/* ============================================
   Liu Peiyu | Personal Homepage
   Photography Gallery Aesthetic
   ============================================ */

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Segoe UI", system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: #F5F6F8;
  color: #2C2C2C;
  line-height: 1.6;
  overflow-x: hidden;
  min-height: 100vh;
}

/* --- CSS Variables --- */
:root {
  --accent: rgb(203, 224, 241);
  --accent-light: rgba(203, 224, 241, 0.3);
  --accent-dark: #8BB8D3;
  --card-bg: rgba(255, 255, 255, 0.72);
  --card-border: rgba(255, 255, 255, 0.35);
  --card-shadow: 0 4px 24px rgba(0, 0, 0, 0.04);
  --card-shadow-hover: 0 12px 48px rgba(0, 0, 0, 0.08);
  --text-primary: #2C2C2C;
  --text-secondary: #6B7280;
  --text-light: #9CA3AF;
  --radius: 16px;
  --max-width: 1200px;
  --nav-height: 64px;
}

/* --- Background Decor --- */
.bg-grid {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background-image:
    linear-gradient(rgba(203, 224, 241, 0.12) 1px, transparent 1px),
    linear-gradient(90deg, rgba(203, 224, 241, 0.12) 1px, transparent 1px);
  background-size: 60px 60px;
}

.bg-orb {
  position: fixed;
  border-radius: 50%;
  pointer-events: none;
  z-index: 0;
  filter: blur(80px);
  opacity: 0.35;
}

.bg-orb--1 {
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgb(203, 224, 241), transparent);
  top: -150px;
  right: -100px;
}

.bg-orb--2 {
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(203, 224, 241, 0.6), transparent);
  bottom: 10%;
  left: -120px;
}

.bg-orb--3 {
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, rgba(203, 224, 241, 0.4), transparent);
  bottom: -80px;
  right: 20%;
}

/* --- Navigation --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(245, 246, 248, 0.75);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.5);
  transition: transform 0.3s ease;
}

.nav__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav__brand {
  font-family: Georgia, "Noto Serif SC", serif;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  text-decoration: none;
  letter-spacing: 0.02em;
}

.nav__links {
  display: flex;
  gap: 24px;
}

.nav__link {
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 0.875rem;
  font-weight: 500;
  transition: color 0.2s ease;
  position: relative;
}

.nav__link::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent-dark);
  transition: width 0.3s ease;
}

.nav__link:hover {
  color: var(--text-primary);
}

.nav__link:hover::after {
  width: 100%;
}

.nav__right {
  display: flex;
  align-items: center;
  gap: 16px;
}

.lang-toggle {
  display: flex;
  align-items: center;
  gap: 6px;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 20px;
  padding: 6px 14px;
  font-size: 0.8rem;
  font-family: inherit;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.3s ease;
  backdrop-filter: blur(8px);
}

.lang-toggle:hover {
  background: rgba(255, 255, 255, 0.9);
  color: var(--text-primary);
}

.lang-toggle__dot {
  color: var(--accent-dark);
  font-weight: 700;
}

.nav__hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav__hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: all 0.3s ease;
}

/* --- Hero --- */
.hero {
  position: relative;
  z-index: 1;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 100px 24px 60px;
  text-align: center;
}

.hero__frame {
  width: 160px;
  height: 160px;
  border-radius: 50%;
  padding: 4px;
  background: linear-gradient(135deg, var(--accent), rgba(255,255,255,0.5));
  margin-bottom: 20px;
  opacity: 0;
  animation: fadeUp 1s 0.2s ease forwards;
}

.hero__avatar {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  overflow: hidden;
  border: 3px solid rgba(255, 255, 255, 0.8);
}

.hero__avatar-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.hero__name {
  font-family: Georgia, "Noto Serif SC", serif;
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: 0.04em;
  opacity: 0;
  animation: fadeUp 1s 0.4s ease forwards;
}

.hero__subtitle {
  font-size: clamp(1rem, 2vw, 1.2rem);
  color: var(--text-secondary);
  margin-top: 4px;
  opacity: 0;
  animation: fadeUp 1s 0.5s ease forwards;
}

.hero__tagline {
  font-family: Georgia, "Noto Serif SC", serif;
  font-style: italic;
  font-size: clamp(1.1rem, 2.5vw, 1.4rem);
  color: var(--accent-dark);
  margin-top: 12px;
  letter-spacing: 0.03em;
  opacity: 0;
  animation: fadeUp 1s 0.6s ease forwards;
}

.hero__badges {
  display: flex;
  gap: 12px;
  margin-top: 20px;
  flex-wrap: wrap;
  justify-content: center;
  opacity: 0;
  animation: fadeUp 1s 0.7s ease forwards;
}

.hero__badge {
  background: var(--card-bg);
  backdrop-filter: blur(8px);
  border: 1px solid var(--card-border);
  border-radius: 20px;
  padding: 8px 20px;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.hero__scroll {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  opacity: 0;
  animation: fadeUp 1s 1s ease forwards;
}

.hero__scroll-icon {
  width: 24px;
  height: 40px;
  border: 2px solid var(--text-light);
  border-radius: 12px;
  position: relative;
}

.hero__scroll-icon::after {
  content: "";
  position: absolute;
  top: 8px;
  left: 50%;
  transform: translateX(-50%);
  width: 3px;
  height: 8px;
  background: var(--accent-dark);
  border-radius: 2px;
  animation: scrollDot 2s ease-in-out infinite;
}

@keyframes scrollDot {
  0%, 100% { transform: translateX(-50%) translateY(0); opacity: 1; }
  50% { transform: translateX(-50%) translateY(10px); opacity: 0.3; }
}

/* --- Sections --- */
.section {
  position: relative;
  z-index: 1;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 48px 24px;
}

.section--photo {
  max-width: 100%;
  padding: 48px 24px;
}

.section__header {
  text-align: center;
  margin-bottom: 32px;
}

.section__title {
  font-family: Georgia, "Noto Serif SC", serif;
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: 0.02em;
}

.section__desc {
  font-size: 1rem;
  color: var(--text-light);
  margin-top: 8px;
  font-style: italic;
}

.section__subtitle {
  font-family: Georgia, "Noto Serif SC", serif;
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 36px 0 16px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--accent);
  letter-spacing: 0.02em;
}

/* --- Grid Layout --- */
.grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

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

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

/* --- Cards (Glassmorphism) --- */
.card {
  background: var(--card-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--card-shadow);
  transition: all 0.35s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  opacity: 0;
  transform: translateY(20px);
}

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

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--card-shadow-hover);
  border-color: rgba(255, 255, 255, 0.6);
}

.card.visible:hover {
  transform: translateY(-4px);
}

.card--wide {
  grid-column: 1 / -1;
}

.card__icon {
  font-size: 1.6rem;
  margin-bottom: 8px;
}

.card__title {
  font-family: Georgia, "Noto Serif SC", serif;
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 12px;
}

/* --- Academics Card --- */
.card--academics {
  text-align: center;
}

.card__stat {
  margin-bottom: 12px;
}

.card__stat:last-child {
  margin-bottom: 0;
}

.card__stat-number {
  display: block;
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  font-size: 2rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.2;
  font-variant-numeric: tabular-nums;
}

.card__stat-label {
  display: block;
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-top: 2px;
}

/* --- Courses Card --- */
.card__course-list {
  list-style: none;
}

.card__course-list li {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 6px 0;
  border-bottom: 1px solid rgba(0, 0, 0, 0.04);
}

.card__course-list li:last-child {
  border-bottom: none;
}

.card__course-name {
  font-size: 0.9rem;
  color: var(--text-primary);
}

.card__course-score {
  font-weight: 600;
  color: var(--accent-dark);
  font-size: 0.95rem;
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  font-variant-numeric: tabular-nums;
}

/* --- Skills Card --- */
.card__skill-group {
  margin-top: 10px;
}

.card__skill-label {
  display: block;
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--accent-dark);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 6px;
}

.card__skills-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.card__skill-tag {
  background: var(--accent-light);
  color: #4A6F8F;
  padding: 4px 14px;
  border-radius: 16px;
  font-size: 0.82rem;
  font-weight: 500;
  transition: all 0.2s ease;
}

.card__skill-tag:hover {
  background: var(--accent);
  transform: scale(1.05);
}

/* --- Research Card --- */
.card--research {
  position: relative;
}

.card__badge {
  position: absolute;
  top: 16px;
  right: 16px;
  background: linear-gradient(135deg, var(--accent), var(--accent-dark));
  color: #fff;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 12px;
  border-radius: 12px;
  letter-spacing: 0.03em;
}

.card__journal {
  font-size: 0.9rem;
  color: var(--accent-dark);
  font-weight: 500;
  margin-bottom: 4px;
}

.card__meta {
  font-size: 0.82rem;
  color: var(--text-light);
  margin-bottom: 12px;
}

.card__desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* --- Awards Card --- */
.card--award {
  text-align: center;
  padding: 20px 16px;
}

.card__award-icon {
  font-size: 2rem;
  display: block;
  margin-bottom: 6px;
}

.card__award-name {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 2px;
  line-height: 1.4;
}

.card__award-level {
  font-size: 0.8rem;
  color: var(--accent-dark);
  font-weight: 500;
}

/* --- English Card --- */
.card--english {
  text-align: center;
  padding: 24px;
}

.card__scores {
  display: flex;
  justify-content: center;
  gap: 24px;
  flex-wrap: wrap;
}

.card__score {
  text-align: center;
}

.card__score-num {
  display: block;
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.2;
  font-variant-numeric: tabular-nums;
}

.card__score-label {
  font-size: 0.8rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.card__score--highlight .card__score-num {
  font-size: 2.4rem;
  color: var(--accent-dark);
  position: relative;
}

.card__score--highlight .card__score-label {
  color: var(--accent-dark);
  font-weight: 600;
}

/* --- Internship Card --- */
.card--internship {
  background: linear-gradient(
    135deg,
    rgba(203, 224, 241, 0.18),
    rgba(255, 255, 255, 0.72)
  );
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.card__internship-list {
  list-style: none;
  padding: 0;
  margin: 12px 0 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.card__internship-list li {
  position: relative;
  padding-left: 18px;
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

.card__internship-list li::before {
  content: "▸";
  position: absolute;
  left: 0;
  top: 0;
  color: var(--accent-dark);
  font-size: 0.75rem;
}

/* --- Photography Section --- */
.section--photo {
  background: linear-gradient(180deg, transparent, rgba(203, 224, 241, 0.08));
}

.photo-showcase {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.6fr 1fr;
  gap: 20px;
}

.card--photo-main {
  background: linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.85),
    rgba(255, 255, 255, 0.6)
  );
  backdrop-filter: blur(20px);
  border: 1px solid rgba(203, 224, 241, 0.3);
  padding: 32px 28px;
}

.card__photo-title {
  font-family: Georgia, "Noto Serif SC", serif;
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: 0.02em;
  text-align: center;
  margin-bottom: 4px;
}

.card__photo-subtitle {
  font-size: 1rem;
  color: var(--text-light);
  font-style: italic;
  text-align: center;
  margin-bottom: 20px;
}

.photo-main__body {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 36px;
  align-items: center;
}

.photo-main__stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding-right: 36px;
  border-right: 1px solid rgba(203, 224, 241, 0.35);
}

.photo-main__num {
  width: 110px;
  height: 110px;
  border-radius: 50%;
  background: linear-gradient(135deg, rgba(203, 224, 241, 0.35), rgba(255, 255, 255, 0.5));
  border: 3px solid rgba(255, 255, 255, 0.7);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  font-size: 2.8rem;
  font-weight: 700;
  line-height: 1;
  color: var(--accent-dark);
  font-variant-numeric: tabular-nums;
  box-shadow: 0 4px 20px rgba(203, 224, 241, 0.25);
}

.photo-main__unit {
  font-size: 1.05rem;
  color: var(--text-secondary);
  font-weight: 500;
  margin-top: 2px;
}

.photo-main__label {
  font-family: Georgia, "Noto Serif SC", serif;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-top: 6px;
}

.photo-main__member {
  color: var(--accent-dark);
  font-size: 0.82rem;
  font-weight: 500;
  margin-top: 8px;
}

.card__photo-timeline {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.timeline__item {
  display: flex;
  gap: 20px;
  align-items: baseline;
  position: relative;
  padding-left: 20px;
}

.timeline__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent-dark);
  border: 2px solid #fff;
  box-shadow: 0 0 0 2px var(--accent-dark);
}

.timeline__year {
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--accent-dark);
  white-space: nowrap;
  min-width: 80px;
}

.timeline__text {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* --- Sports & Honors Side Cards --- */
.photo-showcase__side {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.card--sports {
  flex: 1;
}

.card--social {
  flex: 1;
}

.card__sports-item {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.card__sports-item:last-child {
  margin-bottom: 0;
}

.card__sports-icon {
  font-size: 1.6rem;
  width: 28px;
  text-align: center;
  flex-shrink: 0;
}

.card__sports-name {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text-primary);
}

.card__sports-desc {
  font-size: 0.82rem;
  color: var(--text-secondary);
}

.card--honors {
  flex: 1;
}

.card__honors-list {
  list-style: none;
}

.card__honors-list li {
  padding: 6px 0;
  font-size: 0.9rem;
  color: var(--text-secondary);
  position: relative;
  padding-left: 16px;
}

.card__honors-list li::before {
  content: "—";
  position: absolute;
  left: 0;
  color: var(--accent-dark);
}

/* --- Footer --- */
.footer {
  position: relative;
  z-index: 1;
  background: rgba(255, 255, 255, 0.5);
  backdrop-filter: blur(16px);
  border-top: 1px solid rgba(203, 224, 241, 0.2);
  padding: 32px 24px;
  margin-top: 24px;
}

.footer__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 16px;
}

.footer__name {
  font-family: Georgia, "Noto Serif SC", serif;
  font-size: 1.3rem;
  font-weight: 700;
}

.footer__school {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-top: 4px;
}

.footer__links {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
  justify-content: center;
}

.footer__link {
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 0.88rem;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: color 0.2s ease;
}

.footer__link:hover {
  color: var(--accent-dark);
}

.footer__link-icon {
  font-size: 1rem;
}

.footer__copyright {
  font-size: 0.82rem;
  color: var(--text-light);
  font-style: italic;
}

/* --- Animations --- */
@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Mobile nav open state */
.nav--open .nav__links {
  display: flex;
}

/* --- Responsive --- */
@media (max-width: 1024px) {
  .grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .photo-showcase {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .nav__links {
    display: none;
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: rgba(245, 246, 248, 0.95);
    backdrop-filter: blur(20px);
    flex-direction: column;
    padding: 24px;
    gap: 20px;
    border-bottom: 1px solid var(--card-border);
  }

  .nav__hamburger {
    display: flex;
  }

  .hero {
    min-height: 85vh;
    padding: 80px 20px 40px;
  }

  .hero__frame {
    width: 130px;
    height: 130px;
  }

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

  .section {
    padding: 36px 16px;
  }

  .section__header {
    margin-bottom: 32px;
  }

  .card {
    padding: 20px;
  }

  .card--photo-main {
    padding: 28px 20px;
  }

  .photo-main__body {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .photo-main__stat {
    padding-right: 0;
    padding-bottom: 24px;
    border-right: none;
    border-bottom: 1px solid rgba(203, 224, 241, 0.35);
  }

  .photo-main__num {
    width: 88px;
    height: 88px;
    font-size: 2.2rem;
  }

  .card__scores {
    gap: 20px;
  }

  .card__score-num {
    font-size: 1.8rem;
  }

  .timeline__item {
    flex-direction: column;
    gap: 4px;
    padding-left: 16px;
  }

  .timeline__year {
    min-width: auto;
  }

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

@media (max-width: 480px) {
  .nav__inner {
    padding: 0 16px;
  }

  .hero__badges {
    gap: 8px;
  }

  .hero__badge {
    font-size: 0.78rem;
    padding: 4px 12px;
  }
}