/* ============================================
   LAYOUT CSS - HEADER, SIDEBAR, BOTTOM-SHEET
   ============================================ */

/* Mobile Header */
.mobile-header { 
  display: flex; 
  align-items: center; 
  justify-content: space-between; 
  padding: 12px 16px; 
  background: var(--card-bg); 
  backdrop-filter: blur(20px); 
  -webkit-backdrop-filter: blur(20px); 
  border-bottom: 1px solid var(--border); 
  flex-shrink: 0; 
  z-index: 100; 
}

.menu-btn { 
  width: 40px; 
  height: 40px; 
  background: transparent; 
  border: none; 
  border-radius: 50%; 
  display: flex; 
  align-items: center; 
  justify-content: center; 
  cursor: pointer; 
  font-size: 20px; 
  color: var(--primary); 
  transition: transform 0.2s; 
}
.menu-btn:active { transform: scale(0.9); }

.header-logo { display: flex; align-items: center; gap: 8px; }
.header-logo i { font-size: 28px; background: linear-gradient(135deg, var(--primary), var(--secondary)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.header-logo span { font-weight: 800; font-size: 1.1rem; background: linear-gradient(135deg, var(--primary), var(--secondary)); -webkit-background-clip: text; background-clip: text; color: transparent; }

.theme-btn-header { 
  background: var(--card-bg); 
  border: 1px solid var(--border); 
  border-radius: 30px; 
  padding: 8px 16px; 
  display: flex; 
  align-items: center; 
  gap: 8px; 
  cursor: pointer; 
  transition: transform 0.2s; 
}
.theme-btn-header:active { transform: scale(0.95); }
.theme-btn-header i { font-size: 16px; color: var(--primary); }
.theme-btn-header span { font-size: 0.75rem; font-weight: 500; color: var(--text); }

/* Sheet Overlay */
.sheet-overlay { 
  position: fixed; 
  top: 0; 
  left: 0; 
  right: 0; 
  bottom: 0; 
  background: rgba(0,0,0,0.5); 
  z-index: 250; 
  display: none; 
}
.sheet-overlay.active { display: block; }

/* Bottom Sheet */
.bottom-sheet { 
  position: fixed; 
  bottom: -100%; 
  left: 0; 
  right: 0; 
  background: var(--card-bg); 
  backdrop-filter: blur(20px); 
  -webkit-backdrop-filter: blur(20px); 
  border-top-left-radius: 28px; 
  border-top-right-radius: 28px; 
  z-index: 300; 
  transition: bottom 0.3s ease; 
  max-height: 70%; 
  overflow-y: auto; 
}
.bottom-sheet.open { bottom: 0; }
.bottom-sheet-header { padding: 16px; display: flex; justify-content: space-between; align-items: center; border-bottom: 1px solid var(--border); }
.close-sheet { background: none; border: none; font-size: 20px; cursor: pointer; color: var(--text-light); }
.bottom-sheet-content { padding: 16px; }

.theme-grid-rect { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; margin-bottom: 20px; }
.theme-rect { padding: 10px 6px; border-radius: 12px; text-align: center; cursor: pointer; border: 2px solid transparent; font-size: 0.7rem; font-weight: 600; color: white; transition: transform 0.2s; }
.theme-rect.active { border-color: white; box-shadow: 0 0 0 2px var(--primary); }

.font-row-sheet { display: flex; gap: 6px; justify-content: center; padding-top: 16px; border-top: 1px solid var(--border); flex-wrap: wrap; }
.font-sheet { padding: 8px 14px; border-radius: 30px; background: rgba(0,0,0,0.05); cursor: pointer; font-size: 0.75rem; transition: all 0.2s; border: none; }
.font-sheet.active { background: linear-gradient(135deg, var(--primary), var(--secondary)); color: white; }

/* Sidebar Menu */
.sidebar-menu { 
  position: fixed; 
  top: 0; 
  left: -280px; 
  width: 280px; 
  height: 100%; 
  height: calc(var(--vh, 1vh) * 100); 
  background: var(--card-bg); 
  backdrop-filter: blur(20px); 
  -webkit-backdrop-filter: blur(20px); 
  z-index: 200; 
  transition: left 0.3s ease; 
  display: flex; 
  flex-direction: column; 
  border-right: 1px solid var(--border); 
}
.sidebar-menu.open { left: 0; }
.sidebar-header { padding: 20px; border-bottom: 1px solid var(--border); display: flex; justify-content: space-between; align-items: center; }
.close-sidebar { background: none; border: none; font-size: 20px; cursor: pointer; color: var(--text-light); }
.sidebar-nav { flex: 1; padding: 16px; display: flex; flex-direction: column; gap: 4px; overflow-y: auto; }
.nav-item { display: flex; align-items: center; gap: 14px; padding: 12px 16px; border-radius: 12px; color: var(--text-light); text-decoration: none; font-size: 0.9rem; transition: all 0.2s; }
.nav-item i { width: 24px; font-size: 1.1rem; text-align: center; }
.nav-item.active { background: linear-gradient(135deg, var(--primary), var(--secondary)); color: white; }

.overlay { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.5); z-index: 150; display: none; }
.overlay.active { display: block; }

/* Main Content */
.main-content { flex: 1; padding: 16px; overflow-y: auto; padding-bottom: 20px; }