/* Reset & Base */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  background: var(--bg-secondary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  min-height: 100dvh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--primary-600);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

img {
  max-width: 100%;
  height: auto;
}

input, button, textarea, select {
  font-family: inherit;
  font-size: inherit;
}

button {
  cursor: pointer;
  border: none;
  background: none;
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--gray-300);
  border-radius: var(--radius-full);
}

[data-theme="dark"] ::-webkit-scrollbar-thumb {
  background: var(--gray-600);
}

/* App layout */
#app {
  min-height: 100vh;
  min-height: 100dvh;
}

.screen {
  min-height: 100vh;
  min-height: 100dvh;
}

/* Loading screen */
.loading-screen {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  min-height: 100dvh;
  background: linear-gradient(135deg, var(--primary-600) 0%, var(--primary-800) 100%);
  color: white;
}

.loading-logo {
  text-align: center;
  animation: fadeInUp 0.6s ease;
}

.loading-icon {
  font-size: 64px;
  margin-bottom: var(--space-md);
  animation: pulse 2s ease-in-out infinite;
}

.loading-logo h1 {
  font-size: var(--font-2xl);
  font-weight: 700;
  margin-bottom: var(--space-xs);
}

.loading-logo p {
  opacity: 0.8;
  font-size: var(--font-sm);
}

/* Main app layout */
.main-app {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  min-height: 100dvh;
}

/* Top bar */
.top-bar {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-sm) var(--space-md);
  background: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  height: 56px;
}

.top-bar-left {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.top-bar-logo {
  color: var(--primary-600);
  font-size: 28px;
}

.top-bar-title {
  font-size: var(--font-lg);
  font-weight: 700;
  color: var(--text-primary);
}

.top-bar-right {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.icon-btn {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-full);
  color: var(--text-secondary);
  transition: all var(--transition-fast);
}

.icon-btn:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

.notification-btn {
  position: relative;
}

.notification-badge {
  position: absolute;
  top: 6px;
  right: 6px;
  width: 10px;
  height: 10px;
  border-radius: var(--radius-full);
  background: var(--error);
  border: 2px solid var(--bg-primary);
}

.avatar-btn {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  background: var(--primary-100);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
  overflow: hidden;
}

.avatar-btn:hover {
  transform: scale(1.05);
}

.avatar-text {
  font-size: var(--font-sm);
  font-weight: 600;
  color: var(--primary-700);
}

.avatar-btn img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* Page content */
.page-content {
  flex: 1;
  padding: var(--space-md);
  padding-bottom: calc(72px + var(--space-md) + env(safe-area-inset-bottom));
  max-width: 680px;
  margin: 0 auto;
  width: 100%;
}

.page {
  display: none;
}

.page.active {
  display: block;
  animation: fadeIn 0.2s ease;
}

.page-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-lg);
}

.page-title {
  font-size: var(--font-2xl);
  font-weight: 700;
}

.page-subtitle {
  font-size: var(--font-sm);
  color: var(--text-secondary);
  margin-top: 2px;
}

/* Bottom nav */
.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  display: flex;
  background: var(--bg-primary);
  border-top: 1px solid var(--border-color);
  padding: var(--space-xs) 0;
  padding-bottom: max(var(--space-xs), env(safe-area-inset-bottom));
  z-index: 50;
}

.nav-item {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  padding: var(--space-xs) 0;
  color: var(--text-tertiary);
  font-size: 10px;
  font-weight: 500;
  transition: all var(--transition-fast);
  position: relative;
}

.nav-item .material-icons-round {
  font-size: 24px;
  transition: all var(--transition-fast);
}

.nav-item.active {
  color: var(--primary-600);
}

.nav-item.active .material-icons-round {
  transform: scale(1.1);
}

.nav-item:active {
  transform: scale(0.95);
}

/* Empty states */
.empty-state {
  text-align: center;
  padding: var(--space-3xl) var(--space-lg);
}

.empty-icon {
  font-size: 64px;
  color: var(--text-tertiary);
  margin-bottom: var(--space-md);
}

.empty-state h3 {
  font-size: var(--font-xl);
  font-weight: 600;
  margin-bottom: var(--space-xs);
}

.empty-state p {
  color: var(--text-secondary);
  margin-bottom: var(--space-lg);
}

/* ============================================
   TABLET — 768px to 1023px
   ============================================ */
@media (min-width: 768px) {
  .bottom-nav {
    position: fixed;
    top: 56px;
    left: 0;
    bottom: 0;
    right: auto;
    width: 80px;
    flex-direction: column;
    border-top: none;
    border-right: 1px solid var(--border-color);
    padding: var(--space-md) 0;
    gap: var(--space-xs);
  }

  .nav-item {
    flex: 0;
    padding: var(--space-sm) 0;
    border-radius: var(--radius-md);
    margin: 0 var(--space-xs);
  }

  .nav-item:hover {
    background: var(--bg-tertiary);
  }

  .nav-item.active {
    background: var(--primary-50);
  }

  .page-content {
    margin-left: 80px;
    padding: var(--space-lg) var(--space-xl);
    padding-bottom: var(--space-lg);
    max-width: 900px;
  }

  .top-bar {
    padding-left: var(--space-lg);
    padding-right: var(--space-lg);
  }

  .page-header {
    margin-bottom: var(--space-xl);
  }

  .page-title {
    font-size: var(--font-3xl);
  }

  /* Modal improvements */
  .modal-content {
    max-width: 520px;
    padding: var(--space-xl);
  }

  .empty-state {
    padding: var(--space-4xl) var(--space-xl);
  }
}

/* ============================================
   DESKTOP — 1024px to 1439px
   ============================================ */
@media (min-width: 1024px) {
  :root {
    --sidebar-width: 240px;
  }

  .bottom-nav {
    width: var(--sidebar-width);
    padding: var(--space-lg);
    gap: var(--space-sm);
  }

  .nav-item {
    flex-direction: row;
    justify-content: flex-start;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-md);
    font-size: var(--font-sm);
  }

  .nav-item .material-icons-round {
    font-size: 22px;
  }

  .page-content {
    margin-left: var(--sidebar-width);
    max-width: 1000px;
    padding: var(--space-xl) var(--space-2xl);
  }

  .top-bar {
    padding-left: var(--space-xl);
    padding-right: var(--space-xl);
  }

  .top-bar-title {
    font-size: var(--font-xl);
  }

  /* Larger touch targets on desktop too */
  .icon-btn {
    width: 44px;
    height: 44px;
  }

  .avatar-btn {
    width: 40px;
    height: 40px;
  }
}

/* ============================================
   LARGE DESKTOP — 1440px and above
   ============================================ */
@media (min-width: 1440px) {
  .page-content {
    max-width: 1200px;
    padding: var(--space-2xl) var(--space-3xl);
  }
}

/* ============================================
   TOUCH OPTIMIZATION — iPad/Tablet
   ============================================ */
@media (min-width: 768px) and (pointer: coarse) {
  .nav-item {
    min-height: 48px;
    min-width: 48px;
  }

  .icon-btn {
    min-width: 48px;
    min-height: 48px;
  }

  .btn {
    min-height: 48px;
  }
}