/* ==================================================
   SKILL LINKR - ULTIMATE ENHANCED STYLESHEET v2.0
   Professional Freelancer Platform - 2026 Standards
==================================================== */

/* CSS Custom Properties - Design System */
:root {
  /* Colors */
  --primary-50:  #e3f2fd;
  --primary-100: #bbdefb;
  --primary-500: #2196f3;
  --primary-600: #1976d2;
  --secondary-500: #00f2fe;
  --accent-500:  #ff6b6b;
  --accent-600:  #ff5252;
  --dark-900:    #0a192f;
  --dark-800:    #1a2a44;
  --dark-500:    #334155;
  --gray-50:     #f8fafc;
  --gray-100:    #f1f5f9;
  --gray-900:    #0f172a;
  --success-500: #10b981;
  --warning-500: #f59e0b;
  
  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  --space-2xl: 4rem;
  
  /* Effects */
  --shadow-sm:     0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md:     0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg:     0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl:     0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  --shadow-2xl:    0 25px 50px -12px rgb(0 0 0 / 0.25);
  --border-radius: 1rem;
  --border-radius-lg: 1.5rem;
  
  /* Transitions */
  --transition-fast:  all 0.15s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow:  all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Base Styles */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 8rem; /* Account for fixed header */
}

body {
  font-family: 'Poppins', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  line-height: 1.7;
  color: var(--dark-500);
  background: var(--gray-50);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.container {
  width: 100%;
  padding-right: var(--space-md);
  padding-left: var(--space-md);
  margin-right: auto;
  margin-left: auto;
  max-width: 1200px;
}

/* Typography System */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  margin-top: 0;
  margin-bottom: var(--space-md);
  color: var(--dark-900);
}

h1 { font-size: clamp(2.5rem, 5vw, 4.5rem); }
h2 { font-size: clamp(2rem, 4vw, 3rem); }
h3 { font-size: clamp(1.5rem, 3vw, 2rem); }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
  color: var(--dark-500);
  font-size: 1.125rem;
  line-height: 1.8;
  margin-bottom: var(--space-md);
}

/* Header - Enhanced */
header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.2);
  z-index: 1000;
  transition: var(--transition-normal);
}

header.scrolled {
  box-shadow: var(--shadow-xl);
}

header .container {
  height: 5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-md);
}

.logo img {
  height: 2.5rem;
  width: auto;
  transition: var(--transition-normal);
}

.logo:hover img {
  transform: scale(1.05) rotate(2deg);
}

nav ul {
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0;
  gap: var(--space-xl);
  align-items: center;
}

nav a {
  position: relative;
  text-decoration: none;
  color: var(--dark-500);
  font-weight: 500;
  font-size: 0.95rem;
  padding: var(--space-xs) 0;
  transition: var(--transition-normal);
}

nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--primary-500), var(--secondary-500));
  transition: var(--transition-normal);
  transform: translateX(-50%);
}

nav a:hover::after,
nav a.active::after {
  width: 100%;
}

nav a:hover,
nav a.active {
  color: var(--primary-500);
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--dark-500);
  padding: var(--space-sm);
  border-radius: var(--border-radius);
  transition: var(--transition-fast);
}

.menu-toggle:hover {
  background: rgba(33, 150, 243, 0.1);
  color: var(--primary-500);
}

/* Buttons - Glassmorphism */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-md) var(--space-xl);
  border-radius: 50px;
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  transition: var(--transition-normal);
  backdrop-filter: blur(10px);
  border: 1px solid transparent;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-500), var(--secondary-500));
  color: white;
  box-shadow: var(--shadow-lg);
  border-color: rgba(33, 150, 243, 0.2);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.9);
  color: var(--primary-500);
  border-color: rgba(33, 150, 243, 0.2);
  box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: var(--shadow-2xl);
}

.btn-secondary:hover {
  background: rgba(33, 150, 243, 0.1);
  transform: translateY(-2px);
}

.btn-large {
  padding: 1.25rem 2.5rem;
  font-size: 1.125rem;
}

/* Hero Sections - Parallax & Advanced */
.hero,
.hero-student,
.hero-clients {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
}

.hero-student {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.hero-clients {
  background: linear-gradient(135deg, #ff6b6b 0%, #ff8e8e 100%);
}

.hero::before,
.hero-student::before,
.hero-clients::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: 
    radial-gradient(circle at 20% 50%, rgba(255,255,255,0.15) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(255,255,255,0.1) 0%, transparent 50%),
    radial-gradient(circle at 40% 80%, rgba(255,255,255,0.08) 0%, transparent 50%);
  animation: heroFloat 25s ease-in-out infinite;
  pointer-events: none;
}

@keyframes heroFloat {
  0%, 100% { transform: translateY(0px) scale(1); }
  33% { transform: translateY(-20px) scale(1.02); }
  66% { transform: translateY(-10px) scale(1.01); }
}

.hero-content {
  max-width: 700px;
  z-index: 2;
  position: relative;
}

.hero-content h1 {
  background: linear-gradient(135deg, white 0%, rgba(255,255,255,0.9) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: var(--space-lg);
  animation: slideInUp 1s ease-out;
}

.hero-buttons {
  display: flex;
  gap: var(--space-lg);
  flex-wrap: wrap;
  justify-content: flex-start;
  margin-top: var(--space-xl);
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: var(--space-xl);
  margin-top: var(--space-2xl);
  flex-wrap: wrap;
}

.stat {
  text-align: center;
  padding: var(--space-md);
  background: rgba(255,255,255,0.1);
  backdrop-filter: blur(10px);
  border-radius: var(--border-radius);
  border: 1px solid rgba(255,255,255,0.2);
  min-width: 140px;
}

.stat h3 {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 800;
  background: linear-gradient(135deg, white, rgba(255,255,255,0.8));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: var(--space-xs);
}

/* Sections */
section {
  padding: var(--space-2xl) 0;
}

section h2 {
  text-align: center;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
  margin-bottom: var(--space-2xl);
  position: relative;
}

section h2::after {
  content: '';
  position: absolute;
  bottom: -1rem;
  left: 50%;
  transform: translateX(-50%);
  width: 4rem;
  height: 4px;
  background: linear-gradient(90deg, var(--primary-500), var(--secondary-500));
  border-radius: 2px;
}

/* Cards Grid */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: var(--space-xl);
  margin-top: var(--space-xl);
}

.card {
  background: white;
  padding: var(--space-xl);
  border-radius: var(--border-radius-lg);
  text-align: center;
  box-shadow: var(--shadow-md);
  transition: var(--transition-normal);
  position: relative;
  overflow: hidden;
  border: 1px solid rgba(255,255,255,0.8);
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary-500), var(--secondary-500));
  transform: scaleX(0);
  transition: var(--transition-normal);
}

.card:hover {
  transform: translateY(-1rem) rotateX(1deg);
  box-shadow: var(--shadow-2xl);
}

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

.card-icon {
  width: 5rem;
  height: 5rem;
  background: linear-gradient(135deg, var(--primary-500), var(--secondary-500));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--space-lg);
  font-size: 1.5rem;
  color: white;
  box-shadow: 0 10px 30px rgba(33, 150, 243, 0.3);
}

.popular {
  border: 2px solid var(--accent-500);
  transform: scale(1.02);
}

.popular::before {
  content: '⭐ MOST POPULAR';
  position: absolute;
  top: -1rem;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent-500);
  color: white;
  padding: 0.5rem 1.5rem;
  border-radius: 2rem;
  font-size: 0.875rem;
  font-weight: 700;
  box-shadow: 0 8px 25px rgba(255, 107, 107, 0.4);
}

/* Steps */
.step-container {
  display: flex;
  gap: var(--space-xl);
  justify-content: center;
  flex-wrap: wrap;
}

.step {
  flex: 1;
  min-width: 300px;
  text-align: center;
  padding: var(--space-xl);
  position: relative;
}

.step-number {
  width: 4rem;
  height: 4rem;
  background: linear-gradient(135deg, var(--accent-500), var(--accent-600));
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  font-weight: 800;
  margin: 0 auto var(--space-lg);
  box-shadow: 0 12px 30px rgba(255, 107, 107, 0.4);
}

/* Testimonials */
.testimonials {
  background: var(--gray-50);
}

.testimonial-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
  gap: var(--space-xl);
  margin-top: var(--space-xl);
}

.testimonial-card {
  background: white;
  padding: var(--space-xl);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-lg);
  position: relative;
  overflow: hidden;
}

.testimonial-card::before {
  content: '"';
  position: absolute;
  top: 1.5rem;
  left: 2rem;
  font-size: 6rem;
  color: var(--primary-100);
  font-family: Georgia, serif;
  opacity: 0.1;
  line-height: 1;
  z-index: 0;
}

.testimonial-card > * {
  position: relative;
  z-index: 1;
}

.stars {
  color: #fbbf24;
  font-size: 1.25rem;
  margin-bottom: var(--space-md);
  display: flex;
  gap: 0.25rem;
}

.testimonial-card p {
  font-style: italic;
  color: var(--dark-500);
  margin-bottom: var(--space-lg);
  font-size: 1.125rem;
  line-height: 1.75;
}

.author {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.author img {
  width: 3.5rem;
  height: 3.5rem;
  border-radius: 50%;
  border: 3px solid var(--primary-100);
  object-fit: cover;
}

/* CTA */
.cta {
  background: linear-gradient(135deg, var(--accent-500) 0%, var(--accent-600) 100%);
  color: white;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.cta::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -20%;
  width: 80%;
  height: 200%;
  background: linear-gradient(45deg, transparent 30%, rgba(255,255,255,0.15) 50%, transparent 70%);
  animation: shine 3s infinite;
  transform: rotate(45deg);
}

@keyframes shine {
  0% { transform: translateX(-100%) translateY(-100%) rotate(45deg); }
  100% { transform: translateX(300%) translateY(-100%) rotate(45deg); }
}

/* Forms */
form {
  max-width: 600px;
  margin: 0 auto;
}

input, 
textarea, 
select {
  width: 100%;
  padding: var(--space-md) var(--space-lg);
  margin-bottom: var(--space-md);
  border: 2px solid var(--gray-100);
  border-radius: var(--border-radius);
  font-family: inherit;
  font-size: 1rem;
  background: white;
  transition: var(--transition-normal);
}

input:focus, 
textarea:focus, 
select:focus {
  outline: none;
  border-color: var(--primary-500);
  box-shadow: 0 0 0 4px rgba(33, 150, 243, 0.1);
}

/* Footer */
footer {
  background: var(--dark-900);
  color: white;
  padding: var(--space-2xl) 0 var(--space-lg);
}

.footer-container {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: var(--space-xl);
  margin-bottom: var(--space-xl);
}

.footer-left h4 {
  font-size: 2.25rem;
  margin-bottom: var(--space-md);
}

.footer-left span {
  background: linear-gradient(135deg, var(--primary-500), var(--secondary-500));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.social-icons {
  display: flex;
  gap: var(--space-md);
}

.social-icons a {
  width: 3.5rem;
  height: 3.5rem;
  background: rgba(255,255,255,0.1);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.25rem;
  transition: var(--transition-normal);
  backdrop-filter: blur(20px);
  border: 1px solid rgba(255,255,255,0.1);
}

.social-icons a:hover {
  background: var(--primary-500);
  transform: translateY(-4px) rotate(10deg) scale(1.1);
  box-shadow: var(--shadow-xl);
}

.footer-bottom {
  grid-column: 1 / -1;
  text-align: center;
  padding-top: var(--space-lg);
  border-top: 1px solid rgba(255,255,255,0.1);
  color: rgba(255,255,255,0.6);
}

/* Animations */
@keyframes slideInUp {
  from {
    opacity: 0;
    transform: translateY(3rem);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* Responsive Design */
@media (max-width: 1024px) {
  .hero-stats { gap: var(--space-lg); }
  .cards { grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
}

@media (max-width: 768px) {
  .menu-toggle { display: flex; }
  
  nav ul {
    position: fixed;
    top: 5rem;
    left: 0;
    right: 0;
    height: calc(100vh - 5rem);
    background: rgba(15, 23, 42, 0.98);
    flex-direction: column;
    justify-content: flex-start;
    align-items: center;
    padding: var(--space-xl) 0;
    transform: translateX(-100%);
    transition: var(--transition-slow);
    backdrop-filter: blur(30px);
  }

  nav ul.active {
    transform: translateX(0);
  }

  .hero-buttons,
  .cta-buttons {
    flex-direction: column;
    align-items: center;
    gap: var(--space-md);
  }
  
  .hero-stats {
    flex-direction: column;
    gap: var(--space-lg);
  }
  
  .step-container { 
    flex-direction: column; 
    gap: var(--space-lg);
  }
  
  .cards { 
    grid-template-columns: 1fr; 
    gap: var(--space-lg);
  }
  
  .testimonial-grid {
    grid-template-columns: 1fr;
  }
  
  .footer-container {
    grid-template-columns: 1fr;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .container { padding: 0 var(--space-sm); }
  section { padding: var(--space-xl) 0; }
  .hero-buttons > *,
  .cta-buttons > * {
    width: 100%;
    justify-content: center;
  }
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 10px;
}

::-webkit-scrollbar-track {
  background: var(--gray-100);
  border-radius: 10px;
}

::-webkit-scrollbar-thumb {
  background: linear-gradient(var(--primary-500), var(--secondary-500));
  border-radius: 10px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--primary-600);
}

/* Selection Styles */
::selection {
  background: var(--primary-500);
  color: white;
}

/* Loading Animation */
@keyframes shimmer {
  0% { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

.shimmer {
  background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
}