/* ============================================================
   sec-projects v2 — Layout System
   Container, grid, navigation, sidebar, responsive
   ============================================================ */

/* === Container === */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

/* === Main App Shell === */
.app-shell {
  display: flex;
  min-height: calc(100vh - var(--nav-height));
  margin-top: var(--nav-height);
}

/* === Navigation === */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: var(--color-bg-secondary);
  border-bottom: 1px solid var(--color-border);
  z-index: 100;
  display: flex;
  align-items: center;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-6);
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-weight: 700;
  font-size: var(--font-size-lg);
  color: var(--color-text-primary);
  text-decoration: none;
  white-space: nowrap;
}

.nav-logo-icon {
  color: var(--color-accent);
  font-size: 1.4em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.nav-link {
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  transition: all var(--transition-fast);
}

.nav-link:hover {
  color: var(--color-text-primary);
  background: var(--color-bg-hover);
}

.nav-link.active {
  color: var(--color-accent);
  background: var(--color-accent-dim);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

/* === Search Bar === */
.search-wrapper {
  position: relative;
  flex: 1;
  max-width: 420px;
}

.search-input {
  width: 100%;
  padding: var(--space-3) var(--space-4) var(--space-3) 42px;
  background: var(--color-bg-tertiary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  color: var(--color-text-primary);
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  transition: all var(--transition-fast);
  outline: none;
}

.search-input::placeholder {
  color: var(--color-text-muted);
}

.search-input:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-dim);
}

.search-icon {
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-muted);
  pointer-events: none;
}

.search-shortcut {
  position: absolute;
  right: 12px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-muted);
  font-size: var(--font-size-xs);
  font-family: var(--font-mono);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  padding: 1px 6px;
  border-radius: 4px;
  pointer-events: none;
}

/* === Sidebar Filters === */
.sidebar {
  width: var(--sidebar-width);
  flex-shrink: 0;
  padding: var(--space-6);
  border-right: 1px solid var(--color-border);
  background: var(--color-bg-secondary);
  overflow-y: auto;
  position: sticky;
  top: var(--nav-height);
  height: calc(100vh - var(--nav-height));
}

.filter-group {
  margin-bottom: var(--space-6);
}

.filter-group-title {
  font-size: var(--font-size-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-muted);
  margin-bottom: var(--space-3);
}

.filter-option {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) var(--space-2);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
  user-select: none;
}

.filter-option:hover {
  background: var(--color-bg-hover);
  color: var(--color-text-primary);
}

.filter-option.active {
  color: var(--color-accent);
}

.filter-checkbox {
  width: 16px;
  height: 16px;
  border: 2px solid var(--color-border-strong);
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: all var(--transition-fast);
}

.filter-option.active .filter-checkbox {
  border-color: var(--color-accent);
  background: var(--color-accent);
}

.filter-option.active .filter-checkbox::after {
  content: '';
  display: block;
  width: 5px;
  height: 9px;
  border: solid var(--color-bg);
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
  margin-top: -1px;
}

.filter-count {
  margin-left: auto;
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
  background: var(--color-bg-tertiary);
  padding: 2px 8px;
  border-radius: var(--radius-full);
}

/* === Main Content Area === */
.main-content {
  flex: 1;
  padding: var(--space-6) var(--space-8);
  min-width: 0;
}

.content-header {
  margin-bottom: var(--space-8);
}

.content-title {
  font-size: var(--font-size-2xl);
  margin-bottom: var(--space-2);
}

.content-subtitle {
  color: var(--color-text-muted);
  font-size: var(--font-size-sm);
}

.result-count {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-6);
}

.result-count strong {
  color: var(--color-accent);
}

/* === Project Grid === */
.project-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-5);
}

/* === Responsive === */
@media (max-width: 860px) {
  .app-shell {
    flex-direction: column;
  }

  .sidebar {
    position: relative;
    top: 0;
    width: 100%;
    height: auto;
    border-right: none;
    border-bottom: 1px solid var(--color-border);
    padding: var(--space-4);
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-4);
  }

  .filter-group {
    margin-bottom: 0;
  }

  .main-content {
    padding: var(--space-4);
  }

  .project-grid {
    grid-template-columns: 1fr;
  }

  .search-shortcut { display: none; }

  .nav-links { display: none; }
}

@media (max-width: 480px) {
  .nav-inner { padding: 0 var(--space-3); }
  .search-wrapper { max-width: 100%; }
}