:root {
  /* Color Palette - Deep Space & Nebula */
  --bg-dark: #070913;
  --bg-surface: rgba(18, 22, 38, 0.6);
  --bg-surface-hover: rgba(28, 35, 60, 0.8);
  --header-bg: rgba(7, 9, 19, 0.8);
  --header-bg-scrolled: rgba(7, 9, 19, 0.9);
  --header-shadow-scrolled: 0 4px 30px rgba(0, 0, 0, 0.5);

  --accent-cyan: #00f0ff;
  --accent-blue: #3a86ff;
  --accent-purple: #8338ec;
  --accent-pink: #ff006e;

  --text-primary: #f8f9fa;
  --text-secondary: #adb5bd;
  --text-muted: #6c757d;

  --border-light: rgba(255, 255, 255, 0.08);

  /* Typography */
  --font-main: 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  /* Sizing & Spacing */
  --section-pd: 6rem 2rem;
  --max-width: 1200px;

  /* Glassmorphism */
  --glass-bg: rgba(255, 255, 255, 0.03);
  --glass-blur: blur(12px);
  --glass-border: 1px solid rgba(255, 255, 255, 0.05);
}

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

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

html {
  scroll-behavior: smooth;
  font-family: var(--font-main);
  background-color: var(--bg-dark);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-y: scroll;
  scrollbar-gutter: stable;
}

/* Accessibility - Skip Link */
.skip-link {
  position: absolute;
  top: -100px;
  left: 1rem;
  background: var(--accent-cyan);
  color: var(--bg-dark);
  padding: 0.5rem 1rem;
  z-index: 1001;
  border-radius: 0 0 8px 8px;
  font-weight: 700;
  transition: top 0.3s ease;
}

.skip-link:focus {
  top: 0;
  outline: none;
}

/* Focus visibility for keyboards */
a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--accent-cyan);
  outline-offset: 4px;
  border-radius: 4px;
}

body {
  overflow-x: hidden;
  position: relative;
}

/* Premium Mesh Background */
.background-mesh {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: -3; /* behind everything */
  overflow: hidden;
  background-color: var(--bg-dark); /* #070913 */
}

.blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(100px);
  opacity: 0.4;
  animation: float-blob 20s infinite alternate cubic-bezier(0.4, 0, 0.2, 1);
  will-change: transform;
}

.blob-cyan {
  top: -10%;
  right: -5%;
  width: 45vw;
  height: 45vw;
  background: var(--accent-cyan);
}

.blob-purple {
  bottom: -15%;
  left: -10%;
  width: 55vw;
  height: 55vw;
  background: var(--accent-purple);
  animation-delay: -7s;
}

.blob-blue {
  top: 30%;
  left: 20%;
  width: 35vw;
  height: 35vw;
  background: var(--accent-blue);
  animation-delay: -14s;
  opacity: 0.3;
}

@keyframes float-blob {
  0% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(-3%, 4%) scale(1.05); }
  100% { transform: translate(2%, -4%) scale(0.95); }
}

.noise-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: -2;
  pointer-events: none;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.65' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noiseFilter)'/%3E%3C/svg%3E");
  opacity: 0.04;
}

/* Typography styles */
h1, h2, h3, h4 {
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 1rem;
}

h1 {
  font-size: clamp(3rem, 6vw, 5rem);
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, var(--text-primary), var(--accent-blue));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

h2 {
  font-size: clamp(2rem, 4vw, 3rem);
  margin-bottom: 2rem;
  display: inline-block;
  position: relative;
}

h2::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -5px;
  width: 50px;
  height: 3px;
  background: linear-gradient(90deg, var(--accent-cyan), var(--accent-purple));
  border-radius: 2px;
}

h3 {
  font-size: 1.5rem;
  color: var(--text-primary);
}

p {
  color: var(--text-secondary);
  font-size: 1.1rem;
  margin-bottom: 1.5rem;
}

a {
  color: var(--accent-cyan);
  text-decoration: none;
  transition: all 0.3s ease;
}

a:hover {
  color: var(--accent-pink);
  text-shadow: 0 0 10px rgba(255, 0, 110, 0.5);
}

/* Layout Classes */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 2rem;
}

section {
  padding: var(--section-pd);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

/* Navigation */
header {
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 100;
  background: var(--header-bg);
  backdrop-filter: blur(15px);
  border-bottom: 1px solid var(--border-light);
  box-shadow: none;
  transition: all 0.3s ease;
}

header.is-scrolled {
  background: var(--header-bg-scrolled);
  box-shadow: var(--header-shadow-scrolled);
}

nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
  max-width: var(--max-width);
  margin: 0 auto;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: 1px;
}

.menu-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border: 1px solid var(--border-light);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.06);
  color: var(--text-primary);
  cursor: pointer;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 4px;
}

.menu-toggle span {
  width: 18px;
  height: 2px;
  background: currentColor;
  border-radius: 999px;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.menu-toggle.is-open span:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.menu-toggle.is-open span:nth-child(2) {
  opacity: 0;
}

.menu-toggle.is-open span:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
  align-items: center;
}

.nav-links li {
  display: flex;
  align-items: center;
}

.nav-links a {
  color: var(--text-primary);
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  font-weight: 500;
  position: relative;
}

.nav-links a:hover, .nav-links a.active {
  color: var(--accent-cyan);
}

.nav-links a::after {
  content: '';
  position: absolute;
  width: 0;
  height: 2px;
  bottom: -4px;
  left: 0;
  background: var(--accent-cyan);
  transition: width 0.3s ease;
}

.nav-links a:hover::after, .nav-links a.active::after {
  width: 100%;
}

/* Language Button */
.lang-btn {
  background: rgba(255, 255, 255, 0.1);
  color: var(--text-primary);
  border: 1px solid var(--border-light);
  padding: 0.5rem 1rem;
  border-radius: 20px;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 90px;
}

.lang-btn:hover {
  background: rgba(255, 255, 255, 0.2);
  border-color: var(--accent-cyan);
}

/* Language Toggle Logic */
body .ja { display: none; }
body.lang-ja .en { display: none; }
body.lang-ja .ja { display: inline; }

/* Overriding display for block elements when in JA mode */
body.lang-ja div.ja,
body.lang-ja p.ja,
body.lang-ja h1.ja,
body.lang-ja h2.ja,
body.lang-ja h3.ja,
body.lang-ja h4.ja {
  display: block;
}

/* Hide block elements by default if they are .ja */
div.ja, p.ja, h1.ja, h2.ja, h3.ja, h4.ja { display: none; }

/* Home / Hero Section */
#home {
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: left;
  position: relative;
  min-height: auto;
  padding-top: 8rem;
  padding-bottom: 3rem;
}

.hero-content {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(430px, 470px);
  gap: 3rem;
  align-items: center;
  padding-top: 3rem;
}

.hero-text span.role {
  display: inline-block;
  color: var(--accent-cyan);
  font-family: var(--font-mono);
  font-size: 1.1rem;
  margin-bottom: 1rem;
  padding: 0.5rem 1rem;
  background: rgba(0, 240, 255, 0.1);
  border-radius: 20px;
  border: 1px solid rgba(0, 240, 255, 0.2);
}

.hero-copy {
  max-width: 720px;
  margin-bottom: 1.75rem;
}

.hero-line {
  font-size: 1.08rem;
  line-height: 1.85;
  margin-bottom: 0.85rem;
}

.hero-cta {
  display: flex;
  gap: 0.8rem;
  flex-wrap: wrap;
  margin-bottom: 0;
}

.hero-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0.75rem 1.15rem;
  border-radius: 999px;
  border: 1px solid var(--border-light);
  background: rgba(255, 255, 255, 0.04);
  color: var(--text-primary);
  text-decoration: none;
}

.hero-btn:hover {
  text-shadow: none;
}

.hero-btn-primary {
  background: rgba(0, 240, 255, 0.1);
  border-color: rgba(0, 240, 255, 0.22);
  color: var(--accent-cyan);
}

.hero-btn-primary:hover {
  color: var(--accent-cyan);
}

.hero-btn-secondary:hover {
  color: var(--text-primary);
}

.hero-image {
  position: relative;
  width: 460px;
  height: 460px;
  margin: 0 auto;
  isolation: isolate;
  z-index: 0;
  overflow: visible;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-image-glow {
  position: absolute;
  inset: 12%;
  background: conic-gradient(from 0deg, var(--accent-cyan), var(--accent-purple), var(--accent-blue), var(--accent-cyan));
  border-radius: 50%;
  filter: blur(32px);
  opacity: 0.24;
  animation: none;
  z-index: 0;
  pointer-events: none;
}

.hero-image picture {
  display: block;
  width: 350px;
  height: 350px;
  position: relative;
  z-index: 1;
}

.hero-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 50%;
  border: 2px solid rgba(255, 255, 255, 0.1);
  box-shadow: 0 0 30px rgba(0,0,0,0.5);
}

/* Glass Card Reusable Class */
.glass-card {
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: var(--glass-border);
  border-radius: 16px;
  padding: 2rem;
  transition: transform 0.3s ease, box-shadow 0.3s ease, background 0.3s ease;
}

.glass-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 30px rgba(0,0,0,0.3);
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

/* Research Section */
#research {
  min-height: auto;
  padding-top: 2rem;
}

.research-overview {
  max-width: 820px;
}

.narrow {
  max-width: 820px;
}

.research-intro-text {
  font-size: 1.04rem;
  line-height: 1.85;
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.research-topic-list {
  margin-top: 2rem;
  border-top: 1px solid var(--border-light);
}

.research-topic {
  padding: 1.1rem 0 1.2rem;
  border-bottom: 1px solid var(--border-light);
}

.research-topic h4 {
  font-size: 1.1rem;
  color: var(--text-primary);
  margin-bottom: 0.55rem;
}

.research-topic p {
  color: var(--text-secondary);
  font-size: 0.98rem;
  line-height: 1.78;
  margin-bottom: 0.7rem;
}

.research-topic p:last-child {
  margin-bottom: 0;
}

.research-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin-top: 2rem;
}

/* Experience / CV Section */
.timeline {
  position: relative;
  max-width: 800px;
  margin: 2rem auto;
}

.timeline::before {
  content: '';
  position: absolute;
  top: 0;
  left: 20px;
  height: 100%;
  width: 2px;
  background: var(--border-light);
}

.timeline-item {
  position: relative;
  padding-left: 60px;
  margin-bottom: 2rem;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: 14px;
  top: 5px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--accent-purple);
  box-shadow: 0 0 10px var(--accent-purple);
}

.timeline-date {
  font-family: var(--font-mono);
  color: var(--accent-cyan);
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
}

/* Publications Section */
.pub-list {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.pub-item {
  display: flex;
  gap: 1.5rem;
  align-items: flex-start;
}

.pub-year {
  font-family: var(--font-mono);
  color: var(--accent-pink);
  font-weight: 700;
  min-width: 60px;
}

.pub-details h4 {
  font-size: 1.1rem;
  margin-bottom: 0.15rem;
}

.pub-authors {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin: 0 0 0.15rem 0;
}

.pub-journal {
  color: var(--text-muted);
  font-style: italic;
  font-size: 0.9rem;
  margin: 0 0 0.15rem 0;
}

/* Subheadings for the 4-category grouping */
.presentations-subheading {
  font-size: 1.15rem;
  font-family: var(--font-main);
  color: var(--accent-cyan);
  margin: 2rem 0 1rem 0;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  width: 100%;
  display: block;
}

.presentations-subheading:first-child {
  margin-top: 0;
}

.pub-meta {
  color: var(--text-muted);
  font-size: 0.82rem;
  font-family: var(--font-mono);
  margin: 0;
  opacity: 0.75;
}

.deferred-status {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin: 0;
  padding: 1rem 0;
}

.deferred-status-error {
  color: #ff8aa3;
}

.print-publications-list {
  display: none;
}

.pub-link {
  margin-top: 0.35rem;
}

.pub-link a {
  color: var(--accent-cyan);
  text-decoration: underline;
  text-underline-offset: 0.2em;
}

.compact-seminar-list {
  gap: 0;
}

.compact-seminar-list .pub-item {
  padding: 0.9rem 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.compact-seminar-list .pub-item:first-child {
  padding-top: 0;
}

.compact-seminar-list .pub-item:last-child {
  padding-bottom: 0;
  border-bottom: none;
}

.compact-seminar-list .pub-year {
  min-width: 88px;
  font-size: 0.82rem;
}

.compact-seminar-list .pub-details h4 {
  font-size: 1rem;
  line-height: 1.45;
  margin-bottom: 0.2rem;
}

.compact-seminar-list .pub-journal {
  font-style: normal;
  margin-bottom: 0.15rem;
}

.compact-seminar-list .pub-meta {
  margin-top: 0.15rem;
}

.compact-seminar-list .pub-meta a {
  color: var(--accent-cyan);
  text-decoration: underline;
  text-underline-offset: 0.2em;
}

#presentations {
  justify-content: flex-start;
  padding-top: 8rem;
}

/* Presentations Filter & Scroll Box */
.filter-tabs {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 2rem;
}

.filter-btn {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-light);
  color: var(--text-secondary);
  padding: 0.5rem 1.5rem;
  border-radius: 20px;
  cursor: pointer;
  font-family: var(--font-main);
  transition: all 0.3s ease;
}

.filter-btn:hover {
  border-color: var(--accent-blue);
  color: var(--text-primary);
}

.filter-btn.active {
  background: rgba(58, 134, 255, 0.2);
  border-color: var(--accent-blue);
  color: var(--accent-cyan);
  box-shadow: 0 0 10px rgba(58, 134, 255, 0.3);
}

.glass-scroll-box {
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: var(--glass-border);
  border-radius: 16px;
  min-height: 500px;
  max-height: 500px;
  overflow-y: scroll;
  padding: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

/* Custom Scrollbar for Glass Box */
.glass-scroll-box::-webkit-scrollbar {
  width: 8px;
}
.glass-scroll-box::-webkit-scrollbar-track {
  background: rgba(255, 255, 255, 0.02);
  border-radius: 10px;
}
.glass-scroll-box::-webkit-scrollbar-thumb {
  background: rgba(58, 134, 255, 0.4);
  border-radius: 10px;
}
.glass-scroll-box::-webkit-scrollbar-thumb:hover {
  background: var(--accent-blue);
}

/* Animations */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1), transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Responsive */
@media (max-width: 768px) {
  :root {
    --section-pd: 4rem 1rem;
  }

  .container {
    padding: 0 1rem;
  }

  nav {
    padding: 1rem 1rem;
  }

  .glass-card {
    padding: 1.5rem 1rem;
  }

  .glass-scroll-box {
    padding: 1.5rem 1rem;
  }

  .hero-content {
    grid-template-columns: 1fr;
    text-align: center;
  }

  h2::after {
    left: 50%;
    transform: translateX(-50%);
  }

  .timeline::before {
    left: 10px;
  }
  .timeline-item {
    padding-left: 40px;
  }
  .timeline-item::before {
    left: 4px;
  }
  .pub-item {
    flex-direction: column;
    gap: 0.5rem;
  }
  .nav-links {
    flex-direction: column;
    background: var(--bg-dark);
    position: absolute;
    top: 60px;
    left: 0;
    width: 100%;
    padding: 1rem;
    display: none;
    border-bottom: 1px solid var(--border-light);
  }

  .nav-links.open {
    display: flex;
  }

  .menu-toggle {
    display: inline-flex;
  }
}
/* Final Polish Components */
.tag {
  display: inline-block;
  padding: 0.3rem 0.8rem;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 20px;
  font-size: 0.75rem;
  font-family: var(--font-mono);
  color: var(--accent-cyan);
  transition: all 0.3s ease;
}

.tag:hover {
  background: rgba(0, 240, 255, 0.1);
  border-color: var(--accent-cyan);
  transform: translateY(-2px);
}

.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 45px;
  height: 45px;
  background: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: 50%;
  color: var(--accent-cyan);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 99;
  transition: all 0.3s ease;
  opacity: 0;
  pointer-events: none;
  backdrop-filter: blur(10px);
}

.back-to-top.visible {
  opacity: 1;
  pointer-events: auto;
}

.back-to-top:hover {
  background: var(--bg-surface-hover);
  transform: translateY(-5px);
  border-color: var(--accent-cyan);
  box-shadow: 0 0 15px rgba(0, 240, 255, 0.3);
}

/* Abstract Toggles */
.abstract-toggle {
  background: none;
  border: 1px solid var(--accent-cyan);
  color: var(--accent-cyan);
  padding: 0.4rem 0.8rem;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.8rem;
  font-family: var(--font-mono);
  margin-top: 1rem;
  transition: all 0.3s ease;
  display: inline-block;
}

.abstract-toggle:hover {
  background: rgba(0, 240, 255, 0.1);
  box-shadow: 0 0 10px rgba(0, 240, 255, 0.2);
}

.abstract-content {
  max-height: 0;
  overflow: hidden;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  font-size: 0.95rem;
  color: var(--text-secondary);
  border-left: 2px solid var(--accent-cyan);
  padding-left: 1.5rem;
  opacity: 0;
  background: rgba(255, 255, 255, 0.02);
}

.abstract-content.open,
.abstract-content.active {
  max-height: 1000px;
  margin-top: 1rem;
  padding-top: 1rem;
  padding-bottom: 1rem;
  opacity: 1;
}

/* Contact Section */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: 4rem;
  margin-top: 3rem;
}

.contact-info p {
  max-width: 400px;
}

.contact-links {
  margin-top: 2rem;
}

.contact-links .glass-card {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
}

#contact-form {
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
}

.hp-field {
  position: absolute;
  left: -9999px;
  width: 1px;
  height: 1px;
  overflow: hidden;
}

#contact-form:hover {
  transform: none;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 1.2rem;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-light);
  border-radius: 12px;
  color: var(--text-primary);
  font-family: var(--font-main);
  transition: all 0.3s ease;
}

.form-group textarea {
  resize: vertical;
  min-height: 160px;
}

.turnstile-wrap {
  display: flex;
  justify-content: flex-start;
  min-height: 65px;
}

.turnstile-widget {
  min-height: 65px;
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--accent-cyan);
  background: rgba(255, 255, 255, 0.05);
  box-shadow: 0 0 20px rgba(0, 240, 255, 0.1);
}

.submit-btn {
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
  color: white;
  border: none;
  padding: 1.2rem;
  border-radius: 12px;
  font-weight: 700;
  font-size: 1rem;
  cursor: pointer;
  transition: all 0.3s ease;
  overflow: hidden;
  position: relative;
}

.submit-btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
  transition: 0.5s;
}

.submit-btn:hover::before {
  left: 100%;
}

.submit-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 20px rgba(131, 56, 236, 0.3);
}

.submit-btn:disabled {
  cursor: wait;
  opacity: 0.7;
  transform: none;
  box-shadow: none;
}

.submit-btn:disabled::before {
  display: none;
}

.form-note {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 0;
}

#form-status {
  text-align: center;
  font-size: 0.9rem;
  min-height: 1.2rem;
  color: var(--accent-cyan);
  font-weight: 600;
}

#form-status.is-pending {
  color: var(--accent-cyan);
}

#form-status.is-success {
  color: var(--accent-cyan);
}

#form-status.is-error {
  color: #ff8aa3;
}

/* Final Responsive Tweaks */
@media (max-width: 992px) {
  .contact-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }
}

@media (max-width: 768px) {
  .hero-content {
    gap: 2rem;
    padding-top: 2rem;
  }

  .hero-image {
    width: 320px;
    height: 320px;
  }

  .hero-image picture {
    width: 250px;
    height: 250px;
  }

  .hero-line {
    font-size: 1rem;
  }

  .research-intro-text,
  .research-topic p {
    font-size: 0.98rem;
  }

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

  .back-to-top {
    bottom: 1rem;
    right: 1rem;
  }
}

/* Print Specific Styles */
@media print {
  /* Isolate Presentations for PDF */
  body.print-presentations-only {
    background: #fff !important;
    color: #000 !important;
  }

  /* Unify font for the entire printed page */
  body.print-presentations-only,
  /* --- PDF Export Styles (Academic CV Style) --- */
  body.print-presentations-only *,
  body.print-publications-only * {
    font-family: "Times New Roman", Times, "Yu Mincho", "MS Mincho", serif !important;
    color: #000000 !important;
    opacity: 1 !important;
  }

  body.print-presentations-only header, body.print-publications-only header,
  body.print-presentations-only footer, body.print-publications-only footer,
  body.print-presentations-only .background-mesh, body.print-publications-only .background-mesh,
  body.print-presentations-only .noise-overlay, body.print-publications-only .noise-overlay,
  body.print-presentations-only .back-to-top, body.print-publications-only .back-to-top,
  body.print-presentations-only section:not(#presentations),
  body.print-publications-only section:not(#publications),
  body.print-presentations-only .filter-tabs-wrapper,
  body.print-publications-only .pdf-export-controls,
  body.print-presentations-only .pdf-export-controls,
  body.print-publications-only .pub-links {
    display: none !important;
  }

  body.print-presentations-only #presentations,
  body.print-publications-only #publications {
    padding: 0 !important;
    min-height: auto !important;
    display: block !important;
    justify-content: flex-start !important;
    overflow: visible !important;
  }

  body.print-presentations-only main,
  body.print-publications-only main,
  body.print-presentations-only .container,
  body.print-publications-only .container,
  body.print-presentations-only #presentations-container,
  body.print-publications-only #publications-container,
  body.print-presentations-only .pub-list,
  body.print-publications-only .pub-list {
    height: auto !important;
    max-height: none !important;
    overflow: visible !important;
  }

  body.print-presentations-only #presentations-container,
  body.print-publications-only #publications-container {
    counter-reset: pub-counter;
  }

  body.print-publications-only #publications-container {
    display: none !important;
  }

  body.print-publications-only #publications-print-container {
    display: block !important;
  }

  body.print-presentations-only h2,
  body.print-publications-only h2 {
    color: #000 !important;
    border-bottom: 2px solid #ccc;
    padding-bottom: 0.5rem;
    margin-bottom: 2rem;
  }

  /* Presentation Heading Logic */
  body.print-presentations-only #presentations-heading .en,
  body.print-presentations-only #presentations-heading .ja {
    display: none !important;
  }
  body.print-presentations-only.lang-ja #presentations-heading .print-title-ja {
    display: block !important;
  }
  body.print-presentations-only:not(.lang-ja) #presentations-heading .print-title-en {
    display: block !important;
  }

  /* Publications Heading Logic */
  body.print-publications-only #publications-heading .en,
  body.print-publications-only #publications-heading .ja {
    display: none !important;
  }
  body.print-publications-only.lang-ja #publications-heading .print-title-ja {
    display: block !important;
  }
  body.print-publications-only:not(.lang-ja) #publications-heading .print-title-en {
    display: block !important;
  }

  body.print-presentations-only .glass-scroll-box,
  body.print-publications-only .glass-scroll-box {
    max-height: none !important;
    overflow: visible !important;
    background: none !important;
    border: none !important;
    box-shadow: none !important;
    backdrop-filter: none !important;
    -webkit-backdrop-filter: none !important;
    padding: 0 !important;
    margin: 0 !important;
    display: block !important;
  }

  body.print-presentations-only .glass-card,
  body.print-presentations-only .pub-item,
  body.print-publications-only .glass-card,
  body.print-publications-only .pub-item {
    background: none !important;
    border: none !important;
    box-shadow: none !important;
    padding: 0 !important;
    margin: 0 !important;
    page-break-inside: avoid;
    break-inside: avoid;
    display: block !important;
    font-size: 0.72rem !important;
    line-height: 1.15 !important;
    color: #000 !important;
  }

  body.print-presentations-only .pub-list,
  body.print-publications-only .pub-list {
    display: block !important;
    gap: 0 !important;
  }

  body.print-publications-only .print-publication-item {
    margin: 0 0 0.08rem 0 !important;
    padding: 0 !important;
    font-size: 0.75rem !important;
    line-height: 1.12 !important;
    color: #000 !important;
    white-space: normal !important;
    page-break-inside: auto !important;
    break-inside: auto !important;
  }

  body.print-publications-only .print-publication-item * {
    margin: 0 !important;
    padding: 0 !important;
    color: #000 !important;
  }

  body.print-publications-only .print-publication-index {
    margin-right: 0.25rem !important;
    font-weight: bold !important;
  }

  body.print-presentations-only .pub-item,
  body.print-publications-only .pub-item {
    margin-bottom: 0 !important;
    overflow: visible !important;
  }

  body.print-publications-only .pub-item {
    page-break-inside: auto !important;
    break-inside: auto !important;
  }

  body.print-presentations-only .pub-item *,
  body.print-publications-only .pub-item * {
    margin: 0 !important;
    padding: 0 !important;
    color: #000 !important;
    display: inline;
  }

  body.print-presentations-only .pub-item::before,
  body.print-publications-only .pub-item::before {
    counter-increment: pub-counter;
    content: counter(pub-counter) ". ";
    font-weight: bold;
    margin-right: 0.3rem;
    display: inline !important;
    color: #000 !important;
  }

  body.print-presentations-only a,
  body.print-publications-only a {
    color: #000 !important;
    text-decoration: none !important;
  }

  body.print-presentations-only .pub-year,
  body.print-publications-only .pub-year {
    display: none !important;
  }

  body.print-presentations-only .pub-details,
  body.print-publications-only .pub-details {
    display: inline !important;
  }

  body.print-presentations-only .pub-details h4,
  body.print-presentations-only .pub-authors,
  body.print-presentations-only .pub-journal,
  body.print-presentations-only .pub-meta,
  body.print-publications-only .pub-details h4,
  body.print-publications-only .pub-authors,
  body.print-publications-only .pub-journal,
  body.print-publications-only .pub-meta {
    display: inline !important;
    color: #000 !important;
    font-size: 0.75rem !important;
    margin: 0 !important;
    padding: 0 !important;
    font-weight: normal !important;
  }

  body.print-presentations-only .pub-details h4::after,
  body.print-publications-only .pub-details h4::after {
    content: ", ";
    font-weight: normal !important;
  }

  body.print-presentations-only .pub-authors::after,
  body.print-presentations-only .pub-journal::after,
  body.print-publications-only .pub-authors::after,
  body.print-publications-only .pub-journal::after {
    content: ", ";
  }

  body.print-presentations-only .presentations-subheading {
    font-size: 0.85rem !important;
    color: #000 !important;
    border-bottom: 1px solid #ccc !important;
    margin: 1.2rem 0 0.4rem 0 !important;
    padding-bottom: 0.2rem !important;
    font-weight: bold !important;
    page-break-after: avoid;
    break-after: avoid;
  }

  body.print-presentations-only .abstract-toggle,
  body.print-publications-only .abstract-toggle,
  body.print-presentations-only .pub-note:not(.is-invited),
  body.print-publications-only .pub-link,
  body.print-publications-only .abstract-content {
    display: none !important;
  }

  body.print-presentations-only .pub-note.is-invited {
    display: inline !important;
    margin-left: 0.5rem !important;
  }

  /* Language visibility overrides */
  [class*="print-"] .pub-details h4.en,
  [class*="print-"] .pub-authors .en,
  [class*="print-"] .pub-journal .en,
  [class*="print-"] .pub-meta .en,
  [class*="print-"] .pub-details h4.ja,
  [class*="print-"] .pub-authors .ja,
  [class*="print-"] .pub-journal .ja,
  [class*="print-"] .pub-meta .ja,
  [class*="print-"] .en,
  [class*="print-"] .ja {
    display: none !important;
  }

  [class*="print-"]:not(.lang-ja) .en,
  [class*="print-"]:not(.lang-ja) .pub-details h4.en,
  [class*="print-"]:not(.lang-ja) .pub-authors .en,
  [class*="print-"]:not(.lang-ja) .pub-journal .en,
  [class*="print-"]:not(.lang-ja) .pub-meta .en {
    display: inline !important;
  }

  [class*="print-"].lang-ja .ja,
  [class*="print-"].lang-ja .pub-details h4.ja,
  [class*="print-"].lang-ja .pub-authors .ja,
  [class*="print-"].lang-ja .pub-journal .ja,
  [class*="print-"].lang-ja .pub-meta .ja {
    display: inline !important;
  }

  [class*="print-"] .abstract-toggle,
  [class*="print-"] .abstract-toggle.en,
  [class*="print-"] .abstract-toggle.ja {
    display: none !important;
  }
}