/* ================================================
   BRANDON LIU — Personal Website
   Palette: Warm cream / Dark green / Burnt orange
   Aesthetic: Flat, restrained, editorial
   ================================================ */

:root {
  --bg:       #F7F4EE;
  --bg-alt:   #EFEBE3;
  --text:     #1B2B1B;
  --text-mid: #4A5D4A;
  --text-dim: #7A8A7A;
  --green:    #2D4A2D;
  --orange:   #C06030;
  --orange-bg:#FDF0E8;
  --line:     #D8D2C6;
  --surface:  #FFFFFF;
  --font-sans: 'Inter', -apple-system, sans-serif;
  --font-serif: 'Crimson Pro', Georgia, serif;
}

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

::selection {
  background: var(--orange);
  color: #fff;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-serif);
  font-size: 18px;
  line-height: 1.75;
  overflow-x: hidden;
}

/* ---- Top Navigation ---- */
#top-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 48px;
  height: 60px;
  background: var(--bg);
  border-bottom: 1px solid var(--line);
  font-family: var(--font-sans);
  font-size: 13px;
}

.nav-logo {
  font-weight: 600;
  font-size: 14px;
  color: var(--text);
  text-decoration: none;
  letter-spacing: -0.3px;
}

.nav-links {
  display: flex;
  gap: 28px;
}

.nav-links a {
  color: var(--text-dim);
  text-decoration: none;
  font-weight: 400;
  transition: color 0.2s;
}

.nav-links a:hover {
  color: var(--green);
}

.nav-contact {
  padding: 6px 16px;
  border: 1px solid var(--green);
  color: var(--green) !important;
  border-radius: 4px;
  font-weight: 500 !important;
  transition: all 0.2s;
}

.nav-contact:hover {
  background: var(--green);
  color: #fff !important;
}

/* ---- Container ---- */
.container {
  max-width: 780px;
  margin: 0 auto;
  padding: 0 24px;
}

.page-section {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 120px 0;
}

/* ---- Section Label ---- */
.section-label {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 52px;
  font-family: var(--font-sans);
}

.label-num {
  font-size: 12px;
  font-weight: 500;
  color: var(--orange);
  letter-spacing: 1px;
  font-variant-numeric: tabular-nums;
}

.label-text {
  font-size: 28px;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.5px;
}

/* ================================================
   HERO
   ================================================ */
#hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 0 48px;
}

.hero-inner {
  max-width: 780px;
  padding-top: 60px;
}

.hero-eyebrow {
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 500;
  color: var(--orange);
  letter-spacing: 2px;
  text-transform: uppercase;
  margin-bottom: 20px;
}

.hero-name {
  font-family: var(--font-sans);
  font-size: clamp(52px, 9vw, 96px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -3px;
  color: var(--text);
  margin-bottom: 16px;
}

.hero-sub {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: clamp(18px, 2.5vw, 24px);
  color: var(--text-dim);
  margin-bottom: 24px;
}

.hero-meta {
  font-family: var(--font-sans);
  font-size: 14px;
  color: var(--text-mid);
  display: flex;
  gap: 8px;
}

.meta-sep {
  color: var(--line);
}

/* ================================================
   ABOUT
   ================================================ */
.about-body p {
  margin-bottom: 20px;
  color: var(--text-mid);
}

.about-body p:last-child {
  margin-bottom: 0;
}

.about-body strong {
  color: var(--text);
  font-weight: 600;
}

/* ================================================
   RESEARCH
   ================================================ */
.research-list {
  display: flex;
  flex-direction: column;
}

.research-item {
  display: flex;
  gap: 24px;
  padding: 28px 0;
  border-bottom: 1px solid var(--line);
}

.research-item:first-child {
  padding-top: 0;
}

.research-item:last-child {
  border-bottom: none;
}

.research-num {
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 500;
  color: var(--orange);
  flex-shrink: 0;
  padding-top: 4px;
  width: 24px;
}

.research-item h3 {
  font-family: var(--font-sans);
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 4px;
}

.research-item p {
  font-size: 15px;
  color: var(--text-dim);
  line-height: 1.6;
}

/* ================================================
   PROJECTS
   ================================================ */
.project-list {
  display: flex;
  flex-direction: column;
}

.project-row {
  display: flex;
  gap: 24px;
  padding: 32px 0;
  border-bottom: 1px solid var(--line);
  transition: padding-left 0.2s;
}

.project-row:first-child {
  padding-top: 0;
}

.project-row:last-child {
  border-bottom: none;
}

.project-row:hover {
  padding-left: 12px;
}

.project-year {
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 500;
  color: var(--orange);
  flex-shrink: 0;
  width: 64px;
  padding-top: 3px;
}

.project-body h3 {
  font-family: var(--font-sans);
  font-size: 17px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 6px;
}

.project-body p {
  font-size: 15px;
  color: var(--text-dim);
  line-height: 1.6;
  margin-bottom: 8px;
}

.project-tag {
  font-family: var(--font-sans);
  font-size: 11px;
  font-weight: 500;
  color: var(--green);
  border: 1px solid var(--green);
  padding: 2px 8px;
  border-radius: 3px;
  margin-right: 8px;
}

.project-loc {
  font-family: var(--font-sans);
  font-size: 12px;
  color: var(--text-dim);
}

/* ================================================
   PUBLICATIONS
   ================================================ */
.pub-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.pub-row {
  display: flex;
  gap: 20px;
  padding: 28px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 6px;
  transition: border-color 0.2s;
}

.pub-row:hover {
  border-color: var(--orange);
}

.pub-tag-col {
  flex-shrink: 0;
  padding-top: 2px;
}

.pub-badge {
  font-family: var(--font-sans);
  font-size: 11px;
  font-weight: 600;
  color: var(--orange);
  border: 1px solid var(--orange);
  padding: 3px 10px;
  border-radius: 3px;
}

.pub-body h3 {
  font-family: var(--font-serif);
  font-size: 17px;
  font-weight: 600;
  color: var(--text);
  line-height: 1.4;
  margin-bottom: 8px;
}

.pub-body p {
  font-family: var(--font-sans);
  font-size: 13px;
  color: var(--text-dim);
}

/* ================================================
   TIMELINE
   ================================================ */
.timeline {
  display: flex;
  flex-direction: column;
}

.tl-row {
  display: flex;
  gap: 24px;
  padding: 24px 0;
  border-bottom: 1px solid var(--line);
}

.tl-row:first-child {
  padding-top: 0;
}

.tl-row:last-child {
  border-bottom: none;
}

.tl-year {
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 500;
  color: var(--orange);
  flex-shrink: 0;
  width: 64px;
  padding-top: 2px;
}

.tl-body h3 {
  font-family: var(--font-sans);
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 2px;
}

.tl-body p {
  font-family: var(--font-sans);
  font-size: 13px;
  color: var(--text-dim);
}

.mentor-note {
  margin-top: 40px;
  padding: 16px 20px;
  background: var(--orange-bg);
  border-left: 3px solid var(--orange);
  border-radius: 0 4px 4px 0;
  font-family: var(--font-sans);
  font-size: 14px;
  color: var(--text-mid);
}

/* ================================================
   FOOTER
   ================================================ */
#footer {
  padding: 40px 0;
  border-top: 1px solid var(--line);
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-name {
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 500;
  color: var(--text-dim);
}

.footer-links {
  display: flex;
  gap: 20px;
}

.footer-links a {
  font-family: var(--font-sans);
  font-size: 13px;
  color: var(--text-dim);
  text-decoration: none;
  transition: color 0.2s;
}

.footer-links a:hover {
  color: var(--green);
}

/* ================================================
   ANIMATIONS
   ================================================ */
.anim {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.anim.visible {
  opacity: 1;
  transform: translateY(0);
}

.stagger-in > *:nth-child(1) { transition-delay: 0s; }
.stagger-in > *:nth-child(2) { transition-delay: 0.08s; }
.stagger-in > *:nth-child(3) { transition-delay: 0.16s; }
.stagger-in > *:nth-child(4) { transition-delay: 0.24s; }
.stagger-in > *:nth-child(5) { transition-delay: 0.32s; }
.stagger-in > *:nth-child(6) { transition-delay: 0.40s; }

/* ================================================
   RESPONSIVE
   ================================================ */
@media (max-width: 768px) {
  #top-nav {
    padding: 0 20px;
  }

  .nav-links {
    gap: 16px;
    font-size: 12px;
  }

  .nav-links a:not(.nav-contact) {
    display: none;
  }

  #hero {
    padding: 0 20px;
  }

  .hero-name {
    letter-spacing: -2px;
  }

  .project-row:hover {
    padding-left: 0;
  }

  .pub-row {
    flex-direction: column;
    gap: 12px;
  }

  .page-section {
    padding: 80px 0;
  }
}

@media (max-width: 480px) {
  .hero-meta {
    flex-wrap: wrap;
  }

  .footer-inner {
    flex-direction: column;
    gap: 12px;
    align-items: flex-start;
  }
}