/* BRDF Viewer - Scientific Paper Website Styles */
/* Clean academic style inspired by SIGGRAPH/CVPR supplemental pages */

:root {
  --primary: #1a237e;
  --accent: #283593;
  --text: #212121;
  --text-secondary: #546e7a;
  --background: #ffffff;
  --surface: #f5f5f5;
  --border: #e0e0e0;
  --canvas-bg: #1a1a1a;
  --success: #388e3c;
  --error: #d32f2f;
  --info: #1976d2;

  --font-serif: Georgia, 'Times New Roman', Times, serif;
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-mono: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
  --content-width: 900px;
  --viewer-max-width: 1380px;
  --viewer-height: 620px;
  --viewer-height-mobile: 420px;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-serif);
  color: var(--text);
  background: var(--background);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* ===== Layout ===== */
.page-wrapper {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ===== Header / Paper Title ===== */
.paper-header {
  text-align: center;
  padding: 3rem 0 2rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 2.5rem;
}

.paper-title {
  font-family: var(--font-serif);
  font-size: 2.0rem;
  font-weight: 700;
  color: var(--primary);
  line-height: 1.3;
  margin-bottom: 1.25rem;
  letter-spacing: -0.02em;
}

.paper-venue {
  display: inline-block;
  background: var(--primary);
  color: white;
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.25rem 0.75rem;
  border-radius: 2px;
  margin-bottom: 1.5rem;
}

/* ===== Authors ===== */
.authors {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.5rem 2rem;
  margin-bottom: 0.75rem;
}

.author {
  font-family: var(--font-sans);
  font-size: 1.0rem;
  color: var(--text);
}

.author sup {
  font-size: 0.7em;
  color: var(--primary);
}

.affiliations {
  font-family: var(--font-sans);
  font-size: 0.875rem;
  color: var(--text-secondary);
  text-align: center;
  margin-bottom: 1.5rem;
}

/* ===== Links Row ===== */
.paper-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.75rem;
  margin-top: 1.25rem;
}

.paper-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-family: var(--font-sans);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--primary);
  border: 1.5px solid var(--primary);
  padding: 0.35rem 1rem;
  border-radius: 4px;
  text-decoration: none;
  transition: background 0.15s, color 0.15s;
}

.paper-link:hover {
  background: var(--primary);
  color: white;
}

/* ===== Sections ===== */
.paper-section {
  margin-bottom: 3rem;
}

.section-header {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--primary);
  border-bottom: 2px solid var(--primary);
  padding-bottom: 0.3rem;
  margin-bottom: 1.25rem;
}

/* ===== Abstract ===== */
.abstract-text {
  font-size: 0.9375rem;
  line-height: 1.8;
  text-align: justify;
  hyphens: auto;
  color: var(--text);
}

/* ===== Teaser image ===== */
.teaser-figure {
  text-align: center;
  margin: 1.5rem 0;
}

.teaser-figure img {
  max-width: 100%;
  border: 1px solid var(--border);
}

.figure-caption {
  font-size: 0.825rem;
  color: var(--text-secondary);
  margin-top: 0.5rem;
  font-style: italic;
}

/* ===== Interactive Demo Section ===== */
.demo-section {
  background: var(--canvas-bg);
  border-radius: 8px;
  overflow: hidden;
  margin-bottom: 3rem;
  box-shadow: 0 4px 24px rgba(0,0,0,0.3);
}

.demo-header {
  background: #222;
  padding: 0.75rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.demo-title {
  font-family: var(--font-sans);
  font-size: 0.875rem;
  font-weight: 600;
  color: #e0e0e0;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.demo-layout {
  display: grid;
  grid-template-columns: 1fr 280px;
  height: var(--viewer-height);
}

@media (min-width: 1180px) {
  #interactive-demo .demo-section {
    width: min(var(--viewer-max-width), calc(100vw - 3rem));
    margin-left: 50%;
    transform: translateX(-50%);
  }
}

.canvas-wrapper {
  position: relative;
  background: #111;
  overflow: hidden;
}

#brdf-canvas {
  width: 100%;
  height: 100%;
  display: block;
}

.viewer-toggle {
  position: absolute;
  top: 0.75rem;
  right: 0.75rem;
  z-index: 30;
  border: 1px solid rgba(159, 168, 218, 0.65);
  border-radius: 6px;
  padding: 0.5rem 0.8rem;
  background: rgba(30, 30, 30, 0.92);
  color: #e8eaf6;
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 600;
  cursor: pointer;
}

.viewer-toggle[aria-pressed="false"]:not(:disabled) {
  top: 50%;
  right: auto;
  left: 50%;
  transform: translate(-50%, -50%);
}

.viewer-toggle[aria-pressed="false"]:not(:disabled) + .loading-overlay .loading-text {
  transform: translateY(3rem);
}

.viewer-toggle:hover:not(:disabled) {
  background: #3949ab;
  border-color: #9fa8da;
}

.viewer-toggle:disabled {
  cursor: wait;
  opacity: 0.7;
}

/* Loading overlay */
.loading-overlay {
  position: absolute;
  inset: 0;
  background: rgba(17, 17, 17, 0.92);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 10;
}

.loading-spinner {
  width: 40px;
  height: 40px;
  border: 3px solid rgba(255,255,255,0.1);
  border-top-color: #7986cb;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin-bottom: 1rem;
}

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

.loading-text {
  font-family: var(--font-sans);
  font-size: 0.875rem;
  color: #bdbdbd;
}

/* Status message */
.status-message {
  position: absolute;
  bottom: 1rem;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(0,0,0,0.75);
  color: white;
  font-family: var(--font-sans);
  font-size: 0.8125rem;
  padding: 0.4rem 1rem;
  border-radius: 20px;
  pointer-events: none;
  transition: opacity 0.5s ease;
  white-space: nowrap;
  z-index: 20;
}

.status-message.success { color: #a5d6a7; }
.status-message.error { color: #ef9a9a; }
.status-message.info { color: #90caf9; }

/* ===== Controls Panel ===== */
.controls-panel {
  background: #1e1e1e;
  overflow-y: auto;
  padding: 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 0;
}

.viewer-idle-message {
  margin: auto;
  padding: 1rem;
  color: #9e9e9e;
  font-family: var(--font-sans);
  font-size: 0.8rem;
  line-height: 1.5;
  text-align: center;
}

.controls-panel::-webkit-scrollbar {
  width: 4px;
}
.controls-panel::-webkit-scrollbar-track {
  background: transparent;
}
.controls-panel::-webkit-scrollbar-thumb {
  background: #444;
  border-radius: 2px;
}

.control-section {
  border-bottom: 1px solid #333;
  padding: 0.65rem 0;
}

.control-section:last-child {
  border-bottom: none;
}

.section-toggle {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  background: transparent;
  border: none;
  padding: 0;
  margin-bottom: 0.5rem;
  cursor: pointer;
  text-align: left;
}

.section-title {
  font-family: var(--font-sans);
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: #7986cb;
  margin: 0;
}

.section-chevron {
  font-family: var(--font-sans);
  font-size: 0.8rem;
  color: #7986cb;
  transition: transform 0.15s ease;
}

.control-section-body {
  overflow: hidden;
}

.control-section.collapsed .control-section-body {
  display: none;
}

.control-section.collapsed .section-chevron {
  transform: rotate(-90deg);
}

.control-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 0.4rem;
  align-items: center;
}

.control-label {
  font-family: var(--font-sans);
  font-size: 0.75rem;
  color: #9e9e9e;
  min-width: 45px;
}

/* Slider rows */
.slider-row {
  display: grid;
  grid-template-columns: 90px 1fr 48px;
  align-items: center;
  gap: 0.4rem;
  margin-bottom: 0.35rem;
}

.slider-label {
  font-family: var(--font-sans);
  font-size: 0.72rem;
  color: #bdbdbd;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 3px;
  background: #444;
  border-radius: 2px;
  outline: none;
  cursor: pointer;
}

.slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 12px;
  height: 12px;
  background: #7986cb;
  border-radius: 50%;
  cursor: pointer;
  transition: background 0.15s;
}

.slider::-webkit-slider-thumb:hover {
  background: #9fa8da;
}

.slider::-moz-range-thumb {
  width: 12px;
  height: 12px;
  background: #7986cb;
  border: none;
  border-radius: 50%;
  cursor: pointer;
}

.slider-value {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: #9e9e9e;
  text-align: right;
  min-width: 42px;
}

/* Checkbox rows */
.checkbox-row {
  margin-bottom: 0.3rem;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-family: var(--font-sans);
  font-size: 0.75rem;
  color: #bdbdbd;
  cursor: pointer;
}

.checkbox-label input[type="checkbox"] {
  accent-color: #7986cb;
  width: 13px;
  height: 13px;
  cursor: pointer;
}

/* Select inputs */
.select-input {
  background: #2d2d2d;
  color: #e0e0e0;
  border: 1px solid #444;
  border-radius: 3px;
  padding: 0.3rem 0.4rem;
  font-family: var(--font-sans);
  font-size: 0.75rem;
  outline: none;
  cursor: pointer;
  flex: 1;
  min-width: 0;
}

.select-input:focus {
  border-color: #7986cb;
}

/* File upload button */
.file-upload-btn {
  display: inline-flex;
  align-items: center;
  background: #333;
  color: #bdbdbd;
  border: 1px solid #444;
  border-radius: 3px;
  padding: 0.3rem 0.6rem;
  font-family: var(--font-sans);
  font-size: 0.72rem;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.15s;
}

.file-upload-btn:hover {
  background: #3d3d3d;
  color: #e0e0e0;
}

/* Mode buttons */
.mode-btn {
  background: #2d2d2d;
  color: #9e9e9e;
  border: 1px solid #444;
  border-radius: 3px;
  padding: 0.25rem 0.5rem;
  font-family: var(--font-sans);
  font-size: 0.72rem;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
  flex: 1;
}

.mode-btn:hover {
  background: #3d3d3d;
  color: #e0e0e0;
}

.mode-btn.active {
  background: #3949ab;
  color: white;
  border-color: #5c6bc0;
}

/* Sample count & reset */
.sample-count {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: #80cbc4;
}

.reset-btn {
  background: #333;
  color: #bdbdbd;
  border: 1px solid #444;
  border-radius: 3px;
  padding: 0.25rem 0.75rem;
  font-family: var(--font-sans);
  font-size: 0.72rem;
  cursor: pointer;
  transition: background 0.15s;
}

.reset-btn:hover {
  background: #c62828;
  color: white;
  border-color: #c62828;
}

.hint-text {
  font-family: var(--font-sans);
  font-size: 0.69rem;
  color: #616161;
  line-height: 1.5;
  margin-top: 0.35rem;
}

/* ===== Paper content sections ===== */
.method-text {
  font-size: 0.9375rem;
  line-height: 1.8;
}

.method-text p + p {
  margin-top: 1rem;
}

/* Two-column figures */
.figure-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin: 1.5rem 0;
}

/* ===== BibTeX ===== */
.bibtex-block {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 4px solid var(--primary);
  border-radius: 4px;
  padding: 1rem 1.25rem;
  overflow-x: auto;
}

.bibtex-block pre {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  line-height: 1.6;
  color: var(--text);
  text-align: left;
  white-space: pre;
  margin: 0;
}

.copy-bibtex-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  background: var(--primary);
  color: white;
  border: none;
  border-radius: 4px;
  padding: 0.4rem 0.9rem;
  font-family: var(--font-sans);
  font-size: 0.8125rem;
  cursor: pointer;
  margin-top: 0.75rem;
  transition: background 0.15s;
}

.copy-bibtex-btn:hover {
  background: var(--accent);
}

/* ===== Footer ===== */
.paper-footer {
  text-align: center;
  padding: 2rem 0;
  border-top: 1px solid var(--border);
  margin-top: 3rem;
}

.footer-text {
  font-family: var(--font-sans);
  font-size: 0.8125rem;
  color: var(--text-secondary);
}

/* ===== Responsive ===== */
@media (max-width: 700px) {
  .paper-title {
    font-size: 1.5rem;
  }

  .demo-layout {
    grid-template-columns: 1fr;
    grid-template-rows: var(--viewer-height-mobile) auto;
    height: auto;
  }

  .controls-panel {
    max-height: 280px;
  }

  .figure-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .paper-header {
    padding: 2rem 0 1.5rem;
  }

  .paper-title {
    font-size: 1.3rem;
  }
}