/* Dev Journey — theme
   Every color lives in these variables. Restyle the whole site here. */

:root {
  --bg: #0d1117;
  --bg-elev: #161b22;
  --bg-elev-2: #1c2128;
  --border: #30363d;
  --border-soft: #21262d;
  --text: #e6edf3;
  --text-strong: #ffffff;
  --muted: #8b949e;
  --accent: #58a6ff;
  --accent-soft: rgba(88, 166, 255, 0.12);
  --good: #3fb950;
  --good-soft: rgba(63, 185, 80, 0.14);
  --bad: #f85149;
  --bad-soft: rgba(248, 81, 73, 0.12);
  --warn: #d29922;
  --code-bg: #1f242c;
  --radius: 10px;
  --radius-sm: 6px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --content-width: 46rem;
  --wrap-width: 64rem;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 16.5px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

.wrap { max-width: var(--wrap-width); margin: 0 auto; padding: 0 1.25rem; }

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

h1, h2, h3 { color: var(--text-strong); line-height: 1.25; letter-spacing: -0.01em; }
h1 { font-size: 2.1rem; margin: 0 0 0.5rem; }
h2 { font-size: 1.5rem; margin: 2.2rem 0 0.8rem; }
h3 { font-size: 1.1rem; margin: 0; }

code, pre {
  font-family: var(--mono);
  font-size: 0.88em;
}

code {
  background: var(--code-bg);
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  padding: 0.12em 0.4em;
}

pre {
  background: var(--code-bg);
  border: 1px solid var(--border-soft);
  border-radius: var(--radius);
  padding: 0.9rem 1.1rem;
  overflow-x: auto;
  line-height: 1.5;
}
pre code { background: none; border: none; padding: 0; }

/* ---------- header ---------- */
.site-header {
  border-bottom: 1px solid var(--border);
  background: rgba(13, 17, 23, 0.85);
  backdrop-filter: blur(8px);
  position: sticky;
  top: 0;
  z-index: 10;
}
.site-header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 3.4rem;
}
.site-logo {
  color: var(--text-strong);
  font-weight: 700;
  font-size: 1.15rem;
}
.site-logo:hover { text-decoration: none; }
.logo-mark {
  color: var(--accent);
  font-family: var(--mono);
  margin-right: 0.1rem;
}
.site-nav { display: flex; gap: 1.4rem; }
.site-nav a { color: var(--muted); font-size: 0.95rem; }
.site-nav a:hover { color: var(--text); text-decoration: none; }

/* ---------- home ---------- */
.hero { padding: 3.5rem 0 1rem; }
.hero h1 { font-size: 2.8rem; }
.tagline { color: var(--muted); font-size: 1.2rem; margin: 0.4rem 0 1rem; max-width: 40rem; }
.hero-stats { color: var(--muted); font-size: 0.95rem; }

.rank { margin: 2.5rem 0 3.5rem; }
.rank-blurb { color: var(--muted); margin: 0 0 1.4rem; }

.course-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1rem;
}

.course-card {
  display: flex;
  gap: 0.9rem;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.1rem;
  color: var(--text);
  transition: border-color 0.15s, transform 0.15s;
}
.course-card:hover { border-color: var(--accent); transform: translateY(-2px); text-decoration: none; }
.course-card-img { width: 64px; height: 64px; border-radius: var(--radius-sm); object-fit: contain; flex-shrink: 0; }
.course-card-body { display: flex; flex-direction: column; gap: 0.25rem; min-width: 0; }
.course-card-body p { margin: 0; color: var(--muted); font-size: 0.9rem; line-height: 1.45; }
.course-card-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: auto;
  font-size: 0.8rem;
  color: var(--muted);
  padding-top: 0.5rem;
}
.course-pct { color: var(--good); font-weight: 600; }

.progress-bar {
  height: 5px;
  background: var(--border-soft);
  border-radius: 3px;
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  background: var(--good);
  border-radius: 3px;
  transition: width 0.3s;
}

/* ---------- course page ---------- */
.breadcrumbs { margin: 1.4rem 0 1.2rem; color: var(--muted); font-size: 0.9rem; }
.breadcrumbs span { margin: 0 0.35rem; }

.page-head { display: flex; gap: 1.2rem; align-items: center; margin-bottom: 1rem; }
.course-head-img { width: 84px; height: 84px; object-fit: contain; flex-shrink: 0; }
.lede { color: var(--muted); margin: 0; max-width: 40rem; }

.course-progress { margin: 1.2rem 0 0.4rem; max-width: 36rem; }
.course-progress-text { color: var(--muted); font-size: 0.85rem; margin: 0.4rem 0 0; }

.lesson-list { list-style: none; padding: 0; margin: 1rem 0 0; }
.lesson-row { border-bottom: 1px solid var(--border-soft); }
.lesson-row:first-child { border-top: 1px solid var(--border-soft); }
.lesson-link {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.8rem 0.6rem;
  color: var(--text);
  border-radius: var(--radius-sm);
}
.lesson-link:hover { background: var(--bg-elev); text-decoration: none; }
.lesson-num { color: var(--muted); font-family: var(--mono); font-size: 0.85rem; flex-shrink: 0; }
.lesson-text { display: flex; flex-direction: column; gap: 0.1rem; min-width: 0; }
.lesson-title { font-weight: 600; color: var(--text-strong); }
.lesson-desc { color: var(--muted); font-size: 0.88rem; }
.lesson-check { color: var(--good); font-weight: 700; margin-left: auto; flex-shrink: 0; }
.lesson-row.is-complete .lesson-num { color: var(--good); }

.faq { border: 1px solid var(--border-soft); border-radius: var(--radius-sm); margin: 0.5rem 0; background: var(--bg-elev); }
.faq summary { padding: 0.7rem 0.9rem; cursor: pointer; font-weight: 600; color: var(--text-strong); }
.faq p { padding: 0 0.9rem 0.8rem; margin: 0; color: var(--muted); }

/* ---------- lesson page ---------- */
.page-lesson main { max-width: var(--content-width); }
.page-lesson .wrap { max-width: var(--content-width); }

.lesson { padding-bottom: 3rem; }
.lesson-head { margin: 1rem 0 1.6rem; }
.lesson-kicker { color: var(--muted); font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.06em; margin: 0 0 0.3rem; }
.lesson-progress { color: var(--muted); font-size: 0.9rem; margin: 0.6rem 0 0; }

.lesson-body h2 { font-size: 1.35rem; margin-top: 2.4rem; }
.lesson-body p { margin: 0.9rem 0; }
.lesson-body ul, .lesson-body ol { padding-left: 1.4rem; }
.lesson-body li { margin: 0.35rem 0; }
.lesson-body blockquote {
  border-left: 3px solid var(--accent);
  margin: 1.2rem 0;
  padding: 0.2rem 0 0.2rem 1rem;
  color: var(--muted);
}

/* quiz */
.quiz {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.1rem 1.2rem;
  margin: 1.6rem 0;
}
.quiz-question {
  display: flex;
  gap: 0.6rem;
  align-items: flex-start;
  margin: 0 0 0.9rem;
  font-weight: 600;
  color: var(--text-strong);
}
.quiz-badge {
  background: var(--accent-soft);
  color: var(--accent);
  border: 1px solid var(--accent);
  border-radius: 999px;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.15em 0.7em;
  white-space: nowrap;
  flex-shrink: 0;
}
.quiz-options { display: flex; flex-direction: column; gap: 0.5rem; }
.quiz-option {
  text-align: left;
  background: var(--bg-elev-2);
  border: 1px solid var(--border);
  color: var(--text);
  font-family: var(--font);
  font-size: 0.98rem;
  border-radius: var(--radius-sm);
  padding: 0.6rem 0.9rem;
  cursor: pointer;
  transition: border-color 0.12s, background 0.12s;
}
.quiz-option:hover { border-color: var(--accent); background: var(--bg-elev); }
.quiz-option.picked { pointer-events: none; }
.quiz-option.picked.is-correct, .quiz-option.picked:not(.wrong) {
  border-color: var(--good);
  background: var(--good-soft);
  color: var(--text-strong);
}
.quiz-option.picked.wrong {
  border-color: var(--bad);
  background: var(--bad-soft);
}
.quiz-option.reveal-correct { border-color: var(--good); }
.quiz-feedback {
  margin: 0.9rem 0 0;
  padding: 0.7rem 0.9rem;
  background: var(--bg-elev-2);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-soft);
  font-size: 0.92rem;
  color: var(--muted);
}
.fb-ok { color: var(--good); font-weight: 700; }
.fb-bad { color: var(--bad); font-weight: 700; }
.fb-correct-answer { display: block; margin-top: 0.4rem; }

/* completion + nav */
.lesson-complete {
  margin: 2.2rem 0;
  padding: 1.2rem 1.4rem;
  border: 1px solid var(--good);
  background: var(--good-soft);
  border-radius: var(--radius);
}
.lesson-complete h2 { margin: 0 0 0.4rem; color: var(--good); font-size: 1.2rem; }
.lesson-complete p { margin: 0; color: var(--text); }

.lesson-nav {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 2.5rem;
  padding-top: 1.2rem;
  border-top: 1px solid var(--border);
}
.lesson-nav a {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.55rem 0.9rem;
  font-size: 0.92rem;
  color: var(--text);
  max-width: 48%;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.lesson-nav a:hover { border-color: var(--accent); text-decoration: none; }

/* ---------- footer ---------- */
.site-footer {
  border-top: 1px solid var(--border);
  margin-top: 4rem;
  padding: 1.6rem 0 2.2rem;
  color: var(--muted);
  font-size: 0.85rem;
}
.site-footer p { max-width: 50rem; }

/* ---------- header search + sync ---------- */
.header-search { flex: 1 1 9rem; max-width: 15rem; margin-left: auto; }
.header-search input {
  width: 100%;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 999px;
  padding: 0.35rem 0.9rem;
  font-size: 0.88rem;
  font-family: var(--font);
}
.header-search input::placeholder { color: var(--muted); }
.header-search input:focus { outline: none; border-color: var(--accent); }

.sync-btn {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 999px;
  padding: 0.3rem 0.8rem;
  font-size: 0.85rem;
  font-family: var(--font);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  white-space: nowrap;
  flex-shrink: 0;
}
.sync-btn:hover { border-color: var(--accent); }
.sync-indicator { font-size: 0.7rem; color: var(--muted); }
.sync-indicator[data-state="synced"] { color: var(--good); }
.sync-indicator[data-state="error"] { color: var(--bad); }
.sync-indicator[data-state="pending"] { color: var(--warn); }

/* ---------- modal ---------- */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(1, 4, 9, 0.68);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 40;
  padding: 1rem;
}
.modal-backdrop[hidden] { display: none; }
.modal {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.4rem;
  width: 100%;
  max-width: 26rem;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.55);
}
.modal h2 { margin: 0 0 0.5rem; font-size: 1.25rem; }
.modal-help { color: var(--muted); font-size: 0.88rem; margin: 0 0 1rem; }
.modal-label {
  display: block;
  font-size: 0.75rem;
  color: var(--muted);
  margin-bottom: 0.3rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.modal-input {
  width: 100%;
  background: var(--bg-elev-2);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: var(--radius-sm);
  padding: 0.5rem 0.7rem;
  font-size: 0.95rem;
  font-family: var(--font);
}
.modal-input:focus { outline: none; border-color: var(--accent); }
.modal-actions { display: flex; gap: 0.5rem; margin-top: 1.1rem; align-items: center; }
.modal-spacer { flex: 1; }
.btn {
  border-radius: var(--radius-sm);
  padding: 0.45rem 0.9rem;
  font-size: 0.9rem;
  cursor: pointer;
  border: 1px solid var(--border);
  font-family: var(--font);
}
.btn-ghost { background: transparent; color: var(--muted); }
.btn-ghost:hover { color: var(--text); border-color: var(--muted); }
.btn-danger:hover { color: var(--bad); border-color: var(--bad); }
.btn-primary { background: var(--accent); border-color: var(--accent); color: #0d1117; font-weight: 600; }
.btn-primary:hover { filter: brightness(1.12); }

/* ---------- AI tutor chat widget ---------- */
.chat-fab {
  position: fixed;
  right: 1.1rem;
  bottom: 1.1rem;
  z-index: 30;
  width: 3.3rem;
  height: 3.3rem;
  border-radius: 50%;
  background: var(--bg-elev);
  border: 1px solid var(--accent);
  color: var(--accent);
  font-weight: 700;
  font-family: var(--mono);
  font-size: 0.95rem;
  cursor: pointer;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.45);
  transition: transform 0.15s;
}
.chat-fab:hover { transform: scale(1.06); }

.chat-panel {
  position: fixed;
  right: 1.1rem;
  bottom: 5rem;
  z-index: 30;
  width: 22rem;
  max-width: calc(100vw - 2.2rem);
  height: min(28rem, calc(100vh - 7rem));
  display: flex;
  flex-direction: column;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.55);
  overflow: hidden;
}
.chat-panel[hidden] { display: none; }
.chat-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.7rem 0.9rem;
  border-bottom: 1px solid var(--border-soft);
  font-weight: 600;
  color: var(--text-strong);
}
.chat-close {
  background: none;
  border: none;
  color: var(--muted);
  font-size: 1.25rem;
  cursor: pointer;
  line-height: 1;
  padding: 0 0.2rem;
}
.chat-close:hover { color: var(--text); }
.chat-msgs {
  flex: 1;
  overflow-y: auto;
  padding: 0.8rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.chat-msg {
  max-width: 85%;
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius-sm);
  font-size: 0.92rem;
  line-height: 1.5;
  white-space: pre-wrap;
  word-wrap: break-word;
  overflow-wrap: break-word;
  background: var(--bg-elev-2);
  border: 1px solid var(--border-soft);
  align-self: flex-start;
}
.chat-msg-user {
  align-self: flex-end;
  background: var(--accent-soft);
  border-color: var(--accent);
}
.chat-msg.chat-error {
  background: var(--bad-soft);
  border-color: var(--bad);
}
.chat-status {
  margin: 0;
  padding: 0.4rem 0.9rem;
  font-size: 0.82rem;
  color: var(--warn);
  border-top: 1px solid var(--border-soft);
}
.chat-form {
  display: flex;
  gap: 0.5rem;
  padding: 0.6rem;
  border-top: 1px solid var(--border-soft);
}
.chat-input {
  flex: 1;
  min-width: 0;
  background: var(--bg-elev-2);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: var(--radius-sm);
  padding: 0.5rem 0.7rem;
  font-size: 0.92rem;
  font-family: var(--font);
}
.chat-input:focus { outline: none; border-color: var(--accent); }
.chat-send {
  background: var(--accent);
  color: #0d1117;
  border: none;
  border-radius: var(--radius-sm);
  padding: 0 0.9rem;
  font-weight: 600;
  cursor: pointer;
  font-family: var(--font);
}

/* ---------- practice links ---------- */
.practice-area { margin: 0.9rem 0 0; }
.practice-link {
  display: inline-block;
  border: 1px solid var(--border);
  background: var(--bg-elev);
  color: var(--accent);
  border-radius: 999px;
  padding: 0.35rem 0.9rem;
  font-size: 0.88rem;
}
.practice-link:hover { border-color: var(--accent); text-decoration: none; }

/* ---------- quiz keyboard hint ---------- */
.quiz-hint { margin: -0.5rem 0 0.8rem; font-size: 0.75rem; color: var(--muted); }
.quiz-hint[hidden] { display: none; }

/* ---------- playgrounds page ---------- */
.playground-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1rem;
  margin: 1.5rem 0;
}
.playground-card {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.1rem;
  color: var(--text);
  display: block;
  transition: border-color 0.15s, transform 0.15s;
}
.playground-card:hover { border-color: var(--accent); transform: translateY(-2px); text-decoration: none; }
.playground-card h3 { margin-bottom: 0.4rem; }
.playground-card p { margin: 0 0 0.6rem; color: var(--muted); font-size: 0.9rem; }
.playground-port { font-family: var(--mono); font-size: 0.78rem; color: var(--accent); }

/* ---------- home: distros + books ---------- */
.distro-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 0.6rem;
}
.distro-card {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.6rem 0.85rem;
  color: var(--text);
  font-weight: 600;
  font-size: 0.92rem;
}
.distro-card:hover { border-color: var(--accent); text-decoration: none; }

.book-list {
  list-style: none;
  padding: 0;
  margin: 0.6rem 0 0;
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
}
.book-list li { display: flex; flex-wrap: wrap; gap: 0 0.5rem; align-items: baseline; }
.book-note { color: var(--muted); font-size: 0.88rem; }

/* ---------- search page ---------- */
.search-page { padding-bottom: 2rem; }
.search-page h1 { margin-top: 1.6rem; }
.search-input-big {
  width: 100%;
  max-width: 34rem;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: var(--radius);
  padding: 0.7rem 1rem;
  font-size: 1.05rem;
  margin: 1rem 0 0.2rem;
  font-family: var(--font);
}
.search-input-big:focus { outline: none; border-color: var(--accent); }
.search-meta { color: var(--muted); font-size: 0.85rem; margin: 0 0 1rem; }
.search-results { list-style: none; padding: 0; margin: 0; }
.search-result { border-bottom: 1px solid var(--border-soft); }
.search-result:first-child { border-top: 1px solid var(--border-soft); }
.search-result a { display: block; padding: 0.8rem 0.5rem; color: var(--text); border-radius: var(--radius-sm); }
.search-result a:hover { background: var(--bg-elev); text-decoration: none; }
.search-result-title { font-weight: 600; color: var(--text-strong); }
.search-result-course { color: var(--accent); font-size: 0.8rem; margin-left: 0.5rem; }
.search-result-desc { color: var(--muted); font-size: 0.88rem; margin: 0.15rem 0 0; }
.search-empty { color: var(--muted); padding: 2rem 0; }

/* ---------- responsive ---------- */
@media (max-width: 800px) {
  .site-header-inner { flex-wrap: wrap; padding-top: 0.6rem; padding-bottom: 0.6rem; }
  .header-search { order: 3; flex-basis: 100%; max-width: none; margin-left: 0; }
  .sync-btn { margin-left: auto; }
}

@media (max-width: 640px) {
  .hero h1 { font-size: 2.1rem; }
  .page-head { flex-direction: column; align-items: flex-start; }
  .lesson-nav { flex-direction: column; }
  .lesson-nav a { max-width: 100%; }
  .site-nav { gap: 0.9rem; }
  .chat-panel { right: 0.6rem; bottom: 4.6rem; width: calc(100vw - 1.2rem); max-width: none; }
  .chat-fab { right: 0.6rem; bottom: 0.6rem; }
}