.equation-card {
  position: relative;
  display: block;
  margin: 16px 0;
  padding: 20px 112px 20px 20px;
  border: 1px solid rgba(12, 36, 57, 0.1);
  border-radius: 18px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.92), rgba(247, 251, 252, 0.86)),
    radial-gradient(circle at 92% 12%, rgba(26, 179, 179, 0.08), transparent 20%);
  box-shadow: 0 18px 42px rgba(7, 21, 34, 0.08);
}

.equation-card .equation-render {
  display: block;
  min-width: 0;
}

.equation-card .equation-copy {
  position: absolute;
  top: 12px;
  right: 12px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 108px;
  min-height: 34px;
  padding: 0 12px;
  border: 1px solid rgba(12, 36, 57, 0.12);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.92);
  color: #0b3550;
  font-family: "Noto Sans SC", "Microsoft YaHei", sans-serif;
  font-size: 12px;
  font-weight: 700;
  line-height: 1;
  cursor: pointer;
  transition: transform 0.18s ease, background 0.18s ease, border-color 0.18s ease;
}

.equation-card .equation-copy:hover {
  transform: translateY(-1px);
  background: rgba(26, 179, 179, 0.1);
  border-color: rgba(26, 179, 179, 0.22);
}

.equation-card .equation-copy.is-copied {
  color: #0d6b46;
  background: rgba(54, 179, 126, 0.12);
  border-color: rgba(54, 179, 126, 0.24);
}

.equation-card .equation-copy.is-failed {
  color: #8b2e17;
  background: rgba(216, 103, 45, 0.1);
  border-color: rgba(216, 103, 45, 0.22);
}

.equation-card .equation-number {
  position: absolute;
  right: 16px;
  top: 50%;
  transform: translateY(-50%);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 62px;
  min-height: 34px;
  padding: 0 10px;
  border-radius: 999px;
  background: rgba(12, 36, 57, 0.06);
  color: #0b3550;
  font-family: "JetBrains Mono", "Cascadia Code", Consolas, monospace;
  font-size: 12px;
  font-weight: 700;
  line-height: 1;
  white-space: nowrap;
}

.equation-card mjx-container[display="true"] {
  display: block;
  overflow-x: auto;
  overflow-y: hidden;
  margin: 0;
  padding: 0;
  text-align: center;
}

.equation-card mjx-container[display="true"] svg {
  display: block;
  margin: 0 auto;
}

.equation-card mjx-container:not([display="true"]) {
  display: inline;
}

.equation-card.equation {
  overflow: visible;
}

.note-prose p > .equation-card,
.lesson-body p > .equation-card {
  margin-top: 14px;
}

.note-prose li > .equation-card,
.lesson-body li > .equation-card {
  margin-top: 12px;
}

@media (max-width: 760px) {
  .equation-card {
    padding: 58px 18px 18px;
  }

  .equation-card .equation-copy {
    min-width: 96px;
    min-height: 32px;
    padding: 0 10px;
    font-size: 11px;
  }

  .equation-card .equation-number {
    top: 14px;
    right: 118px;
    transform: none;
    min-width: 54px;
    min-height: 32px;
    font-size: 11px;
  }
}