/* ===== DESIGN TOKENS ===== */
:root {
  /* Color Palette - Pure Black & White */
  --primary-color: #000000;
  --primary-dark: #000000;
  --primary-light: #333333;
  --accent-color: #000000;
  --accent-gradient: linear-gradient(135deg, #000000, #333333);
  --success-color: #4A4A4A;
  --warning-color: #666666;

  /* Neutrals */
  --bg-primary: #FFFFFF;
  --bg-secondary: #F5F5F7;
  --bg-tertiary: #E5E5EA;
  --text-primary: #000000;
  --text-secondary: #3A3A3C;
  --text-muted: #8E8E93;

  /* Glass Effects */
  --glass-bg: rgba(255, 255, 255, 0.8);
  --glass-border: rgba(0, 0, 0, 0.1);
  --glass-shadow: rgba(0, 0, 0, 0.1);

  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;

  /* Typography */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-display: 'Outfit', sans-serif;

  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-base: 0.3s ease;
  --transition-slow: 0.5s ease;

  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.12);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.16);
  --shadow-glow: 0 0 40px rgba(0, 0, 0, 0.15);

  /* Border Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
}

/* ===== RESET & BASE ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-primary);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

/* Animated Background */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background:
    radial-gradient(circle at 20% 30%, rgba(255, 59, 48, 0.03) 0%, transparent 50%),
    radial-gradient(circle at 80% 70%, rgba(0, 0, 0, 0.02) 0%, transparent 50%),
    linear-gradient(180deg, rgba(255, 255, 255, 0) 0%, rgba(245, 245, 247, 0.3) 100%);
  pointer-events: none;
  z-index: 0;
  animation: gradientShift 20s ease infinite;
}

@keyframes gradientShift {

  0%,
  100% {
    opacity: 1;
    transform: scale(1);
  }

  50% {
    opacity: 0.8;
    transform: scale(1.1);
  }
}

/* ===== TYPOGRAPHY ===== */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
}

h1 {
  font-size: clamp(2.5rem, 5vw, 4rem);
  color: var(--text-primary);
  font-weight: 900;
}

h2 {
  font-size: clamp(2rem, 4vw, 3rem);
  color: var(--text-primary);
}

h3 {
  font-size: clamp(1.5rem, 3vw, 2rem);
  color: var(--text-primary);
}

p {
  margin-bottom: var(--spacing-sm);
  color: var(--text-secondary);
}

/* ===== LAYOUT ===== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
  position: relative;
  z-index: 1;
}

/* ===== HEADER ===== */
header {
  padding: var(--spacing-md) 0;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--glass-border);
  position: sticky;
  top: 0;
  z-index: 100;
  animation: slideDown 0.5s ease;
  box-shadow: var(--shadow-sm);
}

@keyframes slideDown {
  from {
    transform: translateY(-100%);
    opacity: 0;
  }

  to {
    transform: translateY(0);
    opacity: 1;
  }
}

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

.logo {
  font-size: 1.75rem;
  font-weight: 800;
  font-family: var(--font-display);
  color: var(--primary-color);
  text-decoration: none;
  transition: transform var(--transition-fast);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.logo img {
  height: 40px;
  width: auto;
}

.logo:hover {
  transform: scale(1.05);
}

nav ul {
  display: flex;
  gap: var(--spacing-lg);
  list-style: none;
}

nav a {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  transition: color var(--transition-fast);
  position: relative;
}

nav a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent-gradient);
  transition: width var(--transition-base);
}

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

nav a:hover::after {
  width: 100%;
}

/* ===== HERO SECTION ===== */
.hero {
  padding: var(--spacing-2xl) 0;
  text-align: center;
  animation: fadeInUp 0.8s ease;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero h1 {
  margin-bottom: var(--spacing-md);
  animation: fadeInUp 0.8s ease 0.2s both;
}

.hero p {
  font-size: 1.25rem;
  max-width: 700px;
  margin: 0 auto var(--spacing-xl);
  animation: fadeInUp 0.8s ease 0.4s both;
}

.cta-button {
  display: inline-block;
  padding: 1rem 2.5rem;
  background: var(--accent-gradient);
  color: white;
  text-decoration: none;
  font-weight: 600;
  font-size: 1.1rem;
  border-radius: var(--radius-lg);
  border: none;
  cursor: pointer;
  transition: all var(--transition-base);
  box-shadow: var(--shadow-md), var(--shadow-glow);
  animation: fadeInUp 0.8s ease 0.6s both;
}

.cta-button:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg), 0 0 60px rgba(104, 85, 224, 0.5);
}

.cta-button:active {
  transform: translateY(0);
}

/* ===== COURSES SECTION ===== */
.courses {
  padding: var(--spacing-2xl) 0;
}

.section-title {
  text-align: center;
  margin-bottom: var(--spacing-xl);
}

.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-xl);
}

.course-card {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  transition: all var(--transition-base);
  cursor: pointer;
  animation: fadeInUp 0.6s ease both;
}

.course-card:nth-child(1) {
  animation-delay: 0.1s;
}

.course-card:nth-child(2) {
  animation-delay: 0.2s;
}

.course-card:nth-child(3) {
  animation-delay: 0.3s;
}

.course-card:hover {
  transform: translateY(-8px);
  border-color: var(--primary-light);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
}

.course-icon {
  font-size: 3rem;
  margin-bottom: var(--spacing-sm);
  display: block;
}

.course-card h3 {
  color: var(--text-primary);
  margin-bottom: var(--spacing-sm);
}

.course-card p {
  color: var(--text-muted);
  margin-bottom: var(--spacing-md);
  font-size: 0.95rem;
}

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

.course-duration,
.course-level {
  font-size: 0.875rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* ===== REGISTRATION SECTION ===== */
.registration {
  padding: var(--spacing-2xl) 0;
  max-width: 600px;
  margin: 0 auto;
}

.registration-form {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  padding: var(--spacing-xl);
  box-shadow: var(--shadow-lg);
  animation: fadeInUp 0.8s ease;
}

.form-group {
  margin-bottom: var(--spacing-md);
}

label {
  display: block;
  margin-bottom: var(--spacing-xs);
  color: var(--text-primary);
  font-weight: 500;
  font-size: 0.95rem;
}

input,
select,
textarea {
  width: 100%;
  padding: 0.875rem 1rem;
  background: var(--bg-secondary);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: var(--font-primary);
  font-size: 1rem;
  transition: all var(--transition-base);
}

input:focus,
select:focus,
textarea:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(104, 85, 224, 0.2);
  background: var(--bg-tertiary);
}

textarea {
  resize: vertical;
  min-height: 100px;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-sm);
}

.submit-button {
  width: 100%;
  padding: 1rem;
  background: var(--accent-gradient);
  color: white;
  border: none;
  border-radius: var(--radius-md);
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-base);
  box-shadow: var(--shadow-md);
  margin-top: var(--spacing-sm);
}

.submit-button:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
}

.submit-button:active {
  transform: translateY(0);
}

.submit-button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
}

/* Form Validation */
.error {
  border-color: hsl(0, 75%, 60%) !important;
}

.error-message {
  color: hsl(0, 75%, 60%);
  font-size: 0.875rem;
  margin-top: var(--spacing-xs);
  display: none;
}

.error-message.show {
  display: block;
  animation: shake 0.3s ease;
}

@keyframes shake {

  0%,
  100% {
    transform: translateX(0);
  }

  25% {
    transform: translateX(-5px);
  }

  75% {
    transform: translateX(5px);
  }
}

.success-message {
  background: linear-gradient(135deg, hsl(150, 70%, 50%), hsl(170, 70%, 50%));
  color: white;
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  text-align: center;
  margin-bottom: var(--spacing-md);
  display: none;
  animation: slideDown 0.5s ease;
}

.success-message.show {
  display: block;
}

/* ===== FOOTER ===== */
footer {
  padding: var(--spacing-xl) 0 var(--spacing-md);
  border-top: 1px solid var(--glass-border);
  margin-top: var(--spacing-2xl);
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-lg);
}

.footer-section h3 {
  font-size: 1.25rem;
  margin-bottom: var(--spacing-sm);
}

.footer-section ul {
  list-style: none;
}

.footer-section a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color var(--transition-fast);
  display: block;
  margin-bottom: var(--spacing-xs);
}

.footer-section a:hover {
  color: var(--primary-light);
}

.social-links {
  display: flex;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-sm);
}

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

.social-links a:hover {
  background: var(--accent-gradient);
  border-color: transparent;
  transform: translateY(-3px);
}

.copyright {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.9rem;
  padding-top: var(--spacing-md);
  border-top: 1px solid var(--glass-border);
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  nav ul {
    gap: var(--spacing-sm);
  }

  .form-row {
    grid-template-columns: 1fr;
  }

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

  .hero {
    padding: var(--spacing-xl) 0;
  }
}

/* ===== UTILITIES ===== */
.hidden {
  display: none;
}

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