/* Causal Security */
:root {
  /* Surface */
  --paper:    #F7F5EF;      /* warm near-white paper */
  --paper-hi: #FCFAF4;
  --paper-lo: #EEEADD;
  --paper-dk: #E4DFCD;

  /* Ink */
  --ink:      #0C0D0F;
  --ink-soft: #1A1C1F;
  --muted:    #4E5258;
  --dim:      #787C83;
  --faint:    #B4B6B9;

  /* Rules */
  --hair:        rgba(12,13,15,0.10);
  --hair-sf:     rgba(12,13,15,0.05);
  --hair-strong: rgba(12,13,15,0.18);
  --rule:        #141618;

  /* Accent — deep teal, enterprise-grade, different from Cipher product violet */
  --accent:      #0B5D5A;
  --accent-mid:  #0E7370;
  --accent-soft: #D9E8E6;
  --accent-glow: rgba(11,93,90,0.12);
  --accent-hi:   #15807C;

  /* Semantic */
  --signal:  #C9E88E;      /* desaturated lime, supporting */
  --red:     #B23A2B;
  --amber:   #7A5A10;
  --blue:    #1E4D8E;

  /* Type */
  --font-sans:  'Inter', ui-sans-serif, system-ui, -apple-system, 'Helvetica Neue', Arial, sans-serif;
  --font-serif: 'Newsreader', Georgia, 'Times New Roman', serif;
  --font-mono:  'JetBrains Mono', ui-monospace, 'SF Mono', Menlo, Consolas, monospace;

  /* Layout */
  --max: 1280px;
  --col: 48px;
}

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

html, body {
  background: var(--paper);
  color: var(--ink);
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: inherit; text-decoration: none; }

.wrap {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 clamp(24px, 4vw, 48px);
}

.rule-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
  padding-bottom: 8px;
  border-bottom: 1px solid var(--accent);
  margin-bottom: 24px;
}
.rule-tag.ghost {
  color: var(--muted);
  border-color: var(--hair-strong);
}

.h-serif em {
  font-family: var(--font-serif);
  font-style: italic;
  font-weight: 400;
  color: var(--accent);
  letter-spacing: -0.015em;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  padding: 14px 22px;
  border-radius: 0;
  transition: transform .15s, background .15s, border-color .15s, color .15s;
  cursor: pointer;
  border: none;
}
.btn-primary { background: var(--ink); color: #fff; }
.btn-primary:hover { background: var(--accent); transform: translateY(-1px); }
.btn-ghost { color: var(--ink); border: 1px solid var(--hair-strong); background: transparent; }
.btn-ghost:hover { background: var(--paper-lo); border-color: var(--rule); }
.btn .arrow { display: inline-block; transition: transform .2s; }
.btn:hover .arrow { transform: translateX(3px); }

/* reset focus */
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }