/* =============================================
   ROOT VARIABLES & RESET
   ============================================= */
:root {
  --primary: #0070f3;
  --primary-dark: #0050b3;
  --accent: #7c3aed;
  --bg: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-card: #ffffff;
  --text: #0f172a;
  --text-secondary: #475569;
  --border: #e2e8f0;
  --shadow: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -1px rgba(0,0,0,0.06);
  --shadow-lg: 0 20px 25px -5px rgba(0,0,0,0.1), 0 10px 10px -5px rgba(0,0,0,0.04);
  --radius: 0.75rem;
  --transition: all 0.3s ease;
  --navbar-height: 64px;
}

[data-theme="dark"] {
  --bg: #0f172a;
  --bg-secondary: #1e293b;
  --bg-card: #1e293b;
  --text: #f1f5f9;
  --text-secondary: #94a3b8;
  --border: #334155;
  --shadow: 0 4px 6px -1px rgba(0,0,0,0.3);
  --shadow-lg: 0 20px 25px -5px rgba(0,0,0,0.4);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  transition: background 0.3s ease, color 0.3s ease;
}

a { color: var(--primary); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--primary-dark); }

img { max-width: 100%; height: auto; display: block; }

/* =============================================
   UTILITY
   ============================================= */
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section {
  padding: 5rem 0;
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 0.5rem;
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  display: block;
  width: 48px;
  height: 4px;
  background: var(--primary);
  border-radius: 2px;
  margin-top: 0.4rem;
}

.section-header {
  margin-bottom: 3rem;
}

.section-subtitle {
  color: var(--text-secondary);
  margin-top: 0.75rem;
  font-size: 1.05rem;
}

.tag {
  display: inline-block;
  background: var(--bg-secondary);
  color: var(--primary);
  border: 1px solid var(--border);
  border-radius: 2rem;
  padding: 0.25rem 0.85rem;
  font-size: 0.82rem;
  font-weight: 500;
  transition: var(--transition);
}

.tag:hover {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.7rem 1.5rem;
  border-radius: var(--radius);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  border: 2px solid transparent;
  transition: var(--transition);
}

.btn-primary {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.btn-primary:hover {
  background: var(--primary-dark);
  border-color: var(--primary-dark);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-outline {
  background: transparent;
  color: var(--primary);
  border-color: var(--primary);
}

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

/* =============================================
   NAVBAR
   ============================================= */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--navbar-height);
  background: rgba(255,255,255,0.9);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  z-index: 1000;
  transition: var(--transition);
}

[data-theme="dark"] .navbar {
  background: rgba(15,23,42,0.9);
}

.navbar .container {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-size: 1.3rem;
  font-weight: 800;
  color: var(--text);
  letter-spacing: -0.5px;
}

.nav-logo span { color: var(--primary); }

.nav-links {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  padding: 0.4rem 0.75rem;
  border-radius: 0.5rem;
  transition: var(--transition);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--primary);
  background: var(--bg-secondary);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

/* Dark mode toggle */
.theme-toggle {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 2rem;
  width: 52px;
  height: 28px;
  cursor: pointer;
  position: relative;
  transition: var(--transition);
}

.theme-toggle::before {
  content: '';
  position: absolute;
  top: 3px;
  left: 3px;
  width: 20px;
  height: 20px;
  background: var(--primary);
  border-radius: 50%;
  transition: var(--transition);
}

[data-theme="dark"] .theme-toggle::before {
  transform: translateX(24px);
}

.theme-icon {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  font-size: 0.7rem;
  pointer-events: none;
}

.theme-icon.sun { left: 6px; }
.theme-icon.moon { right: 6px; }

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 0.25rem;
}

.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: var(--transition);
}

.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* =============================================
   HERO SECTION
   ============================================= */
#hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  background: linear-gradient(135deg, var(--bg) 0%, var(--bg-secondary) 100%);
  padding-top: var(--navbar-height);
  position: relative;
  overflow: hidden;
}

#hero::before {
  content: '';
  position: absolute;
  top: -30%;
  right: -10%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(0,112,243,0.08) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

#hero::after {
  content: '';
  position: absolute;
  bottom: -20%;
  left: -10%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(124,58,237,0.06) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero-content {
  max-width: 700px;
  animation: fadeInUp 0.8s ease both;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 2rem;
  padding: 0.35rem 1rem;
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  font-weight: 500;
}

.hero-badge .dot {
  width: 8px;
  height: 8px;
  background: #22c55e;
  border-radius: 50%;
  animation: pulse 2s infinite;
}

.hero-title {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 800;
  color: var(--text);
  line-height: 1.15;
  letter-spacing: -1px;
  margin-bottom: 1rem;
}

.hero-title .gradient {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 1.2rem;
  color: var(--text-secondary);
  margin-bottom: 1rem;
  font-weight: 500;
}

.hero-desc {
  font-size: 1rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  max-width: 560px;
  line-height: 1.75;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 2.5rem;
}

.hero-social {
  display: flex;
  gap: 0.75rem;
}

.social-link {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  font-size: 1rem;
  transition: var(--transition);
}

.social-link:hover {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
  transform: translateY(-3px);
  box-shadow: var(--shadow);
}

.scroll-indicator {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.4rem;
  color: var(--text-secondary);
  font-size: 0.75rem;
  animation: bounce 2s infinite;
}

.scroll-indicator svg {
  width: 20px;
  height: 20px;
  stroke: currentColor;
}

/* =============================================
   ABOUT SECTION
   ============================================= */
#about {
  background: var(--bg-secondary);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1.4fr;
  gap: 4rem;
  align-items: center;
}

.about-avatar-wrap {
  position: relative;
}

.about-avatar {
  width: 100%;
  max-width: 340px;
  aspect-ratio: 1;
  border-radius: 1.5rem;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 7rem;
  box-shadow: var(--shadow-lg);
  margin: 0 auto;
}

.about-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin-top: 2rem;
}

.stat-item {
  text-align: center;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem;
}

.stat-value {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
}

.stat-label {
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-top: 0.2rem;
}

.about-text p {
  color: var(--text-secondary);
  margin-bottom: 1.25rem;
  line-height: 1.8;
}

.about-interests {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1.5rem;
}

/* =============================================
   EXPERIENCE SECTION
   ============================================= */
#experience {
  background: var(--bg);
}

.timeline {
  position: relative;
  padding-left: 2rem;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: var(--border);
}

.timeline-item {
  position: relative;
  margin-bottom: 2.5rem;
  opacity: 0;
  transform: translateX(-20px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.timeline-item.visible {
  opacity: 1;
  transform: translateX(0);
}

.timeline-dot {
  position: absolute;
  left: -2.45rem;
  top: 0.4rem;
  width: 16px;
  height: 16px;
  background: var(--primary);
  border-radius: 50%;
  border: 3px solid var(--bg);
  box-shadow: 0 0 0 2px var(--primary);
}

.exp-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.75rem;
  box-shadow: var(--shadow);
  transition: var(--transition);
}

.exp-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.exp-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

.exp-role {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text);
}

.exp-company {
  font-size: 0.95rem;
  color: var(--primary);
  font-weight: 600;
  margin-top: 0.1rem;
}

.exp-location {
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-top: 0.15rem;
  display: flex;
  align-items: center;
  gap: 0.3rem;
}

.exp-meta {
  text-align: right;
}

.exp-period {
  display: inline-block;
  background: var(--bg-secondary);
  color: var(--text-secondary);
  border: 1px solid var(--border);
  border-radius: 2rem;
  padding: 0.2rem 0.8rem;
  font-size: 0.8rem;
  font-weight: 500;
}

.exp-desc {
  color: var(--text-secondary);
  font-size: 0.92rem;
  line-height: 1.75;
  margin-bottom: 1rem;
}

.exp-skills {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

/* =============================================
   EDUCATION SECTION
   ============================================= */
#education {
  background: var(--bg-secondary);
}

.education-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.5rem;
}

.edu-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.75rem;
  box-shadow: var(--shadow);
  transition: var(--transition);
  opacity: 0;
  transform: translateY(20px);
}

.edu-card.visible {
  opacity: 1;
  transform: translateY(0);
}

.edu-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-3px);
}

.edu-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-radius: 0.75rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  margin-bottom: 1rem;
}

.edu-degree {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 0.25rem;
}

.edu-uni {
  font-size: 0.88rem;
  color: var(--primary);
  margin-bottom: 0.75rem;
  font-weight: 500;
}

.edu-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 0.75rem;
  padding-top: 0.75rem;
  border-top: 1px solid var(--border);
}

.edu-year, .edu-marks {
  font-size: 0.82rem;
  color: var(--text-secondary);
}

.edu-marks {
  font-weight: 600;
  color: var(--primary);
}

/* =============================================
   SKILLS SECTION
   ============================================= */
#skills {
  background: var(--bg);
}

.skills-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.skill-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.65rem 1.2rem;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text);
  transition: var(--transition);
  cursor: default;
  opacity: 0;
  transform: scale(0.9);
}

.skill-tag.visible {
  opacity: 1;
  transform: scale(1);
}

.skill-tag:hover {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
  transform: translateY(-3px) scale(1.05);
  box-shadow: var(--shadow);
}

.skill-dot {
  width: 8px;
  height: 8px;
  background: var(--primary);
  border-radius: 50%;
  transition: var(--transition);
}

.skill-tag:hover .skill-dot {
  background: #fff;
}

/* =============================================
   PROJECTS SECTION
   ============================================= */
#projects {
  background: var(--bg-secondary);
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
}

.project-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  opacity: 0;
  transform: translateY(20px);
}

.project-card.visible {
  opacity: 1;
  transform: translateY(0);
}

.project-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-5px);
}

.project-img {
  height: 160px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3.5rem;
  background: linear-gradient(135deg, var(--bg-secondary), var(--border));
  position: relative;
  overflow: hidden;
}

.project-img::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(0,112,243,0.1), rgba(124,58,237,0.1));
}

.project-body {
  padding: 1.5rem;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.project-name {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 0.5rem;
}

.project-desc {
  color: var(--text-secondary);
  font-size: 0.88rem;
  line-height: 1.7;
  flex: 1;
  margin-bottom: 1.25rem;
}

.project-footer {
  display: flex;
  justify-content: flex-end;
}

.project-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--primary);
  font-size: 0.85rem;
  font-weight: 600;
  padding: 0.4rem 0.9rem;
  border: 1px solid var(--primary);
  border-radius: 0.5rem;
  transition: var(--transition);
}

.project-link:hover {
  background: var(--primary);
  color: #fff;
}

/* =============================================
   CONTACT SECTION
   ============================================= */
#contact {
  background: var(--bg);
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: 4rem;
  align-items: start;
}

.contact-info-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  margin-top: 1.5rem;
}

.contact-info-item {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
}

.contact-info-icon {
  width: 44px;
  height: 44px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 0.75rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  flex-shrink: 0;
}

.contact-info-label {
  font-size: 0.78rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.2rem;
}

.contact-info-value {
  font-size: 0.95rem;
  color: var(--text);
  font-weight: 500;
}

.contact-social {
  display: flex;
  gap: 0.75rem;
  margin-top: 2rem;
}

/* Form */
.contact-form {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  box-shadow: var(--shadow);
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 0.4rem;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.7rem 1rem;
  border: 1px solid var(--border);
  border-radius: 0.5rem;
  background: var(--bg-secondary);
  color: var(--text);
  font-size: 0.95rem;
  font-family: inherit;
  transition: var(--transition);
  outline: none;
}

.form-group input:focus,
.form-group textarea:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(0,112,243,0.1);
}

.form-group textarea {
  min-height: 130px;
  resize: vertical;
}

.form-submit {
  width: 100%;
  padding: 0.8rem;
  border: none;
  border-radius: 0.5rem;
  background: var(--primary);
  color: #fff;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  font-family: inherit;
}

.form-submit:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow);
}

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

.form-message {
  margin-top: 1rem;
  padding: 0.75rem 1rem;
  border-radius: 0.5rem;
  font-size: 0.9rem;
  font-weight: 500;
  display: none;
}

.form-message.success {
  background: #dcfce7;
  color: #166534;
  border: 1px solid #86efac;
  display: block;
}

.form-message.error {
  background: #fee2e2;
  color: #991b1b;
  border: 1px solid #fca5a5;
  display: block;
}

/* =============================================
   FOOTER
   ============================================= */
footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  padding: 2rem 0;
  text-align: center;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
}

.footer-logo {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text);
}

.footer-logo span { color: var(--primary); }

.footer-text {
  color: var(--text-secondary);
  font-size: 0.85rem;
}

/* =============================================
   ANIMATIONS
   ============================================= */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(30px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes bounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50%       { transform: translateX(-50%) translateY(-8px); }
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50%       { opacity: 0.6; transform: scale(0.85); }
}

/* =============================================
   RESPONSIVE
   ============================================= */
@media (max-width: 768px) {
  .section { padding: 3.5rem 0; }

  .nav-links {
    display: none;
    position: fixed;
    top: var(--navbar-height);
    left: 0;
    right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    padding: 1rem;
    gap: 0.25rem;
    box-shadow: var(--shadow);
  }

  .nav-links.open { display: flex; }

  .nav-links a {
    width: 100%;
    text-align: center;
    padding: 0.65rem;
  }

  .hamburger { display: flex; }

  .about-grid { grid-template-columns: 1fr; gap: 2rem; }
  .about-stats { grid-template-columns: repeat(3, 1fr); }
  .contact-grid { grid-template-columns: 1fr; gap: 2rem; }
  .hero-title { font-size: 2.4rem; }

  .exp-header { flex-direction: column; }
  .exp-meta { text-align: left; }
}

@media (max-width: 480px) {
  .about-stats { grid-template-columns: repeat(3, 1fr); gap: 0.5rem; }
  .projects-grid { grid-template-columns: 1fr; }
  .education-grid { grid-template-columns: 1fr; }
}