section {
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  color: #fff;
}

.wrapper {
  position: relative;
  overflow-x: hidden;
}

/* Sliding filter panel (left) – used on index and about */
.filter-panel-side {
  position: fixed;
  left: 0;
  top: 56px;
  z-index: 90;
  width: 280px;
  max-width: 85vw;
  height: calc(100vh - 56px);
  background: #fff;
  box-shadow: 4px 0 24px rgba(0,0,0,0.1);
  transition: transform 0.3s ease;
  transform: translateX(-100%);
  overflow-y: auto;
  padding: 0;
  border-right: 1px solid #e9ecef;
}
.filter-panel-side.filter-panel-side_active {
  transform: translateX(0);
}
.filter-panel-header {
  background: #0d1b2a;
  color: #fff;
  font-size: 1rem;
  font-weight: 700;
  padding: 1rem 1.25rem;
  letter-spacing: 0.02em;
}
.filter-section {
  padding: 1rem 1.25rem;
  border-bottom: 1px solid #f1f3f5;
}
.filter-section:last-child {
  border-bottom: none;
}
.filter-section-title {
  font-size: 0.8rem;
  font-weight: 700;
  color: #495057;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin: 0 0 0.75rem 0;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid #e9ecef;
}
.filter-options {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.filter-option {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.6rem 0.75rem;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.9rem;
  color: #212529;
  transition: background 0.15s ease;
}
.filter-option:hover {
  background: #f8f9fa;
}
.filter-option input[type="radio"] {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
}
.filter-option-radio {
  flex-shrink: 0;
  width: 18px;
  height: 18px;
  border: 2px solid #adb5bd;
  border-radius: 50%;
  background: #fff;
  transition: border-color 0.15s, background 0.15s, box-shadow 0.15s;
}
.filter-option input:focus-visible + .filter-option-radio {
  outline: 2px solid #0d1b2a;
  outline-offset: 2px;
}
.filter-option input:checked + .filter-option-radio {
  border-color: #0d1b2a;
  background: #0d1b2a;
  box-shadow: inset 0 0 0 3px #fff;
}
.filter-option:hover .filter-option-radio {
  border-color: #6c757d;
}
.filter-option input:checked:hover + .filter-option-radio {
  border-color: #1b263b;
  background: #1b263b;
}
.filter-option-text {
  line-height: 1.35;
}
.filter-toggle-btn {
  position: fixed;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  z-index: 91;
  width: 40px;
  height: 48px;
  background: #0d1b2a;
  color: #fff;
  border: none;
  border-radius: 0 8px 8px 0;
  cursor: pointer;
  font-size: 0.75rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 2px 0 8px rgba(0,0,0,0.2);
  transition: left 0.3s ease, background 0.2s;
}
.filter-toggle-btn:hover {
  background: #1b263b;
}
.filter-panel-side_active ~ .filter-toggle-btn,
body.filter-panel-open .filter-toggle-btn {
  left: 280px;
}
.page-with-filters {
  transition: margin-left 0.3s ease;
}
body.filter-panel-open .page-with-filters {
  margin-left: 280px;
}

/* Dark overlay for mobile when filter panel is open */
.filter-backdrop {
  position: fixed;
  left: 0;
  right: 0;
  top: 56px;
  bottom: 0;
  background: rgba(0,0,0,0.35);
  z-index: 80;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease;
  display: none;
}
@media (max-width: 991.98px) {
  .filter-backdrop { display: block; }
  body.filter-panel-open .page-with-filters { margin-left: 0; }
  body.filter-panel-open .filter-backdrop {
    opacity: 1;
    pointer-events: auto;
  }
}

/* Legacy menu (about page old structure – kept for compatibility) */
.menu {
  position: fixed;
  left: 0;
  top: 0;
  z-index: 99;
  width: 15%;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: #fff;
  transition: 0.5s;
  transform: translateX(-100%);
}
.menu_active {
  transform: translateX(0%);
}
.menu-list {
  display: flex;
  align-items: left;
  height: 80%;
  flex-direction: column;
}
.menu-list a {
  text-decoration: none;
  text-transform: uppercase;
  font-weight: 900;
}
.menu-btn {
  width: 30px;
  height: 30px;
  position: absolute;
  right: -40px;
  top: 68px;
}
.content {
  transition: 0.5s;
  position: relative;
  z-index: 0;
}
.content_active {
  transform: translateX(30%);
}
.add {
  align-items: left;
  justify-content: left;
}