/* ============================================
   CHRIS YANG PORTFOLIO — GLOBAL STYLES
   ============================================ */

@import url('https://fonts.googleapis.com/css2?family=DM+Serif+Display:ital@0;1&family=DM+Sans:wght@300;400;500;600&display=swap');

/* ── CSS Variables ── */
:root {
  --white: #ffffff;
  --off-white: #f8f8f6;
  --light-gray: #f0f0ee;
  --mid-gray: #e0e0dc;
  --text-muted: #8a8a85;
  --text-body: #3a3a38;
  --text-dark: #1a1a18;
  --teal: #2ab5b5;
  --teal-dark: #1f9494;
  --teal-light: rgba(42, 181, 181, 0.1);
  --serif: 'DM Serif Display', Georgia, serif;
  --sans: 'DM Sans', system-ui, sans-serif;
  --nav-h: 72px;
  --max-w: 960px;
  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }
body {
  font-family: var(--sans);
  color: var(--text-body);
  background: var(--white);
  line-height: 1.6;
  opacity: 1;
  transition: opacity 0.3s ease;
}
body.page-exit { opacity: 0; }
body.page-enter { animation: fadeIn 0.4s ease forwards; }

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }

/* ── Navigation ── */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--mid-gray);
  z-index: 100;
  display: flex;
  align-items: center;
}
.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  font-size: 1rem;
  color: var(--text-dark);
  letter-spacing: -0.01em;
}
.nav-logo-icon {
  width: 22px; height: 22px;
  display: block;
  object-fit: contain;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Works dropdown */
.nav-dropdown { position: relative; }
.nav-dropdown-trigger {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 8px 12px;
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--text-body);
  cursor: pointer;
  border-radius: 6px;
  transition: background var(--transition);
  user-select: none;
}
.nav-dropdown-trigger:hover { background: var(--light-gray); }
.nav-dropdown-trigger svg {
  transition: transform var(--transition);
  flex-shrink: 0;
}
.nav-dropdown.open .nav-dropdown-trigger svg { transform: rotate(180deg); }

.nav-dropdown-menu {
  position: absolute;
  top: calc(100% + 8px);
  left: 0;
  background: var(--white);
  border: 1px solid var(--mid-gray);
  border-radius: 10px;
  box-shadow: 0 16px 48px rgba(0,0,0,0.08), 0 4px 16px rgba(0,0,0,0.04);
  min-width: 240px;
  overflow: hidden;
  opacity: 0;
  pointer-events: none;
  transform: translateY(-6px);
  transition: opacity 0.2s ease, transform 0.2s ease;
  z-index: 200;
}
.nav-dropdown.open .nav-dropdown-menu {
  opacity: 1;
  pointer-events: all;
  transform: translateY(0);
}
.nav-dropdown-item {
  display: block;
  padding: 12px 16px;
  font-size: 0.875rem;
  border-bottom: 1px solid var(--light-gray);
  transition: background var(--transition);
}
.nav-dropdown-item:last-child { border-bottom: none; }
.nav-dropdown-item:hover { background: var(--off-white); }
.nav-dropdown-item-title {
  font-weight: 500;
  color: var(--text-dark);
  display: block;
}
.nav-dropdown-item-sub {
  font-size: 0.8125rem;
  color: var(--text-muted);
  display: block;
  margin-top: 1px;
}

.nav-resume {
  padding: 8px 12px;
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--text-body);
  border-radius: 6px;
  transition: background var(--transition);
}
.nav-resume:hover { background: var(--light-gray); }

.nav-cta {
  padding: 9px 18px;
  background: var(--teal);
  color: white;
  font-size: 0.9375rem;
  font-weight: 500;
  border-radius: 7px;
  transition: background var(--transition), transform var(--transition);
}
.nav-cta:hover { background: var(--teal-dark); transform: translateY(-1px); }

/* Mobile nav toggle */
.nav-mobile-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
}
.nav-mobile-toggle span {
  width: 22px; height: 2px;
  background: var(--text-dark);
  border-radius: 2px;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

/* ── Page Wrapper ── */
.page { padding-top: var(--nav-h); min-height: 100vh; }
.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}

/* ── HOME PAGE ── */
.hero {
  padding: 72px 0 56px;
  animation: fadeIn 0.6s ease both;
}
.hero-avatar {
  width: 140px; height: 140px;
  border-radius: 50%;
  overflow: hidden;
  margin-bottom: 28px;
  filter: grayscale(100%);
  border: 2px solid var(--mid-gray);
}
.hero-avatar img { width: 100%; height: 100%; object-fit: cover; object-position: center top; }
.hero h1 {
  font-family: var(--serif);
  font-size: clamp(2.75rem, 8vw, 6.25rem);
  font-weight: 400;
  color: var(--text-dark);
  line-height: 1.05;
  letter-spacing: -0.02em;
  margin-bottom: 28px;
  animation: fadeIn 0.6s 0.1s ease both;
}
.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 24px;
  animation: fadeIn 0.6s 0.2s ease both;
}
.hero-meta-item {
  display: flex;
  align-items: center;
  gap: 7px;
  font-size: 1.5rem;
  font-weight: 300;
  color: var(--text-muted);
}
.hero-meta-item svg { flex-shrink: 0; opacity: 0.6; }
.hero-meta-item a:hover { color: var(--teal); }

.works-section { padding: 48px 0 80px; }
.works-section-title {
  font-size: 1.0625rem;
  font-weight: 400;
  color: var(--text-muted);
  margin-bottom: 36px;
  animation: fadeIn 0.6s 0.25s ease both;
}
.works-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
  animation: fadeIn 0.6s 0.3s ease both;
}
.work-card {
  cursor: pointer;
  transition: transform 0.3s ease;
}
.work-card:hover { transform: translateY(-4px); }
.work-card-img {
  width: 100%;
  aspect-ratio: 4/3;
  object-fit: cover;
  border-radius: 10px;
  margin-bottom: 14px;
  background: var(--light-gray);
  opacity: 0;
  transform: scale(1.08);
  transition: opacity 0.6s ease, transform 0.6s ease, box-shadow 0.3s ease;
}
.work-card-img.in-view { opacity: 1; transform: scale(1); }
.work-card:nth-child(2n) .work-card-img { transition-delay: 1s; }
.work-card:hover .work-card-img { box-shadow: 0 12px 32px rgba(0,0,0,0.12); }
.work-card-title {
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-dark);
  margin-bottom: 3px;
}
.work-card-sub {
  font-size: 0.875rem;
  color: var(--text-muted);
}

/* ── CASE STUDY PAGES ── */
.back-home-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-muted);
  letter-spacing: 0.02em;
  margin-top: 32px;
  transition: color var(--transition);
}
.back-home-link:hover { color: var(--text-dark); }
.case-hero {
  padding: 64px 0 48px;
  border-bottom: 1px solid var(--mid-gray);
  margin-bottom: 56px;
  animation: fadeIn 0.5s ease both;
}
.case-hero-eyebrow {
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--teal);
  margin-bottom: 12px;
}
.case-hero h1 {
  font-family: var(--serif);
  font-size: clamp(2.25rem, 5vw, 3.5rem);
  font-weight: 400;
  color: var(--text-dark);
  line-height: 1.1;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}
.case-hero-sub {
  font-size: 1.125rem;
  color: var(--text-muted);
  font-weight: 300;
}
.case-hero-img {
  width: 100%;
  border-radius: 12px;
  margin-top: 40px;
  box-shadow: 0 4px 24px rgba(0,0,0,0.08);
}

.case-body { padding-bottom: 96px; animation: fadeIn 0.5s 0.15s ease both; }
.case-section { margin-bottom: 56px; }
.case-section h3 {
  font-family: var(--serif);
  font-size: 1.5rem;
  font-weight: 400;
  color: var(--text-dark);
  margin-bottom: 16px;
  letter-spacing: -0.01em;
}
.case-section p {
  font-size: 1rem;
  line-height: 1.75;
  color: var(--text-body);
  margin-bottom: 16px;
}
.case-section p:last-child { margin-bottom: 0; }
.case-section ul, .case-section ol {
  padding-left: 20px;
  margin-bottom: 16px;
}
.case-section li {
  font-size: 1rem;
  line-height: 1.75;
  color: var(--text-body);
  margin-bottom: 4px;
}
.case-section strong { font-weight: 600; color: var(--text-dark); }
.case-section a { color: var(--teal); text-decoration: underline; text-underline-offset: 3px; }
.case-section a:hover { color: var(--teal-dark); }

.case-img-block { margin: 32px 0; }
.case-img-block img {
  width: 100%;
  border-radius: 10px;
  border: 1px solid var(--mid-gray);
}
.case-img-caption {
  font-size: 0.8125rem;
  color: var(--text-muted);
  margin-top: 10px;
  font-style: italic;
}

.cta-block {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--off-white);
  border-radius: 12px;
  padding: 32px 36px;
  margin-top: 56px;
  gap: 24px;
}
.cta-block h3 {
  font-family: var(--serif);
  font-size: 1.375rem;
  color: var(--text-dark);
  margin-bottom: 6px;
  font-weight: 400;
}
.cta-block p { font-size: 0.9375rem; color: var(--text-muted); margin: 0; }
.cta-link {
  padding: 12px 24px;
  background: var(--teal);
  color: white;
  border-radius: 7px;
  font-weight: 500;
  font-size: 0.9375rem;
  white-space: nowrap;
}
.cta-link:hover { background: var(--teal-dark); }

.case-divider {
  border: none;
  border-top: 1px solid var(--mid-gray);
  margin: 48px 0;
}

/* Results callout */
.results-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin: 24px 0;
}
.result-stat {
  background: var(--off-white);
  border-radius: 10px;
  padding: 24px;
  text-align: center;
}
.result-stat-num {
  font-family: var(--serif);
  font-size: 2.25rem;
  color: var(--teal);
  display: block;
  margin-bottom: 6px;
}
.result-stat-label {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.4;
}

/* Testimonial */
.testimonial {
  background: var(--off-white);
  border-left: 3px solid var(--teal);
  border-radius: 0 8px 8px 0;
  padding: 20px 24px;
  margin: 24px 0;
}
.testimonial p {
  font-style: italic;
  font-size: 1rem;
  color: var(--text-body);
  margin-bottom: 8px !important;
}
.testimonial cite {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
  font-style: normal;
}

/* Prototype button */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 22px;
  background: var(--teal);
  color: white;
  font-size: 0.9375rem;
  font-weight: 500;
  border-radius: 7px;
  transition: background var(--transition), transform var(--transition);
  margin-top: 8px;
}
.btn-primary:hover { background: var(--teal-dark); transform: translateY(-1px); }

/* ── CONTACT PAGE ── */
.contact-hero {
  padding: 72px 0 48px;
  animation: fadeIn 0.5s ease both;
}
.contact-hero h1 {
  font-family: var(--serif);
  font-size: clamp(3rem, 6vw, 4.5rem);
  font-weight: 400;
  color: var(--text-dark);
  line-height: 1.05;
  letter-spacing: -0.02em;
  margin-bottom: 14px;
}
.contact-hero p {
  font-size: 1.0625rem;
  color: var(--text-muted);
  margin-bottom: 40px;
}
.contact-form {
  max-width: 560px;
  animation: fadeIn 0.5s 0.15s ease both;
}
.form-group { margin-bottom: 20px; }
.form-group label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-dark);
  margin-bottom: 6px;
}
.form-group input,
.form-group textarea {
  width: 100%;
  padding: 11px 14px;
  border: 1px solid var(--mid-gray);
  border-radius: 7px;
  font-family: var(--sans);
  font-size: 0.9375rem;
  color: var(--text-dark);
  background: var(--white);
  transition: border-color var(--transition), box-shadow var(--transition);
  outline: none;
  resize: vertical;
}
.form-group input:focus,
.form-group textarea:focus {
  border-color: var(--teal);
  box-shadow: 0 0 0 3px var(--teal-light);
}
.form-group textarea { min-height: 140px; }
.form-submit {
  width: 100%;
  padding: 13px;
  background: var(--teal);
  color: white;
  border: none;
  border-radius: 7px;
  font-family: var(--sans);
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition: background var(--transition), transform var(--transition);
}
.form-submit:hover { background: var(--teal-dark); transform: translateY(-1px); }
.form-success {
  display: none;
  padding: 16px;
  background: var(--teal-light);
  border: 1px solid var(--teal);
  border-radius: 7px;
  color: var(--teal-dark);
  font-weight: 500;
  margin-top: 16px;
  font-size: 0.9375rem;
}

/* ── FOOTER ── */
.footer {
  border-top: 1px solid var(--mid-gray);
  padding: 24px 0;
  margin-top: auto;
}
.footer-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}
.footer-copy {
  font-size: 0.875rem;
  color: var(--text-muted);
}
.footer-copy a { color: var(--teal); }
.footer-links {
  display: flex;
  align-items: center;
  gap: 20px;
}
.footer-links a {
  font-size: 0.875rem;
  color: var(--text-muted);
  transition: color var(--transition);
}
.footer-links a:hover { color: var(--text-dark); }

/* ── MOBILE ── */
@media (max-width: 680px) {
  .nav-links { display: none; }
  .nav-links.mobile-open {
    display: flex;
    flex-direction: column;
    position: fixed;
    top: var(--nav-h);
    left: 0; right: 0;
    background: var(--white);
    border-bottom: 1px solid var(--mid-gray);
    padding: 16px 24px 24px;
    gap: 4px;
    align-items: stretch;
    box-shadow: 0 8px 24px rgba(0,0,0,0.08);
  }
  .nav-mobile-toggle { display: flex; }
  .nav-dropdown-trigger { padding: 10px 12px; }
  .nav-dropdown-menu { position: static; box-shadow: none; border: none; border-radius: 0; opacity: 1; pointer-events: all; transform: none; padding-left: 12px; display: none; }
  .nav-dropdown.open .nav-dropdown-menu { display: block; }
  .nav-resume, .nav-cta { padding: 10px 12px; }

  .works-grid { grid-template-columns: 1fr; gap: 28px; }
  .results-grid { grid-template-columns: 1fr; gap: 16px; }

  .hero { padding: 48px 0 40px; }
  .case-hero { padding: 48px 0 36px; }
  .contact-hero { padding: 48px 0 36px; }
  .cta-block { flex-direction: column; align-items: flex-start; }
}