/* =========================================================================
   WebApp Full-Stack — lesson-page chrome
   Loaded by each level's layout.tsx. Accent colour is driven by a per-level
   class on the page root (.level--web1 / web2 / web3 / web4) so a single
   stylesheet styles every level.
   ========================================================================= */

.lesson-page {
  --accent:       #06B6D4;   /* L1 cyan — overridden below */
  --accent-deep:  #0891B2;
  --accent-soft:  #ECFEFF;
  --accent-edge:  #A5F3FC;
  --ink:          #0F172A;
  --muted:        #64748B;
  --border:       #E2E8F0;

  color: var(--ink);
  background: #fff;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.level--web1 { --accent: #06B6D4; --accent-deep: #0891B2; --accent-soft: #ECFEFF; --accent-edge: #A5F3FC; }
.level--web2 { --accent: #6366F1; --accent-deep: #4F46E5; --accent-soft: #EEF2FF; --accent-edge: #C7D2FE; }
.level--web3 { --accent: #10B981; --accent-deep: #059669; --accent-soft: #ECFDF5; --accent-edge: #A7F3D0; }
.level--web4 { --accent: #F59E0B; --accent-deep: #D97706; --accent-soft: #FFFBEB; --accent-edge: #FDE68A; }

/* ---------- hero ---------- */

.lesson-hero {
  background: linear-gradient(135deg, var(--accent-soft) 0%, #fff 100%);
  border-bottom: 1px solid var(--border);
  padding: 32px 24px 36px;
}
.lesson-hero__inner { max-width: 820px; margin: 0 auto; }
.lesson-hero__crumbs { font-size: 0.85rem; color: var(--muted); margin: 0 0 16px; }
.lesson-hero__crumbs a { color: var(--accent-deep); text-decoration: none; }
.lesson-hero__crumbs a:hover { text-decoration: underline; }
.lesson-hero__crumbs .sep { margin: 0 8px; color: var(--accent-edge); }
.lesson-hero__crumbs .here { color: var(--ink); font-weight: 600; }

.lesson-hero__num {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.06em;
  color: var(--accent-deep);
  background: #fff;
  border: 1px solid var(--accent-edge);
  border-radius: 999px;
  padding: 4px 12px;
}
.lesson-hero__title {
  margin: 12px 0 8px;
  font-size: 2.4rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.15;
}
.lesson-hero__sub {
  margin: 0 0 16px;
  font-size: 1.05rem;
  color: #334155;
  max-width: 620px;
  line-height: 1.55;
}
.lesson-hero__meta { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 8px; }
.lesson-hero__meta-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--ink);
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 6px 12px;
}

/* ---------- body shell ---------- */

.lesson-body {
  flex: 1;
  max-width: 820px;
  width: 100%;
  margin: 0 auto;
  padding: 32px 24px 64px;
  display: grid;
  gap: 28px;
}

.lesson-section {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 16px;
  overflow: hidden;
}
.lesson-section__head {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px 22px;
  background: var(--accent-soft);
  border-bottom: 1px solid var(--accent-edge);
}
.lesson-section__num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  font-weight: 800;
  font-size: 0.85rem;
  color: #fff;
  background: var(--accent-deep);
  border-radius: 50%;
  flex-shrink: 0;
}
.lesson-section__title {
  margin: 0;
  font-size: 1.15rem;
  font-weight: 800;
  flex: 1;
  min-width: 0;
}
.lesson-section__time {
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--accent-deep);
  background: #fff;
  border: 1px solid var(--accent-edge);
  border-radius: 6px;
  padding: 3px 10px;
  white-space: nowrap;
}

.lesson-section__body { padding: 22px; line-height: 1.65; color: #1E293B; }
.lesson-section__body > * + * { margin-top: 14px; }
.lesson-section__body p { margin: 0; }
.lesson-section__body h3 {
  margin: 22px 0 10px;
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--ink);
}
.lesson-section__body h4 {
  margin: 14px 0 6px;
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--ink);
}
.lesson-section__body ul,
.lesson-section__body ol { margin: 0; padding-left: 22px; display: grid; gap: 6px; }
.lesson-section__body li { line-height: 1.55; }
.lesson-section__body strong { color: var(--ink); }
.lesson-section__body a {
  color: var(--accent-deep);
  text-decoration: underline;
  text-underline-offset: 2px;
}
.lesson-section__body code {
  font-family: "JetBrains Mono", "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.88em;
  background: #F1F5F9;
  border: 1px solid var(--border);
  border-radius: 5px;
  padding: 1px 6px;
}
.lesson-section__body kbd {
  font-family: "JetBrains Mono", "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.82em;
  background: #fff;
  border: 1px solid #94A3B8;
  border-bottom-width: 2px;
  border-radius: 5px;
  padding: 1px 7px;
  color: #334155;
}
.lesson-section__body details {
  background: #F8FAFC;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px 16px;
}
.lesson-section__body details > summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--accent-deep);
}
.lesson-section__body details[open] > summary { margin-bottom: 10px; }

.lesson-section--homework .lesson-section__head {
  background: linear-gradient(135deg, var(--accent-soft) 0%, #fff 100%);
}

/* ---------- WebApp custom widgets ---------- */

/* Client / Server two-up card */
.webapp-twocol {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.webapp-twocol__item {
  background: #F8FAFC;
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: 10px;
  padding: 14px 16px;
}
.webapp-twocol__item h4 { margin: 0 0 6px; color: var(--accent-deep); }
.webapp-twocol__item p { margin: 6px 0 0; }
@media (max-width: 620px) { .webapp-twocol { grid-template-columns: 1fr; } }

/* Numbered steps */
.webapp-steps {
  background: #F8FAFC;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px 20px 16px 38px !important;
}
.webapp-steps li::marker { color: var(--accent-deep); font-weight: 800; }

/* URL display block */
.webapp-url {
  background: #0F172A;
  color: #E2E8F0;
  border-radius: 10px;
  padding: 14px 18px;
  font-family: "JetBrains Mono", "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.95rem;
  overflow-x: auto;
  word-break: break-all;
}
.webapp-url code { background: transparent; border: 0; padding: 0; font-size: inherit; color: inherit; }

/* URL-anatomy grid */
.webapp-url-anatomy {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 12px;
}
.webapp-url-anatomy__part {
  background: #fff;
  border: 1px solid var(--border);
  border-top: 3px solid var(--accent);
  border-radius: 10px;
  padding: 12px 14px;
  display: grid;
  gap: 6px;
}
.webapp-url-anatomy__part > code {
  font-size: 0.82rem;
  background: var(--accent-soft);
  border-color: var(--accent-edge);
  color: var(--accent-deep);
  width: max-content;
  max-width: 100%;
  overflow: hidden;
  text-overflow: ellipsis;
}
.webapp-url-anatomy__label {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
}
.webapp-url-anatomy__part p { font-size: 0.88rem; margin: 0; color: #334155; }

/* Task cards */
.webapp-tasks {
  display: grid;
  gap: 14px;
  list-style: none !important;
  padding-left: 0 !important;
}
.webapp-tasks > li {
  background: #F8FAFC;
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: 10px;
  padding: 14px 16px;
}
.webapp-tasks > li h4 { margin: 0 0 6px; color: var(--accent-deep); }
.webapp-tasks > li ul { padding-left: 22px; }

/* Answer reveal */
.webapp-answer {
  background: var(--accent-soft) !important;
  border-color: var(--accent-edge) !important;
}

/* Recap list */
.webapp-recap {
  background: var(--accent-soft);
  border: 1px solid var(--accent-edge);
  border-radius: 10px;
  padding: 14px 20px 14px 38px !important;
  display: grid;
  gap: 8px;
}
.webapp-recap li::marker { color: var(--accent-deep); font-weight: 800; }

/* Prev / next lesson nav */
.lesson-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 12px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  font-size: 0.92rem;
  font-weight: 600;
}
.lesson-nav__prev { color: var(--muted); }
.lesson-nav__next {
  color: var(--accent-deep);
  text-decoration: none;
  padding: 8px 16px;
  background: var(--accent-soft);
  border: 1px solid var(--accent-edge);
  border-radius: 8px;
}
.lesson-nav__next:hover { background: var(--accent-edge); }

/* mobile tweaks */
@media (max-width: 720px) {
  .lesson-hero { padding: 28px 18px 30px; }
  .lesson-hero__title { font-size: 1.85rem; }
  .lesson-body { padding: 24px 18px 56px; }
  .lesson-section__head { padding: 14px 16px; }
  .lesson-section__body { padding: 18px; }
}