.problems-section {
  padding: 60px 80px;
  max-width: 1300px;
  margin: auto;
}

/* HEADER */

.problems-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 30px;
}

.problems-header h1 {
  font-size: 36px;
  font-weight: 700;
}

.controls {
  display: flex;
  gap: 15px;
}

.controls input,
.controls select {
  padding: 10px 16px;
  border-radius: 8px;
  border: 1px solid rgba(255,255,255,0.1);
  background: #0f172a;
  color: white;
  font-size: 14px;
}

.controls select option {
  background: #0f172a;
}

/* TABLE */

.problems-wrapper {
  background: #0f172a;
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid rgba(255,255,255,0.05);
}

.problem-row {
  display: grid;
  grid-template-columns: 0.6fr 2fr 1fr 1fr 1fr 0.6fr;
  padding: 18px 24px;
  align-items: center;
  border-bottom: 1px solid rgba(255,255,255,0.04);
  transition: 0.2s ease;
  cursor: pointer;
}

.problem-row:last-child {
  border-bottom: none;
}

.problem-row:hover {
  background: rgba(255,255,255,0.04);
}

.problem-row.header {
  background: rgba(255,255,255,0.05);
  font-weight: 600;
  cursor: default;
}

.problem-row.header:hover {
  background: rgba(255,255,255,0.05);
}

/* Difficulty Colors */

.difficulty.easy { color: #22c55e; }
.difficulty.medium { color: #f59e0b; }
.difficulty.hard { color: #ef4444; }

/* Tag */

.tag {
  font-size: 13px;
  opacity: 0.8;
}

/* Status */

.status {
  font-size: 18px;
  text-align: center;
  color: #64748b;
}

.problem-row.solved .status {
  color: #22c55e;
}

/* Solved Title */

.problem-row.solved .title {
  color: #22c55e;
}

/* Sortable */

.sortable {
  cursor: pointer;
  user-select: none;
}