/* =====================================================================
 * bienac — trang bảng tuần hoàn
 * ===================================================================== */

.pt-page { padding-top: 90px; }
.pt-section { max-width: 1280px; }
.site-nav .nav-active { color: var(--cyan); }

/* ------------------------------------------------------ Chú giải -- */
.pt-legend {
  margin-top: 26px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px 10px;
}
.pt-chip {
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--text-dim);
  border: 1px solid var(--glass-border);
  background: var(--glass);
  border-radius: 999px;
  padding: 4px 12px 4px 9px;
  display: inline-flex;
  align-items: center;
  gap: 7px;
}
.pt-chip::before {
  content: '';
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--c);
  box-shadow: 0 0 8px var(--c);
}

/* --------------------------------------------------------- Bảng -- */
.pt-scroll {
  margin-top: 30px;
  overflow-x: auto;
  padding-bottom: 12px;
  -webkit-overflow-scrolling: touch;
}
.pt-grid {
  display: grid;
  grid-template-columns: repeat(18, minmax(0, 1fr));
  grid-auto-rows: 1fr;
  gap: 5px;
  min-width: 820px;
}
/* hàng 8 là khoảng trống giữa bảng chính và khối f */
.pt-grid::after {
  content: '';
  grid-column: 1 / -1;
  grid-row: 8;
  height: 14px;
}

.pt-el {
  position: relative;
  aspect-ratio: 1 / 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1px;
  font-family: var(--font);
  color: var(--text);
  background: var(--glass);
  border: 1px solid color-mix(in srgb, var(--c) 35%, transparent);
  border-radius: 8px;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.2s ease, border-color 0.2s ease,
              background 0.2s ease;
}
.pt-el:hover, .pt-el:focus-visible {
  transform: scale(1.18);
  z-index: 5;
  border-color: var(--c);
  background: color-mix(in srgb, var(--c) 16%, rgba(10, 22, 34, 0.85));
  box-shadow: 0 0 18px color-mix(in srgb, var(--c) 60%, transparent),
              0 8px 22px rgba(0, 0, 0, 0.5);
  outline: none;
}
.pt-num {
  font-size: 0.52rem;
  color: var(--text-dim);
  line-height: 1;
}
.pt-sym {
  font-size: clamp(0.7rem, 1.4vw, 1.02rem);
  font-weight: 800;
  line-height: 1.1;
  color: var(--c);
  text-shadow: 0 0 12px color-mix(in srgb, var(--c) 55%, transparent);
}

.pt-fmark {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.55rem;
  color: var(--text-dim);
  border: 1px dashed rgba(159, 182, 192, 0.3);
  border-radius: 8px;
}

/* -------------------------------------------------------- Modal -- */
.el-modal {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}
/* display:flex ở trên đè mất [hidden] mặc định của trình duyệt */
.el-modal[hidden] { display: none; }
.el-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(2, 5, 10, 0.72);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}
.el-card {
  position: relative;
  width: min(560px, 100%);
  background: rgba(8, 14, 24, 0.92);
  border: 1px solid color-mix(in srgb, var(--el-color, var(--cyan)) 40%, transparent);
  border-radius: 22px;
  overflow: hidden;
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.6),
              0 0 50px color-mix(in srgb, var(--el-color, var(--cyan)) 22%, transparent);
  animation: el-pop 0.28s cubic-bezier(0.2, 0.9, 0.3, 1.2);
}
@keyframes el-pop {
  from { transform: scale(0.86); opacity: 0; }
  to   { transform: scale(1); opacity: 1; }
}

.el-canvas {
  display: block;
  width: 100%;
  height: clamp(220px, 40vh, 320px);
  background: #05080f;
}

.el-close {
  position: absolute;
  top: 12px;
  right: 12px;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 1px solid var(--glass-border);
  background: rgba(5, 10, 20, 0.6);
  color: var(--text);
  font-size: 0.95rem;
  cursor: pointer;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  z-index: 2;
}
.el-close:hover {
  transform: rotate(90deg);
  box-shadow: 0 0 16px rgba(30, 227, 227, 0.4);
}

.el-info { padding: 22px 26px 26px; }
.el-head {
  display: flex;
  align-items: center;
  gap: 18px;
}
.el-symbol {
  width: 72px;
  height: 72px;
  flex: none;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.9rem;
  font-weight: 800;
  color: var(--el-color, var(--cyan));
  border: 1px solid color-mix(in srgb, var(--el-color, var(--cyan)) 55%, transparent);
  border-radius: 16px;
  background: color-mix(in srgb, var(--el-color, var(--cyan)) 10%, transparent);
  text-shadow: 0 0 18px color-mix(in srgb, var(--el-color, var(--cyan)) 70%, transparent);
}
.el-name {
  font-size: 1.5rem;
  font-weight: 800;
}
.el-sub {
  margin-top: 4px;
  font-size: 0.85rem;
  color: var(--text-dim);
}
.el-desc {
  margin-top: 16px;
  color: var(--text-dim);
  line-height: 1.7;
  font-size: 0.98rem;
  min-height: 3.2em;
}
.el-replay {
  margin-top: 18px;
  padding: 10px 20px;
  font-size: 0.92rem;
  cursor: pointer;
  font-family: var(--font);
}

@media (max-width: 640px) {
  .el-info { padding: 18px 20px 22px; }
  .el-symbol { width: 58px; height: 58px; font-size: 1.5rem; }
  .el-name { font-size: 1.25rem; }
}

@media (prefers-reduced-motion: reduce) {
  .el-card { animation: none; }
  .pt-el, .pt-el:hover { transition: none; transform: none; }
}