/* ===== CSS Variables ===== */
:root {
  --color-bg: #fafafa;
  --color-bg-alt: #f0f0f0;
  --color-surface: #ffffff;
  --color-text: #1a1a2e;
  --color-text-secondary: #555566;
  --color-text-muted: #888899;
  --color-accent: #2563eb;
  --color-accent-light: #3b82f6;
  --color-accent-bg: rgba(37, 99, 235, 0.08);
  --color-border: #e5e5e5;
  --font-sans: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', monospace;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.1);
  --radius: 12px;
  --radius-sm: 8px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --max-width: 1100px;
}

/* ===== Reset & Base ===== */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: var(--color-accent-light);
}

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

/* ===== Container ===== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== Navbar ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(250, 250, 250, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: all var(--transition);
}

.navbar.scrolled {
  border-bottom-color: var(--color-border);
  box-shadow: var(--shadow-sm);
}

.nav-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav-logo {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--color-text);
  letter-spacing: -0.5px;
}

.nav-logo:hover {
  color: var(--color-accent);
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 32px;
}

.nav-links a {
  color: var(--color-text-secondary);
  font-size: 0.875rem;
  font-weight: 500;
  position: relative;
  padding: 4px 0;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-accent);
  border-radius: 1px;
  transition: width var(--transition);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-accent);
}

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

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: all var(--transition);
}

.nav-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.nav-toggle.active span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ===== Hero Section ===== */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 120px 24px 80px;
  position: relative;
  background: linear-gradient(180deg, var(--color-bg) 0%, var(--color-surface) 100%);
}

.hero-content {
  max-width: 640px;
}

.hero-avatar {
  margin-bottom: 32px;
}

.avatar-placeholder {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-accent) 0%, #7c3aed 100%);
  color: white;
  font-size: 2.5rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto;
  box-shadow: 0 8px 32px rgba(37, 99, 235, 0.25);
}

.hero-name {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 700;
  letter-spacing: -1.5px;
  line-height: 1.1;
  margin-bottom: 12px;
}

.hero-title {
  font-size: 1.25rem;
  color: var(--color-accent);
  font-weight: 500;
  margin-bottom: 16px;
}

.hero-subtitle {
  font-size: 1.0625rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
  margin-bottom: 40px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  border-radius: var(--radius-sm);
  font-size: 0.9375rem;
  font-weight: 500;
  font-family: var(--font-sans);
  cursor: pointer;
  transition: all var(--transition);
  border: none;
  text-decoration: none;
}

.btn-primary {
  background: var(--color-accent);
  color: white;
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.3);
}

.btn-primary:hover {
  background: var(--color-accent-light);
  color: white;
  box-shadow: 0 4px 16px rgba(37, 99, 235, 0.4);
  transform: translateY(-1px);
}

.btn-outline {
  background: transparent;
  color: var(--color-text);
  border: 1.5px solid var(--color-border);
}

.btn-outline:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  transform: translateY(-1px);
}

.btn-full {
  width: 100%;
}

/* ===== Scroll Indicator ===== */
.scroll-indicator {
  position: absolute;
  bottom: 40px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  animation: fadeInUp 1s ease 1s both;
}

.scroll-indicator span {
  font-size: 0.75rem;
  color: var(--color-text-muted);
  letter-spacing: 1px;
  text-transform: uppercase;
}

.scroll-arrow {
  width: 20px;
  height: 20px;
  border-right: 2px solid var(--color-text-muted);
  border-bottom: 2px solid var(--color-text-muted);
  transform: rotate(45deg);
  animation: scrollBounce 2s infinite;
}

/* ===== Sections ===== */
.section {
  padding: 100px 0;
}

.section-alt {
  background: var(--color-bg-alt);
}

.section-title {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.5px;
  margin-bottom: 48px;
  display: flex;
  align-items: center;
  gap: 16px;
}

.title-number {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-accent);
  background: var(--color-accent-bg);
  padding: 4px 12px;
  border-radius: 20px;
  font-family: var(--font-mono);
}

/* ===== About ===== */
.about-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: start;
}

.about-text p {
  color: var(--color-text-secondary);
  margin-bottom: 16px;
  font-size: 1.0625rem;
}

.about-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.stat-item {
  text-align: center;
  padding: 24px 16px;
  background: var(--color-surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
}

.stat-item:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.stat-number {
  font-size: 2.25rem;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1;
}

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

.stat-label {
  display: block;
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  margin-top: 8px;
}

/* ===== Skills ===== */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.skill-category {
  background: var(--color-surface);
  padding: 28px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
}

.skill-category:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.skill-category-title {
  font-size: 1.0625rem;
  font-weight: 600;
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--color-accent-bg);
}

.skill-items {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.skill-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: 6px;
}

.skill-name {
  font-size: 0.875rem;
  font-weight: 500;
}

.skill-level {
  font-size: 0.8125rem;
  color: var(--color-accent);
  font-weight: 500;
  font-family: var(--font-mono);
}

.skill-bar {
  height: 6px;
  background: var(--color-bg-alt);
  border-radius: 3px;
  overflow: hidden;
}

.skill-progress {
  height: 100%;
  background: linear-gradient(90deg, var(--color-accent) 0%, var(--color-accent-light) 100%);
  border-radius: 3px;
  width: 0;
  transition: width 1.2s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== Timeline (Experience) ===== */
.timeline {
  position: relative;
  padding-left: 40px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: var(--color-border);
}

.timeline-item {
  position: relative;
  margin-bottom: 40px;
}

.timeline-item:last-child {
  margin-bottom: 0;
}

.timeline-marker {
  position: absolute;
  left: -40px;
  top: 6px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--color-surface);
  border: 3px solid var(--color-accent);
  z-index: 1;
}

.timeline-content {
  background: var(--color-surface);
  padding: 28px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
}

.timeline-content:hover {
  box-shadow: var(--shadow-md);
  transform: translateX(4px);
}

.timeline-header {
  margin-bottom: 16px;
}

.timeline-title {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.timeline-company {
  display: inline-block;
  color: var(--color-accent);
  font-weight: 500;
  font-size: 0.9375rem;
  margin-right: 16px;
}

.timeline-date {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  font-family: var(--font-mono);
}

.timeline-desc {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.timeline-desc li {
  position: relative;
  padding-left: 16px;
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.timeline-desc li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-accent-bg);
  border: 1.5px solid var(--color-accent);
}

/* ===== Education ===== */
.education-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.education-card {
  background: var(--color-surface);
  padding: 32px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  text-align: center;
  transition: all var(--transition);
}

.education-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}

.education-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-bg);
  border-radius: 50%;
  color: var(--color-accent);
}

.education-icon svg {
  width: 28px;
  height: 28px;
}

.education-school {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.education-degree {
  color: var(--color-accent);
  font-weight: 500;
  font-size: 0.9375rem;
  margin-bottom: 8px;
}

.education-date {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  margin-bottom: 12px;
}

.education-desc {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
}

/* ===== Projects ===== */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.project-card {
  background: var(--color-surface);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
}

.project-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
}

.project-image {
  height: 180px;
  background: linear-gradient(135deg, var(--color-accent-bg) 0%, rgba(124, 58, 237, 0.08) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
}

.project-placeholder {
  font-size: 3rem;
}

.project-body {
  padding: 24px;
}

.project-title {
  font-size: 1.0625rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.project-desc {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: 16px;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 16px;
}

.tag {
  font-size: 0.75rem;
  font-weight: 500;
  padding: 4px 10px;
  border-radius: 20px;
  background: var(--color-accent-bg);
  color: var(--color-accent);
}

.project-links {
  display: flex;
  gap: 16px;
}

.project-link {
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--color-accent);
}

.project-link:hover {
  text-decoration: underline;
}

/* ===== Contact ===== */
.contact-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: start;
}

.contact-intro {
  font-size: 1.0625rem;
  color: var(--color-text-secondary);
  margin-bottom: 32px;
  line-height: 1.7;
}

.contact-items {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 16px;
}

.contact-icon {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-bg);
  border-radius: 50%;
  color: var(--color-accent);
  flex-shrink: 0;
}

.contact-icon svg {
  width: 20px;
  height: 20px;
}

.contact-label {
  display: block;
  font-size: 0.75rem;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 2px;
}

.contact-value {
  display: block;
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-text);
}

/* ===== Contact Form ===== */
.contact-form {
  background: var(--color-surface);
  padding: 32px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 6px;
  color: var(--color-text);
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 0.9375rem;
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  transition: all var(--transition);
  outline: none;
}

.form-group input:focus,
.form-group textarea:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-bg);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: var(--color-text-muted);
}

.form-group textarea {
  resize: vertical;
  min-height: 120px;
}

/* ===== Footer ===== */
.footer {
  padding: 40px 0;
  border-top: 1px solid var(--color-border);
}

.footer-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}

.footer-logo {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--color-text);
}

.footer-text {
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

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

.footer-social a {
  color: var(--color-text-muted);
  transition: color var(--transition);
}

.footer-social a:hover {
  color: var(--color-accent);
}

/* ===== Animations ===== */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes scrollBounce {
  0%, 20%, 50%, 80%, 100% {
    transform: rotate(45deg) translateY(0);
  }
  40% {
    transform: rotate(45deg) translateY(8px);
  }
  60% {
    transform: rotate(45deg) translateY(4px);
  }
}

/* Scroll reveal animation */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

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

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .skills-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .projects-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: rgba(250, 250, 250, 0.98);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    flex-direction: column;
    padding: 16px 24px;
    gap: 4px;
    border-bottom: 1px solid var(--color-border);
  }

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

  .nav-links a {
    display: block;
    padding: 10px 0;
    font-size: 1rem;
  }

  .nav-links a::after {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }

  .about-content {
    grid-template-columns: 1fr;
    gap: 40px;
  }

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

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

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

  .contact-content {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .section {
    padding: 72px 0;
  }

  .section-title {
    font-size: 1.5rem;
    margin-bottom: 36px;
  }

  .about-stats {
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
  }

  .stat-item {
    padding: 16px 8px;
  }

  .stat-number {
    font-size: 1.75rem;
  }
}

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

  .hero-title {
    font-size: 1.0625rem;
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .about-stats {
    grid-template-columns: 1fr;
  }

  .timeline {
    padding-left: 32px;
  }

  .footer-content {
    flex-direction: column;
    text-align: center;
  }
}

/* ===== Print Styles ===== */
@media print {
  .navbar,
  .scroll-indicator,
  .contact-form,
  .footer-social {
    display: none;
  }

  .hero {
    min-height: auto;
    padding: 40px 0;
  }

  .section {
    padding: 40px 0;
  }

  .btn {
    display: none;
  }
}