:root {
  --primary: #ff7600;
  --primary-dark: #cc5e00;
  --primary-light: #ff9933;
  --primary-glow: rgba(255, 118, 0, 0.3);
  --primary-glow-strong: rgba(255, 118, 0, 0.5);
  --bg: #0a0a0a;
  --bg-card: #111111;
  --bg-card-hover: #1a1a1a;
  --border: #1e1e1e;
  --border-hover: #333333;
  --text: #cccccc;
  --text-muted: #888888;
  --text-heading: #ffffff;
  --font: 'Courier New', Courier, monospace;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
  --shadow-glow: 0 0 20px var(--primary-glow);
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --max-width: 1280px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  background-color: var(--bg);
  color: var(--text);
  font-family: var(--font);
  line-height: 1.7;
  scroll-behavior: smooth;
}

::selection {
  background-color: var(--primary);
  color: #fff;
}

::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg);
}

::-webkit-scrollbar-thumb {
  background: var(--primary);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--primary-light);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-heading);
  letter-spacing: -0.02em;
}

p {
  margin-bottom: 1.2em;
  line-height: 1.7;
}

a {
  color: var(--primary);
  text-underline-offset: 3px;
  transition: var(--transition);
}

a:hover {
  filter: brightness(1.2);
  text-decoration: underline;
}

/* Layout */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 2rem;
}

.section {
  padding: 4rem 0;
}

.section-title {
  font-size: 2rem;
  text-align: center;
  margin-bottom: 3rem;
  position: relative;
}

.section-title::after {
  content: '';
  display: block;
  width: 60px;
  height: 3px;
  background-color: var(--primary);
  margin: 1rem auto 0;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(10, 10, 10, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}

.logo-link {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  white-space: nowrap;
}

.logo-link:hover {
  text-decoration: none;
}

.logo-img {
  width: 45px;
  height: 45px;
  border-radius: 50%;
  border: 2px solid var(--primary);
  transition: var(--transition);
}

.logo-img:hover {
  box-shadow: var(--shadow-glow);
  transform: scale(1.05);
}

.site-title {
  font-size: 1.15rem;
  font-weight: bold;
  color: #fff;
  letter-spacing: 0.5px;
}

.site-title .highlight {
  color: var(--primary);
}

.nav-toggle {
  display: none;
}

.nav-links {
  display: flex;
  gap: 0.5rem;
  list-style: none;
}

.nav-link {
  padding: 0.5rem 1rem;
  color: var(--text);
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.nav-link:hover, .nav-link.active {
  color: var(--primary);
  background: rgba(255, 118, 0, 0.1);
  text-decoration: none;
}

.dropdown {
  position: relative;
}

.dropdown-menu {
  position: absolute;
  top: 100%;
  left: 0;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.5rem;
  min-width: 260px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: var(--transition);
  z-index: 100;
  box-shadow: var(--shadow);
}

.dropdown:hover .dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.dropdown-item {
  display: block;
  padding: 0.6rem 1rem;
  color: var(--text);
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: var(--transition);
  white-space: nowrap;
}

.dropdown-item:hover {
  background: rgba(255, 118, 0, 0.1);
  color: var(--primary);
  text-decoration: none;
}

/* Mobile Nav */
@media (max-width: 768px) {
  .nav-toggle {
    display: block;
    background: none;
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
  }

  .site-nav {
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    padding: 1rem;
    transform: translateY(-100%);
    transition: var(--transition);
    z-index: 999;
  }

  .site-nav.active {
    transform: translateY(0);
  }

  .nav-links {
    flex-direction: column;
    gap: 0;
  }

  .dropdown-menu {
    position: static;
    opacity: 1;
    visibility: visible;
    transform: none;
    border: none;
    padding-left: 1rem;
    background: transparent;
    box-shadow: none;
    min-width: 100%;
  }
  
  .site-title {
    font-size: 0.95rem;
  }
}

/* Hero Section */
.hero {
  background: linear-gradient(135deg, #0a0a0a 0%, #1a0a00 50%, #0a0a0a 100%);
  padding: 6rem 0;
  text-align: center;
  position: relative;
  overflow: hidden;
  animation: gradientShift 10s ease infinite alternate;
}

@keyframes gradientShift {
  0% { background-position: 0% 50%; }
  100% { background-position: 100% 50%; }
}

.hero::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 150vw;
  height: 150vw;
  background: radial-gradient(circle, var(--primary) 0%, transparent 70%);
  opacity: 0.15;
  pointer-events: none;
  z-index: 0;
}

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

.hero-logo {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  border: 3px solid var(--primary);
  margin: 0 auto 2rem;
  box-shadow: var(--shadow-glow);
  animation: pulse-glow 3s ease-in-out infinite;
}

.hero-title {
  font-size: 3rem;
  color: white;
  margin-bottom: 1rem;
}

.hero-title .highlight {
  color: var(--primary);
}

.hero-subtitle {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto 2rem;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 3rem;
  margin-top: 2rem;
}

.stat-item {
  text-align: center;
}

.stat-number {
  font-size: 2rem;
  font-weight: bold;
  color: var(--primary);
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
}

/* Category Grid */
.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
}

.category-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  text-decoration: none;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.category-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--primary);
  transform: scaleX(0);
  transition: var(--transition);
  transform-origin: left;
}

.category-card:hover {
  transform: translateY(-4px);
  border-color: var(--primary);
  box-shadow: var(--shadow-glow);
  text-decoration: none;
}

.category-card:hover::before {
  transform: scaleX(1);
}

.card-icon {
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

.card-title {
  font-size: 1.2rem;
  color: var(--text-heading);
  margin-bottom: 0.5rem;
  font-weight: bold;
}

.card-description {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 1rem;
  flex-grow: 1;
}

.card-count {
  font-size: 0.8rem;
  color: var(--primary);
  font-weight: bold;
  text-transform: uppercase;
  letter-spacing: 1px;
}

/* Article List & Cards */
.article-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem 2rem;
  text-decoration: none;
  transition: var(--transition);
  display: block;
}

.article-card:hover {
  border-color: var(--primary);
  transform: translateX(4px);
  box-shadow: var(--shadow-glow);
  text-decoration: none;
}

.article-title {
  font-size: 1.1rem;
  color: var(--text-heading);
  margin-bottom: 0.5rem;
  font-weight: bold;
}

.article-excerpt {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 0.75rem;
}

.article-meta {
  font-size: 0.75rem;
  color: var(--text-muted);
  display: flex;
  gap: 1.5rem;
}

.read-time {
  color: var(--primary);
}

/* Article Content Page */
.article-header {
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
}

.article-header h1 {
  font-size: 2.2rem;
  line-height: 1.3;
  margin-bottom: 1rem;
}

.article-content {
  max-width: 800px;
}

.article-content h2 {
  font-size: 1.5rem;
  margin-top: 2.5rem;
  margin-bottom: 1rem;
  color: var(--primary);
  border-left: 3px solid var(--primary);
  padding-left: 1rem;
}

.article-content h3 {
  font-size: 1.2rem;
  margin-top: 2rem;
  margin-bottom: 0.75rem;
}

.article-content p {
  margin-bottom: 1.2rem;
  line-height: 1.8;
}

.article-content ul, .article-content ol {
  margin-bottom: 1.2rem;
  padding-left: 1.5rem;
}

.article-content li {
  margin-bottom: 0.5rem;
  line-height: 1.7;
}

.article-content a {
  color: var(--primary);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.article-content blockquote {
  border-left: 3px solid var(--primary);
  padding: 1rem 1.5rem;
  margin: 1.5rem 0;
  background: rgba(255, 118, 0, 0.05);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-style: italic;
}

.article-content code {
  background: #1a1a1a;
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  font-size: 0.9em;
  color: var(--primary-light);
}

.article-content pre {
  background: #1a1a1a;
  padding: 1.5rem;
  border-radius: var(--radius-sm);
  overflow-x: auto;
  margin: 1.5rem 0;
  border: 1px solid var(--border);
}

.article-content hr {
  border: none;
  height: 1px;
  background: var(--border);
  margin: 2rem 0;
}

.article-content strong {
  color: var(--text-heading);
  font-weight: bold;
}

/* Article Navigation */
.article-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}

.nav-prev, .nav-next {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  text-decoration: none;
  transition: var(--transition);
}

.nav-next {
  text-align: right;
}

.nav-prev:hover, .nav-next:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-glow);
  text-decoration: none;
}

.nav-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 0.5rem;
  display: block;
}

.nav-title {
  color: var(--text-heading);
  font-weight: bold;
}

/* Content Layout (for article pages with sidebar) */
.content-layout {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 3rem;
  align-items: start;
}

/* Sidebar */
.sidebar {
  position: sticky;
  top: 90px;
}

.sidebar-section {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
}

.sidebar-title {
  font-size: 1rem;
  color: var(--text-heading);
  margin-bottom: 1rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border);
}

.sidebar-list {
  list-style: none;
  padding: 0;
}

.sidebar-item a {
  display: block;
  padding: 0.5rem 0;
  color: var(--text);
  text-decoration: none;
  font-size: 0.85rem;
  transition: var(--transition);
  border-bottom: 1px solid rgba(255,255,255,0.03);
}

.sidebar-item a:hover {
  color: var(--primary);
  padding-left: 0.5rem;
  text-decoration: none;
}

/* Breadcrumbs */
.breadcrumbs {
  padding: 1rem 0;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.breadcrumbs a {
  color: var(--text-muted);
  text-decoration: none;
}

.breadcrumbs a:hover {
  color: var(--primary);
  text-decoration: none;
}

.breadcrumb-separator {
  margin: 0 0.5rem;
  opacity: 0.5;
}

/* Tools Page */
.tools-hero {
  text-align: center;
  padding: 3rem 0;
  margin-bottom: 2rem;
}

.phase-section {
  margin-bottom: 3rem;
}

.phase-title {
  font-size: 1.3rem;
  color: var(--primary);
  margin-bottom: 1.5rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border);
}

.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1rem;
}

.tool-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 1rem 1.25rem;
  text-decoration: none;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.tool-card:hover {
  border-color: var(--primary);
  background: var(--bg-card-hover);
  box-shadow: var(--shadow-glow);
  text-decoration: none;
}

.tool-icon {
  font-size: 1.2rem;
  color: var(--primary);
  flex-shrink: 0;
}

.tool-name {
  color: var(--text-heading);
  font-size: 0.85rem;
  font-weight: bold;
}

/* Pagination */
.pagination {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  margin-top: 3rem;
}

.page-link {
  padding: 0.5rem 1rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  text-decoration: none;
  transition: var(--transition);
}

.page-link:hover, .page-link.active {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
  text-decoration: none;
}

/* Footer */
.site-footer {
  background: #050505;
  border-top: 1px solid var(--border);
  padding: 4rem 0 0;
  margin-top: 4rem;
}

.footer-inner {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 3rem;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 2rem;
}

.footer-col {
  /* normal */
}

.footer-title {
  font-size: 1rem;
  color: var(--text-heading);
  margin-bottom: 1.5rem;
  position: relative;
}

.footer-title::after {
  content: '';
  width: 30px;
  height: 2px;
  background: var(--primary);
  display: block;
  margin-top: 0.5rem;
}

.footer-links {
  list-style: none;
  padding: 0;
}

.footer-link {
  display: block;
  padding: 0.3rem 0;
  font-size: 0.8rem;
}

.footer-link a {
  color: var(--text-muted);
  text-decoration: none;
  transition: var(--transition);
}

.footer-link a:hover {
  color: var(--primary);
  text-decoration: none;
}

.footer-bottom {
  text-align: center;
  padding: 2rem;
  margin-top: 3rem;
  border-top: 1px solid var(--border);
}

.copyright {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 44px;
  height: 44px;
  background: var(--primary);
  color: white;
  border: none;
  border-radius: 50%;
  font-size: 1.2rem;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: var(--transition);
  box-shadow: var(--shadow);
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-glow);
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-weight: bold;
  text-decoration: none;
  transition: var(--transition);
  cursor: pointer;
  font-size: 0.9rem;
}

.btn-primary {
  background: var(--primary);
  color: white;
  border: 2px solid var(--primary);
}

.btn-primary:hover {
  background: transparent;
  color: var(--primary);
}

.btn-outline {
  background: transparent;
  color: var(--primary);
  border: 2px solid var(--primary);
}

.btn-outline:hover {
  background: var(--primary);
  color: white;
}

/* Animations */
@keyframes pulse-glow {
  0% { box-shadow: 0 0 20px rgba(255,118,0,0.3); }
  50% { box-shadow: 0 0 40px rgba(255,118,0,0.5); }
  100% { box-shadow: 0 0 20px rgba(255,118,0,0.3); }
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.fade-in {
  animation: fadeInUp 0.6s ease-out forwards;
}

.category-grid .category-card:nth-child(1),
.article-list .article-card:nth-child(1),
.tools-grid .tool-card:nth-child(1) { animation-delay: 0.05s; }
.category-grid .category-card:nth-child(2),
.article-list .article-card:nth-child(2),
.tools-grid .tool-card:nth-child(2) { animation-delay: 0.10s; }
.category-grid .category-card:nth-child(3),
.article-list .article-card:nth-child(3),
.tools-grid .tool-card:nth-child(3) { animation-delay: 0.15s; }
.category-grid .category-card:nth-child(4),
.article-list .article-card:nth-child(4),
.tools-grid .tool-card:nth-child(4) { animation-delay: 0.20s; }
.category-grid .category-card:nth-child(5),
.article-list .article-card:nth-child(5),
.tools-grid .tool-card:nth-child(5) { animation-delay: 0.25s; }
.category-grid .category-card:nth-child(6),
.article-list .article-card:nth-child(6),
.tools-grid .tool-card:nth-child(6) { animation-delay: 0.30s; }
.category-grid .category-card:nth-child(7),
.article-list .article-card:nth-child(7),
.tools-grid .tool-card:nth-child(7) { animation-delay: 0.35s; }
.category-grid .category-card:nth-child(8),
.article-list .article-card:nth-child(8),
.tools-grid .tool-card:nth-child(8) { animation-delay: 0.40s; }

/* Search/Filter Bar */
.search-bar {
  margin-bottom: 2rem;
}

.search-input {
  width: 100%;
  padding: 0.75rem 1.25rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  font-family: var(--font);
  font-size: 0.9rem;
  transition: var(--transition);
}

.search-input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: var(--shadow-glow);
}

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

@media (max-width: 768px) {
  .hero-title {
    font-size: 2rem;
  }
  .hero-logo {
    width: 80px;
    height: 80px;
  }
  .hero {
    padding: 3rem 1rem;
  }
  .category-grid {
    grid-template-columns: 1fr;
  }
  .footer-inner {
    grid-template-columns: 1fr;
  }
  .container {
    padding: 0 1rem;
  }
  .article-header h1 {
    font-size: 1.5rem;
  }
  .article-nav {
    grid-template-columns: 1fr;
  }
}