/* ============================================
   Kashu Yamazaki — Personal Academic Website
   Modern, minimal, responsive design
   ============================================ */

/* ---------- Reset & Base ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:       #fafafa;
  --bg-card:  #ffffff;
  --text:     #1a1a1a;
  --text-sec: #555;
  --accent:   #1b5e7a;       /* dark blue-teal */
  --accent-light: #d0e0ea;
  --border:   #e0e0e0;
  --radius:   10px;
  --shadow:   0 2px 12px rgba(0,0,0,.06);
  --max-w:    960px;
  --font:     'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --mono:     'JetBrains Mono', 'Fira Code', monospace;
  --transition: .25s ease;
}

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

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

a { color: var(--accent); text-decoration: none; transition: color var(--transition); }
a:hover { color: #134052; }

img { max-width: 100%; height: auto; display: block; }

::selection { background: var(--accent-light); color: var(--text); }

/* ---------- Navigation ---------- */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(255,255,255,.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  transition: box-shadow var(--transition);
}
.nav.scrolled { box-shadow: 0 2px 20px rgba(0,0,0,.08); }

.nav__inner {
  max-width: var(--max-w);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 1.5rem;
  height: 56px;
}

.nav__logo {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--text);
  letter-spacing: -.02em;
}
.nav__logo span { color: var(--accent); }

.nav__links { display: flex; gap: 1.8rem; list-style: none; }
.nav__links a {
  color: var(--text-sec);
  font-size: .875rem;
  font-weight: 500;
  position: relative;
  padding-bottom: 2px;
}
.nav__links a::after {
  content: '';
  position: absolute; bottom: -2px; left: 0; right: 0;
  height: 2px; background: var(--accent);
  transform: scaleX(0); transform-origin: right;
  transition: transform var(--transition);
}
.nav__links a:hover, .nav__links a.active { color: var(--text); }
.nav__links a:hover::after, .nav__links a.active::after {
  transform: scaleX(1); transform-origin: left;
}

.nav__hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  background: none; border: none; padding: 4px;
}
.nav__hamburger span {
  display: block; width: 22px; height: 2px;
  background: var(--text);
  transition: transform var(--transition), opacity var(--transition);
}
.nav__hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav__hamburger.open span:nth-child(2) { opacity: 0; }
.nav__hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- Layout ---------- */
.container { max-width: var(--max-w); margin: 0 auto; padding: 0 1.5rem; }
main { padding-top: 56px; }

section {
  padding: 4rem 0;
  border-bottom: 1px solid var(--border);
}
section:last-child { border-bottom: none; }

.section-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 2rem;
  letter-spacing: -.02em;
  display: flex;
  align-items: center;
  gap: .6rem;
}
.section-title::before {
  content: '';
  width: 4px; height: 1.3em;
  background: var(--accent);
  border-radius: 2px;
}

/* ---------- Hero / About ---------- */
.hero {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 2.5rem;
  align-items: start;
  padding: 5rem 0 3rem;
  border-bottom: 1px solid var(--border);
}

.hero__photo {
  width: 200px; height: 200px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--border);
}

.hero__content h1 {
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -.03em;
  line-height: 1.2;
  margin-bottom: .3rem;
}

.hero__content .tagline {
  color: var(--text-sec);
  font-size: 1.05rem;
  margin-bottom: 1rem;
}

.hero__content .bio {
  font-size: .95rem;
  color: var(--text-sec);
  line-height: 1.75;
  margin-bottom: 1.2rem;
}

.hero__content .bio a { font-weight: 500; }

.hero__links {
  display: flex;
  flex-wrap: wrap;
  gap: .6rem;
}

.icon-link {
  display: inline-flex;
  align-items: center;
  gap: .35rem;
  padding: .4rem .8rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: .8rem;
  font-weight: 500;
  color: var(--text-sec);
  transition: all var(--transition);
}
.icon-link:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(27,94,122,.06);
}
.icon-link svg { width: 15px; height: 15px; }

/* ---------- Interests ---------- */
.interests {
  display: flex;
  gap: .5rem;
  flex-wrap: wrap;
  margin-top: .8rem;
}
.interest-tag {
  padding: .3rem .75rem;
  background: var(--accent-light);
  color: var(--accent);
  border-radius: 20px;
  font-size: .78rem;
  font-weight: 600;
  letter-spacing: .01em;
}

/* ---------- News ---------- */
.news-list {
  max-height: 320px;
  overflow-y: auto;
  list-style: none;
  padding-right: .5rem;
}
.news-list::-webkit-scrollbar { width: 4px; }
.news-list::-webkit-scrollbar-track { background: transparent; }
.news-list::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

.news-item {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 1rem;
  padding: .7rem 0;
  border-bottom: 1px solid #f0f0f0;
  font-size: .9rem;
}
.news-item:last-child { border-bottom: none; }

.news-date {
  color: var(--text-sec);
  font-size: .82rem;
  font-weight: 500;
  font-variant-numeric: tabular-nums;
}

.news-text { line-height: 1.6; }
.news-text strong { font-weight: 600; }

/* ---------- Publications ---------- */
.pub-filter {
  display: flex;
  gap: .5rem;
  flex-wrap: wrap;
  margin-bottom: 2rem;
}
.pub-filter button {
  padding: .4rem 1rem;
  border: 1px solid var(--border);
  border-radius: 20px;
  background: transparent;
  font-size: .82rem;
  font-weight: 500;
  color: var(--text-sec);
  cursor: pointer;
  transition: all var(--transition);
  font-family: var(--font);
}
.pub-filter button.active,
.pub-filter button:hover {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

.pub-year-heading {
  font-size: 1.15rem;
  font-weight: 700;
  margin: 2rem 0 1rem;
  padding-bottom: .3rem;
  border-bottom: 2px solid var(--accent-light);
  display: inline-block;
}

.pub-card {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 1.2rem;
  padding: 1rem 0;
  border-bottom: 1px solid #f0f0f0;
  transition: background var(--transition);
}
.pub-card:last-child { border-bottom: none; }
.pub-card:hover { background: rgba(0,0,0,.015); }

.pub-card__img {
  width: 120px;
  height: 80px;
  object-fit: cover;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: #f5f5f5;
}

.pub-card__title {
  font-size: .95rem;
  font-weight: 600;
  line-height: 1.4;
  margin-bottom: .25rem;
}
.pub-card__title a { color: var(--text); }
.pub-card__title a:hover { color: var(--accent); }

.pub-card__authors {
  font-size: .82rem;
  color: var(--text-sec);
  margin-bottom: .2rem;
  line-height: 1.5;
}

.pub-card__venue {
  font-size: .8rem;
  color: var(--accent);
  font-weight: 500;
  font-style: italic;
}

.pub-card__links {
  display: flex;
  gap: .4rem;
  margin-top: .4rem;
}
.pub-card__links a {
  display: inline-flex;
  align-items: center;
  gap: .25rem;
  font-size: .75rem;
  font-weight: 500;
  padding: .2rem .55rem;
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--text-sec);
  transition: all var(--transition);
}
.pub-card__links a:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* ---------- Experience ---------- */
.exp-section { margin-bottom: 2.5rem; }

.exp-section__title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 1rem;
  color: var(--text);
}

.exp-card {
  display: grid;
  grid-template-columns: 70px 1fr;
  gap: 1.2rem;
  align-items: center;
  padding: .8rem 0;
  border-bottom: 1px solid #f0f0f0;
}
.exp-card:last-child { border-bottom: none; }

.exp-card__logo {
  width: 60px;
  height: 60px;
  object-fit: contain;
  border-radius: 8px;
  background: #fff;
  padding: 4px;
  border: 1px solid var(--border);
}

.exp-card__role { font-weight: 600; font-size: .95rem; }
.exp-card__org { color: var(--text-sec); font-size: .85rem; }
.exp-card__detail { color: var(--text-sec); font-size: .82rem; font-style: italic; }

/* ---------- Carousel ---------- */
.carousel {
  position: relative;
  display: flex;
  align-items: center;
  gap: .5rem;
}

.carousel__track-container {
  overflow: hidden;
  flex: 1;
  border-radius: var(--radius);
}

.carousel__track {
  display: flex;
  gap: 1.2rem;
  transition: transform .4s cubic-bezier(.25,.8,.25,1);
}

.carousel__slide {
  flex: 0 0 calc((100% - 2.4rem) / 3);
  min-width: 0;
}

.carousel__btn {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  border: 1px solid var(--border);
  border-radius: 50%;
  background: var(--bg-card);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition);
  color: var(--text-sec);
}
.carousel__btn:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(27,94,122,.06);
}
.carousel__btn:disabled {
  opacity: .3;
  cursor: default;
}
.carousel__btn:disabled:hover {
  border-color: var(--border);
  color: var(--text-sec);
  background: var(--bg-card);
}
.carousel__btn svg { width: 18px; height: 18px; }

.carousel__dots {
  display: flex;
  justify-content: center;
  gap: .4rem;
  margin-top: 1rem;
}
.carousel__dot {
  width: 7px; height: 7px;
  border-radius: 50%;
  background: var(--border);
  border: none;
  cursor: pointer;
  padding: 0;
  transition: background var(--transition), transform var(--transition);
}
.carousel__dot.active {
  background: var(--accent);
  transform: scale(1.3);
}

/* ---------- Projects ---------- */
.project-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: transform var(--transition), box-shadow var(--transition);
}
.project-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow);
}

.project-card__media {
  height: 160px;
  overflow: hidden;
  background: #f5f5f5;
  display: flex;
  align-items: center;
  justify-content: center;
}
.project-card__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.project-card__body { padding: 1rem 1.2rem; }
.project-card__title { font-weight: 700; font-size: 1rem; margin-bottom: .4rem; }
.project-card__desc {
  font-size: .85rem;
  color: var(--text-sec);
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 4;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.project-card__tags {
  display: flex;
  gap: .4rem;
  flex-wrap: wrap;
  padding: .6rem 1.2rem 1rem;
}

/* ---------- More / Awards ---------- */
.more-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
}

.more-block h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: .8rem;
  color: var(--text);
}

.more-block ul {
  list-style: none;
  padding: 0;
}
.more-block li {
  font-size: .88rem;
  color: var(--text-sec);
  padding: .35rem 0;
  padding-left: 1rem;
  position: relative;
  line-height: 1.6;
}
.more-block li::before {
  content: ''; position: absolute; left: 0; top: .75rem;
  width: 5px; height: 5px; border-radius: 50%;
  background: var(--accent);
}

/* ---------- Footer ---------- */
.footer {
  padding: 2rem 0;
  text-align: center;
  font-size: .82rem;
  color: var(--text-sec);
  border-top: 1px solid var(--border);
}

/* ---------- Page Header (for sub-pages) ---------- */
.page-header {
  padding: 3rem 0 1.5rem;
  border-bottom: 1px solid var(--border);
}
.page-header h1 {
  font-size: 1.8rem;
  font-weight: 800;
  letter-spacing: -.02em;
}
.page-header p {
  color: var(--text-sec);
  font-size: .95rem;
  margin-top: .3rem;
}

/* ---------- Back to top ---------- */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition), transform var(--transition);
  border: none;
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(27,94,122,.3);
}
.back-to-top.visible { opacity: 1; pointer-events: auto; }
.back-to-top:hover { transform: translateY(-2px); }
.back-to-top svg { width: 18px; height: 18px; }

/* ---------- Dynamic Publications ---------- */
.pub-card--dynamic {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  padding: .9rem 0;
  border-bottom: 1px solid #f0f0f0;
}
.pub-card--dynamic:last-child { border-bottom: none; }

.pub-card__links button {
  display: inline-flex;
  align-items: center;
  gap: .25rem;
  font-size: .75rem;
  font-weight: 500;
  padding: .2rem .55rem;
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--text-sec);
  background: transparent;
  cursor: pointer;
  font-family: var(--font);
  transition: all var(--transition);
}
.pub-card__links button:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.pub-card__cite {
  font-size: .78rem;
  color: var(--text-sec);
}

/* Spinner */
.spinner {
  width: 24px; height: 24px;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin .6s linear infinite;
  margin: 0 auto .8rem;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* BibTeX Modal */
.bibtex-overlay {
  position: fixed; inset: 0; z-index: 200;
  background: rgba(0,0,0,.4);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity .2s ease;
}
.bibtex-overlay.open {
  opacity: 1;
  pointer-events: auto;
}

.bibtex-modal {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 1.5rem;
  max-width: 600px;
  width: 90%;
  max-height: 80vh;
  box-shadow: 0 8px 40px rgba(0,0,0,.15);
  position: relative;
}

.bibtex-modal__header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}
.bibtex-modal__header h3 {
  font-size: 1rem;
  font-weight: 700;
}

.bibtex-modal__close {
  background: none; border: none; cursor: pointer;
  font-size: 1.3rem; color: var(--text-sec);
  padding: 4px;
  line-height: 1;
}
.bibtex-modal__close:hover { color: var(--text); }

.bibtex-modal pre {
  background: #f5f5f5;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 1rem;
  font-size: .8rem;
  font-family: var(--mono);
  overflow-x: auto;
  white-space: pre-wrap;
  word-break: break-all;
  max-height: 50vh;
  overflow-y: auto;
  line-height: 1.6;
}

.bibtex-modal__copy {
  margin-top: .8rem;
  padding: .45rem 1.2rem;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 6px;
  font-size: .82rem;
  font-weight: 600;
  cursor: pointer;
  font-family: var(--font);
  transition: background var(--transition);
}
.bibtex-modal__copy:hover { background: #134052; }
.bibtex-modal__copy.copied { background: #2d8a4e; }

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
  .hero {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 1.5rem;
    padding: 3.5rem 0 2rem;
  }
  .hero__photo { margin: 0 auto; width: 160px; height: 160px; }
  .hero__links { justify-content: center; }
  .interests { justify-content: center; }

  .nav__links {
    display: none;
    position: absolute;
    top: 56px; left: 0; right: 0;
    background: rgba(255,255,255,.98);
    backdrop-filter: blur(12px);
    flex-direction: column;
    padding: 1rem 1.5rem;
    gap: 0;
    border-bottom: 1px solid var(--border);
  }
  .nav__links.open { display: flex; }
  .nav__links li { padding: .6rem 0; }
  .nav__hamburger { display: flex; }

  .news-item { grid-template-columns: 1fr; gap: .2rem; }
  .news-date { font-size: .78rem; }

  .pub-card { grid-template-columns: 1fr; }
  .pub-card__img { width: 100%; height: 140px; }

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

  .carousel__slide { flex: 0 0 calc((100% - 1.2rem) / 2); }

  .pub-card--dynamic { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
  html { font-size: 15px; }
  .hero__content h1 { font-size: 1.6rem; }
  section { padding: 2.5rem 0; }
  .carousel__slide { flex: 0 0 100%; }
  .carousel__track { gap: 0; }
}