/**
 * About timeline section: center line, alternating left/right events, icon on line, year in content.
 */
.about-timeline {
  padding: var(--space-3xl) var(--container-padding);
  background: var(--color-bg);
}

.about-timeline__inner {
  max-width: var(--container-max);
  margin: 0 auto;
  position: relative;
}

.about-timeline__header {
  text-align: center;
  margin-bottom: var(--space-2xl);
}

.about-timeline__title {
  margin: 0 0 var(--space-sm);
  font-size: var(--font-size-3xl);
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  background: linear-gradient(90deg, var(--color-secondary) 0%, var(--color-text-muted) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  -webkit-text-fill-color: transparent;
}

.about-timeline__subtitle {
  margin: 0;
  font-size: var(--font-size-base);
  line-height: var(--line-height-relaxed);
  color: var(--color-text-muted);
  max-width: 55rem;
  margin-left: auto;
  margin-right: auto;
}

.about-timeline__list {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

/* Vertical line in center */
.about-timeline__list::before {
  content: "";
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 3px;
  margin-left: -1.5px;
  background: linear-gradient(180deg, var(--color-secondary-light) 0%, var(--color-primary) 100%);
  border-radius: 2px;
}

.about-timeline__item {
  display: grid;
  grid-template-columns: 1fr 4rem 1fr;
  gap: var(--space-xl);
  align-items: center;
  padding-bottom: var(--space-2xl);
}

.about-timeline__item:last-child {
  padding-bottom: 0;
}

/* Content: left column for --left, right column for --right */
.about-timeline__item--left .about-timeline__content {
  grid-column: 1;
  grid-row: 1;
  justify-self: end;
  align-self: center;
}

.about-timeline__item--right .about-timeline__content {
  grid-column: 3;
  grid-row: 1;
  justify-self: start;
  align-self: center;
}

.about-timeline__node {
  grid-column: 2;
  grid-row: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 4rem;
  height: 4rem;
  margin: 0 auto;
  background: linear-gradient(var(--color-bg-header), var(--color-bg-header)) padding-box,
    linear-gradient(135deg, var(--color-secondary) 0%, var(--color-primary) 100%) border-box;
  border: 3px solid transparent;
  border-radius: 50%;
  background-origin: border-box;
  background-clip: padding-box, border-box;
  box-shadow: var(--shadow-md);
  position: relative;
  z-index: 1;
}

.about-timeline__icon {
  color: var(--color-secondary);
  font-size: 1.75rem;
}

.about-timeline__content {
  width: 100%;
  max-width: 28rem;
  min-width: 0;
  padding: var(--space-xl) var(--space-2xl);
  background: var(--color-bg-header);
  border-radius: var(--radius-xl);
  border: none;
  box-shadow:
    0 0 1rem 0.1rem rgba(0, 0, 0, 0.06),
    -0.75rem 0 0.75rem 0.1rem rgba(59, 130, 246, 0.2),
    0.75rem 0 0.75rem 0.1rem rgba(242, 147, 24, 0.2);
  box-sizing: border-box;
  transition: transform var(--transition-normal);
}

.about-timeline__content:hover {
  transform: scale(1.03);
}

.about-timeline__year {
  display: inline-block;
  margin-bottom: var(--space-sm);
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  background: linear-gradient(90deg, var(--color-secondary) 0%, var(--color-primary) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  -webkit-text-fill-color: transparent;
  letter-spacing: 0.02em;
}

.about-timeline__item-title {
  margin: 0 0 var(--space-sm);
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  color: #050b1a;
}

.about-timeline__item-desc {
  margin: 0;
  font-size: var(--font-size-base);
  line-height: var(--line-height-relaxed);
  color: var(--color-text-muted);
}

/* Tablet/mobile: single column, line on left, icon on line */
@media (max-width: 64rem) {
  .about-timeline__list::before {
    left: 1.5rem;
    margin-left: 0;
  }

  .about-timeline__item {
    grid-template-columns: 3rem 1fr;
    gap: var(--space-lg);
    padding-bottom: var(--space-xl);
  }

  .about-timeline__item--left .about-timeline__content,
  .about-timeline__item--right .about-timeline__content {
    grid-column: 2;
    grid-row: 1;
    justify-self: start;
    max-width: none;
  }

  .about-timeline__node {
    grid-column: 1;
    grid-row: 1;
    justify-self: center;
  }
}

@media (max-width: 48rem) {
  .about-timeline {
    padding: var(--space-2xl) var(--container-padding);
  }

  .about-timeline__title {
    font-size: var(--font-size-2xl);
  }

  .about-timeline__list::before {
    left: 1.25rem;
  }

  .about-timeline__item {
    gap: var(--space-md);
    padding-bottom: var(--space-xl);
  }

  .about-timeline__node {
    width: 2.5rem;
    height: 2.5rem;
  }

  .about-timeline__icon {
    font-size: 1rem;
  }

  .about-timeline__content {
    padding: var(--space-lg) var(--space-xl);
  }

  .about-timeline__item-title {
    font-size: var(--font-size-lg);
  }
}