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

body {
  font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: #fafafa;
  color: #1a1a2e;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  text-decoration: none;
  color: inherit;
}

/* ===== Navbar ===== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
}

.navbar-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 20px;
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, #3b82f6, #60a5fa);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  color: #fff;
  line-height: 1;
}

.logo-icon svg {
  width: 20px;
  height: 20px;
  fill: none;
  stroke: #fff;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.logo-text {
  background: linear-gradient(135deg, #1e3a5f, #3b82f6);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-link {
  font-size: 15px;
  font-weight: 500;
  color: #4a4a6a;
  transition: color 0.2s;
  display: flex;
  align-items: center;
  gap: 6px;
}

.nav-link:hover {
  color: #1a1a2e;
}

.badge-soon {
  font-size: 10px;
  font-weight: 700;
  color: #fff;
  background: linear-gradient(135deg, #f97316, #ef4444);
  padding: 2px 8px;
  border-radius: 20px;
  letter-spacing: 0.5px;
}

.nav-search {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  color: #888;
  background: #f3f4f6;
  padding: 8px 16px;
  border-radius: 10px;
  cursor: pointer;
  transition: all 0.2s;
}

.nav-search:hover {
  background: #e5e7eb;
  color: #555;
}

.nav-github {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 10px;
  color: #888;
  transition: all 0.2s;
}

.nav-github:hover {
  background: #e5e7eb;
  color: #333;
}

/* ===== Hero Section ===== */
.hero {
  position: relative;
  overflow: hidden;
  padding: 80px 0 100px;
}

.hero-bg-blur {
  position: absolute;
  top: -100px;
  left: -100px;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.12) 0%, rgba(99, 102, 241, 0.06) 40%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
  z-index: 0;
}

.hero::after {
  content: '';
  position: absolute;
  top: 50px;
  right: -50px;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(249, 115, 22, 0.08) 0%, transparent 60%);
  border-radius: 50%;
  pointer-events: none;
  z-index: 0;
}

.hero-inner {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px;
  display: flex;
  align-items: flex-start;
  gap: 64px;
}

.hero-left {
  flex: 1;
  padding-top: 20px;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 500;
  color: #6366f1;
  background: rgba(99, 102, 241, 0.08);
  padding: 6px 16px;
  border-radius: 20px;
  margin-bottom: 28px;
  border: 1px solid rgba(99, 102, 241, 0.12);
}

.tag-icon {
  font-size: 14px;
}

.hero-title {
  font-size: 48px;
  font-weight: 900;
  line-height: 1.25;
  letter-spacing: -1px;
  margin-bottom: 20px;
  color: #0f172a;
}

.hero-title-gradient {
  background: linear-gradient(135deg, #3b82f6, #6366f1, #8b5cf6);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  font-size: 16px;
  color: #64748b;
  line-height: 1.8;
  margin-bottom: 36px;
  max-width: 460px;
}

.hero-buttons {
  display: flex;
  gap: 16px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  border-radius: 24px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.25s;
  border: none;
}

.btn-primary {
  background: linear-gradient(135deg, #f97316, #ef4444);
  color: #fff;
  box-shadow: 0 4px 16px rgba(249, 115, 22, 0.3);
}

.btn-primary:hover {
  box-shadow: 0 6px 24px rgba(249, 115, 22, 0.4);
  transform: translateY(-1px);
}

.btn-outline {
  background: #fff;
  color: #f97316;
  border: 1.5px solid #f97316;
}

.btn-outline:hover {
  background: #fff7ed;
  transform: translateY(-1px);
}

/* ===== Hero Card ===== */
.hero-right {
  flex-shrink: 0;
  width: 420px;
}

.hero-card {
  background: #fff;
  border-radius: 16px;
  padding: 24px;
  box-shadow:
    0 1px 3px rgba(0, 0, 0, 0.04),
    0 8px 32px rgba(0, 0, 0, 0.06);
  border: 1px solid rgba(0, 0, 0, 0.06);
}

.card-tabs {
  display: flex;
  gap: 0;
  margin-bottom: 20px;
  border: 1px solid #e5e7eb;
  border-radius: 10px;
  overflow: hidden;
}

.card-tab {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 0;
  font-size: 14px;
  font-weight: 500;
  color: #888;
  cursor: pointer;
  transition: all 0.2s;
  background: #fafafa;
}

.card-tab.active {
  background: #fff;
  color: #1a1a2e;
  font-weight: 600;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.05);
}

.card-hint {
  font-size: 12.5px;
  color: #94a3b8;
  margin-bottom: 10px;
  line-height: 1.6;
}

.card-code-block {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: #f8fafc;
  border: 1px solid #e2e8f0;
  border-radius: 10px;
  padding: 12px 14px;
  margin-bottom: 16px;
}

.card-code-text {
  font-size: 13px;
  color: #64748b;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
  flex: 1;
  margin-right: 8px;
}

.card-copy-btn {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 12px;
  color: #64748b;
  background: #fff;
  border: 1px solid #e2e8f0;
  border-radius: 6px;
  padding: 5px 10px;
  cursor: pointer;
  transition: all 0.2s;
  flex-shrink: 0;
}

.card-copy-btn:hover {
  background: #f1f5f9;
  color: #334155;
}

/* ===== Explore Section (Homepage) ===== */
.explore-section {
  padding: 60px 0 80px;
  background: #fff;
}

.explore-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px;
}

.explore-header {
  text-align: center;
  margin-bottom: 48px;
}

.explore-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 500;
  color: #6366f1;
  background: rgba(99, 102, 241, 0.08);
  padding: 6px 18px;
  border-radius: 20px;
  margin-bottom: 20px;
  border: 1px solid rgba(99, 102, 241, 0.12);
}

.explore-title {
  font-size: 36px;
  font-weight: 900;
  color: #0f172a;
  margin-bottom: 14px;
  letter-spacing: -0.5px;
}

.explore-desc {
  font-size: 16px;
  color: #64748b;
  line-height: 1.8;
  max-width: 560px;
  margin: 0 auto;
}

/* --- Explore Grid --- */
.explore-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

/* --- Explore Card --- */
.explore-card {
  position: relative;
  border-radius: 16px;
  padding: 28px;
  background: #fff;
  border: 1px solid #e8ecf1;
  text-decoration: none;
  color: inherit;
  transition: all 0.3s;
  overflow: hidden;
}

.explore-card:hover {
  border-color: #cbd5e1;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.08);
  transform: translateY(-3px);
}

.explore-card-glow {
  position: absolute;
  top: -60px;
  right: -60px;
  width: 200px;
  height: 200px;
  border-radius: 50%;
  opacity: 0.5;
  pointer-events: none;
  transition: opacity 0.3s;
}

.explore-card-tools .explore-card-glow {
  background: radial-gradient(circle, rgba(249, 115, 22, 0.12) 0%, transparent 70%);
}

.explore-card-papers .explore-card-glow {
  background: radial-gradient(circle, rgba(99, 102, 241, 0.12) 0%, transparent 70%);
}

.explore-card-articles .explore-card-glow {
  background: radial-gradient(circle, rgba(16, 185, 129, 0.12) 0%, transparent 70%);
}

.explore-card-daily .explore-card-glow {
  background: radial-gradient(circle, rgba(239, 68, 68, 0.12) 0%, transparent 70%);
}

.explore-card:hover .explore-card-glow {
  opacity: 1;
}

.explore-card-content {
  position: relative;
  z-index: 1;
}

.explore-card-icon {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  margin-bottom: 18px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.explore-card-info {
  margin-bottom: 16px;
}

.explore-card-title {
  font-size: 22px;
  font-weight: 800;
  color: #0f172a;
  margin-bottom: 6px;
}

.explore-card-subtitle {
  font-size: 13px;
  font-weight: 600;
  color: #3b82f6;
  margin-bottom: 8px;
}

.explore-card-desc {
  font-size: 14px;
  color: #64748b;
  line-height: 1.7;
}

/* --- Mini Tags --- */
.explore-card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 18px;
}

.explore-mini-tag {
  display: inline-flex;
  align-items: center;
  gap: 3px;
  font-size: 12px;
  font-weight: 500;
  color: var(--tag-color, #64748b);
  background: color-mix(in srgb, var(--tag-color, #64748b) 8%, #fff);
  border: 1px solid color-mix(in srgb, var(--tag-color, #64748b) 15%, transparent);
  padding: 4px 12px;
  border-radius: 16px;
  white-space: nowrap;
}

/* --- Card Arrow / CTA --- */
.explore-card-arrow {
  display: inline-flex;
  align-items: center;
  font-size: 14px;
  font-weight: 600;
  color: #3b82f6;
  transition: all 0.2s;
}

.explore-card:hover .explore-card-arrow {
  color: #2563eb;
  gap: 4px;
}

/* --- Coming Soon Card --- */
.explore-card-coming {
  opacity: 0.65;
  cursor: default;
}

.explore-card-coming:hover {
  transform: none;
  box-shadow: none;
  border-color: #e8ecf1;
}

.explore-card-badge-soon {
  display: inline-block;
  font-size: 11px;
  font-weight: 700;
  color: #fff;
  background: linear-gradient(135deg, #94a3b8, #64748b);
  padding: 4px 14px;
  border-radius: 20px;
  letter-spacing: 1px;
  margin-top: 12px;
}

/* --- Full-width last card --- */
.explore-grid > .explore-card:last-child:nth-child(odd) {
  grid-column: 1 / -1;
}

/* ===== Nav link active state ===== */
.nav-link.active {
  color: #3b82f6;
  font-weight: 600;
}

/* ===== Footer ===== */
.footer {
  border-top: 1px solid #f1f5f9;
  background: #fafafa;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 32px;
  text-align: center;
}

.footer-inner p {
  font-size: 13px;
  color: #94a3b8;
}

/* ===== Mobile Hamburger Menu ===== */
.nav-hamburger {
  display: none;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 10px;
  cursor: pointer;
  border: none;
  background: transparent;
  color: #4a4a6a;
  transition: all 0.2s;
  -webkit-tap-highlight-color: transparent;
}

.nav-hamburger:hover {
  background: #f3f4f6;
  color: #1a1a2e;
}

.nav-hamburger svg {
  width: 22px;
  height: 22px;
}

/* Mobile menu overlay */
.mobile-menu-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.4);
  z-index: 199;
  opacity: 0;
  transition: opacity 0.3s;
}

.mobile-menu-overlay.active {
  opacity: 1;
}

/* Mobile slide-in menu */
.mobile-menu {
  display: none;
  position: fixed;
  top: 0;
  right: -280px;
  width: 280px;
  height: 100%;
  background: #fff;
  z-index: 200;
  box-shadow: -4px 0 24px rgba(0, 0, 0, 0.1);
  transition: right 0.3s ease;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
}

.mobile-menu.active {
  right: 0;
}

.mobile-menu-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  border-bottom: 1px solid #f1f5f9;
}

.mobile-menu-title {
  font-size: 16px;
  font-weight: 700;
  color: #0f172a;
}

.mobile-menu-close {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 8px;
  border: none;
  background: #f3f4f6;
  color: #64748b;
  cursor: pointer;
  transition: all 0.2s;
  -webkit-tap-highlight-color: transparent;
}

.mobile-menu-close:hover {
  background: #e5e7eb;
  color: #334155;
}

.mobile-menu-links {
  padding: 12px 16px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.mobile-menu-links .mobile-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 14px 16px;
  border-radius: 10px;
  font-size: 15px;
  font-weight: 500;
  color: #4a4a6a;
  text-decoration: none;
  transition: all 0.2s;
  -webkit-tap-highlight-color: transparent;
}

.mobile-menu-links .mobile-link:hover,
.mobile-menu-links .mobile-link:active {
  background: #f1f5f9;
  color: #1a1a2e;
}

.mobile-menu-links .mobile-link.active {
  background: #eff6ff;
  color: #3b82f6;
  font-weight: 600;
}

.mobile-menu-links .mobile-link-icon {
  font-size: 18px;
  width: 24px;
  text-align: center;
}

/* ===== Responsive ===== */
@media (max-width: 900px) {
  .hero-inner {
    flex-direction: column;
    gap: 40px;
  }

  .hero-right {
    width: 100%;
  }

  .hero-title {
    font-size: 36px;
  }

  .nav-links {
    display: none;
  }

  .nav-search {
    display: none;
  }

  .nav-hamburger {
    display: flex;
  }

  .mobile-menu-overlay {
    display: block;
  }

  .mobile-menu {
    display: block;
  }

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

  .explore-title {
    font-size: 28px;
  }
}

@media (max-width: 600px) {
  .navbar-inner {
    padding: 0 16px;
  }

  .hero {
    padding: 40px 0 60px;
  }

  .hero-inner {
    padding: 0 16px;
  }

  .hero-title {
    font-size: 28px;
  }

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

  .explore-inner {
    padding: 0 16px;
  }

  .explore-title {
    font-size: 24px;
  }

  .explore-card {
    padding: 20px;
  }

  .explore-card-title {
    font-size: 18px;
  }

  .explore-card-tags {
    gap: 6px;
  }

  .explore-mini-tag {
    font-size: 11px;
    padding: 3px 10px;
  }
}