:root {
  --bg-color: #0f172a;
  --surface-color: #1e293b;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --accent-color: #6366f1;
  --accent-hover: #4f46e5;
  --border-color: #334155;
  --glass-bg: rgba(30, 41, 59, 0.7);
  --glass-border: rgba(255, 255, 255, 0.1);
  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
}

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

body {
  font-family: 'Inter', sans-serif;
  background-color: var(--bg-color);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

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

/* Typography */
h1, h2, h3 {
  font-weight: 800;
  line-height: 1.2;
}

.section-title {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  text-align: center;
  background: linear-gradient(135deg, #f8fafc, #94a3b8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.section-subtitle {
  text-align: center;
  color: var(--text-secondary);
  margin-bottom: 3rem;
}

/* Buttons */
a {
  text-decoration: none;
  transition: all 0.3s ease;
}

.btn-primary {
  display: inline-block;
  background-color: var(--accent-color);
  color: white;
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  box-shadow: 0 4px 14px rgba(99, 102, 241, 0.39);
}

.btn-primary:hover {
  background-color: var(--accent-hover);
  transform: translateY(-2px);
}

.btn-secondary {
  display: inline-block;
  background-color: var(--surface-color);
  color: var(--text-primary);
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  font-weight: 600;
  border: 1px solid var(--border-color);
  cursor: pointer;
}

.btn-secondary:hover {
  background-color: #2a364a;
  transform: translateY(-2px);
}

.btn-outline {
  display: inline-block;
  background-color: transparent;
  color: var(--text-primary);
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  font-weight: 600;
  border: 1px solid var(--accent-color);
  cursor: pointer;
}

.btn-outline:hover {
  background-color: rgba(99, 102, 241, 0.1);
}

.text-link {
  color: var(--accent-color);
  font-weight: 600;
}

.text-link:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}

/* Navigation */
.navbar {
  position: fixed;
  top: 0;
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.5rem 5%;
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--glass-border);
  z-index: 100;
}

.logo {
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.5px;
}

.nav-links a {
  color: var(--text-secondary);
  margin-left: 2rem;
  font-weight: 600;
  font-size: 0.95rem;
}

.nav-links a:hover {
  color: var(--text-primary);
}

.nav-links .btn-outline {
  color: var(--text-primary);
  padding: 0.5rem 1rem;
}

/* Sections */
.section {
  padding: 6rem 0;
}

/* Hero Section */
.hero-section {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  text-align: center;
  padding-top: 80px;
}

.hero-content {
  max-width: 800px;
  z-index: 10;
  padding: 0 2rem;
}

.hero-title {
  font-size: 4rem;
  margin-bottom: 1.5rem;
  background: linear-gradient(to right, #ffffff, #a5b4fc);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-secondary);
  margin-bottom: 2.5rem;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
}

.hero-bg-glow {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 60vw;
  height: 60vw;
  background: radial-gradient(circle, rgba(99, 102, 241, 0.15) 0%, rgba(15, 23, 42, 0) 70%);
  z-index: 1;
  pointer-events: none;
}

/* Problem Section */
.problem-section {
  background-color: var(--surface-color);
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.section-description {
  font-size: 1.25rem;
  text-align: center;
  max-width: 800px;
  margin: 0 auto;
  color: var(--text-secondary);
}

/* Services */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin-top: 3rem;
}

.card {
  background: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 2.5rem 2rem;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.card:hover {
  transform: translateY(-8px);
  border-color: var(--accent-color);
  box-shadow: 0 10px 30px -10px rgba(99, 102, 241, 0.2);
}

.card-icon {
  font-size: 2.5rem;
  margin-bottom: 1.5rem;
}

.card h3 {
  font-size: 1.5rem;
  margin-bottom: 1rem;
}

.card p {
  color: var(--text-secondary);
}

/* Quiz */
.quiz-container {
  max-width: 700px;
  margin: 0 auto;
  background: var(--surface-color);
  padding: 3rem;
  border-radius: 16px;
  border: 1px solid var(--border-color);
}

.question-block {
  margin-bottom: 2rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border-color);
}

.question-block:last-of-type {
  border-bottom: none;
  margin-bottom: 0;
  padding-bottom: 0;
}

.question-block p {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

.quiz-options {
  display: flex;
  gap: 1rem;
}

.quiz-btn {
  flex: 1;
  padding: 0.75rem;
  background: transparent;
  border: 2px solid var(--border-color);
  color: var(--text-primary);
  border-radius: 8px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}

.quiz-btn:hover {
  border-color: var(--accent-color);
  background: rgba(99, 102, 241, 0.05);
}

.quiz-btn.selected {
  background: var(--accent-color);
  border-color: var(--accent-color);
  color: white;
}

.quiz-result {
  text-align: center;
  margin-top: 2rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
}

.quiz-result h3 {
  margin-bottom: 0.5rem;
}

.quiz-result p {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

/* About Section */
.about-content {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
  font-size: 1.1rem;
  color: var(--text-secondary);
}

/* Contact Section */
.contact-section {
  background: var(--surface-color);
  border-top: 1px solid var(--border-color);
}

.contact-desc {
  color: var(--text-secondary);
  margin-bottom: 2.5rem;
  font-size: 1.1rem;
}

.contact-links {
  display: flex;
  gap: 1.5rem;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
}

.social-link {
  color: var(--text-secondary);
  font-weight: 600;
}

.social-link:hover {
  color: var(--text-primary);
}

/* Footer */
footer {
  padding: 2rem 0;
  border-top: 1px solid var(--border-color);
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 768px) {
  .hero-title {
    font-size: 2.5rem;
  }
  
  .nav-links {
    display: none; /* simple mobile nav approach for brief */
  }
  
  .cards-grid {
    grid-template-columns: 1fr;
  }
  
  .quiz-container {
    padding: 1.5rem;
  }
}