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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  height: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: var(--font-base);
  color: var(--text-primary);
  background-color: var(--bg-primary);
  line-height: 1.6;
  overflow: hidden;
  min-height: 100vh;
  min-height: 100dvh;
  width: 100%;
  overscroll-behavior: none;
}

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

a:hover {
  color: var(--accent-hover);
}

button {
  font-family: inherit;
  font-size: inherit;
  cursor: pointer;
  border: none;
  background: none;
  color: inherit;
}

input, textarea, select {
  font-family: inherit;
  font-size: max(16px, 1em);
  color: inherit;
  background: none;
  border: none;
  outline: none;
}

/* App Layout */
.app {
  display: flex;
  min-height: 100vh;
  min-height: 100dvh;
  width: 100%;
  overflow: hidden;
}

.main-area {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 0;
  min-width: 0;
}

/* Header */
.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-sm) var(--space-md);
  border-bottom: 1px solid var(--border-subtle);
  background: var(--bg-primary);
  min-height: 56px;
  flex-shrink: 0;
  z-index: 10;
  gap: var(--space-sm);
}

.header-left {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  min-width: 0;
}

.header-right {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  min-width: 0;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.study-language-switcher {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 3px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-full);
}

.study-language-option {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 74px;
  padding: 6px 10px;
  border-radius: var(--radius-full);
  color: var(--text-secondary);
  transition: background var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast);
  border: 1px solid transparent;
  font-size: var(--font-xs);
  font-weight: 600;
}

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

.study-language-option.active {
  color: var(--accent);
  background: var(--accent-subtle);
  border-color: var(--accent-border);
}

.study-language-short {
  display: none;
}

.header-logo {
  font-size: var(--font-lg);
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.5px;
}

.header-logo span {
  color: var(--accent);
}

/* Sidebar toggle */
.btn-sidebar-toggle {
  display: none;
  width: 36px;
  height: 36px;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  transition: background var(--transition-fast);
}

.btn-sidebar-toggle:hover {
  background: var(--bg-hover);
}

.btn-sidebar-toggle svg {
  width: 20px;
  height: 20px;
  stroke: var(--text-secondary);
}

/* Header buttons */
.btn-icon {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  transition: background var(--transition-fast);
}

.btn-icon:hover {
  background: var(--bg-hover);
}

.btn-icon svg {
  width: 18px;
  height: 18px;
  stroke: var(--text-secondary);
}

/* Model selector dropdown */
.model-selector {
  position: relative;
  min-width: 0;
}

.model-selector-btn {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  font-size: var(--font-sm);
  color: var(--text-secondary);
  transition: background var(--transition-fast);
  border: 1px solid var(--border-subtle);
  max-width: 100%;
}

#modelSelectorLabel {
  display: block;
  min-width: 0;
  max-width: 200px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

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

.model-selector-btn svg {
  width: 14px;
  height: 14px;
  stroke: currentColor;
  transition: transform var(--transition-fast);
}

.model-selector-btn.open svg {
  transform: rotate(180deg);
}

.model-dropdown {
  display: none;
  position: absolute;
  top: calc(100% + 4px);
  right: 0;
  min-width: 280px;
  max-width: min(360px, calc(100vw - 32px));
  background: var(--bg-secondary);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  z-index: 100;
  overflow: hidden;
}

.model-dropdown.show {
  display: block;
}

.model-dropdown-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 10px 14px;
  font-size: var(--font-sm);
  color: var(--text-secondary);
  transition: background var(--transition-fast);
  text-align: left;
}

.model-dropdown-item:hover {
  background: var(--bg-hover);
  color: var(--text-primary);
}

.model-dropdown-item.active {
  color: var(--accent);
}

.model-dropdown-item .model-category {
  font-size: var(--font-xs);
  color: var(--text-muted);
}

/* Sidebar */
.sidebar {
  width: var(--sidebar-width);
  background: var(--bg-secondary);
  border-right: 1px solid var(--border-subtle);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
  min-height: 100vh;
  min-height: 100dvh;
  transition: transform var(--transition-base);
  z-index: 20;
}

.sidebar-header {
  padding: var(--space-md);
  border-bottom: 1px solid var(--border-subtle);
}

.btn-new-session {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  width: 100%;
  padding: 10px;
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-sm);
  font-size: var(--font-sm);
  color: var(--text-primary);
  transition: background var(--transition-fast);
}

.btn-new-session:hover {
  background: var(--bg-hover);
}

.btn-new-session svg {
  width: 16px;
  height: 16px;
  stroke: currentColor;
}

.sidebar-sessions {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-sm);
  -webkit-overflow-scrolling: touch;
  overscroll-behavior: contain;
}

.sidebar-sessions::-webkit-scrollbar {
  width: 4px;
}

.sidebar-sessions::-webkit-scrollbar-track {
  background: transparent;
}

.sidebar-sessions::-webkit-scrollbar-thumb {
  background: var(--border-medium);
  border-radius: 2px;
}

.session-item {
  display: block;
  width: 100%;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  text-align: left;
  transition: background var(--transition-fast);
  margin-bottom: 2px;
}

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

.session-item-date {
  font-size: var(--font-xs);
  color: var(--text-muted);
}

.session-item-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-sm);
}

.session-item-language {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 34px;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  border: 1px solid transparent;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.session-item-language-en {
  background: rgba(96, 165, 250, 0.12);
  border-color: rgba(96, 165, 250, 0.28);
  color: #93c5fd;
}

.session-item-language-es {
  background: rgba(251, 191, 36, 0.12);
  border-color: rgba(251, 191, 36, 0.28);
  color: #fcd34d;
}

.session-item-title {
  font-size: var(--font-sm);
  color: var(--text-secondary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sidebar-footer {
  padding: var(--space-md);
  border-top: 1px solid var(--border-subtle);
}

.sidebar-empty-state {
  padding: 16px;
  color: var(--text-muted);
  font-size: var(--font-sm);
  text-align: center;
}

.btn-settings-sidebar {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  width: 100%;
  padding: 10px;
  border-radius: var(--radius-sm);
  font-size: var(--font-sm);
  color: var(--text-secondary);
  transition: background var(--transition-fast);
}

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

.btn-settings-sidebar svg {
  width: 16px;
  height: 16px;
  stroke: currentColor;
}

/* Sidebar overlay for mobile */
.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 15;
}

.sidebar-overlay.show {
  display: block;
  backdrop-filter: blur(2px);
}

@media (max-width: 1024px) {
  #modelSelectorLabel {
    max-width: 152px;
  }
}

/* Responsividade */
@media (max-width: 768px) {
  .sidebar {
    position: fixed;
    left: 0;
    top: 0;
    width: min(86vw, 320px);
    max-width: calc(100vw - 40px);
    height: 100dvh;
    transform: translateX(-100%);
    box-shadow: var(--shadow-lg);
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .sidebar-header {
    padding-top: calc(var(--space-md) + var(--safe-top));
  }

  .sidebar-footer {
    padding-bottom: calc(var(--space-md) + var(--safe-bottom));
  }

  .btn-sidebar-toggle {
    display: flex;
  }

  .header {
    align-items: flex-start;
    flex-wrap: wrap;
    padding:
      calc(var(--space-sm) + var(--safe-top))
      calc(var(--space-sm) + var(--safe-right))
      var(--space-sm)
      calc(var(--space-sm) + var(--safe-left));
  }

  .header-left {
    width: 100%;
    justify-content: space-between;
  }

  .header-right {
    width: 100%;
    display: grid;
    grid-template-columns: auto minmax(0, 1fr) auto auto;
    gap: var(--space-xs);
    align-items: center;
  }

  .study-language-option {
    min-width: 0;
    min-height: 40px;
    padding: 6px 9px;
  }

  .study-language-full {
    display: none;
  }

  .study-language-short {
    display: inline;
  }

  .model-selector-btn,
  .btn-icon,
  .btn-sidebar-toggle {
    min-height: 40px;
  }

  .btn-icon,
  .btn-sidebar-toggle {
    width: 40px;
    height: 40px;
  }

  .model-selector-btn {
    width: 100%;
    justify-content: space-between;
    padding-inline: 10px;
  }

  .model-dropdown {
    left: 0;
    right: 0;
    width: 100%;
    min-width: 0;
    max-width: none;
  }
}

@media (max-width: 480px) {
  .header-logo {
    font-size: var(--font-md);
  }

  #modelSelectorLabel {
    max-width: 96px;
  }
}

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

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

::-webkit-scrollbar-thumb {
  background: var(--border-medium);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}