/* Digital Infrastructure Explained
   Visual system: Slate + Subtle Copper
   Pen name: E. Sandwell
*/

:root{
  --bg: #F5F6F7;
  --surface: #FFFFFF;

  --text: #1F2427;
  --muted: #6B747B;

  --slate-1: #2F3A40;   /* deep slate */
  --slate-2: #3E4A52;   /* secondary slate */
  --border: #D9DEE2;

  --accent: #B87333;    /* muted copper */
  --accent-soft: rgba(184,115,51,0.14);

  --radius: 14px;
  --shadow: 0 10px 25px rgba(31,36,39,0.06);

  /* layout */
  --wrap: 1500px;                  /* strong desktop, safe laptop */
  --pad-y: 0px;
  --pad-x: clamp(12px, 1.8vw, 22px);
}

*{ box-sizing: border-box; }
html, body{ height: 100%; }

body{
  margin: 0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji","Segoe UI Emoji";
  color: var(--text);
  background: var(--bg);
  line-height: 1.55;
}

a{
  color: var(--accent);
  text-decoration: none;
  text-underline-offset: 3px;
}
a:hover{ text-decoration: underline; }

.wrap{
  max-width: min(var(--wrap), 96vw);
  margin: 0 auto;
  padding: var(--pad-y) var(--pad-x);
}

/* Prevent accidental double-wrapping from narrowing content */
.wrap .wrap{
  max-width: 100%;
  padding-left: 0;
  padding-right: 0;
}

/* Ensure main content can actually expand */
main.wrap{
  max-width: min(var(--wrap), 96vw);
}

/* Cards should fill their grid columns */
.card{
  width: 100%;
}

/* Header */
header{
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}
.header-inner{
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 0;
  gap: 16px;
}

.brand{
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}
.brand-mark{
  width: 40px;   /* explicit dimensions = cross-browser stable */
  height: 40px;
  flex: 0 0 auto;
}
.brand-text{
  display: grid;
  gap: 2px;
  min-width: 0;
}
.brand-title{
  font-size: 1.08rem;
  font-weight: 700;
  letter-spacing: 0.2px;
  color: var(--slate-1);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.brand-tag{
  font-size: 0.92rem;
  color: var(--muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Nav */
nav{
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: flex-end;
}
nav a{
  color: var(--slate-2);
  font-weight: 600;
  font-size: 0.95rem;
  padding: 8px 10px;
  border-radius: 10px;
}
nav a:hover{
  background: var(--accent-soft);
  color: var(--slate-1);
  text-decoration: none;
}

/* Copper “rule” under header (subtle) */
.header-rule{
  height: 2px;
  background: linear-gradient(90deg, var(--accent), transparent 65%);
}

/* Main layout */
main{
  padding: 26px 0 60px;
}

.card{
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 22px;
}

h1, h2, h3{
  margin: 0 0 10px;
  line-height: 1.25;
  color: var(--slate-1);
}
h1{ font-size: 2.0rem; letter-spacing: -0.2px; }
h2{ font-size: 1.35rem; }
h3{ font-size: 1.1rem; color: var(--slate-2); }

p{ margin: 0 0 14px; }
small, .small{ color: var(--muted); font-size: 0.95rem; }

.hr{
  height: 1px;
  background: var(--border);
  margin: 18px 0;
}

/* Simple section grid */
.grid{
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(12, 1fr);
}
.col-7{ grid-column: span 7; }
.col-5{ grid-column: span 5; }
.col-12{ grid-column: span 12; }

.badge{
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 10px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: #FBFBFC;
  color: var(--slate-2);
  font-weight: 600;
  font-size: 0.9rem;
}
.badge-dot{
  width: 8px;
  height: 8px;
  border-radius: 999px;
  background: var(--accent);
}

/* Topic list */
.list{
  margin: 0;
  padding-left: 18px;
}
.list li{ margin: 6px 0; }

/* Footer */
footer{
  border-top: 2px solid var(--accent); /* keep copper */
  padding: 26px 0 40px;
  color: var(--muted);
}
.footer-inner{
  display: flex;
  flex-wrap: wrap;
  gap: 12px 18px;
  align-items: center;
  justify-content: space-between;
}
.footer-links{
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.footer-links a{ color: var(--slate-2); }
.footer-links a:hover{ color: var(--slate-1); }

/* Responsive */
@media (max-width: 820px){
  .header-inner{ align-items: flex-start; }
  nav{ justify-content: flex-start; }
  .grid{ grid-template-columns: 1fr; }
  .col-7, .col-5, .col-12{ grid-column: auto; }
  .brand-title, .brand-tag{ white-space: normal; }
}

/* Mid-size laptop/tablet tuning (prevents boxed/narrow feel) */
@media (max-width: 980px){
  header .wrap{ padding-top:18px; padding-bottom:16px; }
  nav{ gap: 8px; }
  nav a{ padding: 7px 10px; }
}