/* 
  Abul Qasim - Portfolio & Course Portal Design System
  Premium, Dark-mode Cyber/Tech Aesthetic 
*/

:root {
  /* Color Palette */
  --bg-color: #050b14;
  --bg-secondary: #0a1122;
  --text-primary: #e2e8f0;
  --text-secondary: #94a3b8;
  
  --primary-accent: #00e5ff;
  --secondary-accent: #b400ff;
  --tertiary-accent: #4f46e5;
  
  --glass-bg: rgba(255, 255, 255, 0.03);
  --glass-border: rgba(255, 255, 255, 0.08);
  --glass-hover: rgba(255, 255, 255, 0.06);
  
  --gradient-main: linear-gradient(135deg, var(--primary-accent), var(--secondary-accent));
  
  /* Typography */
  --font-heading: 'Outfit', sans-serif;
  --font-body: 'Inter', sans-serif;
  --font-mono: 'Fira Code', 'Courier New', monospace;
  
  /* Spacing */
  --section-padding: 100px 0;
  
  /* Radii */
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-full: 9999px;
  
  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-smooth: 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Reset and Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-color);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
}

ul {
  list-style: none;
}

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

/* Dynamic Background Elements */
.bg-shape {
  position: absolute;
  border-radius: 50%;
  filter: blur(120px);
  z-index: -1;
  pointer-events: none;
  opacity: 0.5;
}

.shape-1 {
  width: 400px;
  height: 400px;
  background: var(--primary-accent);
  top: -10%;
  left: -5%;
}

.shape-2 {
  width: 500px;
  height: 500px;
  background: var(--secondary-accent);
  top: 40%;
  right: -10%;
  opacity: 0.4;
}

.shape-3 {
  width: 600px;
  height: 600px;
  background: var(--tertiary-accent);
  bottom: -10%;
  left: 20%;
  opacity: 0.3;
}

/* Reusable Components */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.section-padding {
  padding: var(--section-padding);
}

.section-header {
  margin-bottom: 64px;
}

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

.section-title {
  font-family: var(--font-heading);
  font-size: 3rem;
  font-weight: 800;
  margin-bottom: 16px;
  line-height: 1.2;
}

.section-desc {
  font-size: 1.125rem;
  color: var(--text-secondary);
  max-width: 600px;
}

.section-header.center .section-desc {
  margin: 0 auto;
}

.gradient-text {
  background: var(--gradient-main);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  display: inline-block;
}

.glass-panel {
  background: var(--glass-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
}

/* Buttons */
.btn-primary, .btn-secondary, .btn-outline {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: var(--radius-full);
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 1rem;
  transition: var(--transition-smooth);
  cursor: pointer;
}

.btn-primary {
  background: var(--primary-accent);
  color: #000;
  border: none;
  box-shadow: 0 4px 20px rgba(0, 229, 255, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(0, 229, 255, 0.5);
  background: #fff;
}

.btn-secondary {
  background: transparent;
  color: var(--text-primary);
  border: 1px solid var(--glass-border);
  background: var(--glass-bg);
}

.btn-secondary:hover {
  background: var(--glass-hover);
  border-color: rgba(255, 255, 255, 0.2);
}

/* Navigation */
.navbar {
  position: fixed;
  top: 0;
  width: 100%;
  padding: 24px 0;
  z-index: 100;
  transition: var(--transition-smooth);
}

.navbar.scrolled {
  padding: 16px 0;
  background: rgba(5, 11, 20, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--glass-border);
}

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

.logo-text {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-primary);
}

.logo-text .highlight {
  color: var(--primary-accent);
}

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

.nav-links a:not(.btn-outline) {
  font-weight: 500;
  color: var(--text-secondary);
  transition: var(--transition-fast);
  position: relative;
}

.nav-links a:not(.btn-outline):hover {
  color: var(--text-primary);
}

.nav-links a:not(.btn-outline)::after {
  content: '';
  position: absolute;
  width: 0;
  height: 2px;
  bottom: -4px;
  left: 0;
  background: var(--primary-accent);
  transition: var(--transition-fast);
}

.nav-links a:not(.btn-outline):hover::after {
  width: 100%;
}

.btn-outline {
  padding: 10px 20px;
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-full);
  font-weight: 500;
  font-size: 0.95rem;
  transition: var(--transition-fast);
}

.btn-outline:hover {
  background: var(--glass-hover);
  border-color: var(--text-primary);
}

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

.hero-container {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 64px;
  align-items: center;
}

.badge {
  display: inline-block;
  padding: 6px 16px;
  background: rgba(180, 0, 255, 0.1);
  border: 1px solid rgba(180, 0, 255, 0.3);
  color: #d8b4fe;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.875rem;
  margin-bottom: 24px;
}

.hero-title {
  font-family: var(--font-heading);
  font-size: 4rem;
  font-weight: 900;
  line-height: 1.1;
  margin-bottom: 24px;
  letter-spacing: -0.02em;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-secondary);
  margin-bottom: 40px;
  max-width: 540px;
}

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

/* Code Editor mockup */
.code-editor-mockup {
  border-radius: var(--radius-md);
  overflow: hidden;
  transform: perspective(1000px) rotateY(-5deg) rotateX(5deg);
  transition: var(--transition-smooth);
  box-shadow: 0 20px 40px rgba(0,0,0,0.4), 0 0 0 1px var(--glass-border);
}

.code-editor-mockup:hover {
  transform: perspective(1000px) rotateY(0deg) rotateX(0deg) translateY(-10px);
  box-shadow: 0 30px 60px rgba(0,229,255,0.15), 0 0 0 1px rgba(0,229,255,0.3);
}

.editor-header {
  background: rgba(0, 0, 0, 0.5);
  padding: 12px 16px;
  display: flex;
  align-items: center;
  gap: 8px;
  border-bottom: 1px solid var(--glass-border);
}

.dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}

.dot.red { background: #ff5f56; }
.dot.yellow { background: #ffbd2e; }
.dot.green { background: #27c93f; }

.editor-title {
  color: var(--text-secondary);
  font-size: 0.875rem;
  font-family: var(--font-mono);
  margin-left: 12px;
}

.editor-body {
  padding: 24px;
  background: rgba(10, 15, 30, 0.9);
  font-family: var(--font-mono);
  font-size: 0.95rem;
  line-height: 1.6;
  overflow-x: auto;
}

.editor-body .keyword { color: #ff79c6; }
.editor-body .variable { color: #50fa7b; }
.editor-body .string { color: #f1fa8c; }
.editor-body .property { color: #8be9fd; }
.editor-body .method { color: #8be9fd; }

/* About / Features */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.feature-card {
  padding: 40px;
  transition: var(--transition-smooth);
}

.feature-card:hover {
  transform: translateY(-10px);
  background: rgba(255, 255, 255, 0.05);
  border-color: rgba(255, 255, 255, 0.15);
}

.feature-icon {
  width: 64px;
  height: 64px;
  border-radius: var(--radius-md);
  background: rgba(180, 0, 255, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
  color: var(--secondary-accent);
  margin-bottom: 24px;
  transition: var(--transition-smooth);
}

.feature-card:hover .feature-icon {
  background: var(--secondary-accent);
  color: #fff;
  transform: scale(1.1);
}

.feature-card h3 {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  margin-bottom: 12px;
}

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

/* Courses Explorer */
.course-filters {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-bottom: 48px;
}

.filter-btn {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  padding: 8px 20px;
  border-radius: var(--radius-full);
  color: var(--text-secondary);
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition-fast);
  font-family: var(--font-body);
}

.filter-btn:hover {
  background: var(--glass-hover);
  color: var(--text-primary);
}

.filter-btn.active {
  background: var(--primary-accent);
  color: #000;
  border-color: var(--primary-accent);
}

.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 32px;
}

.course-card {
  display: flex;
  flex-direction: column;
  padding: 32px;
  height: 100%;
  position: relative;
  overflow: hidden;
  transition: var(--transition-smooth);
}

.course-card:hover {
  transform: translateY(-8px);
  border-color: rgba(0, 229, 255, 0.3);
}

.card-glow {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: radial-gradient(circle at 50% 0%, rgba(0, 229, 255, 0.1), transparent 70%);
  opacity: 0;
  transition: var(--transition-smooth);
  pointer-events: none;
}

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

.course-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 24px;
}

.semester-tag {
  background: rgba(255, 255, 255, 0.1);
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-primary);
}

.course-icon {
  font-size: 2rem;
  color: var(--primary-accent);
}

.course-title {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  margin-bottom: 12px;
}

.course-desc {
  color: var(--text-secondary);
  flex-grow: 1;
  margin-bottom: 24px;
  font-size: 0.95rem;
}

.course-footer {
  border-top: 1px solid var(--glass-border);
  padding-top: 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.view-link {
  color: var(--primary-accent);
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: var(--transition-fast);
}

.view-link i {
  transition: var(--transition-fast);
}

.course-card:hover .view-link i {
  transform: translateX(4px);
}

/* Footer */
.footer {
  border-top: 1px solid var(--glass-border);
  padding: 64px 0 24px;
  margin-top: 64px;
  background: var(--bg-secondary);
}

.footer-content {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 64px;
  margin-bottom: 64px;
}

.footer-brand p {
  color: var(--text-secondary);
  margin-top: 16px;
  max-width: 300px;
}

.footer h3 {
  font-family: var(--font-heading);
  font-size: 1.125rem;
  margin-bottom: 24px;
  color: var(--text-primary);
}

.footer ul li {
  margin-bottom: 12px;
}

.footer ul li a {
  color: var(--text-secondary);
  transition: var(--transition-fast);
}

.footer ul li a:hover {
  color: var(--primary-accent);
  padding-left: 4px;
}

.social-icons {
  display: flex;
  gap: 16px;
}

.social-icons a {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition-smooth);
}

.social-icons a:hover {
  background: var(--primary-accent);
  color: #000;
  border-color: var(--primary-accent);
  transform: translateY(-2px);
}

.footer-bottom {
  text-align: center;
  padding-top: 24px;
  border-top: 1px solid var(--glass-border);
  color: var(--text-secondary);
  font-size: 0.875rem;
  display: flex;
  justify-content: center;
}

/* Responsive */
@media (max-width: 992px) {
  .hero-container {
    grid-template-columns: 1fr;
    text-align: center;
  }
  
  .hero-title {
    font-size: 3rem;
  }
  
  .hero-subtitle {
    margin: 0 auto 40px;
  }
  
  .hero-actions {
    justify-content: center;
  }

  .features-grid {
    grid-template-columns: 1fr;
  }
  
  .footer-content {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none; /* simple hidden on mobile for MVP */
  }
  
  .footer-content {
    grid-template-columns: 1fr;
  }
  
  .section-padding {
    padding: 60px 0;
  }
}