/**
 * 4uonly Music Platform - Header, Navigation, Theme Switcher & Footer
 * Zero-Overflow Mobile-First Architecture
 */

/* Header */
.four-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--bg-surface-1) !important;
  border-bottom: 1px solid var(--border-subtle);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: background-color var(--trans-normal), border-color var(--trans-normal);
  margin: 0 !important;
  padding: 0 !important;
  height: 60px !important;
  max-height: 60px !important;
  width: 100% !important;
  max-width: 100vw !important;
  box-sizing: border-box !important;
}

.four-header-inner {
  display: flex !important;
  align-items: center !important;
  justify-content: space-between !important;
  height: 60px !important;
  max-height: 60px !important;
  gap: var(--sp-8);
  width: 100% !important;
  max-width: 100% !important;
  box-sizing: border-box !important;
}

/* 1 Single Round Brand Logo */
.four-logo {
  display: inline-flex !important;
  align-items: center !important;
  justify-content: center !important;
  text-decoration: none !important;
  flex-shrink: 0 !important;
  height: 42px !important;
  max-height: 42px !important;
  width: 42px !important;
  min-width: 42px !important;
  overflow: hidden !important;
  background: transparent !important;
  padding: 0 !important;
  margin: 0 !important;
}

.four-logo-round {
  width: 38px !important;
  height: 38px !important;
  max-width: 38px !important;
  max-height: 38px !important;
  object-fit: contain !important;
  display: block !important;
  border-radius: 50% !important;
  transition: transform var(--trans-fast);
  margin: 0 !important;
  padding: 0 !important;
  border: none !important;
  background: transparent !important;
}

.four-logo:hover .four-logo-round {
  transform: scale(1.08);
}

/* Desktop Navigation */
.four-nav-desktop {
  display: flex;
  align-items: center;
  gap: 2px;
  flex-wrap: nowrap;
}

.four-nav-link {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-secondary);
  padding: 7px 10px;
  border-radius: var(--radius-md);
  transition: all var(--trans-fast);
  white-space: nowrap;
}

.four-nav-link:hover {
  color: var(--text-primary);
  background: var(--bg-surface-2);
}

.four-nav-link.active {
  color: var(--accent-primary);
  background: rgba(244, 63, 94, 0.12);
}

/* Header Actions / Theme Switcher / Search */
.four-header-actions {
  display: flex !important;
  align-items: center !important;
  gap: 6px !important;
  flex-shrink: 0 !important;
}

.four-header-search-btn {
  display: flex;
  align-items: center;
  gap: var(--sp-8);
  background: var(--bg-surface-2);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  padding: 7px 12px;
  border-radius: var(--radius-full);
  font-size: 0.825rem;
  cursor: pointer;
  transition: all var(--trans-fast);
}

.four-header-search-btn:hover {
  border-color: var(--accent-primary);
  color: var(--text-primary);
  background: var(--bg-surface-hover);
}

.four-search-kbd {
  font-size: 0.675rem;
  background: var(--bg-surface-3);
  padding: 2px 5px;
  border-radius: var(--radius-xs);
  color: var(--text-tertiary);
  border: 1px solid var(--border-subtle);
}

/* Day / Night Theme Switcher Button */
.four-theme-toggle-btn {
  width: 36px !important;
  height: 36px !important;
  min-width: 36px !important;
  max-width: 36px !important;
  background: var(--bg-surface-2) !important;
  border: 1px solid var(--border-medium) !important;
  border-radius: var(--radius-md) !important;
  color: var(--text-primary) !important;
  display: inline-flex !important;
  align-items: center !important;
  justify-content: center !important;
  cursor: pointer !important;
  transition: all var(--trans-fast);
  flex-shrink: 0 !important;
  padding: 0 !important;
  box-sizing: border-box !important;
}

.four-theme-toggle-btn:hover {
  border-color: var(--accent-primary) !important;
  color: var(--accent-primary) !important;
  background: var(--bg-surface-hover) !important;
}

.four-theme-toggle-btn svg {
  width: 18px !important;
  height: 18px !important;
  stroke: currentColor !important;
  fill: none !important;
  stroke-width: 2.2 !important;
  stroke-linecap: round !important;
  stroke-linejoin: round !important;
  display: block !important;
}

/* Mobile Controls */
.four-mobile-search-btn,
.four-mobile-menu-btn {
  display: none;
  background: var(--bg-surface-2) !important;
  border: 1px solid var(--border-medium) !important;
  color: var(--text-primary) !important;
  width: 36px !important;
  height: 36px !important;
  min-width: 36px !important;
  max-width: 36px !important;
  border-radius: var(--radius-md) !important;
  align-items: center !important;
  justify-content: center !important;
  cursor: pointer !important;
  transition: all var(--trans-fast);
  flex-shrink: 0 !important;
  padding: 0 !important;
  box-sizing: border-box !important;
}

.four-mobile-search-btn:hover,
.four-mobile-menu-btn:hover {
  background: var(--bg-surface-hover) !important;
  border-color: var(--accent-primary) !important;
  color: var(--accent-primary) !important;
}

.four-mobile-search-btn svg,
.four-mobile-menu-btn svg {
  width: 18px !important;
  height: 18px !important;
  stroke: currentColor !important;
  fill: none !important;
  stroke-width: 2.2 !important;
  stroke-linecap: round !important;
  stroke-linejoin: round !important;
  display: block !important;
}

/* Mobile Drawer */
.four-mobile-drawer-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(4px);
  z-index: 998;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--trans-normal);
}

.four-mobile-drawer-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

.four-mobile-drawer {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  width: 300px;
  max-width: 85vw;
  background: var(--bg-surface-1);
  border-left: 1px solid var(--border-subtle);
  z-index: 999;
  transform: translateX(100%);
  transition: transform var(--trans-normal);
  display: flex;
  flex-direction: column;
  padding: var(--sp-16);
  overflow-y: auto;
  box-sizing: border-box;
}

.four-mobile-drawer.active {
  transform: translateX(0);
}

.four-mobile-drawer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--sp-16);
  padding-bottom: var(--sp-10);
  border-bottom: 1px solid var(--border-subtle);
}

.four-mobile-drawer-close {
  background: var(--bg-surface-2);
  border: 1px solid var(--border-subtle);
  color: var(--text-primary);
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
}

.four-mobile-nav {
  display: flex;
  flex-direction: column;
  gap: var(--sp-6);
}

.four-mobile-nav .four-nav-link {
  font-size: 0.9rem;
  padding: 10px 12px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  gap: var(--sp-10);
  color: var(--text-primary);
  background: var(--bg-surface-2);
  border: 1px solid var(--border-subtle);
}

.four-mobile-nav .four-nav-link:hover {
  background: var(--bg-surface-hover);
  border-color: var(--accent-primary);
  color: var(--accent-primary);
}

/* Theme Switcher Row in Mobile Drawer */
.four-mobile-theme-box {
  margin-top: var(--sp-20);
  padding-top: var(--sp-14);
  border-top: 1px solid var(--border-subtle);
}

.four-mobile-theme-title {
  font-size: 0.75rem;
  color: var(--text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--sp-8);
  font-weight: 700;
}

.four-theme-pills {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 4px;
}

.four-theme-pill-btn {
  padding: 7px 4px;
  background: var(--bg-surface-2);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 0.75rem;
  font-weight: 600;
  cursor: pointer;
  text-align: center;
  transition: all var(--trans-fast);
}

.four-theme-pill-btn.active {
  background: var(--accent-primary);
  color: #ffffff;
  border-color: var(--accent-primary);
}

/* Instant Search Modal */
.four-search-modal-wrap {
  position: fixed;
  inset: 0;
  z-index: 1000;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(8px);
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: 60px 12px 20px;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--trans-normal);
  width: 100%;
  max-width: 100vw;
  box-sizing: border-box;
}

.four-search-modal-wrap.active {
  opacity: 1;
  pointer-events: auto;
}

.four-search-modal {
  width: 100%;
  max-width: 620px;
  background: var(--bg-surface-1);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transform: translateY(-20px);
  transition: transform var(--trans-normal);
  box-sizing: border-box;
}

.four-search-modal-wrap.active .four-search-modal {
  transform: translateY(0);
}

.four-search-input-box {
  display: flex;
  align-items: center;
  gap: var(--sp-10);
  padding: 12px 14px;
  border-bottom: 1px solid var(--border-subtle);
  background: var(--bg-surface-2);
  width: 100%;
  box-sizing: border-box;
}

.four-search-input-box input {
  flex: 1;
  background: transparent;
  border: none;
  color: var(--text-primary);
  font-size: 0.95rem;
  outline: none;
  min-width: 0;
}

.four-search-input-box input::placeholder {
  color: var(--text-tertiary);
}

.four-search-close-btn {
  background: transparent;
  border: none;
  color: var(--text-tertiary);
  cursor: pointer;
  padding: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.four-search-close-btn:hover {
  color: var(--text-primary);
}

.four-search-results-area {
  max-height: 360px;
  overflow-y: auto;
  padding: var(--sp-12);
  width: 100%;
  box-sizing: border-box;
}

.four-search-suggestions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-6);
  margin-top: var(--sp-8);
}

.four-search-chip {
  font-size: 0.75rem;
  font-weight: 500;
  padding: 5px 10px;
  border-radius: var(--radius-full);
  background: var(--bg-surface-3);
  color: var(--text-secondary);
  border: 1px solid var(--border-subtle);
  cursor: pointer;
  transition: all var(--trans-fast);
}

.four-search-chip:hover {
  color: var(--accent-primary);
  border-color: var(--accent-primary);
  background: rgba(244, 63, 94, 0.12);
}

/* Footer */
.four-footer {
  background: var(--bg-surface-1);
  border-top: 1px solid var(--border-subtle);
  padding-top: var(--sp-40);
  padding-bottom: var(--sp-28);
  margin-top: auto;
  width: 100%;
  max-width: 100vw;
  box-sizing: border-box;
  overflow: hidden;
}

.four-footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: var(--sp-32);
  margin-bottom: var(--sp-32);
  width: 100%;
  box-sizing: border-box;
}

.four-footer-brand p {
  margin-top: var(--sp-10);
  font-size: 0.85rem;
  line-height: 1.55;
  max-width: 320px;
}

.four-footer-col h4 {
  font-size: 0.9rem;
  font-weight: 700;
  margin-bottom: var(--sp-12);
  color: var(--text-primary);
}

.four-footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--sp-10);
}

.four-footer-links a {
  font-size: 0.825rem;
  color: var(--text-secondary);
}

.four-footer-links a:hover {
  color: var(--accent-primary);
}

.four-footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: var(--sp-20);
  border-top: 1px solid var(--border-subtle);
  font-size: 0.775rem;
  color: var(--text-tertiary);
  width: 100%;
  box-sizing: border-box;
}

/* Responsive Navigation Breakpoints */
@media (max-width: 1080px) {
  .four-nav-desktop {
    display: none;
  }
  .four-search-kbd {
    display: none;
  }
  .four-mobile-search-btn,
  .four-mobile-menu-btn {
    display: inline-flex !important;
  }
  .four-header-search-btn {
    display: none;
  }
  .four-footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--sp-24);
  }
}

@media (max-width: 640px) {
  .four-header {
    height: 56px !important;
    max-height: 56px !important;
  }
  .four-header-inner {
    height: 56px !important;
    max-height: 56px !important;
  }
  .four-logo {
    height: 34px !important;
    width: 34px !important;
    min-width: 34px !important;
  }
  .four-logo-round {
    width: 32px !important;
    height: 32px !important;
    max-width: 32px !important;
    max-height: 32px !important;
  }
  .four-footer-grid {
    grid-template-columns: 1fr;
    gap: var(--sp-20);
  }
  .four-footer-bottom {
    flex-direction: column;
    gap: var(--sp-10);
    text-align: center;
  }
}