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

:root {
  --color-bg: #ffffff;
  --color-bg-alt: #f5f6f8;
  --color-text: #2c2c2c;
  --color-text-secondary: #5e5e5e;
  --color-text-light: #888888;
  --color-accent: #1a5276;
  --color-accent-light: #2e7dab;
  --color-border: #e0e0e0;
  --color-card-shadow: rgba(0, 0, 0, 0.06);
  --max-width: 1200px;
  --radius: 6px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

h2 {
  font-size: 1.6rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 1.5rem;
  padding-bottom: 0.6rem;
  border-bottom: 2px solid var(--color-accent);
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
}

h2 .count {
  font-size: 0.85rem;
  font-weight: 400;
  color: var(--color-text-light);
}

/* === Hero === */
.hero {
  position: relative;
  width: 100%;
  height: 100vh;
  min-height: 500px;
  overflow: hidden;
  background: #1a1a1a;
}

.hero-slides {
  position: absolute;
  inset: 0;
}

.hero-slide {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  opacity: 0;
  transition: opacity 1s ease-in-out;
}

.hero-slide.active {
  opacity: 1;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to bottom, rgba(0,0,0,0.3), rgba(0,0,0,0.45));
  z-index: 1;
}

.hero-content {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 2;
  text-align: center;
  color: white;
  width: 90%;
  max-width: 800px;
}

.hero-content h1 {
  font-family: 'Noto Serif SC', 'STSong', 'SimSun', 'Songti SC', serif;
  font-size: 3.2rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  margin-bottom: 0.8rem;
  text-shadow: 0 4px 20px rgba(0,0,0,0.6), 0 1px 4px rgba(0,0,0,0.4);
}

.hero-content p {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 1.2rem;
  font-weight: 400;
  opacity: 0.95;
  text-shadow: 0 2px 8px rgba(0,0,0,0.5);
}

.hero-dots {
  position: absolute;
  bottom: 36px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  display: flex;
  gap: 8px;
}

.hero-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: rgba(255,255,255,0.4);
  cursor: pointer;
  transition: background 0.3s;
}

.hero-dot.active {
  background: white;
}

.hero-scroll {
  position: absolute;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  animation: bounce 2s infinite;
  opacity: 0.7;
}

.hero-scroll:hover { opacity: 1; }

.hero-arrow {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  z-index: 3;
  background: rgba(255,255,255,0.15);
  border: none;
  cursor: pointer;
  padding: 10px 8px;
  border-radius: 4px;
  opacity: 0.5;
  transition: opacity 0.2s;
}

.hero-arrow:hover { opacity: 0.9; }

.hero-prev { left: 16px; }
.hero-next { right: 16px; }

@keyframes bounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(6px); }
}

/* === About === */
.about {
  padding: 80px 0 60px;
}

.about-card {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 36px 40px;
}

.about-card p {
  margin-bottom: 1rem;
  color: var(--color-text-secondary);
  font-size: 1.05rem;
}

.about-card p:last-child { margin-bottom: 0; }

.about-signature {
  text-align: right;
  color: var(--color-text) !important;
  font-weight: 500;
  margin-top: 1.2rem !important;
  padding-top: 1.2rem;
  border-top: 1px solid var(--color-border);
}

/* === Gallery === */
.gallery-section {
  padding: 60px 0;
  background: var(--color-bg-alt);
}

.gallery-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.gallery-item {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius);
  cursor: pointer;
  background: #e8e8e8;
  aspect-ratio: 3 / 2;
}

.gallery-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.35s ease;
  display: block;
}

.gallery-item:hover img {
  transform: scale(1.04);
}

.gallery-item:hover::after {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(0,0,0,0.08);
  pointer-events: none;
}

/* === GIF Section === */
.gif-section {
  padding: 60px 0;
}

.gif-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.gif-item {
  border-radius: var(--radius);
  overflow: hidden;
  background: #f0f0f0;
  box-shadow: 0 1px 4px var(--color-card-shadow);
}

.gif-item video,
.gif-item img {
  width: 100%;
  height: auto;
  display: block;
}

/* === Download === */
.download-section {
  padding: 60px 0;
  background: var(--color-bg-alt);
}

.download-card {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.download-tree {
  background: white;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px 32px;
}

.tree-title {
  font-weight: 600;
  font-size: 1.05rem;
  margin-bottom: 0.8rem;
}

.download-tree ul {
  list-style: none;
  font-size: 0.95rem;
  color: var(--color-text-secondary);
}

.download-tree li {
  padding: 3px 0;
  padding-left: 1.2em;
  text-indent: -1.2em;
}

.download-link {
  display: flex;
  flex-direction: column;
  justify-content: center;
  background: white;
  border: 2px dashed var(--color-accent);
  border-radius: var(--radius);
  padding: 28px 32px;
  gap: 0.8rem;
}

.download-link p {
  font-size: 1.05rem;
  color: var(--color-text-secondary);
  overflow-wrap: break-word;
  word-break: break-all;
}

.placeholder {
  color: var(--color-text-light);
  font-style: italic;
}

/* === Usage === */
.usage-section {
  padding: 60px 0;
}

.usage-card {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.usage-item {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px 24px;
}

.usage-item h3 {
  font-size: 1.05rem;
  margin-bottom: 0.6rem;
}

.usage-item p {
  font-size: 0.92rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.usage-full {
  grid-column: 1 / -1;
  text-align: center;
  margin-top: 0.5rem;
}

.usage-full a {
  color: var(--color-accent);
  text-decoration: none;
  font-size: 0.95rem;
}

.usage-full a:hover {
  text-decoration: underline;
}

/* === Changelog === */
.changelog-section {
  padding: 60px 0;
  background: var(--color-bg-alt);
}

.timeline {
  position: relative;
  padding-left: 24px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 5px;
  top: 4px;
  bottom: 4px;
  width: 2px;
  background: var(--color-border);
}

.timeline-item {
  position: relative;
  margin-bottom: 2rem;
}

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

.timeline-dot {
  position: absolute;
  left: -24px;
  top: 6px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--color-accent);
  border: 2px solid white;
  box-shadow: 0 0 0 2px var(--color-accent);
}

.timeline-date {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--color-accent);
  margin-bottom: 0.4rem;
}

.timeline-body {
  background: white;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 20px 24px;
}

.timeline-body p {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  margin-bottom: 0.5rem;
}

.timeline-body p:last-child { margin-bottom: 0; }

/* === Donate === */
.donate-section {
  padding: 60px 0;
  text-align: center;
}

.donate-section h2 {
  justify-content: center;
  border-bottom: none;
  margin-bottom: 0.8rem;
}

.donate-intro {
  color: var(--color-text-secondary);
  margin-bottom: 1.5rem;
  font-size: 0.95rem;
}

.donate-codes {
  display: flex;
  justify-content: center;
  gap: 40px;
}

.donate-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

.donate-item img {
  width: 300px;
  height: 300px;
  object-fit: contain;
  border-radius: 8px;
  border: 1px solid var(--color-border);
  background: white;
}

.donate-item span {
  font-size: 0.85rem;
  color: var(--color-text-light);
}

/* === Footer === */
.footer {
  padding: 40px 0;
  text-align: center;
  border-top: 1px solid var(--color-border);
}

.footer-text {
  font-size: 0.9rem;
  color: var(--color-text-light);
  margin-bottom: 0.3rem;
}

.footer-email {
  font-size: 0.9rem;
}

.footer-email a {
  color: var(--color-accent);
  text-decoration: none;
}

.footer-email a:hover {
  text-decoration: underline;
}

/* === Lightbox === */
.lightbox {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 9999;
  background: rgba(0, 0, 0, 0.92);
  align-items: center;
  justify-content: center;
}

.lightbox.active {
  display: flex;
}

.lightbox-img {
  max-width: 90vw;
  max-height: 85vh;
  object-fit: contain;
  border-radius: 2px;
}

.lightbox-close {
  position: absolute;
  top: 20px;
  right: 20px;
  background: none;
  border: none;
  cursor: pointer;
  z-index: 10;
  padding: 8px;
  opacity: 0.7;
  transition: opacity 0.2s;
}

.lightbox-close:hover { opacity: 1; }

.lightbox-prev,
.lightbox-next {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  background: rgba(255,255,255,0.1);
  border: none;
  cursor: pointer;
  padding: 12px;
  opacity: 0.6;
  transition: opacity 0.2s;
  border-radius: 4px;
}

.lightbox-prev:hover,
.lightbox-next:hover { opacity: 1; }

.lightbox-prev { left: 20px; }
.lightbox-next { right: 20px; }

/* === Sidebar === */
.sidebar-toggle {
  display: none;
  position: fixed;
  left: 8px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 101;
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(6px);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  padding: 8px 6px;
  cursor: pointer;
  color: var(--color-text-secondary);
  box-shadow: 0 1px 6px rgba(0,0,0,0.08);
}

.sidebar {
  position: fixed;
  left: 24px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 100;
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(6px);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 12px 0;
  box-shadow: 0 2px 12px rgba(0,0,0,0.06);
  transition: opacity 0.2s, visibility 0.2s;
}

.sidebar.collapsed {
  opacity: 0;
  visibility: hidden;
}

.sidebar ul {
  list-style: none;
}

.sidebar-link {
  display: block;
  padding: 6px 18px;
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: color 0.2s, border-color 0.2s;
}

.sidebar-link:hover {
  color: var(--color-accent);
}

.sidebar-link.active {
  color: var(--color-accent);
  border-left-color: var(--color-accent);
  font-weight: 500;
}

/* === Section === */
section {
  scroll-margin-top: 0;
}

/* === Responsive === */
@media (max-width: 768px) {
  .sidebar-toggle { display: block; }
  .sidebar {
    left: 8px;
    padding: 6px 0;
    opacity: 0;
    visibility: hidden;
  }
  .sidebar.visible { opacity: 1; visibility: visible; }
  .sidebar-link { padding: 4px 10px; font-size: 0.75rem; }
  .hero-content h1 { font-size: 2.4rem; white-space: nowrap; }
  .hero-content p { font-size: 1rem; }
  .gallery-grid { grid-template-columns: repeat(2, 1fr); gap: 8px; }
  .gif-grid { grid-template-columns: 1fr 1fr; }
  .download-card { grid-template-columns: 1fr; }
  .usage-card { grid-template-columns: 1fr; }
  .about-card { padding: 24px; }
  .container { padding: 0 16px; }
  h2 { font-size: 1.3rem; }
  .lightbox-prev { left: 8px; }
  .lightbox-next { right: 8px; }
  .donate-item img { width: 160px; height: 160px; }
  .donate-codes { gap: 20px; }
}

@media (max-width: 480px) {
  .gallery-grid { grid-template-columns: repeat(2, 1fr); gap: 6px; }
  .gif-grid { grid-template-columns: 1fr; }
  .hero-content h1 { font-size: 1.9rem; white-space: nowrap; }
  .donate-item img { width: 130px; height: 130px; }
  .donate-codes { gap: 12px; }
}