/* Dark Mode by Default */
:root {
  --bg-primary: #0f1419;
  --bg-secondary: #1a1f26;
  --bg-card: #1e2732;
  --text-primary: #e7e9ea;
  --text-secondary: #8b98a5;
  --border-color: #2f3336;
  --accent: #1d9bf0;
  --accent-hover: #1a8cd8;
  --chip-bg: #2f3336;
  --chip-text: #e7e9ea;
  --chip-active-bg: #1d9bf0;
  --chip-active-text: #ffffff;
  --spinner-color: #1d9bf0;
  --dot-color: #00ba7c;
  --shadow-color: rgba(0,0,0,0.4);
  --transition-speed: 0.2s;
}

/* Light mode */
@media (prefers-color-scheme: light) {
  :root {
    --bg-primary: #ffffff;
    --bg-secondary: #f7f9f9;
    --bg-card: #ffffff;
    --text-primary: #0f1419;
    --text-secondary: #536471;
    --border-color: #eff3f4;
    --accent: #1d9bf0;
    --accent-hover: #1a8cd8;
    --chip-bg: #eff3f4;
    --chip-text: #0f1419;
    --chip-active-bg: #1d9bf0;
    --chip-active-text: #ffffff;
    --spinner-color: #1d9bf0;
    --dot-color: #00ba7c;
    --shadow-color: rgba(0,0,0,0.08);
  }
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.5;
  overflow: hidden;
  transition: background var(--transition-speed), color var(--transition-speed);
}

#app {
  width: 100%;
  height: 100vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  padding: 14px 16px;
  background: var(--bg-primary);
  position: relative;
  transition: background var(--transition-speed);
}

#header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
}

.app-name {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 6px;
}

.app-logo {
  color: var(--text-secondary);
  display: flex;
  align-items: center;
}

#activity-dot {
  width: 10px;
  height: 10px;
  background: var(--dot-color);
  border-radius: 50%;
  box-shadow: 0 0 6px var(--dot-color);
  display: inline-block;
  margin-left: 4px;
  flex-shrink: 0;
}

#mode-tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 10px;
}

.tab {
  background: transparent;
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 4px 16px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-speed);
}

.tab.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.tab:hover:not(.active) {
  background: var(--bg-secondary);
}

#filter-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-bottom: 12px;
}

#filter-input {
  flex: 1;
  min-width: 150px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 24px;
  padding: 8px 16px;
  font-size: 0.9rem;
  color: var(--text-primary);
  outline: none;
  transition: border var(--transition-speed), box-shadow var(--transition-speed);
}

#filter-input::placeholder {
  color: var(--text-secondary);
}

#filter-input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 2px rgba(29,155,240,0.3);
}

#add-filter-btn {
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 50%;
  height: 36px;
  width: 36px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background var(--transition-speed), transform var(--transition-speed);
  flex-shrink: 0;
}

#add-filter-btn:hover {
  background: var(--accent-hover);
  transform: scale(1.05);
}

#tag-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.chip {
  background: var(--chip-bg);
  color: var(--chip-text);
  border: 1px solid transparent;
  border-radius: 20px;
  padding: 5px 14px;
  font-size: 0.8rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-speed);
  display: flex;
  align-items: center;
  gap: 4px;
}

.chip.active {
  background: var(--chip-active-bg);
  color: var(--chip-active-text);
  border-color: var(--accent);
}

.chip:hover {
  opacity: 0.85;
}

.chip-remove {
  margin-left: 2px;
  font-weight: bold;
  font-size: 1rem;
  line-height: 1;
  opacity: 0.8;
  transition: opacity var(--transition-speed);
}

.chip-remove:hover {
  opacity: 1;
}

#tweet-list {
  flex: 1 1 auto;
  min-height: 0;
  overflow-y: auto;
  overflow-x: hidden;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding-right: 2px;
  scroll-behavior: smooth;
}

.tweet-card {
  background: var(--bg-card);
  border-radius: 14px;
  padding: 12px 14px;
  box-shadow: 0 2px 6px var(--shadow-color);
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-size: 0.85rem;
  transition: background var(--transition-speed), box-shadow var(--transition-speed);
  animation: fadeIn 0.2s ease-out;
}

.tweet-card:hover {
  background: var(--bg-secondary);
  box-shadow: 0 4px 10px var(--shadow-color);
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}

.tweet-author {
  display: flex;
  align-items: center;
  gap: 10px;
}

.tweet-avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  object-fit: cover;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
}

.fallback-avatar {
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
}

.tweet-author-info {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px;
  flex: 1;
}

.tweet-author-name {
  font-weight: 700;
  color: var(--text-primary);
  font-size: 0.9rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 110px;
}

.tweet-author-handle {
  color: var(--text-secondary);
  font-size: 0.8rem;
}

.tweet-timestamp {
  color: var(--text-secondary);
  font-size: 0.75rem;
  white-space: nowrap;
  margin-left: auto;
}

.tweet-text {
  color: var(--text-primary);
  line-height: 1.45;
  word-break: break-word;
  white-space: pre-wrap;
  font-size: 0.85rem;
}

.tweet-image {
  width: 100%;
  max-height: 200px;
  object-fit: cover;
  border-radius: 12px;
  margin-top: 4px;
  border: 1px solid var(--border-color);
}

.tweet-link {
  color: var(--accent);
  text-decoration: none;
  font-size: 0.8rem;
  font-weight: 500;
  align-self: flex-start;
  transition: color var(--transition-speed);
}

.tweet-link:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}

#pagination {
  flex-shrink: 0;
  min-height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 8px 0 4px;
}

.page-btn {
  background: transparent;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 6px 12px;
  font-size: 0.8rem;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-speed);
  min-width: 36px;
  text-align: center;
}

.page-btn:hover:not(:disabled) {
  background: var(--bg-secondary);
  border-color: var(--accent);
  color: var(--text-primary);
}

.page-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
  font-weight: 700;
}

.page-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.page-indicator {
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin: 0 6px;
  white-space: nowrap;
}

#loading-indicator {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 30px;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.spinner {
  width: 24px;
  height: 24px;
  border: 3px solid var(--bg-secondary);
  border-top-color: var(--spinner-color);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

#error-message {
  text-align: center;
  padding: 30px;
  color: var(--text-secondary);
  font-size: 0.95rem;
  background: var(--bg-card);
  border-radius: 12px;
  margin: 10px 0;
}

.hidden {
  display: none !important;
}

@media (max-width: 400px) {
  #app {
    padding: 10px 12px;
  }
  .tweet-card {
    padding: 10px 12px;
    font-size: 0.8rem;
  }
  .tweet-avatar {
    width: 28px;
    height: 28px;
  }
  .tweet-author-name {
    max-width: 80px;
    font-size: 0.8rem;
  }
  #filter-input {
    padding: 6px 12px;
    font-size: 0.8rem;
  }
}