/* ============================================================
   learn.cabbagebaggage.net — SSH-Keys unter Windows & GitLab
   ACTA Design System (Skandinavisch-Petroleum, Consulting-Grade)
   Struktur & Lernfluss im DataCamp-Kurs-Stil
   ============================================================ */

:root {
  /* ACTA Palette */
  --primary:        #2C5F7C;  /* Petroleum */
  --primary-dark:   #1A3440;  /* Deep Navy */
  --accent:         #3D8B8B;  /* Teal */
  --slate:          #8A9BA8;
  --charcoal:       #2D3436;
  --off-white:      #F5F6F7;
  --light-gray:     #F2F2F2;
  --dark-text:      #1A1A1A;
  --success:        #387359;
  --warning:        #CC9A33;
  --alert:          #BF3939;

  --surface:        #FFFFFF;
  --surface-alt:    #F7F9FA;
  --border:         #E2E8EC;

  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --mono: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;

  --radius: 10px;
  --shadow: 0 1px 3px rgba(26,52,64,.08), 0 8px 24px rgba(26,52,64,.06);
  --sidebar-w: 300px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  color: var(--dark-text);
  background: var(--off-white);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

/* ---------- Top bar ---------- */
.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 12px 22px;
  background: var(--primary-dark);
  color: #fff;
  border-bottom: 3px solid var(--primary);
}
.topbar .brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-weight: 700;
  letter-spacing: .3px;
}
.topbar .brand .logo { font-size: 20px; }
.topbar .brand .name { font-size: 16px; }
.topbar .tagline {
  font-size: 12px;
  color: rgba(255,255,255,.65);
  margin-left: auto;
  display: none;
}
@media (min-width: 720px) { .topbar .tagline { display: block; } }

/* ---------- Layout ---------- */
.layout {
  display: grid;
  grid-template-columns: var(--sidebar-w) 1fr;
  max-width: 1240px;
  margin: 0 auto;
  gap: 0;
}
@media (max-width: 900px) { .layout { grid-template-columns: 1fr; } }

/* ---------- Sidebar / TOC ---------- */
.sidebar {
  position: sticky;
  top: 61px;
  align-self: start;
  height: calc(100vh - 61px);
  overflow-y: auto;
  padding: 24px 18px 60px;
  border-right: 1px solid var(--border);
  background: var(--surface);
}
@media (max-width: 900px) {
  .sidebar {
    position: static;
    height: auto;
    border-right: none;
    border-bottom: 1px solid var(--border);
    padding: 18px;
  }
}
.sidebar h2 {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 1.2px;
  color: var(--slate);
  margin: 0 0 12px;
}
.toc { list-style: none; margin: 0; padding: 0; }
.toc li { margin: 0 0 2px; }
.toc a {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 10px;
  border-radius: 8px;
  text-decoration: none;
  color: var(--charcoal);
  font-size: 14px;
  transition: background .15s, color .15s;
}
.toc a:hover { background: var(--surface-alt); color: var(--primary); }
.toc a.active { background: #E6F0F7; color: var(--primary); font-weight: 600; }
.toc .num {
  flex: 0 0 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--light-gray);
  color: var(--primary);
  font-size: 12px;
  font-weight: 700;
  display: grid;
  place-items: center;
}
.toc a.active .num { background: var(--primary); color: #fff; }
.toc a.done .num { background: var(--success); color: #fff; }

.progress-wrap {
  margin: 22px 0 0;
  padding: 14px;
  background: var(--surface-alt);
  border-radius: var(--radius);
  border: 1px solid var(--border);
}
.progress-wrap .label {
  font-size: 12px;
  color: var(--slate);
  display: flex;
  justify-content: space-between;
  margin-bottom: 8px;
}
.progress-bar {
  height: 8px;
  background: var(--light-gray);
  border-radius: 99px;
  overflow: hidden;
}
.progress-bar span {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  transition: width .3s ease;
}

/* ---------- Main ---------- */
.main {
  padding: 40px 44px 120px;
  background: var(--surface);
  min-width: 0;
}
@media (max-width: 900px) { .main { padding: 26px 20px 90px; } }

/* Hero */
.hero { margin-bottom: 40px; }
.hero .kicker {
  display: inline-block;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 14px;
}
.hero h1 {
  font-size: 34px;
  line-height: 1.2;
  color: var(--primary-dark);
  margin: 0 0 16px;
  letter-spacing: -.4px;
}
.hero .lead { font-size: 17px; color: var(--charcoal); max-width: 68ch; }
.hero .meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}
.pill {
  font-size: 12.5px;
  padding: 6px 12px;
  border-radius: 99px;
  background: #E6F0F7;
  color: var(--primary);
  font-weight: 600;
}
.pill.ghost { background: var(--light-gray); color: var(--slate); }

hr.rule {
  border: none;
  border-top: 2px solid var(--primary);
  margin: 36px 0;
}

/* Chapter */
.chapter {
  padding-top: 46px;
  scroll-margin-top: 74px;
}
.chapter-head { display: flex; align-items: center; gap: 14px; margin-bottom: 6px; }
.chapter-head .cnum {
  flex: 0 0 40px;
  height: 40px;
  border-radius: 12px;
  background: var(--primary);
  color: #fff;
  font-weight: 700;
  display: grid;
  place-items: center;
  font-size: 16px;
}
.chapter h2 {
  font-size: 24px;
  color: var(--primary-dark);
  margin: 0;
  letter-spacing: -.2px;
}
.chapter .goal {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  background: var(--surface-alt);
  border-left: 4px solid var(--accent);
  border-radius: 0 8px 8px 0;
  padding: 14px 16px;
  margin: 18px 0 22px;
  font-size: 15px;
}
.chapter .goal strong { color: var(--primary); }

h3 { font-size: 17px; color: var(--charcoal); margin: 30px 0 10px; }
p { margin: 0 0 14px; }

/* Code */
code {
  font-family: var(--mono);
  font-size: .88em;
  background: var(--light-gray);
  padding: 2px 6px;
  border-radius: 5px;
  color: var(--primary-dark);
}
pre {
  background: var(--primary-dark);
  color: #E8EEF1;
  border-radius: var(--radius);
  padding: 16px 18px;
  overflow-x: auto;
  font-size: 13.5px;
  line-height: 1.6;
  margin: 0 0 18px;
  position: relative;
}
pre code {
  background: none;
  color: inherit;
  padding: 0;
  font-size: inherit;
}
pre .c { color: #7FB0C7; }        /* comment */
pre .k { color: #8FD3C7; }        /* key/flag */
pre .s { color: #E3BF74; }        /* string */

.copy-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  font-size: 11px;
  padding: 4px 9px;
  border-radius: 6px;
  border: 1px solid rgba(255,255,255,.25);
  background: rgba(255,255,255,.08);
  color: #DCE7EC;
  cursor: pointer;
  font-family: var(--font);
}
.copy-btn:hover { background: rgba(255,255,255,.18); }

/* Tables */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 0 0 20px;
  font-size: 14px;
}
th {
  background: var(--primary);
  color: #fff;
  text-align: left;
  padding: 10px 12px;
  font-weight: 600;
}
td { padding: 10px 12px; border-bottom: 1px solid var(--border); vertical-align: top; }
tr:nth-child(even) td { background: var(--surface-alt); }

/* Callouts */
.callout {
  display: flex;
  gap: 12px;
  border-radius: var(--radius);
  padding: 14px 16px;
  margin: 0 0 20px;
  font-size: 14.5px;
  border: 1px solid var(--border);
  background: var(--surface-alt);
}
.callout .ico { font-size: 18px; line-height: 1.4; }
.callout.tip    { border-left: 4px solid var(--accent); }
.callout.warn   { border-left: 4px solid var(--warning); background: #FDF8EC; }
.callout.alert  { border-left: 4px solid var(--alert); background: #FCEFEF; }
.callout.success{ border-left: 4px solid var(--success); background: #EDF6F1; }
.callout strong { color: var(--primary-dark); }

/* Steps */
.steps { counter-reset: step; list-style: none; padding: 0; margin: 0 0 20px; }
.steps > li {
  position: relative;
  padding: 4px 0 18px 44px;
  counter-increment: step;
  border-left: 2px solid var(--border);
  margin-left: 15px;
}
.steps > li:last-child { border-left-color: transparent; }
.steps > li::before {
  content: counter(step);
  position: absolute;
  left: -16px;
  top: 0;
  width: 30px;
  height: 30px;
  border-radius: 50%;
  background: #E6F0F7;
  color: var(--primary);
  font-weight: 700;
  font-size: 13px;
  display: grid;
  place-items: center;
  border: 2px solid var(--surface);
}

/* Exercise + Checkpoint (DataCamp feel) */
.exercise {
  border: 1px dashed var(--accent);
  border-radius: var(--radius);
  padding: 16px 18px;
  margin: 24px 0;
  background: #F4FAFA;
}
.exercise .tag, .checkpoint .tag {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--accent);
  display: block;
  margin-bottom: 6px;
}
.checkpoint {
  border-radius: var(--radius);
  padding: 16px 18px;
  margin: 24px 0 4px;
  background: #EDF6F1;
  border: 1px solid #CFE6DA;
}
.checkpoint .tag { color: var(--success); }
.checkpoint label {
  display: flex;
  gap: 10px;
  align-items: center;
  font-size: 14.5px;
  cursor: pointer;
  font-weight: 600;
  color: var(--primary-dark);
}
.checkpoint input { width: 18px; height: 18px; accent-color: var(--success); }

/* Diagram */
.diagram {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px;
  background: var(--surface-alt);
  margin: 0 0 22px;
  text-align: center;
}
.diagram .row {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
}
.node {
  background: #fff;
  border: 2px solid var(--primary);
  border-radius: 10px;
  padding: 12px 16px;
  font-size: 13.5px;
  font-weight: 600;
  color: var(--primary-dark);
  min-width: 130px;
}
.node small { display: block; font-weight: 400; color: var(--slate); font-size: 11.5px; }
.node.teal { border-color: var(--accent); }
.arrow { color: var(--slate); font-size: 22px; }
.diagram .caption { font-size: 12.5px; color: var(--slate); margin-top: 14px; }

/* Footer nav */
.footer {
  margin-top: 60px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 13px;
  color: var(--slate);
}
.footer a { color: var(--primary); text-decoration: none; font-weight: 600; }
.footer a:hover { text-decoration: underline; }

.brand-footer {
  text-align: center;
  margin-top: 60px;
  padding-top: 22px;
  border-top: 2px solid var(--primary);
  font-size: 12px;
  color: var(--slate);
}
.brand-footer strong { color: var(--primary); }

/* Cheatsheet two-col */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
@media (max-width: 720px) { .grid-2 { grid-template-columns: 1fr; } }
.card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  background: var(--surface-alt);
}
.card h4 { margin: 0 0 10px; color: var(--primary); font-size: 15px; }
.card ul { margin: 0; padding-left: 18px; font-size: 14px; }
.card li { margin-bottom: 6px; }

/* Mobile menu toggle */
.menu-toggle {
  display: none;
  background: none;
  border: 1px solid rgba(255,255,255,.3);
  color: #fff;
  border-radius: 8px;
  padding: 5px 10px;
  cursor: pointer;
  font-size: 14px;
}
@media (max-width: 900px) {
  .menu-toggle { display: block; margin-left: auto; }
  .toc-collapse { display: none; }
  .toc-collapse.open { display: block; }
}