/* ===== Apple-like Minimalist High-end Style (Enhanced Layout) ===== */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700&display=swap');

html, body {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  width: 100%;
  min-height: 100vh;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue', Arial, sans-serif;
  background: #fff;
  color: #111;
  font-size: 18px;
  line-height: 1.8;
  letter-spacing: 0.01em;
  scroll-behavior: smooth;
}

body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  background: #fff;
}

/* ===== Navigation Bar ===== */
header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,0.85);
  box-shadow: 0 2px 12px 0 rgba(0,0,0,0.04);
  backdrop-filter: blur(8px);
  transition: background 0.3s;
}

.navbar {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 32px;
  height: 68px;
}

.logo a {
  font-size: 2rem;
  color: #111;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 32px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  color: #222;
  font-weight: 500;
  text-decoration: none;
  font-size: 1.05rem;
  padding: 6px 0;
  border-bottom: 2px solid transparent;
  transition: color 0.2s, border-bottom 0.2s;
}

.nav-links a:hover {
  color: #0071e3;
  border-bottom: 2px solid #0071e3;
}

/* ===== Hero Section ===== */
.hero {
  min-height: 70vh;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  background: #fafbfc;
  text-align: center;
  padding: 80px 16px 40px 16px;
}

.hero-content h1 {
  font-size: 3rem;
  font-weight: 700;
  margin-bottom: 18px;
  color: #111;
  letter-spacing: -0.02em;
}

.hero-content .highlight {
  color: #0071e3;
  font-weight: 600;
}

.hero-content .cta-btn {
  display: inline-block;
  margin-top: 28px;
  padding: 14px 36px;
  background: #111;
  color: #fff;
  font-weight: 600;
  border-radius: 32px;
  font-size: 1.1rem;
  border: none;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
  cursor: pointer;
  transition: background 0.2s, box-shadow 0.2s, color 0.2s;
  text-decoration: none;
}
.hero-content .cta-btn:hover {
  background: #0071e3;
  color: #fff;
  box-shadow: 0 4px 16px rgba(0,113,227,0.10);
}

.hero-image img {
  width: 320px;
  height: 320px;
  object-fit: cover;
  border-radius: 24px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.10);
  margin: 32px 0 0 0;
  transition: transform 0.3s, box-shadow 0.3s;
}
.hero-image img:hover {
  transform: scale(1.04);
  box-shadow: 0 16px 48px rgba(0,113,227,0.10);
}

/* ===== Layout & Section ===== */
main, section, .about-container, .skills-grid, .projects-grid, .experience-timeline, .contact-container {
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
}
section {
  margin-top: 64px;
  margin-bottom: 64px;
  padding: 0 24px;
  background: transparent;
}
.about-container, .contact-container {
  background: #fff;
  border-radius: 18px;
  box-shadow: 0 2px 16px rgba(0,0,0,0.06);
  padding: 48px 32px;
  margin-top: 32px;
  margin-bottom: 32px;
}

/* ===== Headings & Typography ===== */
h1, h2, h3 {
  font-family: 'Inter', sans-serif;
  font-weight: 700;
  color: #111;
  margin-bottom: 28px;
  letter-spacing: -0.01em;
}
h1 {
  font-size: 2.8rem;
  margin-top: 0;
}
h2 {
  font-size: 1.6rem;
}
h3 {
  font-size: 1.2rem;
}
p, ul, li {
  color: #444;
  font-size: 1.08rem;
  margin-bottom: 18px;
  line-height: 1.8;
}

/* ===== Card/Grid Layouts ===== */
.projects-grid, .skills-grid, .experience-timeline {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 40px;
  margin: 40px 0;
}
.project-item, .skill-item, .experience-item {
  background: #fff;
  border-radius: 18px;
  box-shadow: 0 2px 16px rgba(0,0,0,0.06);
  padding: 36px 28px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  transition: box-shadow 0.2s, transform 0.2s;
}
.project-item:hover, .skill-item:hover, .experience-item:hover {
  box-shadow: 0 8px 32px rgba(0,113,227,0.10);
  transform: translateY(-4px) scale(1.02);
}
.project-item img, .skill-item img, .experience-item img {
  width: 100%;
  border-radius: 14px;
  margin-bottom: 18px;
  box-shadow: 0 2px 12px rgba(0,0,0,0.04);
}

/* ===== Highlights Section ===== */
.highlights {
  margin-top: 64px;
  margin-bottom: 64px;
  padding: 0 24px;
  background: transparent;
}
.highlights > div {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 40px;
  margin: 40px 0;
}
.highlight-item {
  background: #fff;
  border-radius: 18px;
  box-shadow: 0 2px 16px rgba(0,0,0,0.06);
  padding: 36px 28px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  transition: box-shadow 0.2s, transform 0.2s;
}
.highlight-item img {
  width: 100%;
  border-radius: 14px;
  margin-bottom: 18px;
  box-shadow: 0 2px 12px rgba(0,0,0,0.04);
}

/* ===== Buttons ===== */
button, .btn-portfolio, .cta-btn, .contact-form button {
  display: inline-block;
  padding: 14px 36px;
  background: #111;
  color: #fff;
  font-weight: 600;
  border-radius: 32px;
  font-size: 1.1rem;
  border: none;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
  cursor: pointer;
  transition: background 0.2s, box-shadow 0.2s, color 0.2s;
  text-decoration: none;
  margin-top: 12px;
}
button:hover, .btn-portfolio:hover, .cta-btn:hover, .contact-form button:hover {
  background: #0071e3;
  color: #fff;
  box-shadow: 0 4px 16px rgba(0,113,227,0.10);
}

/* ===== Forms ===== */
input, textarea {
  width: 100%;
  padding: 16px;
  border: 1px solid #e5e5e5;
  border-radius: 12px;
  background: #fafbfc;
  color: #222;
  font-size: 1rem;
  margin-bottom: 16px;
  transition: border 0.2s;
}
input:focus, textarea:focus {
  border: 1.5px solid #0071e3;
  outline: none;
}

/* ===== Links ===== */
a {
  color: #0071e3;
  text-decoration: none;
  transition: color 0.2s;
}
a:hover {
  color: #111;
}

/* ===== Footer ===== */
footer {
  width: 100%;
  padding: 32px 0 16px 0;
  text-align: center;
  background: #fafbfc;
  color: #888;
  font-size: 1rem;
  border-top: 1px solid #eee;
  margin-top: auto;
}
footer a {
  color: #0071e3;
  font-weight: 600;
}
footer a:hover {
  color: #111;
}

/* ===== Responsive ===== */
@media (max-width: 900px) {
  main, section, .about-container, .skills-grid, .projects-grid, .experience-timeline, .contact-container {
    max-width: 98vw;
    padding: 0 8px;
  }
  .projects-grid, .skills-grid, .experience-timeline, .highlights > div {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  .about-container, .contact-container {
    padding: 24px 8px;
  }
  h1 {
    font-size: 2rem;
  }
}
@media (max-width: 600px) {
  .navbar {
    flex-direction: column;
    height: auto;
    gap: 8px;
  }
  .hero {
    flex-direction: column;
    padding: 48px 0 24px 0;
  }
  .hero-content h1 {
    font-size: 1.5rem;
  }
  .hero-image img {
    width: 120px;
    height: 120px;
  }
  .about-container, .contact-container {
    padding: 12px 2px;
  }
}

/* ===== Misc ===== */
::-webkit-scrollbar {
  width: 8px;
  background: #fafbfc;
}
::-webkit-scrollbar-thumb {
  background: #e5e5e5;
  border-radius: 8px;
}

/* ===== Utility ===== */
.center {
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ===== Compatibility for original classes ===== */
/* (Retain original class names for HTML compatibility) */

/* Flip Card Styles for Experience */
.experience-timeline {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 40px;
  margin: 40px 0;
}
.flip-card {
  background: transparent;
  width: 100%;
  height: 260px;
  perspective: 1200px;
  border-radius: 18px;
}
.flip-card-inner {
  position: relative;
  width: 100%;
  height: 100%;
  text-align: left;
  transition: transform 0.35s ease-in-out;
  transform-style: preserve-3d;
  border-radius: 18px;
  box-shadow: 0 2px 16px rgba(0,0,0,0.06);
}
.flip-card:hover .flip-card-inner,
.flip-card:focus-within .flip-card-inner {
  transform: rotateY(180deg);
}
.flip-card-front, .flip-card-back {
  position: absolute;
  width: 100%;
  height: 100%;
  backface-visibility: hidden;
  border-radius: 18px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: flex-start;
  padding: 36px 28px;
  background: #fff;
}
.flip-card-front {
  z-index: 2;
}
.flip-card-back {
  transform: rotateY(180deg);
  z-index: 3;
  box-shadow: 0 8px 32px rgba(0,113,227,0.10);
}
.flip-card-back p {
  margin-bottom: 24px;
  color: #444;
  font-size: 1.08rem;
}
.flip-card .cta-btn {
  margin-top: 0;
}
@media (max-width: 600px) {
  .flip-card {
    height: 220px;
  }
  .flip-card-front, .flip-card-back {
    padding: 18px 8px;
  }
}

/* Experience Flip Card Layout Enhancements */
.experience-timeline {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 48px;
  margin: 56px 0;
}
.flip-card {
  background: transparent;
  width: 100%;
  max-width: 400px;
  min-width: 280px;
  min-height: 260px;
  margin: 0 auto;
  perspective: 1200px;
  border-radius: 22px;
  box-sizing: border-box;
}
.flip-card-inner {
  position: relative;
  width: 100%;
  min-height: 260px;
  height: 100%;
  text-align: left;
  transition: transform 0.35s ease-in-out;
  transform-style: preserve-3d;
  border-radius: 22px;
  box-shadow: 0 4px 24px rgba(0,0,0,0.08);
  background: #fff;
  display: flex;
}
.flip-card-front, .flip-card-back {
  position: absolute;
  width: 100%;
  min-height: 260px;
  height: 100%;
  backface-visibility: hidden;
  border-radius: 22px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 40px 32px;
  box-sizing: border-box;
  background: #fff;
}
.flip-card-front {
  z-index: 2;
}
.flip-card-back {
  transform: rotateY(180deg);
  z-index: 3;
  box-shadow: 0 8px 32px rgba(0,113,227,0.08);
}
.company {
  font-size: 1.25rem;
  font-weight: 700;
  color: #111;
  margin-bottom: 12px;
  text-align: center;
}
.position {
  font-size: 1.08rem;
  color: #0071e3;
  font-weight: 600;
  margin-bottom: 8px;
  text-align: center;
}
.timeline {
  font-size: 1rem;
  color: #888;
  margin-bottom: 0;
  text-align: center;
}
.flip-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 100%;
  text-align: center;
}
.flip-content p {
  margin-bottom: 24px;
  color: #444;
  font-size: 1.08rem;
}
.flip-card .cta-btn {
  margin-top: 0;
  align-self: center;
}
@media (max-width: 900px) {
  .experience-timeline {
    flex-direction: column;
    align-items: center;
    gap: 32px;
  }
  .flip-card {
    max-width: 98vw;
    min-width: 0;
  }
  .flip-card-front, .flip-card-back {
    padding: 24px 8px;
  }
}
@media (max-width: 600px) {
  .flip-card {
    min-height: 180px;
  }
  .flip-card-front, .flip-card-back {
    padding: 12px 2px;
  }
}

@media (max-width: 600px) {
  .projects-grid, .experience-timeline {
    grid-template-columns: 1fr;
    gap: 16px;
    margin: 16px 0;
  }
  .flip-card {
    min-height: 140px;
    height: 160px;
    max-width: 98vw;
    margin: 0 auto 12px auto;
  }
  .flip-card-front, .flip-card-back {
    padding: 10px 4px;
    font-size: 0.98rem;
  }
  .company {
    font-size: 1.05rem;
  }
  .position, .timeline {
    font-size: 0.95rem;
  }
  .flip-content p {
    font-size: 0.98rem;
    margin-bottom: 12px;
  }
  .flip-card .cta-btn {
    font-size: 0.98rem;
    padding: 10px 18px;
  }
}

.flip-card.flipped .flip-card-inner {
  transform: rotateY(180deg) !important;
}

/* ===== Mobile Nav Toggle (Hamburger) ===== */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 40px;
  height: 40px;
  background: none;
  border: none;
  cursor: pointer;
  z-index: 200;
  margin-left: 8px;
}
.nav-toggle .bar {
  display: block;
  width: 26px;
  height: 3px;
  margin: 4px 0;
  background: #222;
  border-radius: 2px;
  transition: 0.3s;
}

@media (max-width: 900px) {
  .nav-toggle {
    display: flex;
  }
  .nav-links.collapsed {
    display: none;
    flex-direction: column;
    width: 100%;
    background: rgba(255,255,255,0.98);
    position: absolute;
    top: 68px;
    left: 0;
    box-shadow: 0 2px 12px 0 rgba(0,0,0,0.04);
    padding: 0;
    z-index: 150;
  }
  .nav-links.collapsed.open {
    display: flex;
  }
  .navbar {
    position: relative;
  }
}

/* ===== 移动端优化：增强响应式布局 ===== */
@media (max-width: 600px) {
  html, body {
    font-size: 15px;
    padding: 0;
  }
  .navbar {
    flex-direction: column;
    height: auto;
    padding: 0 8px;
    gap: 8px;
  }
  .nav-links {
    flex-direction: column;
    gap: 8px;
    align-items: center;
  }
  .hero {
    flex-direction: column;
    padding: 32px 4px 16px 4px;
  }
  .hero-content h1 {
    font-size: 2rem;
  }
  .hero-image img {
    width: 90vw;
    height: auto;
    max-width: 320px;
    border-radius: 18px;
  }
  .about-container, .contact-container, .skills-grid, .projects-grid, .experience-timeline {
    width: 100%;
    padding: 0 4px;
    margin: 0;
    box-sizing: border-box;
    grid-template-columns: 1fr !important;
    display: block !important;
  }
  .projects-grid, .skills-grid, .experience-timeline {
    gap: 16px !important;
  }
  .project-item, .skill-item, .experience-item, .highlight-item, .flip-card {
    width: 100% !important;
    min-width: 0 !important;
    margin: 0 auto 16px auto !important;
    box-sizing: border-box;
  }
  .flip-card {
    height: auto !important;
    min-height: 180px !important;
  }
  .flip-card-front, .flip-card-back {
    min-height: 180px !important;
    padding: 16px 8px !important;
  }
  h1 {
    font-size: 1.5rem;
  }
  h2 {
    font-size: 1.1rem;
  }
  img {
    max-width: 100%;
    height: auto;
  }
  footer {
    font-size: 0.95rem;
    padding: 12px 0;
    text-align: center;
  }
  .cta-btn, .btn-portfolio {
    width: 100%;
    box-sizing: border-box;
    font-size: 1rem;
    padding: 12px 0;
  }
  /* 隐藏不必要的动画或装饰（如有） */
  [data-aos] {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }
}

/* ===== Experience Detail Styles ===== */
.experience-detail, .project-detail {
  padding: 80px 0;
  max-width: 800px;
  margin: 0 auto;
  padding-left: 32px;
  padding-right: 32px;
}

.experience-container, .project-container {
  background: #fff;
  border-radius: 16px;
  padding: 48px;
  box-shadow: 0 4px 24px rgba(0,0,0,0.06);
}

.experience-meta, .project-meta {
  background: #f8f9fa;
  padding: 24px;
  border-radius: 12px;
  margin-bottom: 32px;
  border-left: 4px solid #0071e3;
}

.experience-meta p, .project-meta p {
  margin: 8px 0;
  color: #555;
}

.experience-content h2, .project-content h2 {
  color: #111;
  font-size: 1.5rem;
  margin: 32px 0 16px 0;
  font-weight: 600;
}

.experience-content ul, .project-content ul {
  margin: 16px 0;
  padding-left: 24px;
}

.experience-content li, .project-content li {
  margin: 12px 0;
  color: #555;
  line-height: 1.6;
}

.tech-stack {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 24px 0;
}

.tech-tag {
  background: #0071e3;
  color: white;
  padding: 8px 16px;
  border-radius: 20px;
  font-size: 0.9rem;
  font-weight: 500;
}

/* Mobile styles for experience detail pages */
@media (max-width: 768px) {
  .experience-detail, .project-detail {
    padding: 40px 20px;
  }
  
  .experience-container, .project-container {
    padding: 32px 24px;
  }
  
  .tech-stack {
    gap: 8px;
  }
  
  .tech-tag {
    font-size: 0.8rem;
    padding: 6px 12px;
  }
}