:root {
  --primary-color: #4a90e2;
  --background-color: #121212;
  --surface-color: #1e1e1e;
  --surface-2: #171717;
  --text-color: #e0e0e0;
  --muted-text: #b5b5b5;
  --heading-color: #ffffff;
  --border-color: #2c2c2c;
  --box-shadow: 0 8px 24px rgba(0, 0, 0, 0.25);
  --border-radius: 12px;
  --transition: all 0.25s ease;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
}

body {
  background-color: var(--background-color);
  color: var(--text-color);
  line-height: 1.8;
  font-size: 16px;
  font-family: "Segoe UI", -apple-system, BlinkMacSystemFont, "Roboto",
    "Oxygen", "Ubuntu", "Cantarell", "Fira Sans", "Droid Sans",
    "Helvetica Neue", sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Accessibility */
.skip-link {
  position: absolute;
  left: -9999px;
  top: auto;
  width: 1px;
  height: 1px;
  overflow: hidden;
}
.skip-link:focus {
  position: absolute;
  left: 16px;
  top: 16px;
  width: auto;
  height: auto;
  padding: 8px 12px;
  background: var(--primary-color);
  color: var(--heading-color);
  border-radius: 6px;
}

/* Header */
header {
  background-color: var(--surface-2);
  border-bottom: 1px solid var(--border-color);
  padding: 0.75rem 0;
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: var(--box-shadow);
  backdrop-filter: saturate(120%) blur(6px);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--heading-color);
}

.logo i {
  color: var(--primary-color);
}

nav ul {
  display: flex;
  list-style: none;
  gap: 0.25rem;
  margin: 0;
  padding: 0;
}

nav a {
  color: var(--text-color);
  text-decoration: none;
  font-weight: 600;
  padding: 0.5rem 0.75rem;
  border-radius: 8px;
  transition: var(--transition);
}
nav a:hover,
nav a.active,
nav a[aria-current="page"] {
  background: linear-gradient(
    135deg,
    rgba(74, 144, 226, 0.2),
    rgba(74, 144, 226, 0.05)
  );
  color: var(--heading-color);
  outline: 1px solid rgba(74, 144, 226, 0.35);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: 1px solid var(--border-color);
  color: var(--heading-color);
  font-size: 1.25rem;
  cursor: pointer;
  padding: 0.4rem 0.6rem;
  border-radius: 8px;
}

/* Main Content */
.main-content {
  display: flex;
  gap: 2rem;
  padding: 2rem 0;
}

/* Sidebar */
.sidebar {
  flex: 0 0 280px;
  background-color: var(--surface-color);
  border-radius: var(--border-radius);
  padding: 1.25rem;
  height: calc(100vh - 120px);
  position: sticky;
  top: 80px;
  overflow-y: auto;
  box-shadow: var(--box-shadow);
}

.sidebar h3 {
  color: var(--heading-color);
  margin-bottom: 1rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border-color);
  font-size: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--muted-text);
}

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

.sidebar li {
  margin-bottom: 0.25rem;
}

.sidebar a {
  text-decoration: none;
  color: var(--text-color);
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0.6rem 0.75rem;
  border-radius: 8px;
  transition: var(--transition);
  font-weight: 500;
  position: relative;
  border: 1px solid transparent;
}

.sidebar a:hover {
  background-color: #1a1a1a;
  border-color: var(--border-color);
}

.sidebar a.active {
  background: linear-gradient(
    180deg,
    rgba(74, 144, 226, 0.15),
    rgba(74, 144, 226, 0.05)
  );
  color: var(--heading-color);
  border: 1px solid rgba(74, 144, 226, 0.4);
}

.sidebar a i {
  width: 20px;
  text-align: center;
  color: var(--primary-color);
}

/* Content Area */
.content {
  flex: 1;
  min-width: 0;
}

.section {
  position: relative;
  background-color: var(--surface-color);
  border-radius: var(--border-radius);
  padding: 2rem;
  margin-bottom: 2rem;
  box-shadow: var(--box-shadow);
  border: 1px solid var(--border-color);
}

.section h1,
.section h2,
.section h3,
.section h4 {
  color: var(--heading-color);
  margin: 0 0 1rem 0;
}

.section h2 {
  padding-bottom: 0.6rem;
  border-bottom: 1px solid var(--border-color);
  font-size: 1.35rem;
}

.section h3 {
  margin-top: 1rem;
  font-size: 1.1rem;
  color: var(--muted-text);
}

.section p {
  margin: 0 0 1rem 0;
  color: var(--text-color);
}

.bulleted {
  margin: 0.75rem 0 0 1.25rem;
}
.bulleted li {
  margin: 0.25rem 0;
  color: var(--text-color);
}

/* Hero Section */
.hero {
  padding: 3rem 0 2rem 0;
  text-align: center;
  background-color: var(--background-color);
}

.hero h1 {
  font-size: 2.5rem;
  margin-bottom: 0.75rem;
  color: var(--heading-color);
  letter-spacing: 0.02em;
}

.hero p {
  font-size: 1.1rem;
  max-width: 800px;
  margin: 0 auto 1rem auto;
  color: var(--muted-text);
}

/* Mission Section */
.mission {
  background-color: var(--surface-color);
  border-radius: var(--border-radius);
  padding: 1.5rem;
  margin: 1.5rem auto 0 auto;
  max-width: 900px;
  border-left: 5px solid var(--primary-color);
  box-shadow: var(--box-shadow);
}

/* Features Grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1rem;
}

.feature-card {
  background-color: var(--background-color);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  padding: 1.25rem;
  transition: var(--transition);
  cursor: pointer;
  min-height: 180px;
}
.feature-card:hover {
  transform: translateY(-3px);
  border-color: var(--primary-color);
  box-shadow: 0 12px 30px rgba(74, 144, 226, 0.15);
}
.feature-card:focus {
  outline: 2px solid rgba(74, 144, 226, 0.6);
  outline-offset: 2px;
}
.feature-card i {
  font-size: 1.75rem;
  color: var(--primary-color);
  margin-bottom: 1rem;
}
.feature-card h4 {
  color: var(--heading-color);
  margin-bottom: 0.5rem;
}

/* Benefits List */
.benefits-list {
  display: grid;
  gap: 1rem;
}

.benefit-item {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  background: var(--background-color);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 1rem;
}

.benefit-item i {
  color: #28a745;
  font-size: 1.5rem;
  min-width: 24px;
}

/* Roadmap Timeline */
.roadmap-timeline {
  position: relative;
  padding-left: 1.5rem;
  border-left: 2px solid var(--border-color);
}

.timeline-item {
  position: relative;
  margin-bottom: 1rem;
  padding: 1rem;
  background-color: var(--background-color);
  border-radius: 10px;
  border-left: 3px solid var(--primary-color);
}

.timeline-item::before {
  content: "";
  position: absolute;
  left: -28px;
  top: 16px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background-color: var(--primary-color);
  border: 2px solid var(--background-color);
}

.timeline-item h4 {
  color: var(--primary-color);
  margin-bottom: 0.25rem;
}

/* Mind Map */
.mindmap-wrap {
  position: relative;
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  background: radial-gradient(1200px 600px at 10% 0%, #151515, #111111);
  overflow: hidden;
  min-height: 420px;
}
#mindmap-svg {
  width: 100%;
  height: 70vh;
  min-height: 420px;
  display: block;
}

/* Modal */
.modal {
  display: none;
  position: fixed;
  z-index: 1001;
  inset: 0;
  width: 100%;
  height: 100%;
  overflow: auto;
  background-color: rgba(0, 0, 0, 0.7);
}
.modal-content {
  background-color: var(--surface-color);
  margin: 10vh auto;
  padding: 1.5rem;
  border: 1px solid var(--border-color);
  width: min(90%, 700px);
  border-radius: var(--border-radius);
  position: relative;
  box-shadow: var(--box-shadow);
}
.close-button {
  color: #ccc;
  font-size: 26px;
  font-weight: bold;
  position: absolute;
  top: 10px;
  right: 14px;
  background: transparent;
  border: none;
  cursor: pointer;
}
.close-button:hover,
.close-button:focus {
  color: white;
  text-decoration: none;
  cursor: pointer;
}

/* Responsive Design */
@media (max-width: 992px) {
  .main-content {
    flex-direction: column;
  }
  .sidebar {
    position: static;
    height: auto;
    max-width: 100%;
  }
}

@media (max-width: 768px) {
  nav ul {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 62px;
    left: 0;
    width: 100%;
    background-color: var(--surface-color);
    padding: 0.75rem;
    border-radius: 0 0 10px 10px;
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--box-shadow);
  }
  nav ul.show {
    display: flex;
  }
  .mobile-menu-btn {
    display: block;
  }
  .hero h1 {
    font-size: 2rem;
  }
}

/* Motion preferences */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}