/* ============================================
   YOOSTUDIO V2 — COMPONENTS
   Buttons, Cards, Badges, Inputs, Nav, Footer
   ============================================ */

/* ============================================
   6.1 GLASS NAVIGATION HEADER
   ============================================ */

.yoo-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(10, 10, 15, 0.6);
  backdrop-filter: blur(20px) saturate(1.2);
  -webkit-backdrop-filter: blur(20px) saturate(1.2);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  transition: background var(--duration-normal);
}

.yoo-header--scrolled {
  background: rgba(10, 10, 15, 0.9);
}

.yoo-header__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--content-padding-desktop);
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2xl);
}

.yoo-logo {
  font-family: var(--font-primary);
  font-size: 22px;
  font-weight: 700;
  color: var(--color-white);
  text-decoration: none;
  letter-spacing: -0.01em;
  flex-shrink: 0;
}

.yoo-logo span {
  color: var(--color-cyan);
}

.yoo-logo sup {
  font-size: 10px;
  font-weight: 500;
  color: var(--color-zinc);
  letter-spacing: 0;
  vertical-align: super;
}

.yoo-nav {
  display: flex;
  align-items: center;
  gap: var(--space-2xl);
}

.yoo-nav__link {
  font-family: var(--font-primary);
  font-size: 15px;
  font-weight: 500;
  color: var(--color-silver);
  text-decoration: none;
  letter-spacing: 0.01em;
  transition: color var(--duration-fast);
}

.yoo-nav__link:hover {
  color: var(--color-white);
}

.yoo-nav__link.active {
  color: var(--color-cyan);
}

.yoo-header__actions {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  flex-shrink: 0;
}

/* Hamburger (mobile) */
.yoo-hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  background: transparent;
  border: 1px solid var(--color-glass-border);
  border-radius: var(--radius-tooltip);
  cursor: pointer;
  padding: 8px;
  transition: border-color var(--duration-fast);
}

.yoo-hamburger:hover {
  border-color: var(--color-glass-border-hover);
}

.yoo-hamburger span {
  display: block;
  width: 100%;
  height: 1.5px;
  background: var(--color-silver);
  border-radius: 2px;
  transition: all var(--duration-fast);
}

/* Mobile nav drawer */
.yoo-mobile-nav {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  background: var(--color-surface-1);
  border-bottom: 1px solid var(--color-glass-border);
  padding: var(--space-xl) var(--content-padding-mobile);
  z-index: 99;
  flex-direction: column;
  gap: var(--space-md);
}

.yoo-mobile-nav.open {
  display: flex;
}

.yoo-mobile-nav .yoo-nav__link {
  font-size: 17px;
  padding: var(--space-sm) 0;
  border-bottom: 1px solid var(--color-glass-border);
}

.yoo-mobile-nav .yoo-nav__link:last-child {
  border-bottom: none;
}


/* ============================================
   6.3 BUTTONS
   ============================================ */

/* Primary CTA */
.yoo-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  cursor: pointer;
  border: none;
  font-family: var(--font-primary);
  font-weight: 600;
  letter-spacing: 0.01em;
  transition: all var(--duration-fast) var(--ease-spring);
}

.yoo-btn--primary {
  height: 52px;
  padding: 0 32px;
  background: var(--gradient-cyan-btn);
  border-radius: var(--radius-btn-lg);
  font-size: 16px;
  color: var(--color-obsidian);
  box-shadow: var(--shadow-cyan-glow);
}

.yoo-btn--primary:hover {
  box-shadow: var(--shadow-cyan-glow-hover);
  transform: translateY(-1px);
  color: var(--color-obsidian);
}

.yoo-btn--primary:active {
  background: var(--color-cyan-dark);
  transform: translateY(0);
}

/* Ghost button */
.yoo-btn--ghost {
  height: 52px;
  padding: 0 32px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.10);
  border-radius: var(--radius-btn-lg);
  font-size: 16px;
  color: var(--color-off-white);
  backdrop-filter: blur(12px);
}

.yoo-btn--ghost:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.15);
  color: var(--color-white);
}

/* Outline button */
.yoo-btn--outline {
  gap: 8px;
  height: 44px;
  padding: 0 24px;
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius-btn-sm);
  font-size: 14px;
  color: var(--color-off-white);
}

.yoo-btn--outline:hover {
  border-color: var(--color-cyan);
  color: var(--color-cyan);
}

/* Small solid (nav) */
.yoo-btn--solid-sm {
  padding: 10px 20px;
  background: var(--color-cyan);
  border-radius: var(--radius-btn-sm);
  font-size: 14px;
  color: var(--color-obsidian);
}

.yoo-btn--solid-sm:hover {
  background: var(--color-cyan-light);
  color: var(--color-obsidian);
}


/* ============================================
   6.4 GLASS CARDS
   ============================================ */

.yoo-card--glass {
  background: var(--color-glass);
  border: 1px solid var(--color-glass-border);
  border-radius: var(--radius-card);
  padding: var(--space-2xl);
  backdrop-filter: blur(40px);
  -webkit-backdrop-filter: blur(40px);
  transition: all var(--duration-normal) var(--ease-spring);
}

.yoo-card--glass:hover {
  background: var(--color-glass-hover);
  border-color: var(--color-glass-border-hover);
  transform: translateY(-2px);
}

.yoo-card--compact {
  padding: var(--space-xl);
}

.yoo-card__icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-btn-sm);
  background: var(--color-cyan-muted);
  margin-bottom: var(--space-lg);
  color: var(--color-cyan);
}

.yoo-card__icon svg {
  width: 24px;
  height: 24px;
}

.yoo-card__title {
  font-family: var(--font-primary);
  font-size: 20px;
  font-weight: 600;
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--color-white);
  margin-bottom: var(--space-md);
}

.yoo-card__desc {
  font-family: var(--font-primary);
  font-size: 15px;
  font-weight: 400;
  line-height: 1.6;
  color: var(--color-silver);
}

/* Staggered card reveals */
.yoo-grid .yoo-card--glass:nth-child(1) { transition-delay: 0ms; }
.yoo-grid .yoo-card--glass:nth-child(2) { transition-delay: 80ms; }
.yoo-grid .yoo-card--glass:nth-child(3) { transition-delay: 160ms; }
.yoo-grid .yoo-card--glass:nth-child(4) { transition-delay: 240ms; }


/* ============================================
   6.5 SIMULATION GRID CARDS
   ============================================ */

.yoo-sim-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: var(--space-base);
}

.yoo-sim-card {
  position: relative;
  border-radius: var(--radius-card);
  overflow: hidden;
  background: var(--color-glass);
  border: 1px solid var(--color-glass-border);
  transition: all var(--duration-normal) var(--ease-spring);
  cursor: pointer;
}

.yoo-sim-card:hover {
  border-color: var(--color-glass-border-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-float);
}

.yoo-sim-card__link {
  display: block;
  text-decoration: none;
  color: inherit;
}

.yoo-sim-card__cover {
  overflow: hidden;
}

.yoo-sim-card__cover img {
  width: 100%;
  aspect-ratio: 16/9;
  object-fit: cover;
  display: block;
  filter: brightness(0.85);
  transition: filter var(--duration-normal);
}

.yoo-sim-card:hover .yoo-sim-card__cover img {
  filter: brightness(1);
}

.yoo-sim-card__info {
  padding: var(--space-md) var(--space-base);
}

.yoo-sim-card__name {
  font-family: var(--font-primary);
  font-size: 13px;
  font-weight: 500;
  color: var(--color-silver);
  transition: color var(--duration-fast);
  display: block;
}

.yoo-sim-card:hover .yoo-sim-card__name {
  color: var(--color-cyan);
}

/* Category dividers within sim grid */
.yoo-category-label {
  grid-column: 1 / -1;
  padding: var(--space-xl) 0 var(--space-sm);
  border-bottom: 1px solid var(--color-glass-border);
  margin-bottom: var(--space-sm);
}


/* ============================================
   6.6 BADGES
   ============================================ */

.yoo-badge {
  display: inline-flex;
  align-items: center;
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  font-family: var(--font-primary);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.yoo-badge--accent {
  border: 1px solid rgba(0, 229, 204, 0.25);
  background: rgba(0, 229, 204, 0.08);
  color: var(--color-cyan);
}

.yoo-badge--violet {
  border: 1px solid rgba(123, 97, 255, 0.25);
  background: rgba(123, 97, 255, 0.08);
  color: var(--color-violet-light);
}

.yoo-badge--neutral {
  border: 1px solid rgba(255, 255, 255, 0.10);
  background: rgba(255, 255, 255, 0.05);
  color: var(--color-silver);
}


/* ============================================
   6.7 INPUTS / SEARCH
   ============================================ */

.yoo-input {
  width: 100%;
  font-family: var(--font-primary);
  font-size: 14px;
  color: var(--color-off-white);
  background: var(--color-glass);
  border: 1px solid var(--color-glass-border);
  border-radius: var(--radius-btn-sm);
  padding: var(--space-md) var(--space-base);
  outline: none;
  transition: border-color var(--duration-fast), box-shadow var(--duration-fast);
}

.yoo-input::placeholder {
  color: var(--color-zinc);
}

.yoo-input:focus {
  border-color: rgba(0, 229, 204, 0.4);
  box-shadow: 0 0 0 3px rgba(0, 229, 204, 0.1);
}


/* ============================================
   6.8 FOOTER
   ============================================ */

.yoo-footer {
  background: var(--color-obsidian);
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  padding: var(--space-5xl) var(--content-padding-desktop) var(--space-3xl);
}

.yoo-footer__inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

.yoo-footer__top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-4xl);
  flex-wrap: wrap;
}

.yoo-footer__brand {
  flex-shrink: 0;
}

.yoo-footer__tagline {
  font-size: 14px;
  color: var(--color-zinc);
  margin-top: var(--space-sm);
  max-width: 280px;
  line-height: 1.5;
}

.yoo-footer__links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xl) var(--space-4xl);
}

.yoo-footer__links a {
  font-family: var(--font-primary);
  font-size: 14px;
  font-weight: 400;
  color: var(--color-zinc);
  text-decoration: none;
  transition: color var(--duration-fast);
}

.yoo-footer__links a:hover {
  color: var(--color-off-white);
}

.yoo-footer__divider {
  height: 1px;
  background: rgba(255, 255, 255, 0.06);
  margin: var(--space-2xl) 0;
}

.yoo-footer__bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-xl);
  flex-wrap: wrap;
}

.yoo-footer__copyright {
  font-family: var(--font-primary);
  font-size: 13px;
  color: var(--color-dim);
  line-height: 1.5;
}

.yoo-footer__social {
  display: flex;
  gap: var(--space-sm);
  align-items: center;
}

.yoo-footer__social-icon {
  width: 40px;
  height: 40px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-btn-sm);
  transition: all var(--duration-fast);
  text-decoration: none;
}

.yoo-footer__social-icon:hover {
  background: rgba(0, 229, 204, 0.1);
  border-color: rgba(0, 229, 204, 0.2);
}

.yoo-footer__social-icon svg {
  width: 18px;
  height: 18px;
  fill: var(--color-zinc);
  transition: fill var(--duration-fast);
}

.yoo-footer__social-icon:hover svg {
  fill: var(--color-cyan);
}

/* PayPal donate button */
.yoo-footer__donate {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  flex-wrap: wrap;
}

.yoo-footer__donate-label {
  font-size: 13px;
  color: var(--color-zinc);
}

/* Open Source Credits */
.yoo-footer__credits {
  margin-top: var(--space-3xl);
  padding-top: var(--space-2xl);
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.yoo-footer__credits-title {
  font-family: var(--font-primary);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-zinc);
  margin-bottom: var(--space-base);
}

.yoo-footer__credits-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--space-sm);
}

.yoo-footer__credits-list li {
  font-family: var(--font-primary);
  font-size: 13px;
  color: var(--color-dim);
  line-height: 1.5;
}

.yoo-footer__credits-list li strong {
  color: var(--color-zinc);
  font-weight: 600;
}

.yoo-footer__credits-list li a {
  color: var(--color-cyan);
  opacity: 0.7;
  text-decoration: none;
  transition: opacity var(--duration-fast);
}

.yoo-footer__credits-list li a:hover {
  opacity: 1;
}


/* ============================================
   CTA BLOCK
   ============================================ */

.yoo-cta-block {
  text-align: center;
  padding: var(--space-4xl) var(--space-2xl);
  background: var(--gradient-prism-soft);
  border: 1px solid var(--color-glass-border);
  border-radius: var(--radius-section);
  margin-top: var(--space-4xl);
}

.yoo-cta-block__title {
  font-family: var(--font-display);
  font-size: 36px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--color-white);
  margin-bottom: var(--space-base);
}

.yoo-cta-block__desc {
  font-size: 16px;
  color: var(--color-silver);
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.7;
}


/* ============================================
   RESPONSIVE — HEADER & NAV
   ============================================ */

@media (max-width: 1024px) {
  .yoo-nav,
  .yoo-header__actions .yoo-btn--solid-sm {
    display: none;
  }

  .yoo-hamburger {
    display: flex;
  }
}

@media (max-width: 640px) {
  .yoo-header__inner {
    padding: 0 var(--content-padding-mobile);
  }

  .yoo-footer {
    padding: var(--space-4xl) var(--content-padding-mobile) var(--space-2xl);
  }

  .yoo-footer__top {
    flex-direction: column;
    gap: var(--space-2xl);
  }

  .yoo-footer__credits-list {
    grid-template-columns: 1fr;
  }

  .yoo-cta-block__title {
    font-size: 26px;
  }

  .yoo-btn--primary,
  .yoo-btn--ghost {
    height: 48px;
    padding: 0 24px;
    font-size: 15px;
  }
}

/* ============================================
   LANGUAGE SWITCHER
   .yoo-lang-switcher  — pill group (index/curriculum)
   .yoo-panel-lang     — compact select (sims/theory panel)
   ============================================ */

/* ── Pill group (header) ──────────────────────────────────── */
.yoo-lang-switcher {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.10);
  border-radius: var(--radius-full, 100px);
  padding: 3px;
}

.yoo-lang-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 28px;
  min-width: 36px;
  padding: 0 8px;
  border-radius: var(--radius-full, 100px);
  border: none;
  background: transparent;
  color: var(--color-silver, #a1a1aa);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.06em;
  cursor: pointer;
  transition:
    background var(--duration-fast, 200ms) ease,
    color var(--duration-fast, 200ms) ease;
}

.yoo-lang-toggle:hover {
  color: var(--color-white, #fff);
  background: rgba(255, 255, 255, 0.08);
}

.yoo-lang-toggle--active,
.yoo-lang-toggle[aria-pressed="true"] {
  background: var(--color-cyan, #00e5cc);
  color: var(--color-obsidian, #0a0a0f);
  box-shadow: 0 0 10px rgba(0, 229, 204, 0.35);
}

.yoo-lang-toggle--active:hover,
.yoo-lang-toggle[aria-pressed="true"]:hover {
  background: var(--color-cyan-light, #33ffeb);
  color: var(--color-obsidian, #0a0a0f);
}

/* ── Panel select (sims / theory) ─────────────────────────── */
.yoo-panel-lang {
  appearance: none;
  -webkit-appearance: none;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius-full, 100px);
  color: var(--color-silver, #a1a1aa);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.06em;
  padding: 4px 10px;
  cursor: pointer;
  outline: none;
  transition: border-color var(--duration-fast, 200ms) ease,
              color var(--duration-fast, 200ms) ease;
  margin: 0 6px;
  align-self: center;
}

.yoo-panel-lang:hover,
.yoo-panel-lang:focus {
  border-color: rgba(0, 229, 204, 0.45);
  color: var(--color-white, #fff);
}

.yoo-panel-lang option {
  background: #1a1a24;
  color: #e8e8f0;
  font-size: 12px;
}

/* Mobile: keep lang switcher visible in small headers */
@media (max-width: 640px) {
  .yoo-lang-switcher {
    gap: 1px;
    padding: 2px;
  }

  .yoo-lang-toggle {
    height: 24px;
    min-width: 30px;
    font-size: 10px;
    padding: 0 6px;
  }
}