/* ============================================================
   course.css: shared styles for "tech" course chapters (rule P1 "Styling").

   A chapter links this sheet and its own course sheet, and wraps its content in
       <div class="course-lesson <course>">
   where <course> is the course's slug (styles/courses/<course>.css sets that course's colours).
   Every rule is scoped under .course-lesson, so nothing leaks into the site.

   The colours that differ between courses are CSS variables; the value after the
   comma in var(--cN, value) is the default (the first course's colour). To start a
   new course in this genre, copy a sibling's styles/courses/<course>.css, rename its
   class and change the values.

   Variables:
     --accent         default #6ee7b7    e.g. .course-name
     --accent-strong  default #059669    e.g. .challenge-block .ch-num, h2
     --c1             default #6ee7b7    e.g. .challenge-block .ch-link, .compare-table .kw, .compare-table th
     --c2             default #6a737d    e.g. .code-block .cm
     --c3             default #6ee7b7    e.g. .code-block .kw
     --c4             default #7ecfa0    e.g. .code-block .st
     --c5             default #d2a8ff    e.g. .code-block .fn
     --c6             default #0f2417    e.g. .tip-box
     --c7             default #1f4d2c    e.g. .tip-box
     --c8             default #2ea043    e.g. .tip-box
     --c9             default #7ee787    e.g. .tip-box .tb-label
     --c10            default #1a1424    e.g. .finding-box
     --c11            default #3d2a5c    e.g. .finding-box
     --c12            default #a371f7    e.g. .finding-box
     --c13            default #d2a8ff    e.g. .finding-box .fb-label
     --accent-bg      default #0f2a22    e.g. .compare-table th
     --accent-ink     default #04150e    e.g. .challenge-block .ch-num
     --accent-border  default #14523f    e.g. .challenge-block .ch-link, .challenge-block .ch-link:ho
     --c14            default #0f2a22    e.g. .challenge-block .ch-link
     --c15            default #b3bce0    e.g. .quick-ref li strong
   ============================================================ */
.course-lesson {
  font-family: system-ui, -apple-system, sans-serif;
  background: transparent;
  color: #c9d1d9;
  padding: 1.5rem 0;
  line-height: 1.7;
}

.course-lesson *, .course-lesson *::before, .course-lesson *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

.course-lesson .lesson-head {
  margin-bottom: 1.6rem;
}

.course-lesson .course-name {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--accent, #6ee7b7);
  margin: 0 0 4px;
}

.course-lesson .chapter-sub {
  font-size: 0.85rem;
  color: #8b949e;
  letter-spacing: 0.02em;
  margin: 0;
}

.course-lesson h2 {
  font-size: 1.25rem;
  color: #ffffff;
  border-bottom: 2px solid var(--accent-strong, #059669);
  padding-bottom: 0.4rem;
  margin: 2.5rem 0 1.1rem;
}

.course-lesson h2:first-child {
  margin-top: 0;
}

.course-lesson h3 {
  font-size: 1rem;
  color: var(--c1, #6ee7b7);
  margin: 1.4rem 0 0.6rem;
}

.course-lesson p {
  margin-bottom: 0.9rem;
  color: #c9d1d9;
}

.course-lesson ul, .course-lesson ol {
  padding-left: 1.4rem;
  margin-bottom: 0.9rem;
}

.course-lesson li {
  margin-bottom: 0.35rem;
}

.course-lesson strong {
  color: #ffffff;
}

.course-lesson code {
  background: #161b22;
  border: 1px solid #30363d;
  border-radius: 4px;
  padding: 1px 6px;
  font-family: 'Consolas', monospace;
  color: var(--c1, #6ee7b7);
  font-size: 0.85em;
}

.course-lesson .code-block {
  background: #0d1117;
  border: 1px solid #30363d;
  border-radius: 8px;
  padding: 1rem 1.2rem;
  margin: 1rem 0 1.5rem;
  overflow-x: auto;
  font-family: 'Consolas', monospace;
  font-size: 0.85rem;
  line-height: 1.6;
  white-space: pre;
}

.course-lesson .code-block .cm {
  color: var(--c2, #6a737d);
}

.course-lesson .code-block .kw {
  color: var(--c3, #6ee7b7);
}

.course-lesson .code-block .st {
  color: var(--c4, #7ecfa0);
}

.course-lesson .code-block .vr {
  color: #ffd580;
}

.course-lesson .code-block .fn {
  color: var(--c5, #d2a8ff);
}

.course-lesson .tip-box {
  background: var(--c6, #0f2417);
  border: 1px solid var(--c7, #1f4d2c);
  border-left: 4px solid var(--c8, #2ea043);
  border-radius: 0 8px 8px 0;
  padding: 1rem 1.2rem;
  margin: 1.2rem 0;
  font-size: 0.88rem;
  color: #c9d1d9;
}

.course-lesson .tip-box .tb-label {
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--c9, #7ee787);
  margin-bottom: 0.35rem;
}

.course-lesson .warn-box {
  background: #1f1a0f;
  border: 1px solid #4a3800;
  border-left: 4px solid #e3b341;
  border-radius: 0 8px 8px 0;
  padding: 1rem 1.2rem;
  margin: 1.2rem 0;
  font-size: 0.88rem;
  color: #c9d1d9;
}

.course-lesson .warn-box .wb-label {
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: #e3b341;
  margin-bottom: 0.35rem;
}

.course-lesson .finding-box {
  background: var(--c10, #1a1424);
  border: 1px solid var(--c11, #3d2a5c);
  border-left: 4px solid var(--c12, #a371f7);
  border-radius: 0 8px 8px 0;
  padding: 1rem 1.2rem;
  margin: 1.2rem 0;
  font-size: 0.88rem;
  color: #c9d1d9;
}

.course-lesson .finding-box .fb-label {
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--c13, #d2a8ff);
  margin-bottom: 0.35rem;
}

.course-lesson .compare-table-wrap {
  overflow-x: auto;
  margin: 1rem 0 1.5rem;
}

.course-lesson .compare-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.83rem;
}

.course-lesson .compare-table th {
  background: var(--accent-bg, #0f2a22);
  color: var(--c1, #6ee7b7);
  text-align: left;
  padding: 0.5rem 0.7rem;
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  border-bottom: 2px solid #30363d;
}

.course-lesson .compare-table td {
  padding: 0.5rem 0.7rem;
  border-bottom: 1px solid #21262d;
  vertical-align: top;
}

.course-lesson .compare-table .kw {
  color: var(--c1, #6ee7b7);
  font-weight: 600;
}

.course-lesson .challenge-block {
  background: #161b22;
  border: 1px solid #30363d;
  border-radius: 10px;
  margin: 1rem 0 1.5rem;
  overflow: hidden;
}

.course-lesson .challenge-block .ch-num {
  background: var(--accent-strong, #059669);
  color: var(--accent-ink, #04150e);
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 0.5rem 1rem;
}

.course-lesson .challenge-block .ch-body {
  padding: 0.9rem 1.1rem;
}

.course-lesson .challenge-block .ch-task {
  font-size: 0.88rem;
  color: #c9d1d9;
  margin-bottom: 0.7rem;
}

.course-lesson .challenge-block .ch-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.82rem;
  color: var(--c1, #6ee7b7);
  text-decoration: none;
  border: 1px solid var(--accent-border, #14523f);
  border-radius: 6px;
  padding: 0.4rem 0.8rem;
  background: var(--c14, #0f2a22);
}

.course-lesson .challenge-block .ch-link:hover {
  background: var(--accent-border, #14523f);
}

.course-lesson .quick-ref {
  background: #0d1117;
  border: 1px solid #30363d;
  border-radius: 8px;
  padding: 1.1rem 1.3rem;
  margin-top: 2rem;
}

.course-lesson .quick-ref h3 {
  color: var(--c1, #6ee7b7);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 0.8rem;
}

.course-lesson .quick-ref ul {
  padding-left: 1.2rem;
}

.course-lesson .quick-ref li {
  font-size: 0.85rem;
  color: #c9d1d9;
  margin-bottom: 0.3rem;
}

.course-lesson .quick-ref li strong {
  color: var(--c15, #b3bce0);
}

.course-lesson .code-block-wrap {
  position: relative;
}

.course-lesson .copy-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  background: #21262d;
  border: 1px solid #30363d;
  color: #8b949e;
  font-size: 0.7rem;
  padding: 3px 8px;
  border-radius: 4px;
  cursor: pointer;
  font-family: system-ui, sans-serif;
}

.course-lesson .copy-btn:hover {
  background: #30363d;
  color: #c9d1d9;
}

@media print {
  .course-lesson .copy-btn {
    display: none;
  }
}