:root {
  /*========== Font and typography ==========*/
  --h2-font-size: 1.25rem;
  --h3-font-size: 1.125rem;
  --normal-font-size: .938rem;
  --small-font-size: .813rem;
  --smaller-font-size: .70rem;

  /*========== Margins ==========*/
  --mb-0-25: .25rem;
  --mb-0-5: .5rem;
  --mb-1: 1rem;
  --mb-1-5: 1.5rem;
  --mb-2: 2rem;
  --mb-2-5: 2.5rem;
  --mb-3: 3rem;
}

/* Font size for large devices */
@media screen and (min-width: 968px) {
  :root {
    --h2-font-size: 1.5rem;
    --h3-font-size: 1.25rem;
    --normal-font-size: 1rem;
    --small-font-size: .875rem;
    --smaller-font-size: .813rem;
  }
}

/*==================== ABOUT INFO ====================*/
.about__info {
  display: flex;
  justify-content: space-between;
  align-items: stretch;
  margin: 1.75rem 0 0.75rem;
  padding: 1.1rem 1.75rem;
  border-radius: 18px;
  background: rgba(248, 250, 252, 0.95);
  border: 1px solid rgba(226, 232, 240, 0.95);
  box-shadow: 0 10px 30px rgba(15, 23, 42, 0.04);
  gap: 0;
}

.about__info > div {
  flex: 1 1 0;
  text-align: center;
  padding: 0 1rem;
}

.about__info > div:not(:last-child) {
  border-right: 1px solid rgba(226, 232, 240, 0.9);
}

.about__info > div > a {
  text-decoration: none;
  color: inherit;
}

.about__info-title,
.about__info-name {
  display: block;
  text-align: center;
}

.about__info-title {
  font-size: 1.05rem;
  font-weight: 600;
}

.about__info-name {
  font-size: 0.8rem;
  margin-top: 0.25rem;
  color: #6b7280;
}

/* 深色模式适配 */
[data-md-color-scheme="slate"] .about__info {
  background: rgba(15, 23, 42, 0.98);
  border-color: #1f2937;
  box-shadow: 0 18px 40px rgba(0, 0, 0, 0.7);
}

[data-md-color-scheme="slate"] .about__info > div:not(:last-child) {
  border-color: #1f2937;
}

[data-md-color-scheme="slate"] .about__info-name {
  color: #9ca3af;
}

/* 移动端适配 */
@media (max-width: 768px) {
  .about__info {
    flex-direction: column;
    padding: 1rem 1.25rem;
    margin: 1.5rem 0 0.75rem;
  }

  .about__info > div {
    padding: 0.5rem 0;
  }

  .about__info > div:not(:last-child) {
    border-right: none;
    border-bottom: 1px solid rgba(226, 232, 240, 0.9);
  }

  .about__info-title {
    font-size: 1rem;
  }

  .about__info-name {
    font-size: 0.78rem;
  }
}

/*==================== QUALIFICATION TIMELINE ====================*/
.qualification__tabs {
  display: flex;
  justify-content: center;
  margin-bottom: var(--mb-2);
}

.qualification__data {
  display: grid;
  grid-template-columns: 1fr max-content 1fr;
  column-gap: 0.5rem;
}

.qualification__data > div:first-child,
.qualification__data > div:last-child {
  text-align: center;
}

.qualification__title {
  font-size: var(--normal-font-size);
  font-weight: var(--font-medium);
}

.qualification__subtitle {
  display: inline-block;
  font-size: var(--smaller-font-size);
  margin-bottom: var(--mb-1);
}

.qualification__calendar {
  font-size: var(--smaller-font-size);
  opacity: 0.7;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
}

.qualification__rounder {
  display: inline-block;
  width: 13px;
  height: 13px;
  background-color: var(--md-default-fg-color);
  border-radius: 50%;
}

.qualification__line {
  display: block;
  width: 1px;
  height: 100%;
  background-color: var(--md-default-fg-color);
  transform: translate(6px, -7px);
}

/* 内容切换动画 */
.qualification__sections {
  position: relative;
}

.qualification [data-content] {
  opacity: 0;
  visibility: hidden;
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}

.qualification__active[data-content] {
  opacity: 1;
  visibility: visible;
  position: relative;
}

/*==================== SLIDER TOGGLE ====================*/
.qualification__slider-toggle {
  position: relative;
  display: inline-flex;
  align-items: center;
  cursor: pointer;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

.qualification__checkbox {
  position: absolute;
  opacity: 0;
  width: 100%;
  height: 100%;
  z-index: 3;
  margin: 0;
  cursor: pointer;
}

.qualification__slider-track {
  position: relative;
  width: 260px;
  height: 44px;
  background: #e8ecf1;
  border-radius: 22px;
  padding: 4px;
  z-index: 1;
  box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.08);
}

.qualification__slider-thumb {
  position: absolute;
  top: 4px;
  left: 4px;
  width: calc(50% - 4px);
  height: calc(100% - 8px);
  background: #ffffff;
  border-radius: 18px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.12), 0 1px 2px rgba(0, 0, 0, 0.06);
  transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  z-index: 1;
}

.qualification__checkbox:checked ~ .qualification__slider-track .qualification__slider-thumb {
  transform: translateX(100%);
}

.qualification__options {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  z-index: 2;
  pointer-events: none;
}

.qualification__option {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 50%;
  font-size: var(--small-font-size);
  font-weight: 600;
  transition: color 0.35s ease;
  white-space: nowrap;
}

.option-left {
  color: #409eff;
}

.option-right {
  color: #8896a7;
}

.qualification__checkbox:checked ~ .qualification__options .option-left {
  color: #8896a7;
}

.qualification__checkbox:checked ~ .qualification__options .option-right {
  color: #409eff;
}

/* 深色模式 - 滑动开关 */
[data-md-color-scheme="slate"] .qualification__slider-track {
  background: #1f2937;
  box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.3);
}

[data-md-color-scheme="slate"] .qualification__slider-thumb {
  background: #374151;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.4);
}

[data-md-color-scheme="slate"] .option-left,
[data-md-color-scheme="slate"] .qualification__checkbox:checked ~ .qualification__options .option-right {
  color: #60a5fa;
}

[data-md-color-scheme="slate"] .option-right,
[data-md-color-scheme="slate"] .qualification__checkbox:checked ~ .qualification__options .option-left {
  color: #6b7280;
}

/* 响应式 */
@media (max-width: 480px) {
  .qualification__slider-track {
    width: 220px;
    height: 40px;
    border-radius: 20px;
  }

  .qualification__slider-thumb {
    border-radius: 16px;
  }

  .qualification__option {
    font-size: var(--smaller-font-size);
  }
}