/* People's Daily N-gram Viewer - Styles */

/* === CSS Variables === */
:root {
  /* Colors */
  --color-bg: #fafafa;
  --color-surface: #ffffff;
  --color-text: #1a1a1a;
  --color-text-secondary: #666666;
  --color-border: #e0e0e0;
  --color-primary: #1a73e8;
  --color-primary-hover: #1557b0;
  --color-error: #d93025;

  /* Chart colors (12 distinct) */
  --chart-1: #1f77b4;
  --chart-2: #ff7f0e;
  --chart-3: #2ca02c;
  --chart-4: #d62728;
  --chart-5: #9467bd;
  --chart-6: #8c564b;
  --chart-7: #e377c2;
  --chart-8: #7f7f7f;
  --chart-9: #bcbd22;
  --chart-10: #17becf;
  --chart-11: #aec7e8;
  --chart-12: #ffbb78;

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SF Mono", "Monaco", "Inconsolata", "Fira Mono", monospace;

  /* Layout */
  --max-width: 1200px;
  --header-height: 56px;
}

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

/* === Base === */
html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--font-sans);
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

a:hover {
  text-decoration: underline;
}

/* === Header === */
.site-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  height: var(--header-height);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-content {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-title {
  font-size: 1.25rem;
  font-weight: 600;
}

.site-title a {
  color: var(--color-text);
}

.site-title a:hover {
  text-decoration: none;
}

.site-nav {
  display: flex;
  gap: var(--space-lg);
}

.site-nav a {
  color: var(--color-text-secondary);
  font-size: 0.875rem;
}

.site-nav a:hover {
  color: var(--color-primary);
}

/* === Main content === */
.main-content {
  flex: 1;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-xl) var(--space-lg);
  width: 100%;
}

/* === Search section === */
.search-section {
  margin-bottom: var(--space-xl);
}

.search-form {
  margin-bottom: var(--space-md);
}

.search-input-wrapper {
  display: flex;
  gap: var(--space-sm);
}

.search-input {
  flex: 1;
  min-width: 0;
  padding: var(--space-sm) var(--space-md);
  font-size: 1rem;
  border: 1px solid var(--color-border);
  border-radius: 4px;
  background: var(--color-surface);
}

.search-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 2px rgba(26, 115, 232, 0.2);
}

.search-button {
  padding: var(--space-sm) var(--space-lg);
  background: var(--color-primary);
  color: white;
  border: none;
  border-radius: 4px;
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
}

.search-button:hover {
  background: var(--color-primary-hover);
}

.search-button:active {
  transform: translateY(1px);
}

/* === Filters === */
.filters {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm) var(--space-md);
  align-items: center;
}

.filter-group {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.filter-group label {
  font-size: 0.8125rem;
  color: var(--color-text-secondary);
  white-space: nowrap;
}

.filter-group input[type="number"] {
  width: 60px;
  padding: 2px var(--space-xs);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  font-size: 0.8125rem;
}

.filter-group select {
  padding: 2px var(--space-xs);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  font-size: 0.8125rem;
  background: var(--color-surface);
  cursor: pointer;
}

.filter-checkbox {
  flex-direction: row-reverse;
}

.filter-checkbox input[type="checkbox"] {
  width: 16px;
  height: 16px;
  cursor: pointer;
}

.filter-group.disabled label,
.filter-group.disabled input {
  opacity: 0.5;
  cursor: not-allowed;
}

/* === Chart section === */
.chart-section {
  position: relative;
  margin-bottom: var(--space-xl);
}

.chart-container {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: var(--space-lg);
  min-height: 400px;
  position: relative;
}

.fullscreen-btn {
  position: absolute;
  top: var(--space-sm);
  right: var(--space-sm);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  padding: 6px;
  cursor: pointer;
  color: var(--color-text-secondary);
  opacity: 0.6;
  transition: opacity 0.2s;
  z-index: 10;
}

.fullscreen-btn:hover {
  opacity: 1;
  color: var(--color-text);
}

/* Fullscreen mode */
.chart-container:fullscreen {
  padding: var(--space-xl);
  display: flex;
  align-items: center;
  justify-content: center;
}

.chart-container:fullscreen canvas {
  max-width: 100%;
  max-height: 100%;
}

.chart-container:fullscreen .fullscreen-btn {
  top: var(--space-md);
  right: var(--space-md);
}

.loading-indicator {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
  color: var(--color-text-secondary);
}

.loading-main {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.loading-slow {
  font-size: 0.85em;
  color: var(--color-text-tertiary);
  margin-top: var(--space-xs);
}

.spinner {
  width: 20px;
  height: 20px;
  border: 2px solid var(--color-border);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

.pending-message {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  background: #fff3e0;
  color: #e65100;
  padding: var(--space-sm) var(--space-md);
  border-radius: 4px;
  margin-top: var(--space-md);
  font-size: 0.9em;
}

.pending-spinner {
  width: 14px;
  height: 14px;
  border: 2px solid #ffcc80;
  border-top-color: #e65100;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  flex-shrink: 0;
}

.empty-terms-message {
  color: var(--color-text-secondary);
  font-size: 0.9em;
  padding: var(--space-sm) 0;
  margin-top: var(--space-sm);
}

.error-message {
  background: #fce8e6;
  color: var(--color-error);
  padding: var(--space-md);
  border-radius: 4px;
  margin-top: var(--space-md);
}

.no-data-message {
  text-align: center;
  color: var(--color-text-secondary);
  padding: var(--space-xl);
}

/* === Results section === */
.results-section {
  border-top: 1px solid var(--color-border);
  padding-top: var(--space-xl);
}

.term-results {
  margin-bottom: var(--space-lg);
}

.term-result {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  margin-bottom: var(--space-md);
}

.term-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md);
  cursor: pointer;
}

.term-header:hover {
  background: var(--color-bg);
}

.term-name {
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.term-color {
  width: 12px;
  height: 12px;
  border-radius: 2px;
}

.term-actions {
  display: flex;
  gap: var(--space-sm);
}

.term-expand-hint {
  color: var(--color-text-secondary);
  font-size: 0.875rem;
  user-select: none;
}

.term-data {
  border-top: 1px solid var(--color-border);
}

.term-tabs {
  display: flex;
  gap: 0;
  border-bottom: 1px solid var(--color-border);
  padding: 0 var(--space-md);
}

.term-tab {
  appearance: none;
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  padding: var(--space-sm) var(--space-md);
  font-size: 0.875rem;
  cursor: pointer;
  color: var(--color-text-secondary);
  margin-bottom: -1px;
}

.term-tab:hover {
  color: var(--color-text);
}

.term-tab.active {
  color: var(--color-text);
  border-bottom-color: var(--color-primary);
}

.term-tab-panel {
  padding: var(--space-md);
  max-height: 360px;
  overflow-y: auto;
}

.term-tab-actions {
  display: flex;
  gap: var(--space-sm);
  margin-bottom: var(--space-sm);
}

.articles-placeholder {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  padding: var(--space-md);
}

.articles-placeholder.error {
  color: var(--color-danger, #c41e3a);
}

.preview-note {
  font-size: 0.8125rem;
  color: var(--color-text-secondary);
  margin-top: var(--space-sm);
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
}

.data-table th,
.data-table td {
  text-align: left;
  padding: var(--space-xs) var(--space-sm);
  border-bottom: 1px solid var(--color-border);
}

.data-table th {
  font-weight: 500;
  color: var(--color-text-secondary);
  position: sticky;
  top: 0;
  background: var(--color-surface);
}

.data-table td {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
}

/* === Action buttons === */
.global-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-bottom: var(--space-md);
  align-items: center;
}

.download-dropdown {
  position: relative;
  display: inline-block;
}

.download-menu {
  position: absolute;
  top: calc(100% + 4px);
  left: 0;
  min-width: 11rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
  z-index: 20;
  display: flex;
  flex-direction: column;
  padding: var(--space-xs) 0;
}

.download-menu.hidden {
  display: none;
}

.download-option {
  appearance: none;
  background: none;
  border: none;
  text-align: left;
  padding: var(--space-xs) var(--space-md);
  font-size: 0.875rem;
  color: var(--color-text);
  cursor: pointer;
}

.download-option:hover {
  background: var(--color-bg);
}

.action-button {
  padding: var(--space-xs) var(--space-md);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  font-size: 0.875rem;
  cursor: pointer;
}

.action-button:hover {
  background: var(--color-bg);
}

.action-button:disabled {
  opacity: 0.6;
  cursor: wait;
}

.missing-term-request {
  margin-left: var(--space-xs);
  padding: 2px var(--space-sm);
  font-size: 0.8125rem;
}

/* Progress fill effect for download buttons */
.action-button.downloading {
  position: relative;
  overflow: hidden;
  background: linear-gradient(to right, var(--color-primary) var(--progress, 0%), var(--color-surface) var(--progress, 0%));
  color: var(--color-text);
  transition: none;
}

.action-button.downloading.complete {
  background: var(--color-primary);
  color: white;
  animation: flash 0.3s ease-out;
}

@keyframes flash {
  0% { transform: scale(1); }
  50% { transform: scale(1.05); }
  100% { transform: scale(1); }
}

.export-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  align-items: center;
  margin-bottom: var(--space-md);
  padding-top: var(--space-sm);
  border-top: 1px dashed var(--color-border);
}

.export-label {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  margin-right: var(--space-xs);
}

.data-files-display {
  background: #263238;
  color: #d5e3e8;
  padding: var(--space-md);
  border-radius: 4px;
  font-size: 0.8125rem;
  overflow-x: auto;
}

.data-files-list {
  display: grid;
  gap: var(--space-xs);
}

.data-files-list a {
  display: grid;
  grid-template-columns: 9rem minmax(0, 1fr);
  gap: var(--space-sm);
  align-items: baseline;
  color: #d5e3e8;
  text-decoration: none;
}

.data-files-list a:hover {
  color: white;
}

.data-files-list code {
  color: #aabfc9;
  font-family: var(--font-mono);
  overflow-wrap: anywhere;
}

/* === Footer === */
.site-footer {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding: var(--space-md) var(--space-lg);
}

.footer-content {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  font-size: 0.875rem;
  color: var(--color-text-secondary);
}

.footer-sep {
  margin: 0 var(--space-sm);
  color: var(--color-border);
}

/* === About page === */
.about-content {
  max-width: var(--max-width);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: var(--space-xl);
}

.about-content h2 {
  font-size: 1.5rem;
  margin-bottom: var(--space-lg);
  padding-bottom: var(--space-sm);
  border-bottom: 1px solid var(--color-border);
}

.about-content h3 {
  font-size: 1.1rem;
  margin-top: var(--space-lg);
  margin-bottom: var(--space-sm);
  color: var(--color-text);
}

.about-content p {
  margin-bottom: var(--space-md);
  color: var(--color-text-secondary);
  line-height: 1.7;
}

.about-content ul {
  margin-bottom: var(--space-md);
  padding-left: var(--space-lg);
  color: var(--color-text-secondary);
}

.about-content li {
  margin-bottom: var(--space-xs);
  line-height: 1.6;
}

.about-content em {
  font-style: italic;
}

.about-content code {
  font-family: var(--font-mono);
  font-size: 0.92em;
  background: #f1f3f4;
  color: var(--color-text);
  padding: 0.1rem 0.3rem;
  border-radius: 3px;
}

.about-content pre {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  line-height: 1.55;
  white-space: pre-wrap;
  background: #f8f9fa;
  border: 1px solid var(--color-border);
  border-radius: 4px;
  padding: var(--space-md);
  margin-bottom: var(--space-md);
  overflow-x: auto;
}

.site-nav a.active {
  color: var(--color-primary);
  font-weight: 500;
}

/* === Utilities === */
.hidden {
  display: none !important;
}

/* === Responsive === */
@media (max-width: 768px) {
  .site-header {
    height: auto;
  }

  .header-content {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-sm);
    padding: var(--space-md) var(--space-lg);
  }

  .site-title {
    font-size: 1.1rem;
  }

  .filters {
    flex-direction: column;
    align-items: flex-start;
  }

  .filter-group {
    width: 100%;
    justify-content: space-between;
  }

  .footer-content {
    flex-direction: column;
    gap: var(--space-sm);
    text-align: center;
  }

  .chart-container {
    min-height: 300px;
  }
}