#problem-solving {
  min-height: 100vh;
  padding: 100px 20px;
  background-color: var(--color-box-bg);
  color: var(--color-text-white);
  display: flex;
  flex-direction: column;
  justify-content: center;
}

#problem-solving h2 {
  text-align: center;
  font-size: clamp(1.5rem, 6vw, 2.5rem);
  margin-bottom: 50px;
  line-height: 1.4;
  color: var(--color-text-white);
}

/* 타임라인 */
.timeline {
  max-width: 800px;
  margin: 0 auto 60px;
  border-left: 4px solid var(--color-accent);
  padding-left: 20px;
}

.timeline-item {
  margin-bottom: 40px;
  position: relative;
}

.timeline-item::before {
  content: "";
  width: 16px;
  height: 16px;
  background-color: var(--color-accent);
  border-radius: 50%;
  position: absolute;
  left: -30px;
  top: 4px;
}

.timeline-item h3 {
  font-size: 1.2rem;
  color: var(--color-accent);
  margin-bottom: 10px;
}

.timeline-item p {
  font-size: 1rem;
  line-height: 1.6;
}

/* 기여도 카드 */
.my-contribution {
  max-width: 800px;
  margin: 0 auto;
  background: var(--color-box-bg-light);
  padding: 30px;
  border-radius: 16px;
  box-shadow: var(--color-shadow-light);
  border-left: 8px solid #28a745;
  color: #222;
}

.my-contribution h3 {
  font-size: 1.3rem;
  margin-bottom: 15px;
}

.my-contribution ul {
  list-style: none;
  padding-left: 0;
}

.my-contribution li {
  margin-bottom: 10px;
  font-size: 1rem;
}

body:not(.light-mode) .my-contribution {
  background: var(--color-box-bg);
  color: var(--color-accent);
  box-shadow: var(--color-shadow);
  border-left: 6px solid var(--color-accent);
}

body:not(.light-mode) .my-contribution h3 {
  color: var(--color-accent);
}

body:not(.light-mode) .my-contribution li strong {
  color: var(--color-accent);
}