/* New Design System - Ported from React/Tailwind */
:root {
  --bg-body: #ffffff;
  --bg-subtle: #f9fafb;
  --bg-dark: #111827;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-light: #eff6ff;
  --text-main: #111827;
  --text-body: #4b5563;
  --text-muted: #6b7280;
  --text-inverted: #ffffff;
  --border-light: #f3f4f6;
  --border-medium: #e5e7eb;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1);
  --shadow-2xl: 0 25px 50px -12px rgb(0 0 0 / 0.25);
  --font-sans: 'Inter', system-ui, sans-serif;
  --container-width: 56rem;
  --radius-xl: 0.75rem;
  --radius-2xl: 1rem;
  --radius-3xl: 1.5rem;
  --radius-full: 9999px;
  --transition: 0.2s ease-in-out;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-sans);
  background: var(--bg-body);
  color: var(--text-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3, h4 { color: var(--text-main); font-weight: 700; line-height: 1.1; letter-spacing: -0.025em; }
a { text-decoration: none; color: inherit; transition: color var(--transition); }
img { max-width: 100%; height: auto; display: block; }

.container { max-width: var(--container-width); margin: 0 auto; padding: 0 1.5rem; }

/* Badge */
.badge { display: inline-block; padding: 0.25rem 0.75rem; font-size: 0.75rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.05em; border-radius: var(--radius-full); background: var(--primary-light); color: var(--primary); }

/* Buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; padding: 1rem 2rem; font-weight: 700; border-radius: var(--radius-xl); transition: all var(--transition); cursor: pointer; border: none; gap: 0.5rem; font-size: 1rem; }
.btn-primary { background: var(--bg-dark); color: var(--text-inverted); box-shadow: var(--shadow-lg); }
.btn-primary:hover { background: var(--primary); transform: scale(1.02); }
.btn-secondary { background: var(--bg-body); border: 1px solid var(--border-medium); color: var(--text-main); }
.btn-secondary:hover { background: var(--bg-subtle); }

/* Header */
.site-header { position: sticky; top: 0; z-index: 50; height: 4rem; display: flex; align-items: center; transition: all 0.3s; background: transparent; }
.site-header.scrolled { background: rgba(255,255,255,0.8); backdrop-filter: blur(12px); border-bottom: 1px solid var(--border-light); }
.header-inner { display: flex; justify-content: space-between; align-items: center; width: 100%; }
.header-brand { font-size: 1.25rem; font-weight: 700; letter-spacing: -0.05em; color: var(--text-main); }
.nav-desktop { display: none; gap: 2rem; }
@media (min-width: 768px) { .nav-desktop { display: flex; } }
.nav-link { font-size: 0.875rem; font-weight: 500; color: var(--text-body); }
.nav-link:hover { color: var(--text-main); }
.mobile-menu-btn { display: block; background: none; border: none; cursor: pointer; padding: 0.5rem; color: var(--text-main); border-radius: 50%; }
@media (min-width: 768px) { .mobile-menu-btn { display: none; } }
.mobile-nav { position: fixed; top: 4rem; left: 0; width: 100%; background: var(--bg-body); border-bottom: 1px solid var(--border-light); box-shadow: var(--shadow-2xl); padding: 1.5rem; display: none; flex-direction: column; gap: 1rem; }
.mobile-nav.open { display: flex; }

/* Hero */
.hero-section { padding: 5rem 0; display: flex; flex-direction: column; gap: 3rem; align-items: center; text-align: center; }
@media (min-width: 768px) { .hero-section { flex-direction: row; text-align: left; gap: 4rem; } }
.hero-content { flex: 1; }
.hero-content h1 { font-size: clamp(2.5rem, 5vw, 3.5rem); margin-bottom: 1.5rem; }
.hero-content h1 .highlight { color: var(--primary); font-style: italic; }
.hero-content p { font-size: 1.125rem; color: var(--text-body); margin-bottom: 2rem; max-width: 32rem; line-height: 1.7; }
.hero-buttons { display: flex; flex-wrap: wrap; gap: 1rem; justify-content: center; }
@media (min-width: 768px) { .hero-buttons { justify-content: flex-start; } }
.hero-image { position: relative; flex-shrink: 0; }
.hero-image::before { content: ''; position: absolute; inset: -0.5rem; background: linear-gradient(to right, #2563eb, #06b6d4); border-radius: 50%; opacity: 0.25; filter: blur(12px); }
.hero-img { position: relative; width: 16rem; height: 16rem; border-radius: 50%; overflow: hidden; border: 8px solid var(--bg-body); box-shadow: var(--shadow-2xl); }
@media (min-width: 768px) { .hero-img { width: 20rem; height: 20rem; } }
.hero-img img { width: 100%; height: 100%; object-fit: cover; filter: grayscale(100%); transition: filter 0.7s; }
.hero-img:hover img { filter: grayscale(0); }

/* Showcase/Carousel */
.showcase-section { background: var(--bg-subtle); border-radius: var(--radius-3xl); padding: 3rem 1.5rem; margin-bottom: 5rem; }
.showcase-header { display: flex; justify-content: space-between; align-items: flex-end; margin-bottom: 2rem; flex-wrap: wrap; gap: 1rem; }
.showcase-header h2 { font-size: 1.5rem; margin-bottom: 0.5rem; }
.showcase-header p { color: var(--text-muted); }
.carousel-controls { display: flex; gap: 0.5rem; }
.carousel-controls button { width: 40px; height: 40px; border-radius: 50%; background: var(--bg-body); border: 1px solid var(--border-medium); cursor: pointer; display: flex; align-items: center; justify-content: center; transition: background 0.2s; }
.carousel-controls button:hover { background: var(--bg-subtle); }
.carousel-viewport { position: relative; height: 300px; border-radius: var(--radius-2xl); overflow: hidden; box-shadow: var(--shadow-xl); background: #000; }
@media (min-width: 768px) { .carousel-viewport { height: 450px; } }
.carousel-inner { display: flex; height: 100%; transition: transform 0.7s ease-in-out; }
.carousel-slide { min-width: 100%; height: 100%; position: relative; }
.carousel-slide img { width: 100%; height: 100%; object-fit: cover; }
.video-embed { position: absolute; inset: 0; width: 100%; height: 100%; }
.video-embed iframe { width: 100%; height: 100%; border: none; }
.slide-overlay { position: absolute; inset: 0; background: linear-gradient(to top, rgba(0,0,0,0.7), transparent); display: flex; flex-direction: column; justify-content: flex-end; padding: 2rem; color: #fff; }
.slide-label { font-size: 0.75rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.1em; color: #60a5fa; margin-bottom: 0.5rem; }
.slide-title { font-size: 1.5rem; font-weight: 700; }
@media (min-width: 768px) { .slide-title { font-size: 2rem; } }
.carousel-dots { display: flex; justify-content: center; gap: 0.5rem; margin-top: 1.5rem; }
.dot { width: 0.6rem; height: 0.6rem; border-radius: 50%; background: #d1d5db; cursor: pointer; transition: all 0.3s; border: none; }
.dot.active { width: 2rem; background: var(--bg-dark); border-radius: var(--radius-full); }

/* Approach */
.approach-section { background: var(--bg-dark); color: var(--text-inverted); padding: 5rem 0; margin: 5rem 0; }
.approach-section h2 { text-align: center; margin-bottom: 3rem; color: #fff; }
.approach-grid { display: grid; grid-template-columns: 1fr; gap: 2rem; }
@media (min-width: 768px) { .approach-grid { grid-template-columns: repeat(3, 1fr); } }
.approach-card { background: rgba(255,255,255,0.05); border: 1px solid rgba(255,255,255,0.1); padding: 2rem; border-radius: var(--radius-2xl); transition: background 0.2s; }
.approach-card:hover { background: rgba(255,255,255,0.1); }
.approach-card h4 { font-size: 0.75rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.1em; color: #60a5fa; margin-bottom: 1rem; }
.approach-card p { color: #d1d5db; line-height: 1.6; }

/* Writing/Articles */
.writing-section { padding: 5rem 0; }
.writing-section h2 { font-size: 1.875rem; margin-bottom: 2.5rem; text-align: center; }
@media (min-width: 768px) { .writing-section h2 { text-align: left; } }
.writing-grid { display: grid; grid-template-columns: 1fr; gap: 1rem; }
@media (min-width: 768px) { .writing-grid { grid-template-columns: 1fr 1fr; } }
.article-card { display: flex; flex-direction: column; padding: 2rem; border: 1px solid var(--border-light); border-radius: var(--radius-2xl); transition: all var(--transition); }
.article-card:hover { border-color: #bfdbfe; background: rgba(239, 246, 255, 0.3); box-shadow: var(--shadow-md); }
.article-header { display: flex; justify-content: space-between; align-items: flex-start; margin-bottom: 1rem; }
.article-card h3 { font-size: 1.25rem; color: var(--text-main); line-height: 1.3; }
.article-meta { margin-top: 1rem; font-size: 0.875rem; color: var(--text-muted); }

/* Contact */
.contact-section { padding: 5rem 0; }
.contact-container { background: var(--bg-body); border: 1px solid var(--border-light); border-radius: var(--radius-3xl); padding: 2rem; box-shadow: var(--shadow-2xl); max-width: 40rem; margin: 0 auto; }
@media (min-width: 768px) { .contact-container { padding: 3rem; } }
.contact-container h2 { text-align: center; margin-bottom: 1rem; }
.contact-container > p { text-align: center; color: var(--text-muted); margin-bottom: 2.5rem; }
.form-grid { display: grid; grid-template-columns: 1fr; gap: 1.5rem; margin-bottom: 1.5rem; }
@media (min-width: 640px) { .form-grid { grid-template-columns: 1fr 1fr; } }
.form-group label { display: block; font-size: 0.875rem; font-weight: 700; color: var(--text-main); margin-bottom: 0.5rem; }
.input-field { width: 100%; padding: 0.75rem 1rem; border: 1px solid var(--border-medium); border-radius: var(--radius-xl); outline: none; transition: border-color 0.2s, box-shadow 0.2s; font-family: var(--font-sans); font-size: 1rem; }
.input-field:focus { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1); }
textarea.input-field { resize: none; min-height: 120px; }

/* Footer */
.site-footer { padding: 5rem 0 2rem; background: rgba(249, 250, 251, 0.5); border-top: 1px solid var(--border-light); margin-top: 5rem; }
.footer-grid { display: grid; gap: 3rem; grid-template-columns: 1fr; margin-bottom: 3rem; }
@media (min-width: 768px) { .footer-grid { grid-template-columns: 2fr 1fr 1fr; } }
.footer-brand { font-size: 1.5rem; font-weight: 700; letter-spacing: -0.05em; color: var(--text-main); margin-bottom: 1rem; }
.footer-desc { color: var(--text-muted); max-width: 20rem; margin-bottom: 1.5rem; }
.social-links { display: flex; gap: 0.75rem; }
.social-link { width: 2.5rem; height: 2.5rem; border-radius: 50%; border: 1px solid var(--border-medium); display: flex; align-items: center; justify-content: center; color: var(--text-muted); transition: all 0.2s; }
.social-link:hover { background: var(--bg-body); box-shadow: var(--shadow-sm); color: var(--text-main); }
.footer-nav h4 { font-size: 0.75rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.1em; color: var(--text-main); margin-bottom: 1.5rem; }
.footer-nav a { display: block; color: var(--text-muted); font-size: 0.875rem; margin-bottom: 1rem; }
.footer-nav a:hover { color: var(--text-main); }
.status-badge { display: inline-flex; align-items: center; gap: 0.5rem; font-size: 0.875rem; font-weight: 700; color: #16a34a; background: #dcfce7; padding: 0.25rem 0.75rem; border-radius: var(--radius-full); }
.status-badge::before { content: ''; width: 0.5rem; height: 0.5rem; background: #22c55e; border-radius: 50%; animation: pulse 2s infinite; }
@keyframes pulse { 0%, 100% { opacity: 1; } 50% { opacity: 0.5; } }
.footer-bottom { padding-top: 2rem; border-top: 1px solid var(--border-medium); display: flex; flex-direction: column; gap: 1rem; align-items: center; font-size: 0.75rem; color: var(--text-muted); }
@media (min-width: 768px) { .footer-bottom { flex-direction: row; justify-content: space-between; } }
.footer-links { display: flex; gap: 1.5rem; }
.footer-links a:hover { color: var(--text-body); }

/* About Section */
.about-section { padding: 5rem 0; }
.about-header { text-align: center; max-width: 48rem; margin: 0 auto 3rem; }
.about-header .badge { margin-bottom: 1rem; }
.about-header h2 { font-size: 2.25rem; margin-bottom: 1.5rem; }
.about-intro { font-size: 1.125rem; color: var(--text-body); line-height: 1.8; margin-bottom: 1rem; }
.about-sub { font-size: 1rem; color: var(--text-muted); line-height: 1.7; }

/* Skills Container */
.skills-container { background: var(--bg-subtle); border-radius: var(--radius-3xl); padding: 2rem; margin-bottom: 3rem; }
.skills-tabs { display: flex; gap: 0.5rem; flex-wrap: wrap; margin-bottom: 1.5rem; justify-content: center; }
.skill-tab { padding: 0.75rem 1.5rem; border-radius: var(--radius-full); border: 1px solid var(--border-medium); background: var(--bg-body); cursor: pointer; font-weight: 600; font-size: 0.875rem; color: var(--text-body); transition: all var(--transition); }
.skill-tab:hover { border-color: var(--primary); color: var(--primary); }
.skill-tab.active { background: var(--bg-dark); color: var(--text-inverted); border-color: var(--bg-dark); }
.skills-panels { min-height: 120px; }
.skills-panel { display: none; flex-wrap: wrap; gap: 0.75rem; justify-content: center; animation: fadeIn 0.3s ease; }
.skills-panel.active { display: flex; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }
.skill-pill { display: inline-block; padding: 0.5rem 1rem; font-size: 0.875rem; font-weight: 500; background: var(--bg-body); border: 1px solid var(--border-medium); border-radius: var(--radius-full); color: var(--text-body); transition: all var(--transition); }
.skill-pill:hover { border-color: var(--primary); color: var(--primary); transform: translateY(-2px); box-shadow: var(--shadow-sm); }

/* Experience Container */
.experience-container { margin-bottom: 3rem; }
.experience-container h3 { font-size: 1.5rem; text-align: center; margin-bottom: 2rem; }
.timeline-grid { display: grid; grid-template-columns: 1fr; gap: 1.5rem; }
@media (min-width: 768px) { .timeline-grid { grid-template-columns: repeat(3, 1fr); } }
.timeline-card { background: var(--bg-body); border: 1px solid var(--border-light); border-radius: var(--radius-2xl); padding: 1.5rem; transition: all var(--transition); position: relative; overflow: hidden; }
.timeline-card::before { content: ''; position: absolute; top: 0; left: 0; width: 100%; height: 4px; background: linear-gradient(90deg, var(--primary), #06b6d4); opacity: 0; transition: opacity var(--transition); }
.timeline-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: #bfdbfe; }
.timeline-card:hover::before { opacity: 1; }
.timeline-icon { width: 3rem; height: 3rem; background: var(--primary-light); border-radius: 50%; display: flex; align-items: center; justify-content: center; color: var(--primary); font-size: 1.125rem; margin-bottom: 1rem; }
.timeline-header { margin-bottom: 0.5rem; }
.timeline-header h4 { font-size: 1rem; font-weight: 700; color: var(--text-main); margin-bottom: 0.25rem; }
.timeline-company { font-size: 0.875rem; font-weight: 600; color: var(--primary); }
.timeline-date { display: inline-block; font-size: 0.75rem; font-weight: 500; color: var(--text-muted); background: var(--bg-subtle); padding: 0.25rem 0.75rem; border-radius: var(--radius-full); margin-bottom: 1rem; }
.timeline-points { list-style: none; padding: 0; margin: 0; }
.timeline-points li { position: relative; padding-left: 1rem; font-size: 0.875rem; color: var(--text-body); line-height: 1.6; margin-bottom: 0.5rem; }
.timeline-points li::before { content: '→'; position: absolute; left: 0; color: var(--primary); font-weight: 600; }
.timeline-points li:last-child { margin-bottom: 0; }

/* Credentials Container */
.credentials-container { display: grid; grid-template-columns: 1fr; gap: 1.5rem; }
@media (min-width: 768px) { .credentials-container { grid-template-columns: repeat(3, 1fr); } }
.credential-card { background: var(--bg-body); border: 1px solid var(--border-light); border-radius: var(--radius-2xl); padding: 1.5rem; text-align: center; transition: all var(--transition); }
.credential-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.credential-icon { width: 3.5rem; height: 3.5rem; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 1.25rem; margin: 0 auto 1rem; }
.education-card .credential-icon { background: linear-gradient(135deg, #dbeafe, #eff6ff); color: var(--primary); }
.cert-card .credential-icon { background: linear-gradient(135deg, #dcfce7, #f0fdf4); color: #16a34a; }
.achievement-card .credential-icon { background: linear-gradient(135deg, #fef3c7, #fffbeb); color: #d97706; }
.credential-card h4 { font-size: 0.875rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.05em; color: var(--text-main); margin-bottom: 1rem; }
.credential-item { margin-bottom: 0.75rem; }
.credential-item:last-child { margin-bottom: 0; }
.credential-item strong { display: block; font-size: 0.875rem; font-weight: 600; color: var(--text-main); margin-bottom: 0.125rem; }
.credential-item span { font-size: 0.8125rem; color: var(--text-muted); }

/* Floating Resume CTA */
.floating-cta {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 1rem 1.5rem;
  background: linear-gradient(135deg, var(--primary), #1d4ed8);
  color: var(--text-inverted);
  font-weight: 600;
  font-size: 0.9375rem;
  text-decoration: none;
  border-radius: var(--radius-full);
  box-shadow: 0 10px 40px rgba(37, 99, 235, 0.4), 0 4px 12px rgba(0, 0, 0, 0.15);
  z-index: 100;
  transition: all 0.3s ease;
  animation: floatPulse 3s ease-in-out infinite;
}

.floating-cta:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 14px 50px rgba(37, 99, 235, 0.5), 0 6px 16px rgba(0, 0, 0, 0.2);
  animation: none;
}

.floating-cta i {
  font-size: 1.125rem;
}

@keyframes floatPulse {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-4px); }
}

/* Responsive: Stack icon only on mobile */
@media (max-width: 640px) {
  .floating-cta {
    padding: 1rem;
    border-radius: 50%;
    bottom: 1.5rem;
    right: 1.5rem;
  }
  .floating-cta span {
    display: none;
  }
  .floating-cta i {
    font-size: 1.25rem;
  }
}

/* Utilities */
.visually-hidden { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }