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

:root {
  --white: #ffffff;
  --off-white: #f8f8f6;
  --light-gray: #f0efed;
  --mid-gray: #9a9a98;
  --dark: #1a1a1a;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --text: #2d2d2d;
  --text-light: #6b6b69;
  --border: #e5e5e3;
  --radius: 12px;
  --shadow: 0 2px 12px rgba(0,0,0,0.07);
  --shadow-hover: 0 6px 24px rgba(0,0,0,0.12);
}

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  color: var(--text);
  background: var(--white);
  line-height: 1.6;
}

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

/* ── Nav ── */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2rem;
  height: 60px;
}

.nav-logo {
  font-weight: 700;
  font-size: 1rem;
  letter-spacing: -0.02em;
  color: var(--dark);
}

.nav-links {
  list-style: none;
  display: flex;
  gap: 2rem;
}

.nav-links a {
  font-size: 0.875rem;
  color: var(--text-light);
  transition: color 0.2s;
}

.nav-links a:hover { color: var(--dark); }

/* ── Layout ── */
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 2rem;
}

.section {
  padding: 80px 0;
}

.section-alt {
  background: var(--off-white);
}

.section-sub {
  color: var(--text-light);
  font-size: 1.05rem;
  margin-top: 0.5rem;
  margin-bottom: 2.5rem;
}

h2 {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--dark);
  margin-bottom: 0.5rem;
}

/* ── Button ── */
.btn-primary {
  display: inline-block;
  background: var(--accent);
  color: var(--white);
  padding: 0.75rem 1.75rem;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: background 0.2s, transform 0.15s;
  border: none;
  cursor: pointer;
}

.btn-primary:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
}

/* ── Hero ── */
.hero {
  min-height: 85vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  background: linear-gradient(160deg, #f0f4ff 0%, #ffffff 60%);
  padding: 4rem 2rem;
}

.hero-content {
  max-width: 680px;
}

.hero h1 {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 800;
  letter-spacing: -0.04em;
  color: var(--dark);
  margin-bottom: 1rem;
}

.tagline {
  font-size: clamp(1.1rem, 2.5vw, 1.35rem);
  color: var(--text-light);
  margin-bottom: 2.5rem;
  line-height: 1.5;
}

/* ── What I Do ── */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
  margin-top: 2.5rem;
}

.card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  box-shadow: var(--shadow);
  transition: box-shadow 0.2s, transform 0.2s;
}

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

.card-icon {
  font-size: 1.75rem;
  margin-bottom: 1rem;
}

.card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--dark);
}

.card p {
  font-size: 0.95rem;
  color: var(--text-light);
  line-height: 1.65;
}

/* ── Projects ── */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.5rem;
  margin-top: 2.5rem;
}

.project-card {
  display: block;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: box-shadow 0.2s, transform 0.2s;
}

.project-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-3px);
}

.project-img {
  height: 200px;
  background: linear-gradient(135deg, #dbeafe, #eff6ff);
  display: flex;
  align-items: center;
  justify-content: center;
}

.placeholder-img span {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--accent);
  opacity: 0.6;
}

.project-info {
  padding: 1.5rem;
}

.project-info h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 0.4rem;
}

.project-info p {
  font-size: 0.9rem;
  color: var(--text-light);
  margin-bottom: 1rem;
}

.project-tag {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent);
}

/* ── Presentation ── */
.pdf-placeholder {
  margin-top: 2.5rem;
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 4rem 2rem;
  text-align: center;
  color: var(--text-light);
}

.pdf-placeholder p { margin-bottom: 0.5rem; }
.pdf-placeholder .small { font-size: 0.82rem; opacity: 0.7; }

.pdf-fallback {
  margin-top: 0.75rem;
  font-size: 0.85rem;
  color: var(--text-light);
}

.pdf-fallback a { color: var(--accent); }

.deck-embed {
  margin-top: 2.5rem;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 8px 40px rgba(0,0,0,0.15);
  aspect-ratio: 16 / 9;
  background: #111;
}

.deck-embed iframe {
  width: 100%;
  height: 100%;
  border: none;
  display: block;
}

/* ── About ── */
.about-layout {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 4rem;
  align-items: start;
}

.photo-placeholder {
  width: 220px;
  height: 220px;
  border-radius: 50%;
  background: var(--light-gray);
  border: 2px dashed var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--mid-gray);
  font-size: 0.85rem;
}

.about-photo img {
  width: 220px;
  height: 220px;
  border-radius: 50%;
  object-fit: cover;
  box-shadow: var(--shadow);
}

.about-text h2 { margin-bottom: 1.25rem; }

.about-text p {
  color: var(--text-light);
  font-size: 1.05rem;
  line-height: 1.75;
  margin-bottom: 1rem;
}

/* ── Hobbies ── */
.hobbies-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 1.5rem;
  margin-top: 2.5rem;
}

.hobby-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.75rem;
  text-align: center;
  box-shadow: var(--shadow);
  transition: box-shadow 0.2s, transform 0.2s;
}

.hobby-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}

.hobby-icon {
  font-size: 2rem;
  margin-bottom: 0.75rem;
}

.hobby-card h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 0.4rem;
}

.hobby-card p {
  font-size: 0.875rem;
  color: var(--text-light);
  line-height: 1.6;
}

/* ── Contact ── */
.contact-layout {
  max-width: 680px;
}

.contact-form {
  margin-top: 2.5rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 0.95rem;
  font-family: inherit;
  color: var(--text);
  background: var(--white);
  transition: border-color 0.2s, box-shadow 0.2s;
  outline: none;
}

.contact-form input:focus,
.contact-form textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.1);
}

.contact-form textarea { resize: vertical; }

/* ── Footer ── */
.footer {
  background: var(--dark);
  color: var(--mid-gray);
  text-align: center;
  padding: 2rem;
  font-size: 0.875rem;
}

.footer a {
  color: var(--mid-gray);
  transition: color 0.2s;
}

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

/* ── Hamburger button ── */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--dark);
  border-radius: 2px;
  transition: transform 0.25s, opacity 0.25s;
}

.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ── Responsive ── */
@media (max-width: 768px) {
  .nav-toggle { display: flex; }

  .nav-links {
    display: none;
    position: absolute;
    top: 60px;
    left: 0;
    right: 0;
    background: var(--white);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    padding: 1rem 2rem 1.5rem;
    gap: 0;
  }

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

  .nav-links li { border-bottom: 1px solid var(--border); }
  .nav-links li:last-child { border-bottom: none; }

  .nav-links a {
    display: block;
    padding: 0.75rem 0;
    font-size: 1rem;
    color: var(--text);
  }

  .about-layout {
    grid-template-columns: 1fr;
    gap: 2rem;
    text-align: center;
  }

  .photo-placeholder, .about-photo img {
    margin: 0 auto;
  }

  .form-row { grid-template-columns: 1fr; }

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

  .contact-email-btn {
    display: block;
    text-align: center;
    word-break: break-all;
  }

  .section { padding: 56px 0; }
}