.study-panel {
  --study-panel-accent: #1e5f8f;
  --study-panel-accent-soft: rgba(30, 95, 143, 0.12);
  --study-panel-border: rgba(120, 144, 156, 0.35);
  --study-panel-muted: #607d8b;
  margin-top: 1rem;
}

.study-panel * {
  box-sizing: border-box;
}

.study-panel__grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  margin: 1rem 0;
}

.study-panel__card {
  border: 1px solid var(--study-panel-border);
  border-radius: 0.8rem;
  padding: 1rem;
  background: var(--md-default-bg-color);
  box-shadow: 0 0.35rem 1.2rem rgba(38, 50, 56, 0.08);
}

.study-panel__card--accent {
  border-color: transparent;
  background: linear-gradient(135deg, var(--study-panel-accent-soft), rgba(255, 255, 255, 0));
}

.study-panel__label {
  display: block;
  color: var(--study-panel-muted);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  margin-bottom: 0.25rem;
  text-transform: uppercase;
}

.study-panel__value {
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.25;
}

.study-panel__muted {
  color: var(--study-panel-muted);
  font-size: 0.85rem;
}

.study-panel__section {
  margin-top: 1.4rem;
}

.study-panel__actions,
.study-panel__selector,
.study-panel__links,
.study-panel__status-line {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  align-items: center;
}

.study-panel__selector {
  justify-content: space-between;
  margin: 1rem 0;
}

.study-panel__button,
.study-panel__link {
  border: 1px solid var(--study-panel-border);
  border-radius: 999px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.2rem;
  padding: 0.45rem 0.9rem;
  text-decoration: none;
  transition: background 120ms ease, border-color 120ms ease, color 120ms ease;
}

.study-panel__button {
  background: var(--md-default-bg-color);
  color: var(--md-default-fg-color);
  font: inherit;
}

.study-panel__button:hover,
.study-panel__link:hover {
  border-color: var(--study-panel-accent);
  background: var(--study-panel-accent-soft);
}

.study-panel__button--primary {
  border-color: var(--study-panel-accent);
  background: var(--study-panel-accent);
  color: #fff;
}

.study-panel__button--primary:hover {
  background: #174b72;
  color: #fff;
}

.study-panel__button--danger:hover {
  border-color: #b71c1c;
  background: rgba(183, 28, 28, 0.1);
}

.study-panel__link {
  background: var(--study-panel-accent-soft);
}

.study-panel__field {
  margin: 0.8rem 0;
}

.study-panel__field label {
  display: block;
  font-weight: 700;
  margin-bottom: 0.3rem;
}

.study-panel__input,
.study-panel__select,
.study-panel__textarea {
  width: 100%;
  border: 1px solid var(--study-panel-border);
  border-radius: 0.55rem;
  background: var(--md-default-bg-color);
  color: var(--md-default-fg-color);
  font: inherit;
  padding: 0.55rem 0.65rem;
}

.study-panel__textarea {
  min-height: 7rem;
  resize: vertical;
}

.study-panel__export {
  min-height: 12rem;
  white-space: pre;
}

.study-panel__day-list {
  display: grid;
  gap: 0.55rem;
  margin: 0.8rem 0;
}

.study-panel__day-item {
  border-left: 0.25rem solid var(--study-panel-border);
  padding: 0.45rem 0 0.45rem 0.7rem;
}

.study-panel__day-item--today {
  border-color: var(--study-panel-accent);
  background: var(--study-panel-accent-soft);
  border-radius: 0 0.45rem 0.45rem 0;
}

.study-panel__error-list {
  display: grid;
  gap: 0.5rem;
  margin-top: 0.8rem;
}

.study-panel__error-item {
  border: 1px solid var(--study-panel-border);
  border-radius: 0.55rem;
  padding: 0.65rem;
}

.study-panel__progress {
  background: rgba(120, 144, 156, 0.22);
  border-radius: 999px;
  height: 0.7rem;
  overflow: hidden;
  width: 100%;
}

.study-panel__progress-bar {
  background: var(--study-panel-accent);
  height: 100%;
  transition: width 150ms ease;
}

.study-panel__notice {
  border-left: 0.25rem solid var(--study-panel-accent);
  margin: 1rem 0;
  padding: 0.7rem 0 0.7rem 0.8rem;
}

@media (max-width: 720px) {
  .study-panel__selector {
    align-items: stretch;
  }

  .study-panel__actions,
  .study-panel__selector,
  .study-panel__status-line {
    flex-direction: column;
  }

  .study-panel__button,
  .study-panel__link,
  .study-panel__select {
    width: 100%;
  }
}