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

:root {
  --paper-bg: #fafaf7;
  --paper-text: #1a1a1a;
  --paper-text-dim: #666;
  --paper-accent: #b8860b;
  --paper-accent-light: #daa520;
  --paper-link: #1a5276;
  --paper-border: #e0ddd5;
  --paper-code-bg: #f0ede6;
  --paper-callout-bg: #fef9e7;
  --paper-callout-border: #f0c040;
  --paper-info-bg: #eaf2f8;
  --paper-info-border: #5b9bd5;
  --paper-table-header: #f5f2eb;
  --paper-table-stripe: #faf9f6;
  --paper-nav-bg: #f5f2eb;
  --paper-sim-bg: #111111;
  --arxiv-red: #b31b1b;
  --banana-yellow: #FFE135;
  --font-serif: 'Crimson Pro', Georgia, serif;
  --font-sans: 'IBM Plex Sans', -apple-system, sans-serif;
  --font-mono: 'IBM Plex Mono', monospace;
  --content-width: 780px;
  --nav-width: 200px;
}

/* Dark mode */
body.dark {
  --paper-bg: #1a1a1e;
  --paper-text: #e0ddd5;
  --paper-text-dim: #999;
  --paper-accent: #daa520;
  --paper-accent-light: #f0c040;
  --paper-link: #6db3f2;
  --paper-border: #333;
  --paper-code-bg: #252528;
  --paper-callout-bg: #2a2820;
  --paper-callout-border: #b8860b;
  --paper-info-bg: #1e2a35;
  --paper-info-border: #4a8fc7;
  --paper-table-header: #252528;
  --paper-table-stripe: #1e1e22;
  --paper-nav-bg: #222225;
  --arxiv-red: #e74c3c;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-serif);
  font-size: 17px;
  line-height: 1.75;
  color: var(--paper-text);
  background: var(--paper-bg);
  overflow-x: hidden;
  transition: background 0.3s, color 0.3s;
}

/* arXiv banner */
#arxiv-banner {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: var(--arxiv-red);
  color: #fff;
  font-family: var(--font-sans);
  font-size: 13px;
  padding: 6px 20px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

.arxiv-banner-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.arxiv-logo {
  font-weight: 700;
  letter-spacing: 0.5px;
}

.arxiv-id {
  font-family: var(--font-mono);
  font-weight: 500;
}

.arxiv-meta-top {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 12px;
}

.arxiv-category {
  font-family: var(--font-mono);
  background: rgba(255,255,255,0.15);
  padding: 2px 8px;
  border-radius: 3px;
}

.arxiv-separator {
  opacity: 0.4;
}

.dark-toggle {
  background: none;
  border: 1px solid rgba(255,255,255,0.3);
  color: #fff;
  font-size: 16px;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s;
}

.dark-toggle:hover {
  background: rgba(255,255,255,0.15);
}

/* Navigation sidebar */
#paper-nav {
  position: fixed;
  top: 38px;
  left: 0;
  width: var(--nav-width);
  height: calc(100vh - 38px);
  background: var(--paper-nav-bg);
  border-right: 1px solid var(--paper-border);
  padding: 24px 16px;
  overflow-y: auto;
  z-index: 50;
  transition: background 0.3s, border-color 0.3s;
}

.nav-title {
  font-family: var(--font-sans);
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--paper-text-dim);
  margin-bottom: 16px;
}

.nav-link {
  display: block;
  font-family: var(--font-sans);
  font-size: 12.5px;
  color: var(--paper-text-dim);
  text-decoration: none;
  padding: 5px 10px;
  border-left: 2px solid transparent;
  margin-bottom: 2px;
  border-radius: 0 4px 4px 0;
  transition: all 0.2s;
}

.nav-link:hover {
  color: var(--paper-text);
  background: rgba(0,0,0,0.04);
}

.nav-link.active {
  color: var(--paper-accent);
  border-left-color: var(--paper-accent);
  font-weight: 500;
  background: rgba(184, 134, 11, 0.06);
}

body.dark .nav-link:hover {
  background: rgba(255,255,255,0.04);
}

body.dark .nav-link.active {
  background: rgba(218, 165, 32, 0.08);
}

/* Main paper content */
#paper {
  margin-left: var(--nav-width);
  padding: 38px 0 0 0;
  min-height: 100vh;
}

article {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 40px 32px 80px;
}

/* Paper header */
.paper-header {
  text-align: center;
  margin-bottom: 48px;
  padding-bottom: 32px;
  border-bottom: 1px solid var(--paper-border);
}

.paper-title {
  font-family: var(--font-serif);
  font-size: 28px;
  font-weight: 700;
  line-height: 1.35;
  color: var(--paper-text);
  margin-bottom: 24px;
}

.authors {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 6px 24px;
  margin-bottom: 16px;
}

.author {
  font-family: var(--font-sans);
  font-size: 15px;
  font-weight: 500;
}

.author sup {
  font-size: 10px;
  color: var(--paper-accent);
}

.affiliations {
  margin-bottom: 20px;
}

.affiliations p {
  font-family: var(--font-sans);
  font-size: 12px;
  color: var(--paper-text-dim);
  line-height: 1.6;
}

.affiliations sup {
  font-size: 9px;
  color: var(--paper-accent);
}

.paper-meta-block {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px 24px;
  font-family: var(--font-sans);
  font-size: 12px;
  color: var(--paper-text-dim);
}

.meta-label {
  font-weight: 600;
  color: var(--paper-text-dim);
}

/* Sections */
section {
  margin-bottom: 40px;
}

h2 {
  font-family: var(--font-serif);
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 16px;
  padding-top: 12px;
  color: var(--paper-text);
  border-bottom: 1px solid var(--paper-border);
  padding-bottom: 8px;
}

h3 {
  font-family: var(--font-serif);
  font-size: 18px;
  font-weight: 600;
  margin: 28px 0 12px;
  color: var(--paper-text);
}

h4 {
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 8px;
  color: var(--paper-accent);
}

p {
  margin-bottom: 14px;
  text-align: justify;
  hyphens: auto;
}

/* Abstract */
.abstract-section {
  background: var(--paper-code-bg);
  border-left: 3px solid var(--paper-accent);
  padding: 24px 28px;
  border-radius: 0 8px 8px 0;
  margin-bottom: 32px;
  transition: background 0.3s;
}

.abstract-text {
  font-size: 15px;
  line-height: 1.7;
}

.keywords {
  font-family: var(--font-sans);
  font-size: 12px;
  margin-top: 16px;
  padding-top: 12px;
  border-top: 1px solid var(--paper-border);
  color: var(--paper-text-dim);
}

.kw-label {
  font-weight: 600;
}

/* Figures */
.paper-figure {
  margin: 32px 0;
  text-align: center;
}

.paper-figure.figure-wide {
  margin-left: -40px;
  margin-right: -40px;
}

.figure-img-container {
  background: #f0ede6;
  border: 1px solid var(--paper-border);
  border-radius: 6px;
  overflow: hidden;
  position: relative;
  min-height: 200px;
  transition: background 0.3s, border-color 0.3s;
}

body.dark .figure-img-container {
  background: #252528;
}

.figure-img {
  width: 100%;
  display: block;
  transition: opacity 0.5s;
}

.figure-img[loading] {
  opacity: 0;
}

.figure-img.loaded {
  opacity: 1;
}

figcaption, .sim-caption {
  font-family: var(--font-sans);
  font-size: 12.5px;
  color: var(--paper-text-dim);
  text-align: left;
  margin-top: 10px;
  line-height: 1.6;
  padding: 0 4px;
}

/* Tables */
.table-container {
  overflow-x: auto;
  margin: 24px 0;
}

.paper-table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--font-sans);
  font-size: 13.5px;
}

.paper-table caption {
  text-align: left;
  font-size: 12.5px;
  color: var(--paper-text-dim);
  margin-bottom: 8px;
}

.paper-table th {
  background: var(--paper-table-header);
  font-weight: 600;
  text-align: left;
  padding: 10px 14px;
  border-bottom: 2px solid var(--paper-accent);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  transition: background 0.3s;
}

.paper-table td {
  padding: 9px 14px;
  border-bottom: 1px solid var(--paper-border);
  vertical-align: top;
  transition: border-color 0.3s;
}

.paper-table tbody tr:nth-child(even) {
  background: var(--paper-table-stripe);
}

.paper-table .table-total td {
  border-top: 2px solid var(--paper-text);
  font-weight: 700;
}

/* Equations */
.equation-block {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 24px;
  margin: 20px 0;
  padding: 16px;
  background: var(--paper-code-bg);
  border-radius: 6px;
  transition: background 0.3s;
}

.equation {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--paper-text);
}

.equation-number {
  font-family: var(--font-serif);
  font-size: 14px;
  color: var(--paper-text-dim);
}

/* Callouts */
.callout-box {
  display: flex;
  gap: 14px;
  padding: 18px 20px;
  border-left: 3px solid var(--paper-callout-border);
  background: var(--paper-callout-bg);
  border-radius: 0 8px 8px 0;
  margin: 24px 0;
  transition: background 0.3s, border-color 0.3s;
}

.callout-box.callout-info {
  border-left-color: var(--paper-info-border);
  background: var(--paper-info-bg);
}

.callout-icon {
  font-size: 20px;
  flex-shrink: 0;
  margin-top: 2px;
}

.callout-text {
  font-size: 14px;
  line-height: 1.6;
  color: var(--paper-text);
}

/* Lists */
.paper-list {
  margin: 12px 0 20px 24px;
  font-size: 16px;
}

.paper-list li {
  margin-bottom: 10px;
  padding-left: 4px;
}

/* Citations */
.cite {
  color: var(--paper-link);
  text-decoration: none;
  font-family: var(--font-sans);
  font-size: 13px;
}

.cite:hover {
  text-decoration: underline;
}

/* References */
.references-list {
  font-family: var(--font-sans);
  font-size: 12.5px;
  line-height: 1.65;
  color: var(--paper-text-dim);
  padding-left: 28px;
}

.references-list li {
  margin-bottom: 8px;
  padding-left: 4px;
}

/* Acknowledgments */
.acknowledgments, .appendix {
  font-size: 15px;
  color: var(--paper-text-dim);
}

.acknowledgments h2, .appendix h2 {
  font-size: 20px;
}

/* 3D Simulation container */
.simulation-container {
  position: relative;
  background: var(--paper-sim-bg);
  border: 1px solid var(--paper-border);
  border-radius: 8px;
  overflow: hidden;
  margin: 24px -40px;
  height: 500px;
}

#scene-container {
  width: 100%;
  height: 100%;
}

#scene-container canvas {
  display: block;
}

#sim-controls {
  position: absolute;
  bottom: 16px;
  left: 16px;
  right: 16px;
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  z-index: 10;
  pointer-events: none;
}

.sim-control-group {
  display: flex;
  gap: 10px;
  align-items: center;
  pointer-events: auto;
}

.sim-btn {
  font-family: var(--font-sans);
  font-size: 12px;
  padding: 8px 16px;
  background: rgba(30, 28, 24, 0.85);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 225, 53, 0.2);
  border-radius: 6px;
  color: #FFE135;
  cursor: pointer;
  letter-spacing: 1px;
  transition: all 0.2s;
}

.sim-btn:hover {
  background: rgba(255, 225, 53, 0.15);
}

.sim-btn:active {
  transform: scale(0.96);
}

.sim-toggle {
  display: flex;
  align-items: center;
  gap: 8px;
  background: rgba(30, 28, 24, 0.85);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 225, 53, 0.12);
  border-radius: 6px;
  padding: 6px 14px;
  cursor: pointer;
}

.sim-toggle input {
  display: none;
}

.sim-toggle-slider {
  width: 32px;
  height: 16px;
  border-radius: 8px;
  background: rgba(255,255,255,0.15);
  position: relative;
  transition: background 0.3s;
}

.sim-toggle-slider::before {
  content: '';
  position: absolute;
  top: 2px;
  left: 2px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: #888;
  transition: all 0.3s;
}

.sim-toggle input:checked + .sim-toggle-slider {
  background: rgba(76, 175, 80, 0.4);
}

.sim-toggle input:checked + .sim-toggle-slider::before {
  transform: translateX(16px);
  background: #4CAF50;
}

.sim-toggle-label {
  font-family: var(--font-sans);
  font-size: 11px;
  color: rgba(255, 248, 220, 0.6);
  letter-spacing: 1px;
  text-transform: uppercase;
}

.sim-hint {
  font-family: var(--font-sans);
  font-size: 11px;
  color: rgba(255, 248, 220, 0.4);
  letter-spacing: 1.5px;
  text-transform: uppercase;
  pointer-events: none;
  transition: opacity 1s;
}

/* Detail panel (in 3D viewer) */
.detail-panel {
  position: absolute;
  top: 50%;
  right: 16px;
  transform: translateY(-50%) translateX(0);
  width: 280px;
  background: rgba(30, 28, 24, 0.92);
  backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 225, 53, 0.15);
  border-radius: 12px;
  padding: 24px 22px;
  z-index: 20;
  transition: transform 0.4s cubic-bezier(0.22, 1, 0.36, 1), opacity 0.4s ease;
  opacity: 1;
  color: #FFF8DC;
}

.detail-panel.hidden {
  transform: translateY(-50%) translateX(350px);
  opacity: 0;
  pointer-events: none;
}

.detail-close {
  position: absolute;
  top: 8px;
  right: 12px;
  background: none;
  border: none;
  color: rgba(255, 248, 220, 0.5);
  font-size: 22px;
  cursor: pointer;
  transition: color 0.2s;
}

.detail-close:hover {
  color: #FFE135;
}

.detail-icon {
  font-size: 32px;
  margin-bottom: 8px;
}

.detail-name {
  font-family: var(--font-serif);
  font-size: 20px;
  color: #FFE135;
  margin-bottom: 8px;
  border: none;
  padding: 0;
}

.detail-material {
  font-family: var(--font-sans);
  font-size: 10px;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: #FFBF00;
  margin-bottom: 12px;
  padding-bottom: 12px;
  border-bottom: 1px solid rgba(255, 225, 53, 0.1);
}

.detail-desc {
  font-family: var(--font-sans);
  font-size: 13px;
  line-height: 1.65;
  color: #FFF8DC;
  font-weight: 300;
  text-align: left;
}

/* Ripeness demo */
.ripeness-demo {
  background: var(--paper-code-bg);
  border: 1px solid var(--paper-border);
  border-radius: 8px;
  padding: 24px 28px;
  margin: 28px 0;
  transition: background 0.3s, border-color 0.3s;
}

.ripeness-demo-desc {
  font-family: var(--font-sans);
  font-size: 13px;
  color: var(--paper-text-dim);
  margin-bottom: 16px;
  text-align: left;
}

.ripeness-gauge {
  max-width: 500px;
  margin: 0 auto;
}

.ripeness-labels {
  display: flex;
  justify-content: space-between;
  font-family: var(--font-sans);
  font-size: 10px;
  color: var(--paper-text-dim);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 8px;
  text-align: center;
}

.ripeness-track {
  width: 100%;
  height: 12px;
  border-radius: 6px;
  background: linear-gradient(90deg, #2d6a2e, #4CAF50, #FFE135, #FFBF00, #8B6914, #5C4033);
  position: relative;
  margin-bottom: 16px;
  box-shadow: inset 0 1px 3px rgba(0,0,0,0.2);
}

.ripeness-fill {
  display: none;
}

.ripeness-indicator {
  position: absolute;
  top: 50%;
  transform: translate(-50%, -50%);
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: #fff;
  border: 2px solid var(--paper-accent);
  box-shadow: 0 0 8px rgba(255, 225, 53, 0.5), 0 2px 4px rgba(0,0,0,0.2);
  transition: left 0.5s ease;
}

.ripeness-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.drive-btn {
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 1px;
  padding: 10px 24px;
  border: 1px solid var(--paper-accent);
  border-radius: 6px;
  background: rgba(184, 134, 11, 0.08);
  color: var(--paper-accent);
  cursor: pointer;
  transition: all 0.25s;
}

.drive-btn:hover {
  background: rgba(184, 134, 11, 0.18);
  box-shadow: 0 0 16px rgba(184, 134, 11, 0.15);
}

.drive-btn:active {
  transform: scale(0.97);
}

.ripeness-value {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--paper-text-dim);
}

/* Footer */
#footer {
  text-align: center;
  padding: 24px 20px;
  margin-left: var(--nav-width);
  border-top: 1px solid var(--paper-border);
  transition: border-color 0.3s;
}

#footer p {
  font-family: var(--font-sans);
  font-size: 11px;
  color: var(--paper-text-dim);
  text-align: center;
}

#footer a {
  color: var(--paper-link);
  text-decoration: none;
  transition: color 0.3s;
}

#footer a:hover {
  text-decoration: underline;
}

.footer-tiny {
  font-size: 10px !important;
  margin-top: 4px;
  font-style: italic;
}

/* Mobile */
@media (max-width: 900px) {
  #paper-nav {
    display: none;
  }

  #paper {
    margin-left: 0;
  }

  #footer {
    margin-left: 0;
  }

  article {
    padding: 32px 20px 60px;
  }

  .paper-title {
    font-size: 22px;
  }

  .paper-figure.figure-wide {
    margin-left: -20px;
    margin-right: -20px;
  }

  .simulation-container {
    margin-left: -20px;
    margin-right: -20px;
    height: 400px;
  }

  .authors {
    flex-direction: column;
    gap: 4px;
  }

  .paper-meta-block {
    flex-direction: column;
    gap: 4px;
  }

  .detail-panel {
    width: calc(100% - 24px);
    right: 12px;
    top: auto;
    bottom: 60px;
    transform: translateY(0);
    max-height: 240px;
    overflow-y: auto;
  }

  .detail-panel.hidden {
    transform: translateY(350px);
  }

  h2 {
    font-size: 19px;
  }

  .equation-block {
    flex-direction: column;
    gap: 8px;
    padding: 12px;
  }

  .equation {
    font-size: 12px;
  }

  .paper-table {
    font-size: 12px;
  }

  .paper-table th, .paper-table td {
    padding: 6px 8px;
  }
}

@media (max-width: 600px) {
  .paper-title {
    font-size: 19px;
  }

  body {
    font-size: 15.5px;
  }

  .simulation-container {
    height: 320px;
  }

  .sim-control-group {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }

  .ripeness-gauge {
    max-width: 100%;
  }
}

/* Scrollbar styling */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--paper-bg);
}

::-webkit-scrollbar-thumb {
  background: var(--paper-border);
  border-radius: 4px;
}

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

/* Image loading animation */
.figure-img-container::before {
  content: 'Loading figure...';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-family: var(--font-sans);
  font-size: 12px;
  color: var(--paper-text-dim);
  letter-spacing: 1px;
}

/* Selection color */
::selection {
  background: rgba(218, 165, 32, 0.25);
}