@import url("./typography.css");

:root {
  --lesson-accent: #13aaa3;
  --lesson-accent-dark: #087f78;
  --lesson-accent-soft: #eaf9f8;
  --lesson-ink: #102c4d;
  --lesson-text: #1f2f3f;
  --lesson-muted: #5e6f7f;
  --lesson-line: #c7e7e4;
  --lesson-paper: #ffffff;
  --lesson-bg: #f5fafb;
  --lesson-shadow: 0 18px 48px rgba(24, 58, 83, .10);
  --lesson-radius: 20px;
  --lesson-max: 1480px;
}

/* Future lesson palettes: change the body class only. */
.lesson-theme-teal {
  --lesson-accent: #13aaa3;
  --lesson-accent-dark: #087f78;
  --lesson-accent-soft: #eaf9f8;
  --lesson-line: #bde5e1;
}
.lesson-theme-blue {
  --lesson-accent: #3979c9;
  --lesson-accent-dark: #1f579f;
  --lesson-accent-soft: #edf4fd;
  --lesson-line: #c9dcef;
}
.lesson-theme-amber {
  --lesson-accent: #c27a19;
  --lesson-accent-dark: #86500b;
  --lesson-accent-soft: #fff6e7;
  --lesson-line: #edd4ad;
}
.lesson-theme-violet {
  --lesson-accent: #7562b8;
  --lesson-accent-dark: #51418d;
  --lesson-accent-soft: #f2effb;
  --lesson-line: #d8d0ee;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body.lesson-shell {
  margin: 0;
  min-height: 100vh;
  direction: rtl;
  color: var(--lesson-text);
  background: var(--lesson-bg);
  font-family: Calibri, Carlito, Arial, "Noto Sans Hebrew", sans-serif;
  line-height: 1.55;
  text-align: right;
}
body.lesson-shell * { text-align: right; }
a { color: inherit; }

.lesson-skip {
  position: fixed;
  inset-block-start: 10px;
  inset-inline-start: 10px;
  z-index: 1000;
  transform: translateY(-150%);
  padding: 9px 15px;
  border-radius: 999px;
  background: #fff;
  color: var(--lesson-ink);
  border: 1px solid var(--lesson-line);
}
.lesson-skip:focus { transform: none; }

.lesson-frame {
  width: min(calc(100% - 32px), var(--lesson-max));
  min-height: calc(100vh - 32px);
  margin: 16px auto;
  display: grid;
  grid-template-columns: 1fr 270px;
  grid-template-rows: auto 1fr auto;
  overflow: hidden;
  border: 1px solid var(--lesson-accent);
  border-radius: 22px;
  background: var(--lesson-paper);
  box-shadow: var(--lesson-shadow);
}

.lesson-header {
  grid-column: 1 / -1;
  min-height: 88px;
  padding: 18px 28px;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 20px;
  border-bottom: 1px solid var(--lesson-line);
}
.lesson-brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  text-decoration: none;
  min-width: 190px;
}
.lesson-brand img {
  width: 52px;
  height: 42px;
  object-fit: contain;
}
.lesson-brand-copy { display: grid; line-height: 1.05; }
.lesson-brand-copy strong { color: var(--lesson-ink); font-size: 1.05rem; }
.lesson-brand-copy small { color: var(--lesson-muted); margin-top: 5px; }
.lesson-course-line {
  color: var(--lesson-ink);
  font-size: clamp(.86rem, 1.4vw, 1.08rem);
  font-weight: 600;
  text-align: center !important;
}
.lesson-home-link {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border: 1px solid var(--lesson-line);
  border-radius: 12px;
  text-decoration: none;
  color: var(--lesson-ink);
  font-size: 1.25rem;
}

.lesson-sidebar {
  grid-column: 2;
  grid-row: 2;
  padding: 30px 22px;
  border-inline-start: 1px solid #e4ecef;
  background: #fbfdfe;
}
.lesson-sidebar-title {
  margin: 0 0 22px;
  color: var(--lesson-ink);
  font-size: 1rem;
  font-weight: 800;
}
.lesson-outline { margin: 0; padding: 0; list-style: none; display: grid; gap: 8px; }
.lesson-outline a {
  display: grid;
  grid-template-columns: 34px 1fr;
  gap: 10px;
  align-items: start;
  padding: 11px 10px;
  border-radius: 12px;
  text-decoration: none;
  color: var(--lesson-muted);
}
.lesson-outline a:hover { background: var(--lesson-accent-soft); }
.lesson-outline a[aria-current="step"] {
  background: var(--lesson-accent-soft);
  color: var(--lesson-ink);
  font-weight: 700;
}
.lesson-outline-number {
  width: 30px;
  height: 30px;
  display: grid;
  place-items: center;
  border: 1px solid var(--lesson-line);
  border-radius: 50%;
  direction: ltr;
  font-size: .78rem;
}
.lesson-outline a[aria-current="step"] .lesson-outline-number {
  color: #fff;
  background: var(--lesson-accent);
  border-color: var(--lesson-accent);
}
.lesson-outline-copy { display: grid; }
.lesson-outline-copy small { color: var(--lesson-muted); font-weight: 500; }

.lesson-progress-block { margin-top: 34px; }
.lesson-progress-label { display: flex; justify-content: space-between; color: var(--lesson-muted); font-size: .82rem; }
.lesson-progress-track {
  height: 8px;
  margin-top: 8px;
  overflow: hidden;
  border-radius: 999px;
  background: #dce5ea;
}
.lesson-progress-bar { height: 100%; width: var(--progress, 25%); background: var(--lesson-accent); }

.lesson-main {
  grid-column: 1;
  grid-row: 2;
  min-width: 0;
  display: grid;
}
.lesson-slide {
  min-height: 720px;
  padding: clamp(38px, 5vw, 76px);
  display: none;
  align-content: start;
  background: var(--lesson-paper);
}
.lesson-slide.is-active { display: grid; }
.lesson-slide > * { max-width: 100%; }
.lesson-code {
  justify-self: start;
  direction: ltr;
  margin-bottom: 24px;
  padding: 5px 13px;
  border: 1px solid var(--lesson-accent);
  border-radius: 999px;
  color: var(--lesson-accent-dark);
  background: #fff;
  font-size: .78rem;
  font-weight: 700;
}

/* TEMPLATE 1 — TITLE */
.lesson-slide--title {
  grid-template-columns: minmax(0, 1fr) minmax(180px, .45fr);
  grid-template-rows: auto 1fr auto auto;
  column-gap: clamp(28px, 5vw, 76px);
  background:
    radial-gradient(circle at 20% 16%, color-mix(in srgb, var(--lesson-accent) 12%, transparent), transparent 35%),
    #fff;
}
.lesson-slide--title .lesson-code { grid-column: 1; }
.lesson-title-copy { grid-column: 1; align-self: center; }
.lesson-title-copy h1 {
  margin: 0;
  color: var(--lesson-ink);
  font-size: clamp(2.7rem, 6vw, 5rem);
  line-height: 1.15;
  letter-spacing: -.025em;
}
.lesson-title-rule {
  width: 170px;
  height: 3px;
  margin: 28px 0;
  background: var(--lesson-accent);
}
.lesson-title-copy p {
  max-width: 700px;
  margin: 0;
  color: var(--lesson-text);
  font-size: clamp(1.03rem, 1.6vw, 1.25rem);
}
.lesson-title-visual {
  grid-column: 2;
  grid-row: 1 / span 3;
  align-self: center;
  justify-self: center;
  width: min(100%, 270px);
  aspect-ratio: 1;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--lesson-accent-soft);
  color: var(--lesson-accent);
  font-size: clamp(5rem, 12vw, 9rem);
}
.lesson-goal {
  grid-column: 1 / -1;
  margin-top: 34px;
  padding: 22px 24px;
  display: grid;
  grid-template-columns: 54px 1fr;
  gap: 18px;
  align-items: center;
  border: 1px solid var(--lesson-accent);
  border-radius: 14px;
  background: #fff;
}
.lesson-goal-icon {
  width: 50px;
  height: 50px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  color: #fff;
  background: var(--lesson-accent);
  font-size: 1.25rem;
}
.lesson-goal strong { display: block; color: var(--lesson-ink); margin-bottom: 3px; }
.lesson-topics {
  grid-column: 1 / -1;
  margin-top: 28px;
}
.lesson-topics h2 {
  margin: 0 0 12px;
  color: var(--lesson-accent);
  font-size: 1rem;
}
.lesson-topic-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border: 1px solid var(--lesson-line);
  border-radius: 12px;
  overflow: hidden;
}
.lesson-topic {
  min-height: 80px;
  padding: 16px;
  display: grid;
  grid-template-columns: 34px 1fr;
  align-items: center;
  gap: 10px;
  border-inline-end: 1px solid var(--lesson-line);
}
.lesson-topic:last-child { border-inline-end: 0; }
.lesson-topic-icon { color: var(--lesson-ink); font-size: 1.25rem; }

/* TEMPLATE 2 — TEXT */
.lesson-slide--text { grid-template-columns: minmax(0, 1fr); }
.lesson-text-head {
  padding-bottom: 18px;
  border-bottom: 1px solid var(--lesson-line);
}
.lesson-text-head h1 {
  margin: 0;
  color: var(--lesson-ink);
  font-size: clamp(2rem, 4vw, 3.25rem);
  line-height: 1.18;
}
.lesson-text-head .subtitle {
  margin: 10px 0 0;
  color: var(--lesson-muted);
  font-size: 1.04rem;
}
.lesson-text-content {
  max-width: 1020px;
  margin-top: 30px;
  color: var(--lesson-text);
  font-size: clamp(1rem, 1.25vw, 1.12rem);
}
.lesson-text-content h2 {
  margin: 30px 0 9px;
  color: var(--lesson-accent-dark);
  font-size: 1.32rem;
}
.lesson-text-content h3 {
  margin: 22px 0 7px;
  color: var(--lesson-accent-dark);
  font-size: 1.12rem;
}
.lesson-text-content p { margin: 0 0 13px; }
.lesson-text-content ul { margin: 8px 0 18px; padding-inline-start: 22px; }
.lesson-text-content li { margin-bottom: 7px; }
.lesson-note,
.lesson-example,
.lesson-reference {
  margin-top: 16px;
  padding: 16px 18px;
  border: 1px solid var(--lesson-line);
  border-radius: 12px;
  background: color-mix(in srgb, var(--lesson-accent-soft) 62%, #fff);
}
.lesson-note {
  border-inline-start: 5px solid var(--lesson-accent);
  background: #fff;
}
.lesson-note strong,
.lesson-example strong { color: var(--lesson-accent-dark); }
.lesson-reference { color: var(--lesson-muted); font-size: .9rem; }
.lesson-card-stack { display: grid; gap: 12px; margin-top: 18px; }
.lesson-info-card {
  padding: 16px 18px;
  display: grid;
  grid-template-columns: 42px 1fr;
  gap: 14px;
  align-items: start;
  border: 1px solid var(--lesson-line);
  border-radius: 12px;
  background: #fff;
}
.lesson-info-card-icon {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border: 1px solid var(--lesson-line);
  border-radius: 50%;
  color: var(--lesson-accent-dark);
}
.lesson-info-card h3 { margin-top: 0; }

.lesson-footer {
  grid-column: 1 / -1;
  min-height: 72px;
  padding: 14px 28px;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 18px;
  border-top: 1px solid var(--lesson-line);
  background: #fff;
}
.lesson-footer button,
.lesson-footer a {
  min-height: 46px;
  padding: 0 22px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 1px solid var(--lesson-accent);
  border-radius: 9px;
  background: #fff;
  color: var(--lesson-accent-dark);
  font: inherit;
  font-weight: 700;
  text-decoration: none;
  cursor: pointer;
}
.lesson-footer .lesson-next {
  justify-self: start;
  color: #fff;
  background: var(--lesson-accent);
}
.lesson-footer .lesson-prev { justify-self: end; }
.lesson-page-count { direction: ltr; color: var(--lesson-ink); font-weight: 600; text-align: center !important; }

@media (max-width: 980px) {
  .lesson-frame { grid-template-columns: 1fr; }
  .lesson-sidebar {
    grid-column: 1;
    grid-row: 2;
    padding: 14px 18px;
    border-inline-start: 0;
    border-bottom: 1px solid var(--lesson-line);
  }
  .lesson-outline { display: flex; overflow-x: auto; }
  .lesson-outline a { min-width: 145px; }
  .lesson-progress-block { display: none; }
  .lesson-main { grid-column: 1; grid-row: 3; }
  .lesson-footer { grid-row: 4; }
  .lesson-slide--title { grid-template-columns: 1fr; }
  .lesson-title-visual { grid-column: 1; grid-row: auto; width: 170px; margin: 10px 0 24px; justify-self: start; }
  .lesson-title-copy { grid-column: 1; }
  .lesson-goal, .lesson-topics { grid-column: 1; }
}

@media (max-width: 680px) {
  .lesson-frame { width: 100%; min-height: 100vh; margin: 0; border-radius: 0; border-inline: 0; }
  .lesson-header {
    min-height: 74px;
    padding: 12px 16px;
    grid-template-columns: 1fr auto;
  }
  .lesson-brand { min-width: 0; }
  .lesson-brand-copy small, .lesson-course-line { display: none; }
  .lesson-slide { min-height: auto; padding: 30px 20px 42px; }
  .lesson-topic-grid { grid-template-columns: 1fr; }
  .lesson-topic { border-inline-end: 0; border-bottom: 1px solid var(--lesson-line); }
  .lesson-topic:last-child { border-bottom: 0; }
  .lesson-footer { padding: 12px 16px; grid-template-columns: 1fr auto 1fr; }
  .lesson-footer button, .lesson-footer a { padding: 0 13px; }
  .lesson-info-card { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; }
}

/* SPRINT 9.1 — extended text-slide components */
.lesson-applications {
  margin-top: 24px;
  padding-top: 8px;
}
.lesson-application-grid,
.lesson-comparison-grid,
.lesson-term-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: 14px;
}
.lesson-application-card,
.lesson-comparison-grid section,
.lesson-term-grid > div {
  padding: 16px 18px;
  border: 1px solid var(--lesson-line);
  border-radius: 12px;
  background: #fff;
}
.lesson-application-card h3,
.lesson-comparison-grid h2 {
  margin-top: 0;
}
.lesson-term-grid > div {
  display: grid;
  gap: 4px;
}
.lesson-term-grid strong {
  color: var(--lesson-accent-dark);
}
.lesson-term-grid span {
  color: var(--lesson-muted);
  font-size: .93rem;
}
.lesson-video-block {
  margin-top: 24px;
  padding: 18px;
  display: grid;
  grid-template-columns: minmax(220px, .7fr) minmax(320px, 1.3fr);
  gap: 18px;
  align-items: center;
  border: 1px solid var(--lesson-line);
  border-radius: 14px;
  background: color-mix(in srgb, var(--lesson-accent-soft) 45%, #fff);
}
.lesson-video-copy h2 {
  margin-top: 0;
}
.lesson-video-frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  border-radius: 10px;
  background: #0d2035;
}
.lesson-video-frame iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}
.lesson-warning {
  margin: 20px 0;
  padding: 18px 20px;
  border: 1px solid #e8c6c6;
  border-inline-start: 5px solid #a84747;
  border-radius: 12px;
  background: #fff8f8;
}
.lesson-warning h2 {
  margin-top: 0;
  color: #863737;
}
.lesson-primary-link {
  margin-top: 22px;
  min-height: 46px;
  padding: 0 22px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 9px;
  background: var(--lesson-accent);
  color: #fff;
  font-weight: 700;
  text-decoration: none;
}

@media (max-width: 900px) {
  .lesson-video-block {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 680px) {
  .lesson-application-grid,
  .lesson-comparison-grid,
  .lesson-term-grid {
    grid-template-columns: 1fr;
  }
}