity: 0.55;
}

/* Section heading row */
.sec-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 32px;
  padding-bottom: 36px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 40px;
}
.sec-head .left { max-width: 720px; }
.sec-head h2 { margin-top: 14px; }
.sec-head .right { color: var(--muted); font-size: 14px; max-width: 280px; text-align: right; padding-bottom: 4px; }
@media (max-width: 720px) {
  .sec-head { flex-direction: column; align-items: flex-start; }
  .sec-head .right { text-align: left; }
}

/* Buttons — orange only for action per brand rule 2 */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 14px 22px;
  font-family: inherit;
  font-size: 15px;
  font-weight: 500;
  letter-spacing: -0.005em;
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: background 120ms ease, color 120ms ease, border-color 120ms ease;
  border-radius: 0;
}
.btn-primary {
  background: var(--orange);
  color: #fff;
}
.btn-primary:hover { background: var(--orange-deep); }
.btn-secondary {
  background: transparent;
  color: var(--graphite);
  border-color: var(--border-strong);
}
.btn-secondary:hover { border-color: var(--graphite); }
.btn-ghost {
  background: transparent;
  color: var(--graphite);
  padding: 14px 0;
}
.btn-ghost:hover { color: var(--orange); }
.btn-arrow {
  width: 18px; height: 18px; display: inline-block;
}

/* Dark mode for sections */
.dark {
  background: var(--graphite);
  color: var(--concrete);
}
.dark h1, .dark h2, .dark h3, .dark h4 { color: var(--concrete); }
.dark .tag { color: rgba(245, 243, 238, 0.55); }
.dark .tag::before { background: var(--concrete); opacity: 0.4; }
.dark .sec-head { border-color: rgba(245, 243, 238, 0.14); }
.dark .sec-head .right { color: rgba(245, 243, 238, 0.55); }
.dark .btn-secondary { color: var(--concrete); border-color: rgba(245, 243, 238, 0.25); }
.dark .btn-secondary:hover { border-color: var(--concrete); }

/* Section vertical rhythm */
.sec { padding: 100px 0; }
.sec-sm { padding: 72px 0; }
@media (max-width: 720px) {
  .sec { padding: 64px 0; }
  .sec-sm { padding: 48px 0; }
}

/* Grid utilities */
.grid { display: grid; gap: 24px; }

/* Card patterns */
.card {
  background: var(--concrete);
  border: 1px solid var(--border);
  padding: 28px;
}
.card-steel { background: var(--steel); }
.dark .card { background: var(--graphite-2); border-color: rgba(245, 243, 238, 0.1); }
.dark .card-steel { background: var(--graphite-3); }

/* Parameter (big number) */
.param {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.param-value {
  font-size: clamp(32px, 3.4vw, 48px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  font-feature-settings: 'tnum';
  white-space: nowrap;
}
.param-label {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.4;
}
.dark .param-label { color: rgba(245, 243, 238, 0.6); }

/* Form */
.field {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.field label {
  font-size: 12px;
  font-family: 'IBM Plex Mono', monospace;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
}
.field input, .field select, .field textarea {
  font-family: inherit;
  font-size: 15px;
  padding: 12px 14px;
  background: var(--concrete);
  border: 1px solid var(--border-strong);
  color: var(--graphite);
  border-radius: 0;
  outline: none;
  transition: border-color 120ms ease;
}
.field input:focus, .field select:focus, .field textarea:focus {
  border-color: var(--graphite);
}
.dark .field input, .dark .field select, .dark .field textarea {
  background: var(--graphite-2);
  border-color: rgba(245, 243, 238, 0.18);
  color: var(--concrete);
}
.dark .field label { color: rgba(245, 243, 238, 0.55); }

/* Segmented control */
.seg {
  display: inline-flex;
  border: 1px solid var(--border-strong);
}
.seg button {
  padding: 10px 16px;
  background: transparent;
  border: 0;
  font-family: inherit;
  font-size: 14px;
  color: var(--graphite);
  cursor: pointer;
  border-right: 1px solid var(--border-strong);
}
.seg button:last-child { border-right: 0; }
.seg button.active { background: var(--graphite); color: var(--concrete); }
.dark .seg { border-color: rgba(245, 243, 238, 0.18); }
.dark .seg button { color: var(--concrete); border-right-color: rgba(245, 243, 238, 0.18); }
.dark .seg button.active { background: var(--concrete); color: var(--graphite); }

/* Blueprint grid background */
.bp {
  background-image:
    linear-gradient(to right, var(--grid-line) 1px, transparent 1px),
    linear-gradient(to bottom, var(--grid-line) 1px, transparent 1px);
  background-size: 32px 32px;
}
.dark .bp {
  background-image:
    linear-gradient(to right, rgba(245,243,238,0.05) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(245,243,238,0.05) 1px, transparent 1px);
}

/* Errors text */
.err { color: var(--orange); font-size: 13px; }

/* Helpers */
.hide-sm { }
@media (max-width: 720px) { .hide-sm { display: none !important; } }
.row { display: flex; }
.col { display: flex; flex-direction: column; }

/* Small caps tech label */
.tlabel {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}
.dark .tlabel { color: rgba(245, 243, 238, 0.55); }

/* Divider tick mark */
.tick {
  display: inline-block;
  width: 8px; height: 8px;
  border: 1px solid var(--graphite);
  margin-right: 8px;
  vertical-align: middle;
}
.tick-orange { background: var(--orange); border-color: var(--orange); }
.dark .tick { border-color: var(--concrete); }

/* Smooth anchor scroll */
html { scroll-behavior: smooth; }

/* No tap highlight */
button, a { -webkit-tap-highlight-color: transparent; }

/* Edit mode overrides go below */