/* Mastering Observability, demonstration environments.
   Palette and type taken from the live site at masteringobservability.com
   (IBM Plex Sans, #1F2A2E ink, #2F8F8B teal) and the brand logo specification
   (#0A5C5E, #0D7377, #2DD4BF, #64FFDA on dark). */

:root{
  --ink:      #1F2A2E;
  --ink-soft: #4A5A60;
  --bg:       #F6F8F7;
  --surface:  #E6ECEB;
  --line:     #D3DEDC;
  --teal:     #2F8F8B;
  --teal-deep:#0A5C5E;
  --mint:     #2DD4BF;
  --amber:    #B26B00;
}
@media (prefers-color-scheme: dark){
  :root{
    --ink:      #E6ECEB;
    --ink-soft: #9AAFB2;
    --bg:       #021420;
    --surface:  #0F2B2D;
    --line:     #1D3B3C;
    --teal:     #4FB3AE;
    --teal-deep:#64FFDA;
    --mint:     #2DD4BF;
    --amber:    #E0A458;
  }
}

*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{
  margin:0;
  background:var(--bg);
  color:var(--ink);
  font-family:"IBM Plex Sans",ui-sans-serif,system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
  font-size:17px;
  line-height:1.65;
  -webkit-font-smoothing:antialiased;
}
.wrap{max-width:760px;margin:0 auto;padding:0 24px}

/* ---------------------------------------------------------------- header */
header{border-bottom:1px solid var(--line);background:var(--bg)}
header .wrap{display:flex;align-items:center;gap:12px;padding:18px 24px;flex-wrap:wrap}
header .mark{width:32px;height:32px;flex:0 0 32px}
.brand{font-weight:600;letter-spacing:-.015em;font-size:16px;text-decoration:none;color:var(--ink);white-space:nowrap}
.brand:hover{color:var(--teal)}
nav{margin-left:auto;display:flex;gap:20px;flex-wrap:wrap}
nav a{
  font-size:14px;text-decoration:none;color:var(--ink-soft);
  border-bottom:2px solid transparent;padding-bottom:2px;
}
nav a:hover{color:var(--teal)}
nav a[aria-current="page"]{color:var(--ink);border-bottom-color:var(--teal)}

/* ------------------------------------------------------------------ type */
main{padding:56px 0 40px}
h1{font-size:33px;line-height:1.2;letter-spacing:-.025em;font-weight:700;margin:0 0 18px}
h2{
  font-size:14px;font-weight:600;letter-spacing:.08em;text-transform:uppercase;
  color:var(--teal);margin:46px 0 14px;
  font-family:"IBM Plex Mono",ui-monospace,monospace;
}
h3{font-size:19px;font-weight:600;letter-spacing:-.01em;margin:0 0 8px}
p{margin:0 0 18px}
.lede{font-size:19px;line-height:1.6}
a{color:var(--teal);text-underline-offset:3px}
a:hover{color:var(--teal-deep)}
strong{font-weight:600}
ul{margin:0 0 18px;padding-left:20px}
li{margin:0 0 10px}
.rule{height:3px;width:56px;background:var(--teal);border-radius:2px;margin:0 0 28px}
.muted{color:var(--ink-soft)}
.small{font-size:15px}

dl{margin:0}
dt{font-weight:600;margin-top:18px}
dt:first-child{margin-top:0}
dd{margin:4px 0 0;color:var(--ink-soft)}

/* --------------------------------------------------------------- panels */
.panel{
  background:var(--surface);
  border:1px solid var(--line);
  border-left:3px solid var(--teal);
  border-radius:6px;
  padding:20px 22px;
  margin:32px 0;
}
.panel h2{margin-top:0}
.panel p:last-child{margin-bottom:0}
.panel.warn{border-left-color:var(--amber)}

/* ---------------------------------------------------------------- cards */
.cards{display:grid;gap:18px;margin:28px 0 8px}
.card{
  display:block;text-decoration:none;color:inherit;
  background:var(--surface);border:1px solid var(--line);border-radius:8px;
  padding:20px 22px;transition:border-color .15s ease;
}
.card:hover{border-color:var(--teal)}
.card h3{color:var(--ink)}
.card p{margin:0;color:var(--ink-soft);font-size:16px}
.card .tagline{
  font-family:"IBM Plex Mono",ui-monospace,monospace;
  font-size:11px;letter-spacing:.09em;text-transform:uppercase;color:var(--teal);
  display:block;margin-bottom:6px;
}

/* --------------------------------------------------------------- figures */
figure{margin:26px 0}
figure img{
  width:100%;height:auto;display:block;
  border:1px solid var(--line);border-radius:6px;background:#0b1116;
}
figcaption{
  margin-top:9px;font-size:14px;color:var(--ink-soft);line-height:1.5;
}

/* --------------------------------------------------------------- status */
.status{
  display:inline-flex;align-items:center;gap:8px;
  font-family:"IBM Plex Mono",ui-monospace,monospace;
  font-size:12px;letter-spacing:.06em;text-transform:uppercase;
  border:1px solid var(--line);border-radius:99px;padding:5px 12px;
  color:var(--ink-soft);
}
.status .dot{width:8px;height:8px;border-radius:50%;background:var(--amber)}

.btn{
  display:inline-block;text-decoration:none;
  background:var(--teal);color:#ffffff;font-weight:600;font-size:16px;
  border-radius:6px;padding:11px 20px;margin:4px 0;
}
.btn:hover{background:var(--teal-deep);color:#ffffff}
@media (prefers-color-scheme: dark){
  .btn{color:#021420}
  .btn:hover{color:#021420}
}

.contact{font-family:"IBM Plex Mono",ui-monospace,monospace;font-size:15px;line-height:1.9}

/* --------------------------------------------------------------- footer */
footer{border-top:1px solid var(--line);padding:24px 0 48px;color:var(--ink-soft);font-size:14px}
footer p{margin:0 0 6px}

@media (max-width:560px){
  main{padding:40px 0 28px}
  h1{font-size:27px}
  nav{margin-left:0;width:100%;gap:16px}
}