/* ==========================================================================
   Kurs portal — global stylesheet
   Brand: orange accent (#FF6900) on near-black (#0A0A0A)
   Font: Mona Sans (Google Fonts: 200, 300, 700, 900)
   Edges: sharp (border-radius: 0)
   ========================================================================== */

:root {
  --accent: #FF6900;
  --accent-tint: rgba(255, 105, 0, 0.08);
  --accent-strong: rgba(255, 105, 0, 0.18);
  --bg: #0A0A0A;
  --bg-2: #141414;
  --code-bg: #161616;
  --fg: #FFFFFF;
  --fg-2: rgba(255, 255, 255, 0.65);
  --fg-3: rgba(255, 255, 255, 0.66);
  --border: rgba(255, 255, 255, 0.14);
  --border-strong: rgba(255, 255, 255, 0.28);
  --field-bg: rgba(255, 255, 255, 0.04);
  --ok: #2ecc71;
  --err-c: #ff4d4d;
}

/* ---------- Reset ---------- */

*, *::before, *::after { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  min-height: 100%;
}

body {
  font-family: 'Mona Sans', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-weight: 300;
  font-size: 16px;
  line-height: 1.5;
  letter-spacing: 0;
  background: var(--bg);
  color: var(--fg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

img, svg, video {
  max-width: 100%;
  height: auto;
  display: block;
}

::selection {
  background: var(--accent);
  color: var(--bg);
}

/* ---------- Container ---------- */

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 clamp(20px, 4vw, 48px);
}

/* ---------- Headings (sharp Mona Sans 700/900) ---------- */

h1, h2, h3, h4, h5, h6 {
  font-family: 'Mona Sans', system-ui, sans-serif;
  margin: 0 0 16px;
  letter-spacing: -0.01em;
  line-height: 1.15;
  color: var(--fg);
}

h1 {
  font-weight: 900;
  font-size: clamp(36px, 5vw, 64px);
  line-height: 1.05;
  letter-spacing: -0.02em;
}

h2 {
  font-weight: 900;
  font-size: clamp(28px, 3.4vw, 42px);
  letter-spacing: -0.015em;
  margin-top: 48px;
}

h3 {
  font-weight: 700;
  font-size: clamp(20px, 2.2vw, 26px);
  margin-top: 32px;
}

h4 {
  font-weight: 700;
  font-size: 18px;
  color: var(--fg-2);
}

p {
  margin: 0 0 16px;
  color: var(--fg-2);
}

p.lead {
  font-size: clamp(17px, 1.6vw, 20px);
  color: var(--fg);
  font-weight: 300;
  line-height: 1.45;
}

hr {
  border: 0;
  border-top: 1px solid var(--border);
  margin: 48px 0;
}

/* ---------- Links ---------- */

a {
  color: var(--fg);
  text-decoration: none;
  transition: color .15s ease, text-decoration-color .15s ease;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

a:hover {
  color: var(--accent);
  text-decoration: underline;
  text-decoration-color: var(--accent);
}

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

/* ---------- Hero ---------- */

.hero {
  padding: clamp(64px, 10vw, 140px) 0 clamp(48px, 7vw, 96px);
  border-bottom: 1px solid var(--border);
}

.hero .eyebrow {
  display: inline-block;
  font-weight: 700;
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 22px;
}

.hero h1 {
  font-weight: 900;
  font-size: clamp(40px, 6.5vw, 84px);
  line-height: 1.02;
  letter-spacing: -0.025em;
  margin: 0 0 20px;
  max-width: 14ch;
}

.hero .subtitle,
.hero .sub {
  color: var(--fg-2);
  font-size: clamp(17px, 1.7vw, 22px);
  font-weight: 300;
  line-height: 1.4;
  max-width: 60ch;
  margin: 0 0 32px;
}

.hero .actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 32px;
}

/* ---------- Card ---------- */

.card {
  background: transparent;
  border-left: 3px solid var(--accent);
  padding: clamp(24px, 3vw, 36px) clamp(20px, 2.6vw, 32px);
  margin: 0 0 24px;
}

.card.muted {
  border-left-color: var(--border-strong);
}

.card h2,
.card h3 {
  margin-top: 0;
}

.card .card-title {
  font-weight: 700;
  font-size: 18px;
  margin: 0 0 8px;
  color: var(--fg);
}

.card .card-meta {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--fg-3);
  margin: 0 0 12px;
}

.card p:last-child { margin-bottom: 0; }

/* ---------- Grids ---------- */

.grid-cols-2,
.grid-cols-3 {
  display: grid;
  gap: 24px;
  margin: 0 0 32px;
}

.grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }

/* ---------- Buttons ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  font-family: inherit;
  font-weight: 700;
  font-size: 15px;
  line-height: 1;
  padding: 14px 22px;
  border-radius: 0;
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: filter .15s ease, background .15s ease, border-color .15s ease, color .15s ease;
  white-space: nowrap;
}

.btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.btn-primary:focus-visible,
.btn.primary:focus-visible {
  outline: 2px solid var(--fg);
  outline-offset: 2px;
}

.btn-primary,
.btn.primary {
  background: var(--accent);
  color: var(--bg);
  border-color: var(--accent);
}

.btn-primary:hover,
.btn.primary:hover {
  filter: brightness(1.08);
  color: var(--bg);
  text-decoration: none;
}

.btn-primary:active,
.btn.primary:active { filter: brightness(0.95); }

.btn-secondary,
.btn.secondary {
  background: transparent;
  color: var(--fg);
  border-color: var(--border-strong);
}

.btn-secondary:hover,
.btn.secondary:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-tint);
  text-decoration: none;
}

.btn:disabled,
.btn[aria-disabled="true"] {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

.btn-sm {
  font-size: 13px;
  padding: 12px 18px;
  min-height: 44px;
}

.err {
  color: var(--err-c);
  font-size: 14px;
  margin: 12px 0 0;
  min-height: 1em;
}

.footnote {
  color: var(--fg-3);
  font-size: 13px;
  margin-top: 16px;
}

/* ---------- Nav (sticky top) ---------- */

.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(10, 10, 10, 0.85);
  backdrop-filter: saturate(140%) blur(10px);
  -webkit-backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 16px clamp(20px, 4vw, 48px);
}

.nav-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 900;
  font-size: 16px;
  letter-spacing: -0.01em;
  color: var(--fg);
  text-decoration: none;
}

.nav-brand:hover { color: var(--accent); text-decoration: none; }

.nav-brand .dot {
  width: 10px;
  height: 10px;
  background: var(--accent);
  display: inline-block;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  display: inline-block;
  font-size: 14px;
  font-weight: 700;
  color: var(--fg-2);
  padding: 8px 12px;
  text-decoration: none;
  transition: color .15s ease, background .15s ease;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--accent);
  background: var(--accent-tint);
  text-decoration: none;
}

.nav-logout {
  font-family: inherit;
  font-size: 14px;
  font-weight: 700;
  color: var(--fg-2);
  background: transparent;
  border: 1px solid var(--border);
  padding: 10px 14px;
  min-height: 44px;
  cursor: pointer;
  transition: color .15s ease, border-color .15s ease;
}

.nav-logout:hover {
  color: var(--accent);
  border-color: var(--accent);
}

.nav-logout:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.nav-toggle {
  display: none;
  font-family: inherit;
  font-size: 22px;
  line-height: 1;
  color: var(--fg);
  background: transparent;
  border: 1px solid var(--border);
  padding: 0;
  width: 44px;
  height: 44px;
  cursor: pointer;
  transition: color .15s ease, border-color .15s ease;
}

.nav-toggle:hover,
.nav-toggle:focus-visible {
  color: var(--accent);
  border-color: var(--accent);
  outline: none;
}

.nav-toggle:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* ---------- Code ---------- */

code,
kbd,
samp,
pre {
  font-family: 'JetBrains Mono', 'Fira Code', 'SF Mono', Menlo, Consolas, 'Liberation Mono', monospace;
  font-size: 0.92em;
}

code {
  background: var(--code-bg);
  color: var(--accent);
  border: 1px solid var(--border);
  padding: 2px 6px;
  font-weight: 400;
  white-space: nowrap;
  overflow-wrap: anywhere;
  word-break: break-word;
}

@media (max-width: 480px) {
  code { white-space: normal; }
}

pre {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  padding: 16px 20px;
  margin: 0 0 24px;
  overflow-x: auto;
  line-height: 1.55;
  font-size: 14px;
  color: var(--fg);
}

pre code {
  background: transparent;
  border: 0;
  padding: 0;
  color: inherit;
  white-space: pre;
  font-size: inherit;
}

kbd {
  background: var(--bg-2);
  border: 1px solid var(--border-strong);
  border-bottom-width: 2px;
  padding: 2px 6px;
  font-size: 0.85em;
  color: var(--fg);
}

/* ---------- Badge ---------- */

.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-weight: 700;
  font-size: 11px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-tint);
  border: 1px solid var(--accent-strong);
  padding: 4px 8px;
  line-height: 1.2;
}

.badge.solid {
  background: var(--accent);
  color: var(--bg);
  border-color: var(--accent);
}

.badge.muted {
  color: var(--fg-3);
  background: var(--field-bg);
  border-color: var(--border);
}

/* ---------- Forms (carry-over from reference) ---------- */

label { display: grid; gap: 6px; }

.label-text {
  font-weight: 700;
  font-size: 12px;
  color: var(--fg-3);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

input[type="text"],
input[type="email"],
input[type="password"],
input[type="search"],
input[type="url"],
input[type="number"],
textarea,
select {
  font: inherit;
  font-weight: 300;
  font-size: 16px;
  color: var(--fg);
  background: var(--field-bg);
  border: 1px solid var(--border);
  border-radius: 0;
  padding: 12px 14px;
  outline: none;
  width: 100%;
  transition: border-color .15s ease, background .15s ease;
}

textarea {
  min-height: 100px;
  line-height: 1.5;
  resize: vertical;
  font-family: 'Mona Sans', system-ui, sans-serif;
}

input:focus,
textarea:focus,
select:focus {
  border-color: var(--accent);
  background: var(--accent-tint);
}

input:focus-visible,
textarea:focus-visible,
select:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* ---------- Lists ---------- */

ul, ol {
  margin: 0 0 16px;
  padding-left: 22px;
  color: var(--fg-2);
}

li { margin: 0 0 6px; }

ul.clean {
  list-style: none;
  padding-left: 0;
}

ul.clean li {
  position: relative;
  padding-left: 18px;
}

ul.clean li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.65em;
  width: 8px;
  height: 1px;
  background: var(--accent);
}

/* ---------- Tables ---------- */

table {
  width: 100%;
  border-collapse: collapse;
  margin: 0 0 24px;
  font-size: 14px;
}

th, td {
  padding: 12px 14px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

th {
  font-weight: 700;
  font-size: 12px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--fg-3);
}

td { color: var(--fg-2); }

/* ---------- Mobile ---------- */

@media (max-width: 768px) {
  body { font-size: 15px; }

  .container { padding: 0 20px; }

  .hero { padding: 56px 0 40px; }
  .hero h1 { font-size: clamp(32px, 9vw, 44px); }
  .hero .subtitle,
  .hero .sub { font-size: 16px; }
  .hero .actions { flex-direction: column; align-items: stretch; }
  .hero .actions .btn { width: 100%; }

  h2 { margin-top: 36px; }
  h3 { margin-top: 24px; }

  .card {
    border-left-width: 2px;
    padding: 20px 18px;
  }

  .grid-cols-2,
  .grid-cols-3 {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .nav-inner {
    padding: 12px 20px;
    gap: 12px;
    flex-wrap: wrap;
  }
  .nav-toggle { display: inline-flex; align-items: center; justify-content: center; }
  .nav-links {
    display: none;
    flex-basis: 100%;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    padding: 8px 0 12px;
    border-top: 1px solid var(--border);
    margin-top: 8px;
  }
  .nav-links[data-open="true"] { display: flex; }
  .nav-links a {
    padding: 12px 14px;
    font-size: 15px;
    min-height: 44px;
    display: flex;
    align-items: center;
  }
  .nav-logout { min-height: 44px; padding: 10px 14px; width: 100%; text-align: left; }

  pre { padding: 14px 16px; font-size: 13px; }

  table { font-size: 13px; }
  th, td { padding: 10px 8px; }
}

@media (max-width: 480px) {
  .nav-brand { font-size: 14px; }
  .btn { padding: 13px 18px; font-size: 14px; }
}

/* ---------- Notes rendering ---------- */

.notes-content {
  max-width: 75ch;
  font-size: 16px;
  line-height: 1.7;
}

.notes-content h2 {
  margin-top: 56px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  font-size: clamp(22px, 2.6vw, 30px);
  scroll-margin-top: 80px;
}

.notes-content h2 .anchor {
  color: var(--fg-3);
  font-weight: 400;
  margin-right: 8px;
  text-decoration: none;
  opacity: 0;
  transition: opacity .15s ease;
}

.notes-content h2:hover .anchor,
.notes-content h2 .anchor:focus-visible {
  opacity: 1;
}

.notes-content h3 {
  margin-top: 32px;
  font-size: clamp(18px, 2vw, 22px);
}

.notes-content p {
  margin: 0 0 18px;
  color: var(--fg-2);
}

.notes-content hr {
  border: 0;
  border-top: 1px solid var(--border);
  margin: 32px 0;
}

.notes-content ul {
  color: var(--fg-2);
  padding-left: 24px;
}

.notes-content li {
  margin-bottom: 8px;
}

.notes-content blockquote {
  border-left: 3px solid var(--accent);
  padding: 4px 16px;
  margin: 16px 0;
  background: var(--accent-tint);
}

.notes-content code {
  background: var(--code-bg);
  padding: 2px 6px;
  border: 1px solid var(--border);
}

.notes-content pre {
  margin: 16px 0;
}

/* ---------- A11y helpers ---------- */

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  top: -40px;
  left: 8px;
  background: var(--accent);
  color: var(--bg);
  padding: 10px 16px;
  font-weight: 700;
  text-decoration: none;
  z-index: 9999;
  transition: top .15s ease;
}

.skip-link:focus,
.skip-link:focus-visible {
  top: 8px;
  outline: 2px solid var(--fg);
  outline-offset: 2px;
}

main#main,
.notes-content .slide-anchor,
.card[id] {
  scroll-margin-top: 80px;
}

.notes-content .slide-anchor {
  display: block;
}

/* ---------- Reduced motion ---------- */

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* ---------- Forced colors (Windows high contrast) ---------- */

@media (forced-colors: active) {
  .nav-brand .dot {
    forced-color-adjust: none;
    background: Highlight;
  }
  .btn-primary,
  .btn.primary {
    forced-color-adjust: none;
    background: Highlight;
    color: HighlightText;
    border-color: Highlight;
  }
  .skip-link {
    forced-color-adjust: none;
    background: Highlight;
    color: HighlightText;
  }
  .badge,
  .card {
    border-color: CanvasText;
  }
}

/* ---------- Print ---------- */

@media print {
  :root {
    --bg: #ffffff;
    --bg-2: #f5f5f5;
    --code-bg: #f5f5f5;
    --fg: #000000;
    --fg-2: #1a1a1a;
    --fg-3: #333333;
    --border: rgba(0, 0, 0, 0.2);
    --border-strong: rgba(0, 0, 0, 0.4);
    --field-bg: #ffffff;
  }
  body {
    background: #ffffff;
    color: #000000;
    -webkit-print-color-adjust: exact;
    print-color-adjust: exact;
  }
  .nav,
  .skip-link,
  .nav-toggle,
  .nav-logout,
  .actions,
  .btn {
    display: none !important;
  }
  a {
    color: #000000;
    text-decoration: underline;
  }
  a[href^="http"]::after {
    content: " (" attr(href) ")";
    font-size: 0.85em;
    color: #555;
  }
  .hero {
    padding: 0 0 16px;
    border-bottom: 1px solid #000;
  }
  .notes-content h2 {
    page-break-before: auto;
    page-break-after: avoid;
    border-top: 1px solid #000;
  }
  .notes-content h2 .anchor { display: none; }
  pre, code, blockquote {
    page-break-inside: avoid;
  }
  pre {
    border: 1px solid #000;
    background: #f5f5f5;
    color: #000;
    white-space: pre-wrap;
    word-wrap: break-word;
  }
  pre code {
    white-space: pre-wrap;
    word-wrap: break-word;
  }
  footer {
    border-top: 1px solid #000;
    margin-top: 24px;
    padding: 16px 0;
  }
}