/* 1. CSS Reset & Base */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: 2rem; }
body { font-family: 'Noto Sans SC', sans-serif; background: var(--bg-primary); color: var(--text-primary); overflow-x: hidden; line-height: 1.8; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
img { max-width: 100%; display: block; }

/* 2. CSS Variables */
:root {
  --bg-primary: #0a0a1a;
  --bg-secondary: #1a1035;
  --bg-card: rgba(26, 16, 53, 0.6);
  --accent-primary: #8A2BE2;
  --accent-secondary: #FF6B6B;
  --accent-yellow: #FFE066;
  --accent-teal: #4ECDC4;
  --text-primary: #E8E6F0;
  --text-secondary: #9B96A8;
  --font-display: 'ZCOOL KuaiLe', cursive;
  --font-body: 'Noto Sans SC', sans-serif;
  --container-max: 1200px;
  --section-padding: 6rem 2rem;
  --transition-bounce: cubic-bezier(0.68, -0.6, 0.32, 1.6);
}

/* Light Theme Variables */
:root[data-theme="light"] {
  --bg-primary: #faf5ff;
  --bg-secondary: #ede5ff;
  --bg-card: rgba(255, 255, 255, 0.85);
  --accent-primary: #7C3AED;
  --accent-secondary: #F43F5E;
  --accent-yellow: #F59E0B;
  --accent-teal: #14B8A6;
  --text-primary: #1e1b4b;
  --text-secondary: #6b7280;
}

/* 3. Container */
.container { max-width: var(--container-max); margin: 0 auto; padding: 0 1.5rem; }

/* 4. Section Title */
.section-title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3rem);
  text-align: center;
  margin-bottom: 3rem;
  position: relative;
  display: inline-block;
  width: 100%;
}
.section-title::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: linear-gradient(90deg, var(--accent-primary), var(--accent-secondary));
  margin: 0.5rem auto 0;
  border-radius: 2px;
}

/* 5. Scroll reveal animation class */
.reveal { opacity: 0; transform: translateY(30px); transition: opacity 0.8s ease, transform 0.8s ease; }
.reveal.active { opacity: 1; transform: translateY(0); }

/* 6. Hero Section */
.hero {
  min-height: 100vh;
  background: linear-gradient(135deg, var(--bg-primary) 0%, #1a0a2e 50%, var(--bg-secondary) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}
.hero-content {
  text-align: center;
  z-index: 2;
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  min-height: 100vh;
  justify-content: center;
  width: 100%;
}
.hero-title {
  font-family: var(--font-display);
  font-size: clamp(3rem, 8vw, 5rem);
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary), var(--accent-yellow));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 1rem;
  animation: fadeInUp 1s ease forwards;
}
.hero-subtitle {
  font-size: clamp(1rem, 3vw, 1.5rem);
  color: var(--text-secondary);
  min-height: 2em;
  font-weight: 300;
}
.hero-subtitle .cursor {
  display: inline-block;
  width: 2px;
  height: 1.2em;
  background: var(--accent-primary);
  vertical-align: text-bottom;
  animation: blink 1s step-end infinite;
}
.decoration {
  position: absolute;
  border-radius: 50%;
}
.decoration-1 {
  width: 80px;
  height: 80px;
  background: rgba(138,43,226,0.15);
  top: 15%;
  left: 10%;
  animation: float 6s ease-in-out infinite;
}
.decoration-2 {
  width: 120px;
  height: 120px;
  border: 2px solid rgba(255,107,107,0.2);
  top: 20%;
  right: 15%;
  animation: float 8s ease-in-out infinite 1s;
}
.decoration-3 {
  width: 40px;
  height: 40px;
  background: rgba(78,205,196,0.2);
  bottom: 30%;
  left: 20%;
  animation: float 5s ease-in-out infinite 0.5s;
}
.decoration-4 {
  width: 60px;
  height: 60px;
  border: 2px solid rgba(255,224,102,0.15);
  bottom: 20%;
  right: 25%;
  animation: float 7s ease-in-out infinite 1.5s;
}
.decoration-5 {
  width: 30px;
  height: 30px;
  background: rgba(138,43,226,0.2);
  top: 40%;
  left: 50%;
  animation: float 4s ease-in-out infinite 2s;
}
.decoration-6 {
  width: 100px;
  height: 100px;
  border: 2px solid rgba(167,139,250,0.1);
  top: 60%;
  right: 5%;
  animation: float 9s ease-in-out infinite 0.8s;
  border-radius: 30%;
}
.scroll-indicator {
  margin-top: auto;
  padding-bottom: 2rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-secondary);
  font-size: 0.85rem;
  animation: bounce 2s ease infinite;
}
.scroll-arrow {
  display: block;
  width: 20px;
  height: 20px;
  border-right: 2px solid var(--text-secondary);
  border-bottom: 2px solid var(--text-secondary);
  transform: rotate(45deg);
}

/* 7. About Section */
.section.about {
  padding: var(--section-padding);
  background: var(--bg-primary);
}
.about-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
}
.about-text p {
  margin-bottom: 1.2rem;
  color: var(--text-secondary);
  font-size: 1.05rem;
  line-height: 2;
}
.about-text p:first-child {
  color: var(--text-primary);
  font-size: 1.2rem;
  font-weight: 700;
}
.about-emojis {
  position: relative;
  min-height: 300px;
}
.floating-emoji {
  position: absolute;
  left: var(--x);
  top: var(--y);
  font-size: 2.5rem;
  animation: floatEmoji 3s ease-in-out infinite;
  animation-delay: var(--delay);
  filter: drop-shadow(0 0 10px rgba(138,43,226,0.3));
}

/* 8. Projects Section */
.section.projects {
  padding: var(--section-padding);
  background: var(--bg-secondary);
}
.projects-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}
.project-card {
  background: var(--bg-card);
  border-radius: 16px;
  overflow: hidden;
  transition: transform 0.4s var(--transition-bounce), box-shadow 0.4s ease;
  position: relative;
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255,255,255,0.05);
}
.project-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--accent, var(--accent-primary));
  border-radius: 16px 16px 0 0;
}
.project-card:hover {
  transform: translateY(-8px) scale(1.02);
  box-shadow: 0 20px 40px rgba(0,0,0,0.3);
}
.card-header {
  padding: 2rem;
}
.card-emoji {
  font-size: 3rem;
  display: block;
  margin-bottom: 1rem;
}
.card-title {
  font-family: var(--font-display);
  font-size: 1.4rem;
  margin-bottom: 0.8rem;
  color: var(--text-primary);
}
.card-desc {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.8;
  margin-bottom: 1.2rem;
}
.card-tags {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}
.tag {
  padding: 0.25rem 0.75rem;
  background: rgba(138,43,226,0.15);
  color: var(--accent-primary);
  border-radius: 20px;
  font-size: 0.8rem;
  border: 1px solid rgba(138,43,226,0.2);
}

/* 9. Fun Zone Section */
.section.funzone {
  padding: var(--section-padding);
  background: var(--bg-primary);
  text-align: center;
}
.inspiration-card {
  max-width: 500px;
  margin: 0 auto;
  padding: 3rem;
  background: var(--bg-card);
  border-radius: 20px;
  border: 1px solid rgba(138,43,226,0.2);
  position: relative;
}
.inspiration-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  border-radius: 20px;
  padding: 2px;
  background: linear-gradient(45deg, var(--accent-primary), var(--accent-secondary), var(--accent-teal), var(--accent-yellow));
  background-size: 300% 300%;
  animation: glowBorder 3s linear infinite;
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  mask-composite: exclude;
  pointer-events: none;
}
.inspiration-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
}
.inspiration-card h3 {
  font-family: var(--font-display);
  font-size: 1.5rem;
  margin-bottom: 1rem;
}
.inspiration-text {
  color: var(--text-secondary);
  min-height: 3em;
  font-size: 1.1rem;
  line-height: 1.8;
  margin-bottom: 1.5rem;
  transition: opacity 0.3s ease;
}

.inspiration-text.fade-out {
  opacity: 0;
}
.inspiration-btn {
  padding: 0.8rem 2rem;
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
  color: white;
  border: none;
  border-radius: 30px;
  font-size: 1rem;
  font-family: var(--font-body);
  cursor: pointer;
  transition: transform 0.3s var(--transition-bounce), box-shadow 0.3s ease;
  font-weight: 700;
}
.inspiration-btn:hover {
  transform: scale(1.08);
  box-shadow: 0 8px 25px rgba(138,43,226,0.4);
}
.inspiration-btn:active {
  transform: scale(0.95);
}

/* 10. Footer */
.footer {
  background: #060612;
  padding: 3rem 0 1.5rem;
  border-top: 1px solid rgba(255,255,255,0.05);
}
.footer-content {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 2rem;
  margin-bottom: 2rem;
}
.footer-brand h3 {
  font-family: var(--font-display);
  font-size: 1.3rem;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}
.footer-brand p {
  color: var(--text-secondary);
  font-size: 0.9rem;
}
.footer-nav h4, .footer-contact h4 {
  font-size: 1rem;
  margin-bottom: 0.8rem;
  color: var(--text-primary);
}
.footer-nav li, .footer-contact li {
  margin-bottom: 0.5rem;
}
.footer-nav a, .footer-contact a {
  color: var(--text-secondary);
  font-size: 0.9rem;
  transition: color 0.3s;
}
.footer-nav a:hover, .footer-contact a:hover {
  color: var(--accent-primary);
}
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.05);
  padding-top: 1.5rem;
  text-align: center;
}
.footer-legal {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.8rem;
  flex-wrap: wrap;
  margin-bottom: 0.5rem;
}
.icp-link {
  color: var(--text-secondary);
  font-size: 0.85rem;
  transition: color 0.3s;
}
.icp-link:hover {
  color: var(--accent-primary);
}
.footer-divider {
  color: rgba(255,255,255,0.1);
}
.upyun-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-secondary);
  font-size: 0.85rem;
  transition: color 0.3s;
}
.upyun-link:hover {
  color: var(--accent-primary);
}
.upyun-logo {
  vertical-align: middle;
  height: 24px;
  width: auto;
}
.copyright {
  color: var(--text-secondary);
  font-size: 0.8rem;
  opacity: 0.6;
}

/* 11. Keyframe Animations */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}
@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-20px); }
}
@keyframes floatEmoji {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  50% { transform: translateY(-15px) rotate(5deg); }
}
@keyframes blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}
@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}
@keyframes glowBorder {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

/* 11.5. Theme Toggle Button */
.theme-toggle {
  position: fixed;
  top: 1.5rem;
  right: 1.5rem;
  z-index: 1000;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: 2px solid rgba(255,255,255,0.1);
  cursor: pointer;
  background: var(--bg-card);
  backdrop-filter: blur(10px);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  transition: transform 0.3s var(--transition-bounce), box-shadow 0.3s ease;
  box-shadow: 0 4px 15px rgba(0,0,0,0.2);
  line-height: 1;
  padding: 0;
}
.theme-toggle:hover {
  transform: scale(1.1) rotate(15deg);
  box-shadow: 0 6px 20px rgba(138,43,226,0.3);
}
.theme-toggle:active { transform: scale(0.9); }
.theme-icon--dark { display: none; }
[data-theme="light"] .theme-icon--light { display: none; }
[data-theme="light"] .theme-icon--dark { display: inline; }

/* Theme Transition */
.theme-transitioning,
.theme-transitioning *,
.theme-transitioning *::before,
.theme-transitioning *::after {
  transition: background-color 0.4s ease, color 0.4s ease, border-color 0.4s ease, box-shadow 0.4s ease, background 0.4s ease !important;
}

/* 11.6. Light Theme Component Overrides */
[data-theme="light"] .hero {
  background: linear-gradient(135deg, #faf5ff 0%, #e8d5ff 50%, #ede5ff 100%);
}
[data-theme="light"] .decoration-1 { background: rgba(124,58,237,0.1); }
[data-theme="light"] .decoration-2 { border-color: rgba(244,63,94,0.2); }
[data-theme="light"] .decoration-3 { background: rgba(20,184,166,0.12); }
[data-theme="light"] .decoration-4 { border-color: rgba(245,158,11,0.18); }
[data-theme="light"] .decoration-5 { background: rgba(124,58,237,0.12); }
[data-theme="light"] .decoration-6 { border-color: rgba(124,58,237,0.08); }
[data-theme="light"] .project-card {
  border: 1px solid rgba(124,58,237,0.08);
  box-shadow: 0 4px 20px rgba(124,58,237,0.06);
  backdrop-filter: none;
}
[data-theme="light"] .project-card:hover {
  box-shadow: 0 20px 40px rgba(124,58,237,0.12);
}
[data-theme="light"] .tag {
  background: rgba(124,58,237,0.06);
  border-color: rgba(124,58,237,0.12);
}
[data-theme="light"] .inspiration-card {
  border-color: rgba(124,58,237,0.1);
  box-shadow: 0 4px 30px rgba(124,58,237,0.08);
}
[data-theme="light"] .inspiration-btn:hover {
  box-shadow: 0 8px 25px rgba(124,58,237,0.25);
}
[data-theme="light"] .floating-emoji {
  filter: drop-shadow(0 0 8px rgba(124,58,237,0.15));
}
[data-theme="light"] .footer {
  background: #f3f0f9;
  border-top: 1px solid rgba(124,58,237,0.08);
}
[data-theme="light"] .footer-bottom {
  border-top: 1px solid rgba(124,58,237,0.06);
}
[data-theme="light"] .footer-divider {
  color: rgba(30,27,75,0.15);
}
[data-theme="light"] .copyright {
  opacity: 0.8;
}
[data-theme="light"] .theme-toggle {
  border-color: rgba(124,58,237,0.15);
  box-shadow: 0 4px 15px rgba(124,58,237,0.1);
}
[data-theme="light"] .theme-toggle:hover {
  box-shadow: 0 6px 20px rgba(124,58,237,0.2);
}

/* 12. Responsive Breakpoints */
/* Tablet */
@media (max-width: 1024px) {
  .projects-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-content { grid-template-columns: 1fr 1fr; }
}

/* Mobile */
@media (max-width: 768px) {
  :root { --section-padding: 4rem 1.5rem; }
  .about-content { grid-template-columns: 1fr; }
  .about-emojis { min-height: 200px; }
  .projects-grid { grid-template-columns: 1fr; }
  .footer-content { grid-template-columns: 1fr; text-align: center; }
  .footer-legal { flex-direction: column; gap: 0.5rem; }
  .footer-divider { display: none; }
  .hero-title { font-size: clamp(2rem, 8vw, 3.5rem); }
  .decoration { display: none; }
  .theme-toggle { top: 1rem; right: 1rem; width: 42px; height: 42px; font-size: 1.1rem; }
}