/* ================================
   ExamArchive – browse.css (LOCKED)
   Matches browse.html + browse.js
   ================================ */

/* ---------- Page ---------- */
.browse-page {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.2rem 1rem 2rem;
  overflow-x: hidden;
}

/* ---------- Header ---------- */
.browse-header {
  margin-bottom: 1rem;
}

.browse-header h1 {
  font-size: 1.6rem;
  margin-bottom: 0.4rem;
  color: var(--text);
  line-height: 1.3;
}

.browse-header p {
  color: var(--text-muted);
  font-size: 0.9rem;
  line-height: 1.5;
}

.paper-count {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: 0.4rem;
  font-weight: 500;
}

/* ---------- Filters ---------- */
.filter-group {
  margin-top: 0.9rem;
}

.toggle-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

/* Toggle Buttons */
.toggle-btn {
  padding: 0.5rem 1rem;
  font-size: 0.85rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
  transition: all 0.2s ease;
  font-weight: 500;
  white-space: nowrap;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.toggle-btn.active {
  background: var(--red);
  color: #fff;
  border-color: var(--red);
  font-weight: 600;
}

.toggle-btn:hover:not(.active) {
  background: var(--bg-soft);
  border-color: var(--text-muted);
}

.toggle-btn:active {
  transform: scale(0.98);
}

/* ---------- Search + Sort ---------- */
.sort-search-row {
  margin-top: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

#searchInput {
  width: 100%;
  padding: 0.65rem 0.75rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  font-size: 0.9rem;
  background: var(--surface);
  color: var(--text);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

#searchInput:focus {
  outline: none;
  border-color: var(--red);
  box-shadow: 0 0 0 3px rgba(211, 47, 47, 0.1);
}

/* Sort Trigger Pill */
.sort-trigger {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.6rem 0.9rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface);
  font-size: 0.85rem;
  color: var(--text);
  cursor: pointer;
  transition: background 0.15s ease, border 0.15s ease;
}

.sort-trigger:hover {
  background: var(--bg-soft);
}

.sort-label {
  color: var(--text-muted);
}

.sort-value {
  font-weight: 600;
  color: var(--text);
}

.sort-arrow {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* ---------- Year Toggle ---------- */
#yearToggle {
  flex-wrap: nowrap;
  overflow-x: auto;
  padding-bottom: 0.2rem;
}

#yearToggle::-webkit-scrollbar {
  display: none;
}

#yearToggle .toggle-btn {
  flex-shrink: 0;
}

/* ---------- Papers Grid ---------- */
.papers-list {
  margin-top: 1.3rem;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.9rem;
}

/* ---------- Paper Card ---------- */
.paper-card {
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1rem;
  background: var(--surface);
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
  cursor: pointer;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.2s ease, transform 0.2s ease;
}

.paper-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.paper-name {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text);
}

.paper-code {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.paper-meta {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.open-pdf {
  margin-top: 0.4rem;
  font-size: 0.85rem;
  color: var(--red);
  font-weight: 500;
  text-decoration: none;
}

/* ---------- Skeleton ---------- */
.skeleton-card {
  height: 120px;
  border-radius: var(--radius-md);
  background: var(--bg-soft);
}

/* ---------- Desktop ---------- */
@media (min-width: 768px) {
  .sort-search-row {
    flex-direction: row;
  }

  #searchInput {
    flex: 1;
  }

  .papers-list {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ===============================
   Sort Bottom Sheet
   =============================== */

/* Overlay */
.sort-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.35);
  z-index: 50;
}

/* Sheet */
.sort-sheet {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--surface);
  border-radius: 20px 20px 0 0;
  box-shadow: 0 -10px 25px rgba(0, 0, 0, 0.15);
  padding: 1rem;
  z-index: 60;
}

/* Header */
.sort-sheet-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.8rem;
}

.sort-sheet-header h2 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
}

.sort-close {
  background: none;
  border: none;
  font-size: 1.1rem;
  color: var(--text-muted);
  cursor: pointer;
}

/* Options */
.sort-options {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.sort-option {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.65rem 0.5rem;
  background: none;
  border: none;
  font-size: 0.9rem;
  color: var(--text);
  text-align: left;
  cursor: pointer;
}

.sort-option:hover {
  background: var(--bg-soft);
}

.sort-option .radio {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  border: 2px solid var(--border);
  flex-shrink: 0;
}

.sort-option.active {
  font-weight: 600;
}

.sort-option.active .radio {
  border-color: var(--red);
  background: var(--red);
}

/* Cancel */
.sort-cancel {
  margin-top: 0.8rem;
  width: 100%;
  padding: 0.6rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--bg-soft);
  color: var(--text-muted);
  font-size: 0.85rem;
  cursor: pointer;
}

/* =================================
   Browse Page – Availability Badges
   (Subtle / Grey version)
   ================================= */

.availability-badges {
  display: flex;
  gap: 0.4rem;
  flex-wrap: wrap;
  margin-top: 0.3rem;
}

.availability-badge.subtle {
  font-size: 0.7rem;
  padding: 0.2rem 0.55rem;
  border-radius: 999px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  color: var(--text-muted);
  white-space: nowrap;
}

@media (min-width: 1024px) {
  .papers-list {
    grid-template-columns: repeat(3, 1fr);
  }

  .browse-page {
    padding: 1.5rem 1rem 2.5rem;
  }

  .browse-header h1 {
    font-size: 1.8rem;
  }
}

/* ---------- Mobile Optimizations ---------- */
@media (max-width: 767px) {
  .browse-page {
    padding: 1rem 0.75rem 1.5rem;
  }

  .browse-header h1 {
    font-size: 1.4rem;
  }

  .filter-group {
    margin-top: 0.8rem;
  }

  .toggle-row {
    gap: 0.4rem;
  }

  .toggle-btn {
    padding: 0.45rem 0.85rem;
    font-size: 0.8rem;
  }

  .sort-search-row {
    gap: 0.5rem;
  }

  #searchInput {
    padding: 0.7rem 0.8rem;
    font-size: 0.9rem;
  }
}

/* ---------- Tablet Optimizations ---------- */
@media (min-width: 768px) and (max-width: 1023px) {
  .papers-list {
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
  }
}