/* ============================================
   Ayyappa Swamy Thati — Portfolio
   Design: Minimal, warm, editorial
   ============================================ */

@import url('https://fonts.googleapis.com/css2?family=Instrument+Serif:ital@0;1&family=Inter:wght@300;400;500;600&family=JetBrains+Mono:wght@400;500&display=swap');

/* --- Custom Properties --- */
:root {
  --bg: #f2f2f0;
  --bg-alt: #e8e8e6;
  --text: #1a1a1a;
  --text-muted: #4a4a4a;
  --text-light: #7a7a7a;
  --accent: #2d6a4f;
  --border: #d5d5d3;
  --white: #ffffff;

  --font-serif: 'Instrument Serif', Georgia, serif;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'Courier New', monospace;

  --max-width: 920px;
  --section-gap: 120px;
  --transition: 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

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

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

body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--text);
  text-decoration: none;
  border-bottom: 1px solid var(--border);
  transition: border-color var(--transition), color var(--transition);
}

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

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

::selection {
  background: var(--accent);
  color: var(--white);
}

/* --- Layout --- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 32px;
}

section {
  padding: var(--section-gap) 0;
}

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

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

/* --- Navigation --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 20px 0;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  background: rgba(242, 242, 240, 0.85);
  transition: box-shadow var(--transition);
}

.nav.scrolled {
  box-shadow: 0 1px 0 var(--border);
}

.nav .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-logo {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  border: none;
  letter-spacing: -0.02em;
}

.nav-logo:hover {
  border: none;
}

.nav-links {
  display: flex;
  gap: 28px;
  list-style: none;
}

.nav-links a {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  border: none;
  color: var(--text-muted);
  transition: color var(--transition);
}

.nav-links a:hover {
  color: var(--text);
  border: none;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--text);
  margin: 4px 0;
  transition: var(--transition);
}

/* --- Hero --- */
.hero {
  padding-top: 180px;
  padding-bottom: 80px;
  text-align: center;
}

.hero-label {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 24px;
}

.hero h1 {
  font-family: var(--font-serif);
  font-size: clamp(2.8rem, 6vw, 4.5rem);
  font-weight: 400;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: 28px;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-muted);
  max-width: 620px;
  margin: 0 auto 40px;
  line-height: 1.8;
}

.hero-links {
  display: flex;
  justify-content: center;
  gap: 32px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
}

.hero-links a {
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  border: none;
  position: relative;
}

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

.hero-links a:hover {
  color: var(--accent);
}

.hero-links a:hover::after {
  width: 100%;
}

/* --- Divider --- */
.divider {
  width: 60px;
  height: 1px;
  background: var(--border);
  margin: 0 auto;
}

/* --- Section Labels --- */
.section-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-light);
  margin-bottom: 16px;
}

.section-title {
  font-family: var(--font-serif);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 400;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: 28px;
}

/* --- About --- */
.about-content {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 60px;
  align-items: start;
}

.about-portrait {
  position: relative;
}

.about-portrait-img {
  width: 100%;
  max-width: 340px;
  border-radius: 4px;
  filter: grayscale(0.1);
}

.about-portrait-placeholder {
  width: 100%;
  max-width: 340px;
  aspect-ratio: 3/4;
  background: var(--bg-alt);
  border: 2px dashed var(--border);
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-light);
}

.about-text p {
  margin-bottom: 20px;
  color: var(--text-muted);
  font-size: 1.05rem;
}

.about-text p:first-of-type {
  color: var(--text);
}

/* --- Experience --- */
.experience-card {
  border-top: 1px solid var(--border);
  padding-top: 32px;
  margin-bottom: 48px;
}

.experience-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 8px;
  flex-wrap: wrap;
  gap: 12px;
}

.experience-role {
  font-family: var(--font-serif);
  font-size: 1.6rem;
  font-weight: 400;
}

.experience-period {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-light);
}

.experience-company {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 20px;
}

.experience-company a {
  color: var(--accent);
  border-color: transparent;
}

.experience-company a:hover {
  border-color: var(--accent);
}

.experience-highlights {
  list-style: none;
  padding: 0;
}

.experience-highlights li {
  position: relative;
  padding-left: 20px;
  margin-bottom: 14px;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.experience-highlights li::before {
  content: '—';
  position: absolute;
  left: 0;
  color: var(--text-light);
}

/* --- Projects --- */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}

.project-card {
  background: var(--white);
  border-radius: 8px;
  padding: 32px;
  transition: transform var(--transition), box-shadow var(--transition);
  border: 1px solid rgba(0, 0, 0, 0.04);
}

.project-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.06);
}

.project-tag {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
  margin-bottom: 12px;
}

.project-name {
  font-family: var(--font-serif);
  font-size: 1.4rem;
  margin-bottom: 12px;
  line-height: 1.3;
}

.project-desc {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 16px;
  line-height: 1.7;
}

.project-tech {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.project-tech span {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  padding: 3px 10px;
  background: var(--bg);
  border-radius: 20px;
  color: var(--text-muted);
  letter-spacing: 0.02em;
}

.project-card-link {
  display: block;
  border: none;
}

.project-card-link:hover {
  border: none;
}

/* --- Fun Lab --- */
.funlab {
  text-align: center;
  background: var(--white);
  border-radius: 12px;
  padding: 60px 40px;
  border: 1px solid rgba(0, 0, 0, 0.04);
}

.funlab-emoji {
  font-size: 2.5rem;
  margin-bottom: 20px;
}

.funlab p {
  color: var(--text-muted);
  max-width: 520px;
  margin: 0 auto 24px;
  font-size: 1.05rem;
}

.funlab-link {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--accent);
  border-color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

/* --- Skills --- */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 40px;
}

.skill-group h3 {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-light);
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

.skill-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.skill-pills span {
  font-size: 0.82rem;
  padding: 6px 16px;
  background: var(--white);
  border-radius: 24px;
  color: var(--text-muted);
  border: 1px solid var(--border);
  transition: background var(--transition), color var(--transition);
}

.skill-pills span:hover {
  background: var(--text);
  color: var(--white);
  border-color: var(--text);
}

/* --- Education --- */
.education-card {
  border-top: 1px solid var(--border);
  padding-top: 28px;
  margin-bottom: 28px;
}

.education-card h3 {
  font-family: var(--font-serif);
  font-size: 1.4rem;
  font-weight: 400;
  margin-bottom: 6px;
}

.education-card .edu-institution {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.education-card .edu-period {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-light);
}

/* --- Conferences --- */
.conference-item {
  border-top: 1px solid var(--border);
  padding: 20px 0;
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: 20px;
  align-items: baseline;
}

.conference-date {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-light);
}

.conference-info h4 {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  font-weight: 400;
  margin-bottom: 4px;
}

.conference-info p {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* --- Footer --- */
.footer {
  padding: 60px 0 40px;
  border-top: 1px solid var(--border);
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 20px;
}

.footer-tagline {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 1.1rem;
  color: var(--text-muted);
}

.footer-links {
  display: flex;
  gap: 24px;
}

.footer-links a {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  border: none;
  transition: color var(--transition);
}

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

.footer-bottom {
  margin-top: 40px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-light);
}

/* --- Responsive --- */
@media (max-width: 768px) {
  :root {
    --section-gap: 80px;
  }

  .container {
    padding: 0 20px;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg);
    flex-direction: column;
    padding: 20px 32px;
    gap: 16px;
    border-bottom: 1px solid var(--border);
  }

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

  .nav-toggle {
    display: block;
  }

  .hero {
    padding-top: 140px;
  }

  .about-content {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .about-portrait-img,
  .about-portrait-placeholder {
    max-width: 240px;
    margin: 0 auto;
  }

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

  .skills-grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .experience-header {
    flex-direction: column;
    gap: 4px;
  }

  .conference-item {
    grid-template-columns: 1fr;
    gap: 4px;
  }

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

  .hero-links {
    flex-wrap: wrap;
    gap: 16px;
  }
}

@media (max-width: 480px) {
  .hero h1 {
    font-size: 2.2rem;
  }

  .project-card {
    padding: 24px;
  }

  .funlab {
    padding: 40px 24px;
  }
}