:root {
  --bg: #ffffff;
  --bg-elevated: #f8f9fa;
  --bg-accent: #e8f4f8;
  --text: #2c3e50;
  --text-muted: #7f8c8d;
  --accent: #3498db;
  --accent-dark: #2980b9;
  --accent-dim: rgba(52, 152, 219, 0.1);
  --accent-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --green: #27ae60;
  --green-dim: rgba(39, 174, 96, 0.1);
  --border: #e0e4e8;
  --border-light: #ecf0f1;
  --radius: 8px;
  --font-sans: "DM Sans", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", monospace;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.1);
}

/* ── Dark theme ── */
[data-theme="dark"] {
  --bg: #0a0b0d;
  --bg-elevated: #12141a;
  --bg-accent: rgba(52, 152, 219, 0.12);
  --text: #e8eaed;
  --text-muted: #9aa0a6;
  --accent: #4a9eff;
  --accent-dark: #6bb0ff;
  --accent-dim: rgba(74, 158, 255, 0.15);
  --green: #7ecb9a;
  --green-dim: rgba(126, 203, 154, 0.12);
  --border: #2a2d35;
  --border-light: #1e2028;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.5);
}

[data-theme="dark"] .header {
  background: rgba(10, 11, 13, 0.92);
}

[data-theme="dark"] .hero {
  background: linear-gradient(180deg, #0d1117 0%, #0a0b0d 100%);
}

[data-theme="dark"] .hero-glow {
  background: radial-gradient(ellipse at center, rgba(74, 158, 255, 0.1) 0%, transparent 65%);
}

[data-theme="dark"] .hero-dots {
  background-image: radial-gradient(circle, rgba(74, 158, 255, 0.12) 1px, transparent 1px);
}

[data-theme="dark"] .logo-brand {
  color: #e8eaed;
}

[data-theme="dark"] .logo:hover .logo-brand {
  color: #4a9eff;
}

[data-theme="dark"] .btn-secondary {
  background: transparent;
}

[data-theme="dark"] .contact {
  background: linear-gradient(180deg, #0a0b0d 0%, #0d1117 100%);
}

[data-theme="dark"] .footer {
  border-top-color: #1a1d25;
}

[data-theme="dark"] .project-card--volunteer:hover {
  border-left-color: #7ecb9a;
}

[data-theme="dark"] .nav.open {
  background: #12141a;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

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

a:hover {
  text-decoration: underline;
}

.container {
  max-width: 760px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section-title {
  font-size: 1.75rem;
  font-weight: 700;
  margin: 0 0 0.5rem;
  letter-spacing: -0.02em;
  color: var(--text);
}

.section-intro {
  color: var(--text-muted);
  margin: 0 0 2rem;
}

/* ── Header ── */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}

.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0.75rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.logo-icon {
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.logo-brand {
  font-size: 1.1rem;
  font-weight: 700;
  color: #1a3a5c;
  letter-spacing: 0.02em;
}

.logo-sub {
  font-size: 0.68rem;
  font-weight: 500;
  color: var(--accent);
  letter-spacing: 0.04em;
}

.logo:hover {
  text-decoration: none;
}

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

.nav {
  display: flex;
  gap: 2rem;
}

.nav a {
  color: var(--text-muted);
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.2s;
}

.nav a:hover {
  color: var(--accent);
  text-decoration: none;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.nav-toggle span {
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: background 0.2s;
}

/* ── Theme toggle ── */
.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: var(--accent-dim);
  border: 1px solid var(--border);
  border-radius: 50%;
  cursor: pointer;
  color: var(--accent);
  transition: background 0.2s, color 0.2s, border-color 0.2s;
  padding: 0;
  margin-left: 0.5rem;
  flex-shrink: 0;
}

.theme-toggle:hover {
  background: var(--accent);
  color: #ffffff;
  border-color: var(--accent);
}

.theme-toggle .icon-sun {
  display: none;
}

.theme-toggle .icon-moon {
  display: block;
}

[data-theme="dark"] .theme-toggle .icon-sun {
  display: block;
}

[data-theme="dark"] .theme-toggle .icon-moon {
  display: none;
}

/* ── Hero ── */
.hero {
  position: relative;
  min-height: 80vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 6rem 1.5rem;
  overflow: hidden;
  text-align: center;
  background: linear-gradient(180deg, #f0f6ff 0%, #ffffff 100%);
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 680px;
  width: 100%;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent-dark);
  background: var(--bg-accent);
  border: 1px solid rgba(52, 152, 219, 0.25);
  border-radius: 99px;
  padding: 0.35rem 0.9rem;
  margin-bottom: 1.5rem;
}

.hero-badge svg {
  color: var(--accent);
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.03em;
  margin: 0 0 1.25rem;
  color: var(--text);
}

.hero-sub {
  font-size: 1.1rem;
  color: var(--text-muted);
  margin: 0 auto 2rem;
  max-width: 520px;
}

.hero-cta {
  display: flex;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 2.5rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius);
  transition: all 0.2s;
}

.btn-primary {
  background: var(--accent-gradient);
  background-color: var(--accent);
  color: #ffffff;
  box-shadow: 0 2px 8px rgba(102, 126, 234, 0.3);
}

.btn-primary:hover {
  box-shadow: 0 4px 16px rgba(102, 126, 234, 0.4);
  transform: translateY(-1px);
  text-decoration: none;
}

.btn-secondary {
  background: var(--bg);
  color: var(--accent);
  border: 2px solid var(--accent);
}

.btn-secondary:hover {
  background: var(--accent-dim);
  text-decoration: none;
}

.hero-tech-row {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.6rem;
  opacity: 0.8;
}

.hero-tech-row img {
  width: 32px;
  height: 32px;
  border-radius: 6px;
  transition: opacity 0.2s, transform 0.2s;
}

.hero-tech-row img:hover {
  opacity: 1;
  transform: translateY(-2px);
}

.hero-visual {
  position: absolute;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
}

.hero-glow {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  width: 800px;
  height: 450px;
  background: radial-gradient(ellipse at center, rgba(102, 126, 234, 0.08) 0%, transparent 65%);
  border-radius: 50%;
  filter: blur(40px);
}

.hero-dots {
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle, rgba(52, 152, 219, 0.08) 1px, transparent 1px);
  background-size: 40px 40px;
  mask-image: radial-gradient(ellipse 70% 70% at 50% 50%, black 30%, transparent 100%);
}

/* ── Proof ── */
.proof {
  padding: 4rem 0;
  border-top: 1px solid var(--border);
}

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

.proof-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  transition: border-color 0.2s, box-shadow 0.2s;
  box-shadow: var(--shadow-sm);
}

.proof-card:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-md);
}

.proof-icon {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--accent-dim);
  border-radius: var(--radius);
  color: var(--accent);
  margin-bottom: 0.75rem;
}

.proof-card h4 {
  font-size: 0.95rem;
  font-weight: 600;
  margin: 0 0 0.4rem;
  color: var(--text);
}

.proof-card p {
  margin: 0;
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.5;
}

/* ── Projects ── */
.projects {
  padding: 4rem 0;
  border-top: 1px solid var(--border);
  background: var(--bg-elevated);
}

.project-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.75rem;
  margin-bottom: 1.5rem;
  transition: border-color 0.2s, box-shadow 0.2s;
  border-left: 4px solid var(--accent);
  box-shadow: var(--shadow-sm);
}

.project-card:hover {
  box-shadow: var(--shadow-md);
  border-left-color: var(--accent-dark);
}

.project-top {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  margin-bottom: 1rem;
}

.project-icon-wrap {
  flex-shrink: 0;
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--accent-dim);
  border-radius: var(--radius);
  color: var(--accent);
}

.project-tag {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent);
  margin-bottom: 0.35rem;
}

.project-tag--volunteer {
  color: var(--green);
}

.project-card--volunteer {
  border-left-color: var(--green);
}

.project-card--volunteer:hover {
  border-left-color: #219a52;
}

.project-card--volunteer .project-outcome-lead {
  background: var(--green-dim);
  border-left-color: var(--green);
}

.project-card--volunteer .project-outcome-lead svg {
  color: var(--green);
}

.project-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin: 0;
  line-height: 1.3;
  color: var(--text);
}

.project-problem,
.project-solution {
  margin: 0 0 0.75rem;
  font-size: 0.92rem;
  color: var(--text-muted);
}

.project-problem strong,
.project-solution strong {
  color: var(--text);
}

.project-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin: 1rem 0;
}

.tech {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  padding: 0.2rem 0.5rem;
  background: var(--accent-dim);
  color: var(--accent-dark);
  border-radius: 4px;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}

.tech img {
  display: block;
  border-radius: 2px;
}

.project-outcome {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  font-size: 0.9rem;
  color: var(--text);
  background: var(--accent-dim);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
}

.project-outcome.project-outcome-lead {
  font-size: 0.95rem;
  font-weight: 500;
  background: var(--bg-accent);
  border-left: 4px solid var(--accent);
  margin-bottom: 1.25rem;
}

.project-outcome svg {
  color: var(--accent);
  flex-shrink: 0;
  margin-top: 2px;
}

/* ── Additional Services ── */
.services {
  padding: 4rem 0;
  border-top: 1px solid var(--border);
}

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

.service-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.3rem;
  transition: border-color 0.2s, box-shadow 0.2s;
  box-shadow: var(--shadow-sm);
}

.service-card:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-md);
}

.service-icon {
  color: var(--accent);
  margin-bottom: 0.65rem;
}

.service-card h4 {
  font-size: 0.9rem;
  font-weight: 600;
  margin: 0 0 0.4rem;
  color: var(--text);
}

.service-card p {
  margin: 0;
  font-size: 0.84rem;
  color: var(--text-muted);
  line-height: 1.55;
}

.services-note {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
  margin: 0;
  background: var(--bg-accent);
}

.services-note svg {
  color: var(--accent);
  flex-shrink: 0;
  margin-top: 1px;
}

/* ── Skills ── */
.skills {
  padding: 4rem 0;
  border-top: 1px solid var(--border);
  background: var(--bg-elevated);
}

.skills-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  margin-bottom: 2rem;
}

.skills-col {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.1rem 1.2rem;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.2s;
}

.skills-col:hover {
  box-shadow: var(--shadow-md);
}

.skills-col-icon {
  color: var(--accent);
  margin-bottom: 0.6rem;
}

.skills-col h4 {
  font-size: 0.88rem;
  font-weight: 700;
  margin: 0 0 0.4rem;
  color: var(--accent-dark);
}

.skills-col p {
  margin: 0;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.tech-logos {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  align-items: center;
  padding: 1.25rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}

.tech-logos img {
  width: 40px;
  height: 40px;
  border-radius: 8px;
  opacity: 0.85;
  transition: opacity 0.15s, transform 0.15s;
}

.tech-logos img:hover {
  opacity: 1;
  transform: translateY(-2px);
}

/* ── Process ── */
.process {
  padding: 4rem 0;
  border-top: 1px solid var(--border);
}

.process-steps {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 1rem;
}

.process-step {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  position: relative;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.2s;
}

.process-step:hover {
  box-shadow: var(--shadow-md);
}

.step-icon {
  width: 38px;
  height: 38px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--accent-gradient);
  background-color: var(--accent);
  border-radius: var(--radius);
  color: #ffffff;
  margin-bottom: 0.75rem;
}

.step-num {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--accent);
  margin-bottom: 0.35rem;
  letter-spacing: 0.05em;
  font-weight: 600;
}

.process-step h4 {
  font-size: 0.95rem;
  font-weight: 600;
  margin: 0 0 0.4rem;
  color: var(--text);
}

.process-step p {
  margin: 0;
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.5;
}

/* ── Team ── */
.team {
  padding: 4rem 0;
  border-top: 1px solid var(--border);
  background: var(--bg-elevated);
}

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

.team-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.2s;
}

.team-card:hover {
  box-shadow: var(--shadow-md);
}

.team-card-top {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1rem;
}

.avatar {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1rem;
  flex-shrink: 0;
  letter-spacing: 0.02em;
}

.avatar-blue {
  background: linear-gradient(135deg, #1a4a8a, #2d6fd4);
  color: #ffffff;
  border: 2px solid rgba(52, 152, 219, 0.3);
}

.avatar-teal {
  background: linear-gradient(135deg, #0e5c5c, #1a9090);
  color: #ffffff;
  border: 2px solid rgba(26, 160, 160, 0.3);
}

.avatar-photo {
  object-fit: cover;
  object-position: center 15%;
  border: 2px solid var(--border);
}

.team-card h4 {
  font-size: 1.05rem;
  font-weight: 700;
  margin: 0 0 0.1rem;
  color: var(--text);
}

.team-card .role {
  font-size: 0.82rem;
  color: var(--accent);
  margin: 0;
  font-weight: 600;
}

.team-card > p {
  margin: 0 0 1rem;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.team-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 1rem;
}

.team-tags span {
  font-size: 0.78rem;
  font-family: var(--font-mono);
  padding: 0.2rem 0.5rem;
  background: var(--accent-dim);
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--accent-dark);
}

.team-linkedin {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.85rem;
  color: var(--accent);
  font-weight: 500;
}

/* ── Contact ── */
.contact {
  padding: 5rem 0;
  border-top: 1px solid var(--border);
  background: linear-gradient(180deg, #ffffff 0%, #f0f6ff 100%);
}

.contact-intro {
  color: var(--text-muted);
  margin: 0 0 1.5rem;
}

.contact-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.contact-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1rem;
  font-weight: 600;
  color: #ffffff;
  background: var(--accent-gradient);
  background-color: var(--accent);
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  transition: all 0.2s;
  box-shadow: 0 2px 8px rgba(102, 126, 234, 0.3);
}

.contact-link:hover {
  box-shadow: 0 4px 16px rgba(102, 126, 234, 0.4);
  transform: translateY(-1px);
  text-decoration: none;
  color: #ffffff;
}

/* ── Footer ── */
.footer {
  background: var(--accent-gradient);
  background-color: var(--accent);
  padding: 1.5rem 0;
  border-top: 3px solid var(--accent-dark);
}

.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem;
  text-align: center;
}

.footer-contact {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  margin-bottom: 0.5rem;
}

.footer-contact span {
  font-size: 0.82rem;
  color: rgba(255, 255, 255, 0.9);
}

.footer-brand {
  font-size: 0.78rem;
  color: rgba(255, 255, 255, 0.75);
  margin: 0;
  font-style: italic;
  letter-spacing: 0.3px;
}

.footer p {
  margin: 0;
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.8);
}

/* ── Mobile ── */
@media (max-width: 640px) {
  .nav {
    display: none;
  }

  .nav.open {
    display: flex;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    gap: 0;
    padding: 1rem 1.5rem;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-md);
  }

  .nav.open a {
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border-light);
  }

  .nav.open a:last-child {
    border-bottom: none;
  }

  .nav-toggle {
    display: flex;
  }

  .hero {
    min-height: auto;
    padding: 4rem 1.5rem;
  }

  .hero-cta {
    flex-direction: column;
    align-items: center;
  }

  .btn {
    justify-content: center;
  }

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

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

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

  .process-steps {
    grid-template-columns: 1fr 1fr;
  }

  .logo-brand {
    font-size: 0.95rem;
  }

  .logo-sub {
    font-size: 0.6rem;
  }

  .footer-contact {
    flex-direction: column;
    align-items: center;
    gap: 0.25rem;
  }
}

@media (max-width: 540px) {
  .proof-grid,
  .services-grid,
  .skills-grid,
  .process-steps {
    grid-template-columns: 1fr;
  }
}