.concepts-page { max-width: 72rem; }
.concepts-hero { margin-bottom: 3rem; }
.concepts-hero h1 { font-size: clamp(1.75rem, 4vw, 2.25rem); font-weight: 700; margin-bottom: 0.5rem; }
.concepts-hero p { color: rgba(255,255,255,0.45); line-height: 1.7; max-width: 42rem; }

.concepts-grid {
  display: grid;
  gap: 1.5rem;
}
@media (min-width: 900px) {
  .concepts-grid { grid-template-columns: repeat(2, 1fr); }
}

.concept-card {
  border-radius: 1.25rem;
  border: 1px solid rgba(255,255,255,0.08);
  background: rgba(255,255,255,0.03);
  overflow: hidden;
  transition: border-color 0.2s, box-shadow 0.2s, transform 0.2s;
}
.concept-card:hover {
  border-color: rgba(51,163,255,0.25);
  transform: translateY(-2px);
}
.concept-card.selected {
  border-color: rgba(51,163,255,0.55);
  box-shadow: 0 0 0 1px rgba(51,163,255,0.35), 0 24px 48px -24px rgba(51,163,255,0.35);
}

.concept-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.25rem 1.25rem 0;
}
.concept-header h2 { font-size: 1.125rem; font-weight: 600; margin: 0 0 0.25rem; }
.concept-header p { font-size: 0.8125rem; color: rgba(255,255,255,0.45); margin: 0; line-height: 1.5; }
.concept-num {
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: rgba(255,255,255,0.3);
  font-family: ui-monospace, monospace;
  flex-shrink: 0;
}

.concept-tags { display: flex; flex-wrap: wrap; gap: 0.375rem; padding: 0.75rem 1.25rem 0; }
.concept-tag {
  font-size: 0.625rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 0.25rem 0.5rem;
  border-radius: 9999px;
  background: rgba(255,255,255,0.06);
  color: rgba(255,255,255,0.45);
}
.concept-tag.accent { background: rgba(51,163,255,0.15); color: #8ed8ff; }

.concept-previews {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  padding: 1.25rem;
}
.concept-preview {
  border-radius: 0.875rem;
  border: 1px solid rgba(255,255,255,0.06);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  min-height: 140px;
}
.concept-preview.dark { background: #0a0f1a; }
.concept-preview.light { background: #f4f7fb; }
.concept-preview-label {
  font-size: 0.625rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: rgba(255,255,255,0.3);
}
.concept-preview.light .concept-preview-label { color: rgba(10,15,26,0.35); }

.concept-mock {
  padding: 0 1.25rem 1.25rem;
}
.concept-mock-bar {
  border-radius: 0.75rem;
  border: 1px solid rgba(255,255,255,0.06);
  background: rgba(0,0,0,0.2);
  padding: 0.75rem 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.concept-mock-bar.light {
  background: #fff;
  border-color: #e2e8f0;
}

.concept-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0 1.25rem 1.25rem;
}
.concept-pick {
  font-size: 0.8125rem;
  font-weight: 600;
  padding: 0.5rem 1rem;
  border-radius: 0.625rem;
  border: 1px solid rgba(51,163,255,0.35);
  background: rgba(51,163,255,0.12);
  color: #8ed8ff;
  cursor: pointer;
  transition: background 0.2s;
}
.concept-pick:hover { background: rgba(51,163,255,0.22); }
.concept-card.selected .concept-pick {
  background: #33a3ff;
  border-color: #33a3ff;
  color: #fff;
}
.concept-note { font-size: 0.75rem; color: rgba(255,255,255,0.35); }

.concepts-sticky {
  position: sticky;
  bottom: 1rem;
  z-index: 20;
  margin-top: 2rem;
  padding: 1rem 1.25rem;
  border-radius: 1rem;
  border: 1px solid rgba(51,163,255,0.25);
  background: rgba(10,15,26,0.92);
  backdrop-filter: blur(12px);
  display: none;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}
.concepts-sticky.visible { display: flex; }
.concepts-sticky strong { color: #8ed8ff; }

.concept-icon { width: 72px; height: 72px; }
.concept-icon-sm { width: 36px; height: 36px; }
.concept-lockup { height: 40px; width: auto; max-width: 100%; }

.concept-icon-wide { width: 88px; }

.concept-preview-type { background: #0a0f1a; }

.concepts-grid-hive-flow {
  grid-template-columns: 1fr;
}
@media (min-width: 640px) {
  .concepts-grid-hive-flow { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 1100px) {
  .concepts-grid-hive-flow { grid-template-columns: repeat(3, 1fr); }
}
.concept-hive-flow .concept-icon { width: 88px; height: 88px; }
.concept-hive-flow {
  border-color: rgba(51,163,255,0.15);
  background: rgba(51,163,255,0.03);
}
.concept-hive-flow:hover {
  border-color: rgba(51,163,255,0.3);
}
.concept-top-pick {
  border-color: rgba(51,163,255,0.35);
  background: rgba(51,163,255,0.06);
  box-shadow: 0 0 32px -8px rgba(51,163,255,0.25);
}
.concept-top-pick.selected {
  border-color: rgba(51,163,255,0.6);
  box-shadow: 0 0 0 1px rgba(51,163,255,0.4), 0 24px 48px -16px rgba(51,163,255,0.3);
}
.concepts-section-hive-flow { margin-bottom: 2.5rem; }

.concept-final {
  border-color: rgba(51,163,255,0.22);
  background: rgba(51,163,255,0.04);
}
.concept-final.selected {
  border-color: rgba(51,163,255,0.55);
  box-shadow: 0 0 0 1px rgba(51,163,255,0.35), 0 24px 48px -16px rgba(51,163,255,0.25);
}
.concepts-grid-final {
  grid-template-columns: 1fr;
  gap: 2rem;
}
@media (min-width: 900px) {
  .concepts-grid-final { grid-template-columns: repeat(2, 1fr); }
}
.concept-final .concept-icon { width: 96px; height: 96px; }
.concept-sizes {
  display: flex;
  align-items: flex-end;
  justify-content: center;
  gap: 1.25rem;
  padding: 0 1.25rem 0.5rem;
}
.concept-size {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.375rem;
}
.concept-size-label {
  font-size: 0.5625rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: rgba(255,255,255,0.28);
  font-family: ui-monospace, monospace;
}
.concept-size svg { display: block; }
.concept-compare {
  margin-bottom: 2.5rem;
  padding: 1.25rem 1.5rem;
  border-radius: 1rem;
  border: 1px solid rgba(255,255,255,0.08);
  background: rgba(255,255,255,0.02);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1.5rem 2.5rem;
}
.concept-compare-label {
  font-size: 0.6875rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: rgba(255,255,255,0.35);
  width: 100%;
  margin-bottom: -0.5rem;
}
.concept-compare-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.concept-compare-item span {
  font-size: 0.8125rem;
  color: rgba(255,255,255,0.45);
}
.concepts-section-final { margin-bottom: 2.5rem; }

.concept-fav {
  border-color: rgba(167,139,250,0.25);
  background: rgba(129,140,248,0.06);
}
.concept-hive {
  border-color: rgba(245,158,11,0.2);
  background: rgba(245,158,11,0.04);
}

.concepts-archive summary { list-style: none; }
.concepts-archive summary::-webkit-details-marker { display: none; }

.concepts-section { margin-bottom: 3rem; }
.concepts-section-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: rgba(255,255,255,0.9);
  margin: 0 0 0.25rem;
}
.concepts-section-sub {
  font-size: 0.8125rem;
  color: rgba(255,255,255,0.4);
  margin: 0 0 1.25rem;
}

.concept-current {
  grid-column: 1 / -1;
  border-color: rgba(255,255,255,0.12);
  background: rgba(51,163,255,0.04);
}