/*
  What it does: Styles the Phase 1 structured study shell for topic-based learning pages.
  Phase: Phase 1 - Learning System Upgrade.
  Dependencies: css/main.css design tokens and js/study-shell.js rendering hooks.
*/

.study-shell {
  display: grid;
  gap: 24px;
}

.study-hero,
.study-topic-shell,
.study-source-spine {
  border: 1px solid rgba(30, 58, 95, 0.85);
  border-radius: 18px;
  background:
    linear-gradient(145deg, rgba(10, 22, 40, 0.96), rgba(6, 12, 20, 0.96)),
    radial-gradient(circle at top right, rgba(34, 197, 94, 0.14), transparent 48%);
  box-shadow: 0 24px 60px rgba(2, 6, 23, 0.24);
}

.study-hero {
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(260px, 1fr);
  gap: 18px;
  padding: 24px;
}

.study-hero-kicker,
.study-card-kicker,
.study-topic-kicker,
.study-flash-label {
  font-size: 11px;
  letter-spacing: 1.6px;
  text-transform: uppercase;
  color: var(--green-light);
  font-weight: 800;
}

.study-hero h2 {
  font-family: 'Syne', sans-serif;
  font-size: clamp(26px, 4vw, 38px);
  line-height: 1.1;
  margin: 8px 0 12px;
}

.study-hero-summary,
.study-topic-support,
.study-source-list,
.study-example-scenario,
.study-takeaway,
.study-exam-link p,
.study-empty-copy,
.study-practice-answer {
  color: var(--text-2);
}

.study-hero-pills,
.study-topic-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.study-hero-pills span,
.study-topic-tags span,
.study-exam-status {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  border-radius: 999px;
  padding: 6px 10px;
  background: rgba(34, 197, 94, 0.12);
  border: 1px solid rgba(34, 197, 94, 0.22);
  color: var(--green-light);
  font-size: 12px;
  font-weight: 700;
}

.study-hero-aside {
  display: grid;
  gap: 12px;
}

.study-intel-card {
  border-radius: 14px;
  padding: 14px;
  background: rgba(5, 13, 20, 0.68);
  border: 1px solid rgba(30, 58, 95, 0.8);
}

.study-intel-card span {
  display: block;
  color: var(--text-muted);
  font-size: 11px;
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-bottom: 6px;
}

.study-intel-card strong {
  color: var(--text);
  font-size: 15px;
  line-height: 1.5;
}

.study-source-spine {
  padding: 18px 20px;
}

.study-source-list {
  list-style: disc;
  padding-left: 18px;
  display: grid;
  gap: 8px;
  margin-top: 10px;
}

.study-topic-list {
  display: grid;
  gap: 18px;
}

.study-topic-shell {
  padding: 20px;
}

.study-topic-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 14px;
  align-items: start;
  margin-bottom: 18px;
}

.study-topic-order {
  width: 44px;
  height: 44px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  font-family: 'Syne', sans-serif;
  font-weight: 800;
  color: var(--bg);
  background: linear-gradient(135deg, var(--gold-light), #fde68a);
}

.study-topic-title-wrap h3,
.study-card h4 {
  font-family: 'Syne', sans-serif;
}

.study-topic-title-wrap h3 {
  margin: 6px 0 8px;
  font-size: 24px;
}

.study-topic-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin-top: 16px;
}

.study-card {
  min-width: 0;
  border-radius: 16px;
  border: 1px solid rgba(30, 58, 95, 0.78);
  background: rgba(5, 13, 20, 0.72);
  padding: 18px;
}

.study-card h4 {
  margin: 6px 0 12px;
  font-size: 18px;
  color: var(--text);
}

.study-concept-card p + p {
  margin-top: 10px;
}

.study-bullet-list,
.study-step-list {
  display: grid;
  gap: 10px;
  padding-left: 18px;
  color: var(--text-2);
}

.study-visual-grid {
  display: grid;
  gap: 12px;
}

.study-visual-block {
  border-radius: 14px;
  padding: 14px;
  background: rgba(10, 22, 40, 0.92);
  border: 1px solid rgba(34, 197, 94, 0.14);
}

.study-visual-block h5 {
  font-family: 'Syne', sans-serif;
  font-size: 15px;
  margin-bottom: 10px;
  color: var(--gold-light);
}

.study-example-card ol {
  margin-top: 12px;
}

.study-takeaway {
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px solid rgba(30, 58, 95, 0.72);
}

.study-practice-stack {
  display: grid;
  gap: 14px;
}

.study-practice-prompt {
  color: var(--text);
  margin-bottom: 12px;
  font-weight: 600;
}

.study-practice-options {
  display: grid;
  gap: 8px;
}

.study-practice-option {
  width: 100%;
  text-align: left;
  border: 1px solid rgba(30, 58, 95, 0.82);
  border-radius: 12px;
  padding: 12px 14px;
  background: rgba(10, 22, 40, 0.92);
  color: var(--text);
  font: inherit;
  cursor: pointer;
  transition: transform 0.18s ease, border-color 0.18s ease, background 0.18s ease;
}

.study-practice-option:hover {
  transform: translateY(-1px);
  border-color: rgba(96, 165, 250, 0.48);
}

.study-practice-option.is-correct {
  border-color: rgba(34, 197, 94, 0.55);
  background: rgba(20, 83, 45, 0.45);
}

.study-practice-option.is-wrong {
  border-color: rgba(248, 113, 113, 0.45);
  background: rgba(127, 29, 29, 0.3);
}

.study-practice-feedback {
  margin-top: 12px;
  font-weight: 800;
}

.study-practice-feedback.is-correct {
  color: var(--green-light);
}

.study-practice-feedback.is-wrong {
  color: #fda4af;
}

.study-practice-answer {
  margin-top: 8px;
  line-height: 1.6;
}

.study-flash-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.study-flashcard {
  min-height: 180px;
  border: 0;
  padding: 0;
  background: transparent;
  cursor: pointer;
  perspective: 1200px;
}

.study-flashcard-inner {
  position: relative;
  display: block;
  width: 100%;
  min-height: 180px;
  border-radius: 14px;
  transform-style: preserve-3d;
  transition: transform 0.45s ease;
}

.study-flashcard.is-flipped .study-flashcard-inner {
  transform: rotateY(180deg);
}

.study-flash-face {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  border-radius: 14px;
  padding: 14px;
  backface-visibility: hidden;
  border: 1px solid rgba(30, 58, 95, 0.8);
  background: linear-gradient(145deg, rgba(10, 22, 40, 0.95), rgba(6, 12, 20, 0.92));
}

.study-flash-back {
  transform: rotateY(180deg);
  border-color: rgba(251, 191, 36, 0.26);
}

.study-flash-copy {
  color: var(--text);
  font-weight: 600;
  line-height: 1.55;
}

.study-exam-link-list {
  display: grid;
  gap: 12px;
}

.study-exam-link {
  border-radius: 14px;
  padding: 14px;
  background: rgba(10, 22, 40, 0.88);
  border: 1px solid rgba(30, 58, 95, 0.75);
}

.study-exam-link strong {
  display: block;
  margin: 8px 0 6px;
  color: var(--text);
}

.study-exam-status {
  background: rgba(251, 191, 36, 0.12);
  border-color: rgba(251, 191, 36, 0.22);
  color: var(--gold-light);
}

.study-empty-copy {
  font-style: italic;
}

.study-theme-l3 .study-hero {
  background:
    linear-gradient(145deg, rgba(10, 22, 40, 0.96), rgba(6, 12, 20, 0.96)),
    radial-gradient(circle at top right, rgba(167, 139, 250, 0.18), transparent 42%);
}

@media (max-width: 960px) {
  .study-hero,
  .study-topic-grid,
  .study-topic-grid-secondary,
  .study-flash-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .study-hero,
  .study-topic-shell,
  .study-source-spine {
    padding: 16px;
  }

  .study-topic-head {
    grid-template-columns: auto;
  }

  .study-topic-order {
    width: 40px;
    height: 40px;
  }
}