/* BrickBack - LEGO Reverse Instructions
   Design System: Warm/light, LEGO-inspired, Nunito font
   ================================================== */

@import url('https://fonts.googleapis.com/css2?family=Nunito:wght@400;600;700;800;900&display=swap');

/* CSS Variables */
:root {
  --yellow:    #FFD700;
  --yellow-dk: #E6C200;
  --red:       #E3000B;
  --blue:      #006DB7;
  --dark:      #1A1A1A;
  --text:      #2C2C2C;
  --muted:     #6B7280;
  --bg:        #F7F3EC;
  --white:     #FFFFFF;
  --border:    #E5DDD0;
  --bag-1: #E3000B;
  --bag-2: #006DB7;
  --bag-3: #00A651;
  --bag-4: #FF6B00;
  --bag-5: #9B59B6;
  --bag-6: #E67E22;
  --radius:    14px;
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.12);
  --shadow-lg: 0 8px 40px rgba(0,0,0,0.16);
  --transition: 0.2s ease;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
  font-family: 'Nunito', sans-serif;
  font-size: 16px;
  font-weight: 400;
  color: var(--text);
  background-color: var(--bg);
  background-image: radial-gradient(circle, #C9BFB0 1.2px, transparent 1.2px);
  background-size: 24px 24px;
  line-height: 1.6;
  min-height: 100vh;
}

a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
img { max-width: 100%; display: block; }

/* ==============================
   SITE HEADER
   ============================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--dark);
  border-bottom: 4px solid var(--yellow);
  box-shadow: 0 2px 16px rgba(0,0,0,0.35);
}

.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
  height: 68px;
  display: flex;
  align-items: center;
  gap: 16px;
}

.logo { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }
.logo-bricks { display: flex; gap: 4px; align-items: flex-end; }

.logo-bricks span {
  display: block;
  position: relative;
  width: 20px;
  height: 14px;
  border-radius: 3px;
}

.logo-bricks span::before {
  content: '';
  position: absolute;
  top: -5px;
  left: 50%;
  transform: translateX(-50%);
  width: 8px;
  height: 5px;
  border-radius: 50% 50% 0 0;
  background: inherit;
  filter: brightness(1.15);
}

.brick-r { background-color: var(--red); }
.brick-y { background-color: var(--yellow); height: 18px; }
.brick-b { background-color: var(--blue); }

.logo-text {
  font-size: 1.5rem;
  font-weight: 900;
  color: var(--yellow);
  letter-spacing: -0.5px;
  line-height: 1;
}

.header-tagline {
  font-size: 0.78rem;
  font-weight: 600;
  color: #8A8A8A;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

/* ==============================
   HERO
   ============================== */
.hero {
  background: linear-gradient(160deg, #1A1A1A 0%, #252525 50%, #1C1F2A 100%);
  padding: 72px 24px 80px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle, rgba(255,215,0,0.06) 1px, transparent 1px);
  background-size: 32px 32px;
  pointer-events: none;
}

.hero-inner { position: relative; max-width: 700px; margin: 0 auto; }

.hero-badge {
  display: inline-block;
  background: var(--yellow);
  color: var(--dark);
  font-size: 0.78rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 1px;
  padding: 6px 16px;
  border-radius: 50px;
  margin-bottom: 22px;
}

.hero-title {
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 900;
  color: var(--white);
  line-height: 1.15;
  margin-bottom: 16px;
  letter-spacing: -0.5px;
}

.hero-title em { font-style: normal; color: var(--yellow); }

.hero-desc {
  font-size: 1.1rem;
  font-weight: 600;
  color: #9CA3AF;
  margin-bottom: 36px;
  line-height: 1.6;
}

.search-bar {
  display: flex;
  align-items: center;
  background: var(--white);
  border-radius: 50px;
  padding: 6px 6px 6px 20px;
  max-width: 520px;
  margin: 0 auto;
  box-shadow: 0 4px 24px rgba(0,0,0,0.25);
  gap: 8px;
}

.search-bar svg { flex-shrink: 0; color: var(--muted); width: 20px; height: 20px; }

.search-bar input {
  flex: 1;
  border: none;
  outline: none;
  font-family: 'Nunito', sans-serif;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
  background: transparent;
  min-width: 0;
}

.search-bar input::placeholder { color: #B0B0B0; font-weight: 400; }

.search-btn {
  flex-shrink: 0;
  background: var(--yellow);
  color: var(--dark);
  border: none;
  border-radius: 40px;
  padding: 10px 22px;
  font-family: 'Nunito', sans-serif;
  font-size: 0.9rem;
  font-weight: 800;
  cursor: pointer;
  transition: background var(--transition), transform var(--transition);
}

.search-btn:hover { background: var(--yellow-dk); transform: scale(1.03); }

/* ==============================
   SETS SECTION
   ============================== */
.sets-section { max-width: 1100px; margin: 0 auto; padding: 48px 24px 64px; }

.sets-header { display: flex; align-items: baseline; gap: 12px; margin-bottom: 32px; }
.sets-title { font-size: 1.6rem; font-weight: 900; color: var(--dark); letter-spacing: -0.3px; }
.sets-count { font-size: 0.9rem; font-weight: 700; color: var(--muted); }

.sets-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}

.no-results {
  text-align: center;
  padding: 48px 24px;
  color: var(--muted);
  font-weight: 700;
  font-size: 1rem;
  grid-column: 1 / -1;
}

/* ==============================
   SET CARD
   ============================== */
.set-card {
  background: var(--white);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  border: 1.5px solid var(--border);
  transition: transform var(--transition), box-shadow var(--transition);
  cursor: pointer;
  display: flex;
  flex-direction: column;
}

.set-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }

.set-card-thumb {
  height: 180px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  flex-shrink: 0;
}

.set-card.theme-green .set-card-thumb { background: linear-gradient(135deg, #e8f8ef 0%, #c8eeda 100%); }
.set-card.theme-red   .set-card-thumb { background: linear-gradient(135deg, #fdeaea 0%, #f5c0c0 100%); }
.set-card.theme-blue  .set-card-thumb { background: linear-gradient(135deg, #e5f0fb 0%, #bcd6f5 100%); }

.set-card-thumb svg { width: 120px; height: 120px; opacity: 0.9; overflow: visible; }

.set-card-body { padding: 18px 20px 20px; display: flex; flex-direction: column; flex: 1; }

.set-number-tag {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.8px;
  text-transform: uppercase;
  color: var(--muted);
  background: var(--bg);
  border: 1.5px solid var(--border);
  border-radius: 6px;
  padding: 3px 8px;
  margin-bottom: 8px;
  align-self: flex-start;
}

.set-card-name { font-size: 1.1rem; font-weight: 800; color: var(--dark); line-height: 1.3; margin-bottom: 10px; }

.set-card-meta {
  display: flex;
  gap: 16px;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--muted);
  margin-bottom: 16px;
  flex-wrap: wrap;
}

.set-card-meta span { display: flex; align-items: center; gap: 4px; }

.view-btn {
  display: block;
  width: 100%;
  background: var(--dark);
  color: var(--white);
  border: none;
  border-radius: 10px;
  padding: 11px;
  font-family: 'Nunito', sans-serif;
  font-size: 0.9rem;
  font-weight: 800;
  cursor: pointer;
  transition: background var(--transition), transform var(--transition);
  margin-top: auto;
}

.view-btn:hover { background: #2d2d2d; transform: scale(1.01); }

.set-card.theme-green .view-btn       { background: #00A651; }
.set-card.theme-green .view-btn:hover { background: #008a43; }
.set-card.theme-red   .view-btn       { background: var(--red); }
.set-card.theme-red   .view-btn:hover { background: #c40009; }
.set-card.theme-blue  .view-btn       { background: var(--blue); }
.set-card.theme-blue  .view-btn:hover { background: #005a96; }

/* ==============================
   INSTRUCTIONS PANEL
   ============================== */
.instructions-panel {
  display: none;
  max-width: 860px;
  margin: 0 auto;
  padding: 40px 24px 64px;
}

.instructions-panel.active {
  display: block;
  animation: panelSlideIn 0.3s ease;
}

@keyframes panelSlideIn {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: translateY(0); }
}

.back-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--white);
  color: var(--text);
  border: 1.5px solid var(--border);
  border-radius: 50px;
  padding: 9px 18px;
  font-family: 'Nunito', sans-serif;
  font-size: 0.88rem;
  font-weight: 700;
  cursor: pointer;
  transition: background var(--transition), border-color var(--transition), transform var(--transition);
  margin-bottom: 28px;
}

.back-btn:hover { background: var(--bg); border-color: #ccc; transform: translateX(-2px); }
.back-btn svg { width: 16px; height: 16px; flex-shrink: 0; }

.inst-set-header {
  background: var(--dark);
  border-radius: var(--radius);
  padding: 28px 32px;
  margin-bottom: 20px;
  display: flex;
  align-items: flex-start;
  gap: 20px;
  flex-wrap: wrap;
}

.set-badge {
  background: var(--yellow);
  color: var(--dark);
  font-size: 0.78rem;
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: 1px;
  border-radius: 8px;
  padding: 5px 12px;
  flex-shrink: 0;
  align-self: flex-start;
  margin-top: 4px;
}

.inst-set-info { flex: 1; min-width: 180px; }

.inst-set-name {
  font-size: 1.6rem;
  font-weight: 900;
  color: var(--white);
  line-height: 1.2;
  margin-bottom: 8px;
}

.inst-set-meta { display: flex; flex-wrap: wrap; gap: 20px; font-size: 0.85rem; font-weight: 600; color: #9CA3AF; }
.inst-set-meta span { display: flex; align-items: center; gap: 5px; }

.inst-intro-box {
  background: #EFF6FF;
  border: 1.5px solid #BFDBFE;
  border-radius: var(--radius);
  padding: 18px 22px;
  margin-bottom: 32px;
  display: flex;
  align-items: flex-start;
  gap: 12px;
  font-size: 0.9rem;
  font-weight: 600;
  color: #1E40AF;
  line-height: 1.55;
}

.inst-intro-box svg { flex-shrink: 0; margin-top: 2px; width: 20px; height: 20px; color: #3B82F6; }

.bags-list { display: flex; flex-direction: column; gap: 28px; }

/* ==============================
   BAG SECTION
   ============================== */
.bag-section {
  background: var(--white);
  border-radius: var(--radius);
  border: 1.5px solid var(--border);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.bag-header {
  padding: 20px 24px;
  display: flex;
  align-items: center;
  gap: 18px;
  border-bottom: 1.5px solid var(--border);
  background: var(--bg);
}

.bag-number-pill {
  width: 52px;
  height: 52px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.35rem;
  font-weight: 900;
  color: var(--white);
  flex-shrink: 0;
  position: relative;
  box-shadow: 0 3px 10px rgba(0,0,0,0.2);
}

.bag-number-pill::before {
  content: '';
  position: absolute;
  top: -7px;
  left: 50%;
  transform: translateX(-50%);
  width: 18px;
  height: 7px;
  border-radius: 50% 50% 0 0;
  background: inherit;
  filter: brightness(1.2);
}

[data-bag-color="1"] .bag-number-pill { background-color: var(--bag-1); }
[data-bag-color="2"] .bag-number-pill { background-color: var(--bag-2); }
[data-bag-color="3"] .bag-number-pill { background-color: var(--bag-3); }
[data-bag-color="4"] .bag-number-pill { background-color: var(--bag-4); }
[data-bag-color="5"] .bag-number-pill { background-color: var(--bag-5); }
[data-bag-color="6"] .bag-number-pill { background-color: var(--bag-6); }

.bag-info { flex: 1; min-width: 0; }
.bag-label { font-size: 1rem; font-weight: 800; color: var(--dark); line-height: 1.3; margin-bottom: 2px; }
.bag-sublabel { font-size: 0.82rem; font-weight: 600; color: var(--muted); }

.bag-piece-count {
  flex-shrink: 0;
  background: var(--dark);
  color: var(--white);
  border-radius: 50px;
  padding: 5px 14px;
  font-size: 0.8rem;
  font-weight: 800;
  white-space: nowrap;
}

.steps-list { padding: 20px 24px; display: flex; flex-direction: column; gap: 16px; }

/* ==============================
   STEP CARD
   ============================== */
.step-card { display: flex; gap: 16px; align-items: flex-start; }

.step-num {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
  font-weight: 900;
  color: var(--white);
  flex-shrink: 0;
  margin-top: 1px;
}

[data-bag-color="1"] .step-num { background-color: var(--bag-1); }
[data-bag-color="2"] .step-num { background-color: var(--bag-2); }
[data-bag-color="3"] .step-num { background-color: var(--bag-3); }
[data-bag-color="4"] .step-num { background-color: var(--bag-4); }
[data-bag-color="5"] .step-num { background-color: var(--bag-5); }
[data-bag-color="6"] .step-num { background-color: var(--bag-6); }

.step-content {
  flex: 1;
  min-width: 0;
  background: var(--bg);
  border: 1.5px solid var(--border);
  border-radius: 10px;
  padding: 12px 16px;
}

.step-action { font-size: 0.95rem; font-weight: 700; color: var(--dark); margin-bottom: 10px; line-height: 1.4; }
.step-pieces { display: flex; flex-wrap: wrap; gap: 7px; }

.piece-chip {
  background: var(--white);
  border: 1.5px solid var(--border);
  border-radius: 8px;
  padding: 4px 10px;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--text);
  line-height: 1.3;
  white-space: nowrap;
}

/* ==============================
   SITE FOOTER
   ============================== */
.site-footer {
  background: var(--dark);
  border-top: 4px solid var(--yellow);
  padding: 36px 24px;
  text-align: center;
  margin-top: 48px;
}

.footer-inner { max-width: 1100px; margin: 0 auto; }
.footer-logo { display: inline-flex; align-items: center; gap: 10px; margin-bottom: 12px; }
.footer-logo-bricks { display: flex; gap: 3px; align-items: flex-end; }

.footer-logo-bricks span { display: block; position: relative; border-radius: 2px; }

.footer-logo-bricks span::before {
  content: '';
  position: absolute;
  top: -4px;
  left: 50%;
  transform: translateX(-50%);
  width: 6px;
  height: 4px;
  border-radius: 50% 50% 0 0;
  background: inherit;
  filter: brightness(1.2);
}

.footer-logo-bricks .fb-r { width: 14px; height: 10px; background-color: var(--red); }
.footer-logo-bricks .fb-y { width: 14px; height: 13px; background-color: var(--yellow); }
.footer-logo-bricks .fb-b { width: 14px; height: 10px; background-color: var(--blue); }

.footer-logo-text { font-size: 1.1rem; font-weight: 900; color: var(--yellow); }
.footer-note { font-size: 0.82rem; font-weight: 600; color: #6B7280; line-height: 1.6; }
.footer-note a { color: #9CA3AF; text-decoration: underline; }
.footer-note a:hover { color: var(--yellow); }

/* ==============================
   UTILITY
   ============================== */
.visually-hidden {
  position: absolute; width: 1px; height: 1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap;
}

/* ==============================
   RESPONSIVE — mobile <=640px
   ============================== */
@media (max-width: 640px) {
  .header-inner { padding: 0 16px; height: 60px; }
  .header-tagline { display: none; }
  .logo-text { font-size: 1.25rem; }

  .hero { padding: 48px 16px 56px; }
  .hero-title { font-size: 1.8rem; }
  .hero-desc { font-size: 0.95rem; }
  .search-bar { padding: 5px 5px 5px 14px; }
  .search-btn { padding: 9px 14px; font-size: 0.82rem; }

  .sets-section { padding: 32px 16px 48px; }
  .sets-grid { grid-template-columns: 1fr; gap: 16px; }

  .instructions-panel { padding: 28px 16px 48px; }
  .inst-set-header { padding: 20px; flex-direction: column; gap: 14px; }
  .inst-set-name { font-size: 1.3rem; }
  .bags-list { gap: 20px; }

  .bag-header { padding: 16px; gap: 12px; flex-wrap: wrap; }
  .bag-number-pill { width: 44px; height: 44px; font-size: 1.1rem; }
  .bag-piece-count { margin-left: auto; }

  .steps-list { padding: 16px; gap: 12px; }
  .step-card { gap: 10px; }
  .step-num { width: 28px; height: 28px; font-size: 0.8rem; }
  .step-content { padding: 10px 12px; }
  .step-action { font-size: 0.88rem; }
  .piece-chip { font-size: 0.73rem; padding: 3px 8px; }

  .site-footer { padding: 28px 16px; }
}

/* ---- BAG SKETCH ---- */
.bag-sketch-wrap {
  background: #0D1B2A;
  border-bottom: 2px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  overflow: hidden;
}
.bag-sketch {
  width: 100%;
  max-width: 480px;
  height: auto;
  display: block;
  border-radius: 6px;
  opacity: 0.95;
}