/* Kyu — shell estilo Fundamentos, acento dinámico --kyu-color */

.kyu-page {
  --kyu-color: #9ec2f6;
  --kyu-soft: color-mix(in srgb, var(--kyu-color) 22%, white);
  --kyu-bg: #f5f7f9;
  --kyu-card: #ffffff;
  --kyu-border: rgba(13, 59, 102, 0.12);
  --kyu-text: #1e2430;
  --kyu-muted: #5c6570;
  --kyu-radius: 14px;
  --kyu-touch: 48px;

  width: 100vw;
  position: relative;
  left: 50%;
  right: 50%;
  margin-left: -50vw;
  margin-right: -50vw;
  background:
    radial-gradient(120% 80% at 10% -10%, color-mix(in srgb, var(--kyu-color) 28%, transparent), transparent 55%),
    radial-gradient(90% 60% at 100% 0%, rgba(13, 59, 102, 0.05), transparent 50%),
    var(--kyu-bg);
  color: var(--kyu-text);
  padding: 1.25rem 0 3.5rem;
  min-height: 70vh;
}

.kyu-page * {
  box-sizing: border-box;
}

.kyu-inner {
  width: min(1100px, calc(100% - 1.5rem));
  margin: 0 auto;
}

.kyu-hero {
  margin-bottom: 1.25rem;
  padding: 0.5rem 0 0.25rem;
}

.kyu-kicker {
  display: inline-block;
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: #0d3b66;
  background: var(--kyu-soft);
  padding: 0.28rem 0.65rem;
  border-radius: 999px;
  margin-bottom: 0.65rem;
  font-weight: 600;
}

.kyu-hero h1 {
  font-size: clamp(1.85rem, 6vw, 2.75rem);
  font-weight: 700;
  line-height: 1.15;
  margin: 0 0 0.5rem;
  letter-spacing: -0.02em;
  color: #0d3b66;
}

.kyu-hero p {
  margin: 0;
  max-width: 36rem;
  color: var(--kyu-muted);
  font-size: 1rem;
  line-height: 1.55;
}

/* Grade pills */
.kyu-nav {
  display: flex;
  gap: 0.5rem;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scroll-snap-type: x mandatory;
  padding: 0.5rem 0 1rem;
  margin: 0 0 1rem;
  scrollbar-width: none;
  position: sticky;
  top: 0;
  z-index: 20;
  background: linear-gradient(to bottom, var(--kyu-bg) 70%, transparent);
}

.kyu-nav::-webkit-scrollbar {
  display: none;
}

.kyu-nav-btn {
  flex: 0 0 auto;
  scroll-snap-align: start;
  min-height: var(--kyu-touch);
  padding: 0.65rem 1.05rem;
  border-radius: 999px;
  border: 2px solid transparent;
  font-size: 0.88rem;
  font-weight: 700;
  white-space: nowrap;
  text-decoration: none;
  color: #1e2430;
  box-shadow: 0 1px 3px rgba(13, 59, 102, 0.08);
  transition: transform 0.15s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.kyu-nav-btn:hover {
  color: #1e2430;
  text-decoration: none;
}

.kyu-nav-btn:active {
  transform: scale(0.98);
}

.kyu-nav-btn.is-active {
  border-color: #0d3b66;
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--kyu-color) 45%, transparent), 0 4px 12px rgba(13, 59, 102, 0.12);
}

/* Technique cards */
.kyu-cards {
  display: grid;
  gap: 0.85rem;
}

.kyu-card {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: 0;
  border-radius: var(--kyu-radius);
  background: var(--kyu-card);
  border: 1px solid var(--kyu-border);
  box-shadow: 0 6px 18px rgba(13, 59, 102, 0.06);
  overflow: hidden;
}

.kyu-card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: linear-gradient(180deg, var(--kyu-color), transparent 85%);
  z-index: 1;
}

.kyu-card-media {
  background: linear-gradient(135deg, var(--kyu-soft), #fff);
  padding: 1rem 1rem 0.5rem;
  text-align: center;
}

.kyu-card-media img {
  width: 120px;
  height: 120px;
  object-fit: contain;
  border-radius: 10px;
}

.kyu-card-body {
  display: flex;
  flex-direction: column;
  flex: 1;
  padding: 0.85rem 1.15rem 1.2rem;
  gap: 0.35rem;
}

.kyu-card-cat {
  display: inline-block;
  align-self: flex-start;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 0.28rem 0.6rem;
  border-radius: 999px;
  background: var(--kyu-soft);
  color: #0d3b66;
}

.kyu-card h2 {
  font-size: clamp(1.2rem, 4vw, 1.45rem);
  font-weight: 700;
  margin: 0.15rem 0 0;
  line-height: 1.2;
  color: #0d3b66;
}

.kyu-card-jpn {
  margin: 0;
  font-size: 0.95rem;
  color: var(--kyu-text);
}

.kyu-card-esp {
  margin: 0;
  font-size: 0.88rem;
  font-style: italic;
  color: var(--kyu-muted);
}

.kyu-card-desc {
  margin: 0.45rem 0 0;
  color: var(--kyu-muted);
  font-size: 0.92rem;
  line-height: 1.55;
  flex: 1;
}

.kyu-card-desc p {
  margin: 0 0 0.5rem;
}

.kyu-card-actions {
  margin-top: 0.85rem;
}

.kyu-card-actions .btn {
  min-height: 44px;
  font-weight: 600;
  border-color: color-mix(in srgb, var(--kyu-color) 55%, #0d3b66);
  color: #0d3b66;
  background: #fff;
}

.kyu-card-actions .btn:hover {
  background: var(--kyu-soft);
  border-color: #0d3b66;
  color: #0d3b66;
}

.kyu-empty {
  padding: 1.5rem;
  border-radius: var(--kyu-radius);
  background: var(--kyu-card);
  border: 1px dashed var(--kyu-border);
  color: var(--kyu-muted);
  text-align: center;
}

/* Detail */
.kyu-breadcrumb {
  margin-bottom: 1rem;
}

.kyu-breadcrumb .breadcrumb {
  margin-bottom: 0;
}

.kyu-nav-tech {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  justify-content: space-between;
  margin-bottom: 1rem;
}

.kyu-nav-tech .btn {
  min-height: 44px;
  flex: 1 1 auto;
  max-width: 100%;
}

.kyu-detail-card {
  position: relative;
  border-radius: var(--kyu-radius);
  background: var(--kyu-card);
  border: 1px solid var(--kyu-border);
  box-shadow: 0 8px 24px rgba(13, 59, 102, 0.08);
  overflow: hidden;
}

.kyu-detail-card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  background: var(--kyu-color);
  z-index: 1;
}

.kyu-detail-head {
  padding: 1.25rem 1.2rem;
  background:
    linear-gradient(180deg, color-mix(in srgb, var(--kyu-color) 55%, white) 0%, color-mix(in srgb, var(--kyu-color) 18%, white) 100%);
  border-bottom: 1px solid var(--kyu-border);
}

.kyu-detail-head h1 {
  font-size: clamp(1.6rem, 5vw, 2.2rem);
  font-weight: 700;
  margin: 0;
  color: #0d3b66;
  line-height: 1.2;
}

.kyu-detail-body {
  padding: 1.2rem 1.15rem 1.5rem;
}

.kyu-detail-grid {
  display: grid;
  gap: 1.25rem;
}

.kyu-field {
  margin-bottom: 0.85rem;
}

.kyu-field:last-child {
  margin-bottom: 0;
}

.kyu-field-label {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: #0d3b66;
  margin-bottom: 0.25rem;
}

.kyu-field-value {
  color: var(--kyu-muted);
  font-size: 0.98rem;
  line-height: 1.55;
}

.kyu-detail-media img {
  width: 100%;
  max-height: 360px;
  object-fit: contain;
  border-radius: 10px;
  background: var(--kyu-soft);
}

.kyu-video {
  margin-top: 1.5rem;
}

.kyu-video iframe {
  width: 100%;
  max-width: 560px;
  aspect-ratio: 16 / 9;
  height: auto;
  min-height: 220px;
  border: 0;
  border-radius: 10px;
}

.kyu-steps {
  margin-top: 1.5rem;
}

.kyu-steps .list-group-item {
  border-color: var(--kyu-border);
}

@media (min-width: 768px) {
  .kyu-page {
    padding: 2rem 0 4.5rem;
  }

  .kyu-inner {
    width: min(1100px, calc(100% - 2.5rem));
  }

  .kyu-nav {
    flex-wrap: wrap;
    overflow: visible;
    gap: 0.65rem;
  }

  .kyu-cards {
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
  }

  .kyu-card {
    transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
  }

  .kyu-card:hover {
    transform: translateY(-2px);
    border-color: color-mix(in srgb, var(--kyu-color) 50%, #0d3b66);
    box-shadow: 0 12px 28px rgba(13, 59, 102, 0.1);
  }

  .kyu-detail-grid {
    grid-template-columns: 1.1fr 0.9fr;
    align-items: start;
  }

  .kyu-detail-head {
    padding: 1.5rem 1.6rem;
  }

  .kyu-detail-body {
    padding: 1.5rem 1.6rem 1.75rem;
  }
}

@media (min-width: 992px) {
  .kyu-cards {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* Fallback browsers without color-mix */
@supports not (background: color-mix(in srgb, red 50%, white)) {
  .kyu-page {
    --kyu-soft: rgba(158, 194, 246, 0.25);
  }

  .kyu-detail-head {
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.75), rgba(255, 255, 255, 0.35)), var(--kyu-color);
  }
}