/* ========================================
   VASAN S P PORTFOLIO - GLASSMORPHISM DESIGN
   ======================================== */

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

:root {
  --primary-blue: #1e3a8a;
  --primary-purple: #6366f1;
  --primary-violet: #8b5cf6;
  --glass-bg: rgba(255, 255, 255, 0.1);
  --glass-border: rgba(255, 255, 255, 0.18);
  --text-primary: #ffffff;
  --text-secondary: rgba(255, 255, 255, 0.8);
  --shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.37);
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  margin: 0;
  padding: 0;
  color: var(--text-primary);
  background: linear-gradient(135deg, #1e3a8a 0%, #6366f1 25%, #8b5cf6 50%, #6366f1 75%, #1e3a8a 100%);
  background-size: 400% 400%;
  background-attachment: fixed;
  overflow-x: hidden;
  line-height: 1.6;
  animation: gradientShift 15s ease infinite;
}

@keyframes gradientShift {
  0% { background-position: 0% 50%; }
  25% { background-position: 100% 50%; }
  50% { background-position: 100% 100%; }
  75% { background-position: 0% 100%; }
  100% { background-position: 0% 50%; }
}

/* === FLOATING PARTICLES ANIMATION === */
@keyframes float {
  0% { transform: translateY(0px) rotate(0deg); opacity: 0.4; }
  25% { transform: translateY(-30px) rotate(90deg); opacity: 0.7; }
  50% { transform: translateY(-20px) rotate(180deg); opacity: 0.9; }
  75% { transform: translateY(-40px) rotate(270deg); opacity: 0.6; }
  100% { transform: translateY(0px) rotate(360deg); opacity: 0.4; }
}

@keyframes floatReverse {
  0% { transform: translateY(0px) rotate(360deg); opacity: 0.3; }
  25% { transform: translateY(25px) rotate(270deg); opacity: 0.6; }
  50% { transform: translateY(15px) rotate(180deg); opacity: 0.8; }
  75% { transform: translateY(35px) rotate(90deg); opacity: 0.5; }
  100% { transform: translateY(0px) rotate(0deg); opacity: 0.3; }
}

.particle {
  position: fixed;
  width: 12px;
  height: 12px;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.6) 0%, rgba(255, 255, 255, 0.2) 70%, transparent 100%);
  border-radius: 50%;
  pointer-events: none;
  z-index: 0;
}

.particle:nth-child(odd) {
  animation: float 20s infinite ease-in-out;
}

.particle:nth-child(even) {
  animation: floatReverse 25s infinite ease-in-out;
  background: radial-gradient(circle, rgba(139, 92, 246, 0.5) 0%, rgba(139, 92, 246, 0.2) 70%, transparent 100%);
}

.particle:nth-child(3n) {
  background: radial-gradient(circle, rgba(99, 102, 241, 0.4) 0%, rgba(99, 102, 241, 0.1) 70%, transparent 100%);
  animation-duration: 18s;
}

/* === GLASSMORPHISM CARD === */
.glass-card {
  background: var(--glass-bg);
  backdrop-filter: blur(15px);
  -webkit-backdrop-filter: blur(15px);
  border-radius: 20px;
  border: 1px solid var(--glass-border);
  box-shadow: var(--shadow);
  padding: 2rem;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.glass-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
  transition: left 0.6s ease;
}

.glass-card:hover::before {
  left: 100%;
}

.glass-card:hover {
  transform: translateY(-8px) scale(1.02);
  box-shadow: 0 20px 60px 0 rgba(31, 38, 135, 0.6);
  border-color: rgba(255, 255, 255, 0.3);
}

/* === HERO SECTION === */
#hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 2rem;
  position: relative;
  z-index: 1;
}

.hero-photo {
  width: 220px;
  height: 220px;
  border-radius: 50%;
  object-fit: cover;
  border: 5px solid rgba(255, 255, 255, 0.3);
  box-shadow: 0 0 40px rgba(255, 255, 255, 0.3);
  margin-bottom: 2rem;
  transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.hero-name {
  font-family: 'Montserrat', sans-serif;
  font-size: 5rem;
  font-weight: 800;
  margin-bottom: 1rem;
  text-shadow: 2px 2px 20px rgba(0, 0, 0, 0.3);
  transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.hero-tagline {
  font-size: 1.5rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  font-weight: 400;
}

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

.glass-button {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--glass-border);
  padding: 0.8rem 2rem;
  border-radius: 50px;
  color: var(--text-primary);
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.3s ease;
  display: inline-block;
}

.glass-button:hover {
  background: rgba(255, 255, 255, 0.2);
  transform: scale(1.05);
  box-shadow: 0 5px 20px rgba(255, 255, 255, 0.3);
}

.social-links {
  display: flex;
  gap: 1.5rem;
  margin-top: 2rem;
}

.social-icon {
  width: 40px;
  height: 40px;
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  color: var(--text-primary);
  font-size: 1.2rem;
  transition: all 0.3s ease;
}

.social-icon:hover {
  background: rgba(255, 255, 255, 0.25);
  transform: translateY(-3px);
}

/* === STICKY HEADER === */
#sticky-header {
  position: fixed;
  top: -100px;
  left: 0;
  width: 100%;
  height: 70px;
  background: var(--glass-bg);
  backdrop-filter: blur(15px);
  -webkit-backdrop-filter: blur(15px);
  border-bottom: 1px solid var(--glass-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2rem;
  z-index: 1000;
  transition: top 0.3s ease;
}

#sticky-header.visible {
  top: 0;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.header-photo {
  width: 45px;
  height: 45px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid rgba(255, 255, 255, 0.3);
}

.header-name {
  font-family: 'Montserrat', sans-serif;
  font-size: 1.5rem;
  font-weight: 700;
}

.header-nav {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.header-nav a {
  color: var(--text-primary);
  text-decoration: none;
  font-weight: 600;
  transition: color 0.3s ease;
}

.header-nav a:hover {
  color: var(--primary-violet);
}

/* === SECTIONS === */
section {
  padding: 5rem 2rem;
  max-width: 1200px;
  margin: 0 auto;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

section.visible {
  opacity: 1;
  transform: translateY(0);
}

.section-title {
  font-family: 'Montserrat', sans-serif;
  font-size: 3rem;
  font-weight: 800;
  margin-bottom: 3rem;
  text-align: center;
  text-shadow: 2px 2px 10px rgba(0, 0, 0, 0.5);
  color: #ffffff;
}

/* === ABOUT SECTION === */
.about-content {
  display: grid;
  gap: 2rem;
}

.about-content p {
  color: var(--text-primary);
  text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.3);
}

.cgpa-badge {
  display: inline-block;
  background: linear-gradient(135deg, rgba(255, 215, 0, 0.4), rgba(255, 140, 0, 0.4));
  backdrop-filter: blur(10px);
  padding: 0.5rem 1.5rem;
  border-radius: 50px;
  font-weight: 700;
  font-size: 1.2rem;
  margin: 1rem 0;
  border: 1px solid rgba(255, 215, 0, 0.6);
  color: #ffffff;
  text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.5);
}

/* === SKILLS SECTION === */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
}

.skill-category {
  margin-bottom: 1.5rem;
}

.skill-category h3 {
  font-size: 1.3rem;
  margin-bottom: 1rem;
  color: #ffffff;
  text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.3);
}

.skill-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
}

.skill-chip {
  background: rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(5px);
  padding: 0.5rem 1rem;
  border-radius: 20px;
  font-size: 0.9rem;
  border: 1px solid rgba(255, 255, 255, 0.2);
  transition: all 0.3s ease;
}

.skill-chip:hover {
  background: rgba(255, 255, 255, 0.25);
  transform: translateY(-2px);
}

/* === PROJECTS SECTION === */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}

.project-card {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  border-radius: 20px;
  border: 1px solid var(--glass-border);
  padding: 2rem;
  cursor: pointer;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.project-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--primary-purple), var(--primary-violet));
}

.project-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 15px 50px rgba(99, 102, 241, 0.4);
}

.project-card h3 {
  font-size: 1.5rem;
  margin-bottom: 1rem;
  font-family: 'Montserrat', sans-serif;
  color: #ffffff;
  text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.3);
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 1rem 0;
}

.project-tag {
  background: rgba(139, 92, 246, 0.3);
  padding: 0.3rem 0.8rem;
  border-radius: 15px;
  font-size: 0.8rem;
}

.project-tech {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1rem;
}

.tech-badge {
  background: rgba(99, 102, 241, 0.3);
  padding: 0.3rem 0.8rem;
  border-radius: 12px;
  font-size: 0.85rem;
}

.project-links {
  display: flex;
  gap: 1rem;
  margin-top: 1.5rem;
}

.project-link-btn {
  background: rgba(99, 102, 241, 0.4);
  backdrop-filter: blur(5px);
  padding: 0.6rem 1.5rem;
  border-radius: 25px;
  color: white;
  text-decoration: none;
  font-weight: 600;
  transition: all 0.3s ease;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.project-link-btn:hover {
  background: rgba(99, 102, 241, 0.6);
  transform: scale(1.05);
}

.project-card p {
  color: var(--text-primary);
  text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.2);
}

/* === CERTIFICATIONS SECTION === */
.cert-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

.cert-card {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  border-radius: 15px;
  padding: 1.5rem;
  border: 1px solid var(--glass-border);
  transition: all 0.3s ease;
  text-decoration: none;
  color: var(--text-primary);
  display: block;
}

.cert-card h3 {
  font-size: 1.2rem;
  margin-bottom: 0.5rem;
  color: #ffffff;
  text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.3);
}

.cert-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 30px rgba(139, 92, 246, 0.3);
  cursor: pointer;
}

.cert-card h3 {
  font-size: 1.2rem;
  margin-bottom: 0.5rem;
}

.cert-issuer {
  color: rgba(255, 255, 255, 0.9);
  font-size: 0.9rem;
  text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.2);
}

/* === LEETCODE STATS SECTION === */
.leetcode-container {
  max-width: 800px;
  margin: 0 auto;
}

.leetcode-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2rem;
  margin-top: 2rem;
}

.stat-card {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  border-radius: 15px;
  padding: 1.5rem;
  text-align: center;
  border: 1px solid var(--glass-border);
}

.stat-number {
  font-size: 2.5rem;
  font-weight: 800;
  font-family: 'Montserrat', sans-serif;
  margin: 0.5rem 0;
}

.stat-label {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.progress-bar {
  width: 100%;
  height: 12px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 10px;
  overflow: hidden;
  margin: 0.5rem 0;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary-purple), var(--primary-violet));
  transition: width 1s ease;
}

.progress-fill.easy { background: linear-gradient(90deg, #10b981, #34d399); }
.progress-fill.medium { background: linear-gradient(90deg, #f59e0b, #fbbf24); }
.progress-fill.hard { background: linear-gradient(90deg, #ef4444, #f87171); }

/* === INTERESTS SECTION === */
.interests-container {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  justify-content: center;
}

.interest-chip {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  padding: 1rem 2rem;
  border-radius: 30px;
  border: 1px solid var(--glass-border);
  font-size: 1.1rem;
  transition: all 0.3s ease;
}

.interest-chip:hover {
  transform: scale(1.1);
  box-shadow: 0 5px 20px rgba(139, 92, 246, 0.4);
}

/* === CONTACT SECTION === */
.contact-container {
  max-width: 600px;
  margin: 0 auto;
  text-align: center;
}

.contact-container p {
  color: var(--text-primary);
  text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.3);
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  margin-top: 2rem;
}

.contact-item {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  padding: 1.5rem;
  border-radius: 15px;
  border: 1px solid var(--glass-border);
  text-decoration: none;
  color: var(--text-primary);
  transition: all 0.3s ease;
  display: block;
}

.contact-item strong {
  color: #ffffff;
  text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.3);
}

.contact-item:hover {
  transform: translateX(10px);
  box-shadow: 0 5px 20px rgba(99, 102, 241, 0.4);
}

/* === RESPONSIVE DESIGN === */
@media (max-width: 768px) {
  .hero-name {
      font-size: 3rem;
  }

  .hero-photo {
      width: 150px;
      height: 150px;
  }

  .section-title {
      font-size: 2rem;
  }

  .header-nav {
      display: none; /* Mobile menu toggle needed for production */
  }

  section {
      padding: 3rem 1rem;
  }

  .glass-card {
      padding: 1.5rem;
  }
}

@media (max-width: 480px) {
  .hero-name {
      font-size: 2rem;
  }

  .hero-tagline {
      font-size: 1rem;
  }
}

/* === SCROLL INDICATOR === */
.scroll-indicator {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  animation: bounce 2s infinite;
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
  40% { transform: translateX(-50%) translateY(-10px); }
  60% { transform: translateX(-50%) translateY(-5px); }
}

/* === LOADING STATE === */
.loading {
  text-align: center;
  padding: 2rem;
  color: var(--text-secondary);
}