/* ===== Apple-Style Design System ===== */

* {
  box-sizing: border-box;
}

:root {
  --apple-gray-50: #fafafa;
  --apple-gray-100: #f5f5f7;
  --apple-gray-200: #e8e8ed;
  --apple-gray-300: #d2d2d7;
  --apple-gray-400: #86868b;
  --apple-gray-500: #6e6e73;
  --apple-gray-600: #424245;
  --apple-gray-900: #1d1d1f;
  --apple-blue: #0071e3;
  --apple-blue-hover: #0077ed;
  --apple-accent: #06c;
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.12);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Inter', 'SF Pro Display', 'Segoe UI', 'Roboto', sans-serif;
  background: var(--apple-gray-50);
  color: var(--apple-gray-900);
  margin: 0;
  padding: 0;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ===== Apple Navigation ===== */

.apple-header {
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--apple-gray-200);
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: var(--shadow-sm);
}

.apple-nav {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 48px;
  gap: 32px;
}

.nav-logo a {
  font-size: 21px;
  font-weight: 600;
  color: var(--apple-gray-900);
  text-decoration: none;
  letter-spacing: -0.5px;
}

.nav-links {
  display: flex;
  gap: 32px;
  align-items: center;
}

.nav-link {
  color: var(--apple-gray-600);
  text-decoration: none;
  font-size: 14px;
  font-weight: 400;
  transition: color 0.2s ease;
  position: relative;
}

.nav-link:hover {
  color: var(--apple-gray-900);
}

.nav-link.active {
  color: var(--apple-gray-900);
  font-weight: 500;
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -16px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--apple-gray-900);
}

/* ===== Navigation Icons ===== */

.nav-icons {
  display: flex;
  gap: 16px;
  align-items: center;
  margin-left: auto;
}

.nav-icon {
  color: var(--apple-gray-600);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 6px;
  transition: all 0.2s ease;
  text-decoration: none;
}

.nav-icon:hover {
  color: var(--apple-gray-900);
  background: var(--apple-gray-100);
}

.nav-icon svg {
  width: 20px;
  height: 20px;
}

/* ===== Main Content ===== */

.apple-main {
  max-width: 980px;
  margin: 0 auto;
  padding: 60px 20px 80px;
}

/* ===== Typography ===== */

h1 {
  font-size: 56px;
  line-height: 1.07;
  font-weight: 600;
  letter-spacing: -0.005em;
  color: var(--apple-gray-900);
  margin: 0 0 0.4em 0;
}

h2 {
  font-size: 40px;
  line-height: 1.1;
  font-weight: 600;
  letter-spacing: -0.003em;
  color: var(--apple-gray-900);
  margin: 2.5em 0 0.5em 0;
}

h3 {
  font-size: 28px;
  line-height: 1.14;
  font-weight: 600;
  letter-spacing: 0.007em;
  color: var(--apple-gray-900);
  margin: 2em 0 0.5em 0;
}

h4 {
  font-size: 21px;
  line-height: 1.19;
  font-weight: 600;
  letter-spacing: 0.011em;
  color: var(--apple-gray-900);
  margin: 1.8em 0 0.5em 0;
}

h5 {
  font-size: 17px;
  line-height: 1.23;
  font-weight: 600;
  letter-spacing: -0.022em;
  color: var(--apple-gray-900);
  margin: 1.5em 0 0.3em 0;
}

p {
  font-size: 17px;
  line-height: 1.47;
  font-weight: 400;
  letter-spacing: -0.022em;
  color: var(--apple-gray-600);
  margin: 0 0 1.2em 0;
}

a {
  color: var(--apple-blue);
  text-decoration: none;
  transition: color 0.15s ease;
}

a:hover {
  color: var(--apple-blue-hover);
  text-decoration: underline;
}

/* ===== Images and Media ===== */

img {
  max-width: 100%;
  height: auto;
  border-radius: 12px;
  margin: 2em 0;
}

video {
  max-width: 100%;
  height: auto;
  border-radius: 12px;
  margin: 2em 0;
}

/* ===== Code Blocks ===== */

pre {
  background: var(--apple-gray-100);
  border-radius: 12px;
  padding: 20px 24px;
  overflow-x: auto;
  font-family: 'SF Mono', 'Menlo', 'Monaco', 'Courier New', monospace;
  font-size: 14px;
  line-height: 1.6;
  margin: 2em 0;
}

code {
  font-family: 'SF Mono', 'Menlo', 'Monaco', 'Courier New', monospace;
  font-size: 0.92em;
  background: var(--apple-gray-100);
  padding: 2px 6px;
  border-radius: 4px;
}

pre code {
  background: none;
  padding: 0;
}

/* ===== BibTeX Block ===== */

.bibtex-block {
  position: relative;
  background: var(--apple-gray-100);
  border: 1px solid var(--apple-gray-200);
  border-radius: 12px;
  padding: 24px;
  margin: 2em 0;
  overflow: auto;
}

.bibtex-block pre {
  margin: 0;
  padding: 0;
  background: none;
  white-space: pre-wrap;
  word-wrap: break-word;
}

.bibtex-block code {
  display: block;
  background: none;
  padding: 0;
  font-size: 13px;
  line-height: 1.6;
  color: var(--apple-gray-900);
}

.bibtex-block .copy-btn {
  position: absolute;
  top: 16px;
  right: 16px;
  padding: 6px 16px;
  background: var(--apple-blue);
  color: white;
  border: none;
  border-radius: 980px;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.15s ease;
  letter-spacing: -0.02em;
}

.bibtex-block .copy-btn:hover {
  background: var(--apple-blue-hover);
}

/* ===== Lists ===== */

ul, ol {
  font-size: 17px;
  line-height: 1.47;
  letter-spacing: -0.022em;
  color: var(--apple-gray-600);
  margin: 0 0 1.5em 0;
  padding-left: 1.5em;
}

li {
  margin-bottom: 0.5em;
}

/* ===== Team Section Grid ===== */

.row {
  display: flex;
  flex-wrap: wrap;
  margin: 40px 0;
  justify-content: center;
  gap: 20px;
}

[class^="col-"] {
  padding: 10px;
  text-align: center;
}

.col-md-1 {
  flex: 0 0 8%;
  max-width: 8%;
}

.col-md-2 {
  flex: 0 0 16.66%;
  max-width: 16.66%;
}

.col-md-3 {
  flex: 0 0 25%;
  max-width: 25%;
}

.col-md-2 img,
.col-md-3 img {
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.col-md-2 img:hover,
.col-md-3 img:hover {
  transform: scale(1.05);
  box-shadow: var(--shadow-md);
}

/* ===== Footer ===== */

.apple-footer {
  background: var(--apple-gray-100);
  border-top: 1px solid var(--apple-gray-200);
  margin-top: 100px;
  padding: 40px 0;
}

.footer-content {
  max-width: 980px;
  margin: 0 auto;
  padding: 0 20px;
  text-align: center;
}

.footer-content p {
  font-size: 14px;
  line-height: 1.5;
  color: var(--apple-gray-500);
  margin: 0;
}

/* ===== Horizontal Rules ===== */

hr {
  border: none;
  border-top: 1px solid var(--apple-gray-200);
  margin: 3em 0;
}

/* ===== Blockquotes ===== */

blockquote {
  border-left: 3px solid var(--apple-gray-300);
  padding-left: 20px;
  margin: 2em 0;
  font-style: italic;
  color: var(--apple-gray-500);
}

/* ===== Tables ===== */

table {
  width: 100%;
  border-collapse: collapse;
  margin: 2em 0;
  font-size: 15px;
}

th, td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: 1px solid var(--apple-gray-200);
}

th {
  font-weight: 600;
  color: var(--apple-gray-900);
  background: var(--apple-gray-100);
}

td {
  color: var(--apple-gray-600);
}

/* ===== Responsive Design ===== */

@media (max-width: 1068px) {
  h1 {
    font-size: 48px;
  }
  
  h2 {
    font-size: 32px;
  }
  
  h3 {
    font-size: 24px;
  }
}

@media (max-width: 768px) {
  .apple-nav {
    gap: 16px;
  }
  
  .nav-links {
    gap: 16px;
  }
  
  .nav-link {
    font-size: 13px;
  }
  
  .nav-icons {
    gap: 12px;
  }
  
  .nav-icon {
    width: 28px;
    height: 28px;
  }
  
  .nav-icon svg {
    width: 18px;
    height: 18px;
  }
  
  .apple-main {
    padding: 40px 20px 60px;
  }
  
  h1 {
    font-size: 40px;
  }
  
  h2 {
    font-size: 28px;
  }
  
  h3 {
    font-size: 21px;
  }
  
  p, ul, ol {
    font-size: 16px;
  }
  
  .col-md-1,
  .col-md-2,
  .col-md-3 {
    flex: 0 0 100%;
    max-width: 100%;
  }
}

@media (max-width: 480px) {
  .apple-nav {
    flex-wrap: wrap;
    height: auto;
    padding: 12px 20px;
    gap: 12px;
  }
  
  .nav-logo {
    width: 100%;
    text-align: center;
  }
  
  .nav-links {
    flex: 1;
    flex-wrap: wrap;
    justify-content: center;
    gap: 12px;
  }
  
  .nav-icons {
    gap: 12px;
    margin-left: 0;
  }
  
  h1 {
    font-size: 32px;
  }
}