:root {
  --bg: #0f172a;
  --bg-soft: #111827;
  --surface: #ffffff;
  --surface-2: #f8fafc;
  --text: #0f172a;
  --text-light: #475569;
  --white: #ffffff;
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --border: #e2e8f0;
  --shadow: 0 10px 30px rgba(15, 23, 42, 0.08);
  --radius: 18px;
  --max-width: 1100px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: Arial, Helvetica, sans-serif;
  line-height: 1.6;
  color: var(--text);
  background: var(--surface);
}

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

a {
  text-decoration: none;
  color: inherit;
}

.container {
  width: min(92%, var(--max-width));
  margin: 0 auto;
}

.narrow {
  max-width: 800px;
}

.site-header {
  background: var(--bg);
  color: var(--white);
  position: sticky;
  top: 0;
  z-index: 1000;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 72px;
}

.logo {
  font-size: 1.1rem;
  font-weight: 700;
}

.nav-links {
  list-style: none;
  display: flex;
  gap: 1.25rem;
  flex-wrap: wrap;
}

.nav-links a {
  color: var(--white);
  opacity: 0.9;
  transition: opacity 0.2s ease;
}

.nav-links a:hover {
  opacity: 1;
}

.hero {
  background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
  color: var(--white);
  padding: 72px 0 60px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 2rem;
  align-items: center;
}

.eyebrow,
.section-tag,
.featured-label {
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.8rem;
  font-weight: 700;
}

.eyebrow,
.section-tag {
  color: #94a3b8;
  margin-bottom: 0.75rem;
}

.hero h1 {
  font-size: clamp(2.3rem, 5vw, 4rem);
  line-height: 1.05;
  margin-bottom: 0.75rem;
}

.hero h2 {
  font-size: clamp(1.05rem, 2vw, 1.5rem);
  font-weight: 600;
  color: #cbd5e1;
  margin-bottom: 1rem;
}

.hero-description {
  max-width: 620px;
  color: #e2e8f0;
  margin-bottom: 1.5rem;
  font-size: 1.02rem;
}

.hero-buttons,
.project-links,
.contact-links,
.card-links {
  display: flex;
  gap: 0.9rem;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  padding: 0.85rem 1.2rem;
  border-radius: 999px;
  font-weight: 700;
  transition: transform 0.2s ease, background 0.2s ease, color 0.2s ease;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn-primary {
  background: var(--primary);
  color: var(--white);
}

.btn-primary:hover {
  background: var(--primary-dark);
}

.btn-secondary {
  background: transparent;
  color: var(--white);
  border: 1px solid rgba(255, 255, 255, 0.3);
}

.btn-secondary-dark {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-secondary-dark:hover {
  background: var(--text);
  color: var(--white);
}

.hero-card {
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow);
  backdrop-filter: blur(8px);
}

.featured-label {
  color: #93c5fd;
  display: inline-block;
  margin-bottom: 0.7rem;
}

.hero-card h3 {
  font-size: 1.5rem;
  margin-bottom: 0.75rem;
}

.hero-card p {
  color: #e2e8f0;
  margin-bottom: 1rem;
}

.feature-list {
  padding-left: 1.1rem;
  margin-bottom: 1.2rem;
}

.feature-list li {
  margin-bottom: 0.45rem;
  color: #f8fafc;
}

.section {
  padding: 72px 0;
}

.alt-section {
  background: var(--surface-2);
}

.section-header {
  margin-bottom: 2rem;
}

.section-header h2 {
  font-size: 2rem;
  margin-bottom: 0.5rem;
}

.section-header p {
  color: var(--text-light);
  max-width: 720px;
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.project-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.4rem;
  box-shadow: var(--shadow);
}

.project-card h3 {
  margin-bottom: 0.7rem;
}

.project-card p {
  margin-bottom: 0.8rem;
  color: var(--text-light);
}

.stack {
  font-weight: 700;
  color: var(--text);
}

.card-links a {
  color: var(--primary);
  font-weight: 700;
}

.skills-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
}

.skill-box {
  background: var(--surface-2);
  border: 1px solid var(--border);
  padding: 1rem;
  border-radius: 14px;
  text-align: center;
  font-weight: 700;
}

.architecture-section {
  padding-top: 24px;
}

.architecture-card,
.team-project-card,
.contribution-box,
.phase-box {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.architecture-card,
.team-project-card {
  padding: 1.5rem;
}

.architecture-card h3,
.contribution-box h3,
.phase-box h3 {
  margin-bottom: 0.75rem;
}

.architecture-card p,
.team-project-card p,
.phase-box p {
  color: var(--text-light);
}

.phase-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin-top: 1.5rem;
  margin-bottom: 1.5rem;
}

.phase-box {
  padding: 1.2rem;
}

.contribution-box {
  padding: 1.2rem;
  margin-top: 1rem;
}

.contribution-box ul {
  padding-left: 1.2rem;
}

.contribution-box li {
  margin-bottom: 0.5rem;
  color: var(--text-light);
}

.site-footer {
  background: var(--bg);
  color: var(--white);
  padding: 24px 0;
}

.footer-content {
  text-align: center;
  color: #cbd5e1;
}

@media (max-width: 900px) {
  .hero-grid,
  .projects-grid,
  .skills-grid,
  .phase-grid {
    grid-template-columns: 1fr;
  }

  .nav {
    flex-direction: column;
    gap: 0.8rem;
    padding: 1rem 0;
  }

  .nav-links {
    justify-content: center;
  }

  .hero {
    padding-top: 52px;
  }
}

@media (max-width: 560px) {
  .hero h1 {
    font-size: 2.2rem;
  }

  .hero h2 {
    font-size: 1rem;
  }

  .btn {
    width: 100%;
    text-align: center;
  }
}