/* ============================================================
   YooStudio V2 — Curriculum Page Styles
   "Obsidian Prism" Design System
   ============================================================ */

/* ── Hero / Intro ────────────────────────────────────────── */
.yoo-curriculum-hero {
  position: relative;
  min-height: 72vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  padding: var(--space-24) var(--space-6);
}

.yoo-curriculum-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 70% 60% at 50% 0%, rgba(0, 229, 204, 0.10) 0%, transparent 65%),
    radial-gradient(ellipse 50% 40% at 80% 80%, rgba(123, 97, 255, 0.08) 0%, transparent 60%);
  pointer-events: none;
}

/* Prism divider line */
.yoo-curriculum-hero::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 10%;
  right: 10%;
  height: 1px;
  background: var(--gradient-prism);
  opacity: 0.35;
}

.yoo-curriculum-hero__content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 680px;
  width: 100%;
}

.yoo-curriculum-hero__eyebrow {
  display: inline-block;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-cyan);
  margin-bottom: var(--space-4);
  padding: 4px 12px;
  border: 1px solid rgba(0, 229, 204, 0.25);
  border-radius: var(--radius-full);
  background: rgba(0, 229, 204, 0.06);
}

.yoo-curriculum-hero__title {
  font-family: var(--font-display);
  font-size: clamp(40px, 7vw, 64px);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.03em;
  color: var(--color-white);
  margin: 0 0 var(--space-4) 0;
}

.yoo-curriculum-hero__title span {
  background: var(--gradient-prism);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.yoo-curriculum-hero__subtitle {
  font-size: 17px;
  line-height: 1.65;
  color: var(--color-text-muted);
  margin: 0 0 var(--space-8) 0;
}

.yoo-curriculum-hero__actions {
  display: flex;
  gap: var(--space-3);
  justify-content: center;
  flex-wrap: wrap;
}

/* ── Feature Cards (learning-solutions) ───────────────────── */
.yoo-feature-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-5);
  margin-top: var(--space-10);
}

.yoo-feature-card {
  background: var(--color-surface-1);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  text-align: center;
  transition: transform var(--duration-normal) var(--ease-out),
              border-color var(--duration-normal) var(--ease-out),
              box-shadow var(--duration-normal) var(--ease-out);
}

.yoo-feature-card:hover {
  transform: translateY(-3px);
  border-color: rgba(0, 229, 204, 0.3);
  box-shadow: 0 8px 32px rgba(0, 229, 204, 0.08);
}

.yoo-feature-card__icon {
  width: 48px;
  height: 48px;
  margin: 0 auto var(--space-4);
  border-radius: var(--radius-lg);
  background: rgba(0, 229, 204, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
}

.yoo-feature-card__title {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  color: var(--color-white);
  margin: 0 0 var(--space-2) 0;
}

.yoo-feature-card__text {
  font-size: 14px;
  line-height: 1.6;
  color: var(--color-text-muted);
  margin: 0;
}

/* ── Grade Grid ───────────────────────────────────────────── */
.yoo-grades-section {
  padding: var(--space-20) 0;
}

.yoo-grades-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
  margin-top: var(--space-10);
}

/* Grade card */
.yoo-grade-card {
  position: relative;
  border-radius: var(--radius-2xl);
  overflow: hidden;
  background: var(--color-surface-1);
  border: 1px solid var(--color-border);
  transition: transform var(--duration-normal) var(--ease-out),
              border-color var(--duration-normal) var(--ease-out),
              box-shadow var(--duration-normal) var(--ease-out);
  display: flex;
  flex-direction: column;
  height: 100%;
}

.yoo-grade-card:hover {
  transform: translateY(-4px);
  border-color: rgba(0, 229, 204, 0.35);
  box-shadow:
    0 4px 24px rgba(0, 0, 0, 0.4),
    0 0 0 1px rgba(0, 229, 204, 0.15);
}

/* Cyan accent line at top on hover */
.yoo-grade-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--gradient-prism);
  opacity: 0;
  transition: opacity var(--duration-normal) var(--ease-out);
}

.yoo-grade-card:hover::before {
  opacity: 1;
}

.yoo-grade-card__cover {
  position: relative;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  flex-shrink: 0;
}

.yoo-grade-card__cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--duration-slow) var(--ease-out);
  display: block;
}

.yoo-grade-card:hover .yoo-grade-card__cover img {
  transform: scale(1.04);
}

/* Gradient overlay on image */
.yoo-grade-card__cover::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    to bottom,
    transparent 40%,
    rgba(10, 10, 15, 0.55) 100%
  );
}

.yoo-grade-card__body {
  padding: var(--space-5) var(--space-5) var(--space-6);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  flex: 1;
}

.yoo-grade-card__title {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  color: var(--color-white);
  margin: 0;
  line-height: 1.2;
}

.yoo-grade-card__keywords {
  font-size: 13px;
  color: var(--color-text-muted);
  margin: 0;
  line-height: 1.6;
}

.yoo-grade-card__keywords span {
  display: inline-block;
  background: rgba(0, 229, 204, 0.07);
  border: 1px solid rgba(0, 229, 204, 0.15);
  color: rgba(0, 229, 204, 0.8);
  border-radius: var(--radius-full);
  padding: 2px 8px;
  font-size: 11px;
  font-weight: 500;
  margin: 2px 2px 2px 0;
  letter-spacing: 0.02em;
}

.yoo-grade-card__cta {
  margin-top: auto;
}

.yoo-grade-card__btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 9px 20px;
  border-radius: var(--radius-full);
  font-size: 13px;
  font-weight: 600;
  text-decoration: none;
  background: rgba(0, 229, 204, 0.10);
  color: var(--color-cyan);
  border: 1px solid rgba(0, 229, 204, 0.25);
  transition: background var(--duration-fast) var(--ease-out),
              border-color var(--duration-fast) var(--ease-out),
              color var(--duration-fast) var(--ease-out);
  width: 100%;
  justify-content: center;
  cursor: pointer;
}

.yoo-grade-card__btn:hover {
  background: rgba(0, 229, 204, 0.18);
  border-color: rgba(0, 229, 204, 0.5);
  color: var(--color-white);
  text-decoration: none;
}

/* ── Visualisation / Article Section ─────────────────────── */
.yoo-visual-section {
  padding: var(--space-20) 0;
  border-top: 1px solid var(--color-border);
}

.yoo-visual-section .yoo-section__header {
  margin-bottom: var(--space-8);
}

.yoo-visual-article {
  max-width: 760px;
}

.yoo-visual-article h2 {
  font-family: var(--font-display);
  font-size: 28px;
  font-weight: 700;
  color: var(--color-white);
  margin: var(--space-8) 0 var(--space-3) 0;
}

.yoo-visual-article h2:first-child {
  margin-top: 0;
}

.yoo-visual-article p {
  font-size: 15px;
  line-height: 1.75;
  color: var(--color-text-secondary);
  margin: 0 0 var(--space-5) 0;
}

.yoo-visual-article strong {
  color: var(--color-cyan);
  font-weight: 600;
}

/* ── Responsive ───────────────────────────────────────────── */
@media (max-width: 1024px) {
  .yoo-grades-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-5);
  }

  .yoo-feature-row {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .yoo-curriculum-hero {
    min-height: 60vh;
    padding: var(--space-16) var(--space-4);
  }

  .yoo-curriculum-hero__title {
    font-size: 36px;
  }

  .yoo-grades-grid {
    grid-template-columns: 1fr;
    gap: var(--space-4);
  }

  .yoo-feature-row {
    grid-template-columns: 1fr;
    gap: var(--space-4);
  }

  .yoo-grade-card__cover {
    aspect-ratio: 3 / 2;
  }
}