/* ===== Variables ===== */
:root {
  --color-bg: #ffffff;
  --color-surface: #f8fafc;
  --color-surface-2: #f1f5f9;
  --color-border: #e2e8f0;
  --color-text: #0f172a;
  --color-text-muted: #64748b;
  --color-primary: #1d4ed8;
  --color-primary-hover: #1e40af;
  --color-primary-light: #dbeafe;
  --color-accent: #1e3a5f;

  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --font-mono: 'Fira Code', monospace;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;

  --shadow-sm: 0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,.08), 0 2px 4px rgba(0,0,0,.04);
  --shadow-lg: 0 10px 30px rgba(0,0,0,.1);

  --transition: 0.2s ease;
  --nav-h: 64px;
}

/* ===== Reset ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }

/* ===== Layout ===== */
.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
}
.section {
  padding: 96px 0;
}
.section__header {
  margin-bottom: 56px;
}
.section__label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: 10px;
  font-family: var(--font-mono);
}
.section__title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  color: var(--color-accent);
  letter-spacing: -0.02em;
  line-height: 1.15;
}

/* ===== Nav ===== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--nav-h);
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition), box-shadow var(--transition);
}
.nav.scrolled {
  border-color: var(--color-border);
  box-shadow: var(--shadow-sm);
}
.nav__inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav__logo {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--color-accent);
  letter-spacing: -0.02em;
}
.nav__logo:hover { color: var(--color-primary); }
.nav__links {
  display: flex;
  gap: 36px;
}
.nav__links a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-muted);
  transition: color var(--transition);
  position: relative;
}
.nav__links a::after {
  content: '';
  position: absolute;
  bottom: -3px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--color-primary);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition);
}
.nav__links a:hover,
.nav__links a.active {
  color: var(--color-text);
}
.nav__links a:hover::after,
.nav__links a.active::after {
  transform: scaleX(1);
}
.nav__toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}
.nav__toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  transition: transform var(--transition), opacity var(--transition);
}
.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); }

/* ===== Hero ===== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: var(--nav-h);
  background: var(--color-bg);
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  top: -200px;
  right: -200px;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, var(--color-primary-light) 0%, transparent 70%);
  pointer-events: none;
  opacity: 0.6;
}
.hero__inner {
  padding-top: 48px;
  padding-bottom: 48px;
  max-width: 680px;
}
.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.8rem;
  font-weight: 500;
  color: #166534;
  background: #dcfce7;
  border: 1px solid #bbf7d0;
  padding: 4px 14px;
  border-radius: var(--radius-full);
  margin-bottom: 28px;
}
.hero__badge::before {
  content: '';
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #16a34a;
  animation: pulse 2s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}
.hero__name {
  font-size: clamp(2.8rem, 8vw, 5.5rem);
  font-weight: 700;
  color: var(--color-accent);
  letter-spacing: -0.04em;
  line-height: 1.05;
  margin-bottom: 16px;
}
.hero__tagline {
  font-size: clamp(1.1rem, 2.5vw, 1.4rem);
  font-weight: 500;
  color: var(--color-primary);
  font-family: var(--font-mono);
  margin-bottom: 20px;
}
.hero__sub {
  font-size: 1.05rem;
  color: var(--color-text-muted);
  line-height: 1.75;
  max-width: 520px;
  margin-bottom: 40px;
}
.hero__cta {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}
.hero__scroll-hint {
  position: absolute;
  bottom: 36px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--color-text-muted);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-family: var(--font-mono);
  opacity: 0.6;
}
.scroll-dot {
  animation: scrollDot 2s ease-in-out infinite;
}
@keyframes scrollDot {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(8px); }
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 26px;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  border: 2px solid transparent;
}
.btn--primary {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}
.btn--primary:hover {
  background: var(--color-primary-hover);
  border-color: var(--color-primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(29, 78, 216, 0.3);
}
.btn--outline {
  background: transparent;
  color: var(--color-primary);
  border-color: var(--color-border);
}
.btn--outline:hover {
  border-color: var(--color-primary);
  background: var(--color-primary-light);
  transform: translateY(-1px);
}

/* ===== About ===== */
.about {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}
.about__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: start;
}
.about__text p {
  color: var(--color-text-muted);
  margin-bottom: 18px;
  font-size: 1rem;
}
.about__text p:last-child { margin-bottom: 0; }
.about__skills h3 {
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: 16px;
}
.skills-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.skill-tag {
  font-size: 0.82rem;
  font-weight: 500;
  font-family: var(--font-mono);
  color: var(--color-primary);
  background: var(--color-primary-light);
  border: 1px solid #bfdbfe;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  transition: background var(--transition), border-color var(--transition);
}
.skill-tag:hover {
  background: #bfdbfe;
  border-color: #93c5fd;
}

/* ===== Projects ===== */
.projects__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
}
.project-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: box-shadow var(--transition), transform var(--transition), border-color var(--transition);
  position: relative;
}
.project-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
  border-color: #bfdbfe;
}
.project-card__header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 20px;
}
.project-card__icon {
  width: 44px;
  height: 44px;
  background: var(--color-primary-light);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary);
}
.project-card__links {
  display: flex;
  gap: 10px;
  opacity: 0;
  transition: opacity var(--transition);
}
.project-card:hover .project-card__links {
  opacity: 1;
}
.icon-link {
  color: var(--color-text-muted);
  transition: color var(--transition);
}
.icon-link:hover { color: var(--color-primary); }
.project-card__title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-accent);
  margin-bottom: 10px;
  letter-spacing: -0.01em;
}
.project-card__desc {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: 20px;
}
.project-card__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}
.project-card__tags span {
  font-size: 0.75rem;
  font-family: var(--font-mono);
  font-weight: 500;
  color: var(--color-text-muted);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  padding: 2px 10px;
  border-radius: var(--radius-full);
}

/* ===== Contact ===== */
.contact {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
}
.contact__inner {
  max-width: 560px;
}
.contact__text {
  font-size: 1.05rem;
  color: var(--color-text-muted);
  margin-bottom: 36px;
  line-height: 1.75;
}
.contact__channels {
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.contact-card {
  display: flex;
  align-items: center;
  gap: 16px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 18px 22px;
  transition: box-shadow var(--transition), border-color var(--transition), transform var(--transition);
  width: fit-content;
  min-width: 260px;
}
.contact-card:hover {
  box-shadow: var(--shadow-md);
  border-color: #bfdbfe;
  transform: translateY(-2px);
}
.contact-card__icon {
  width: 32px;
  height: 32px;
  color: #5865F2;
  flex-shrink: 0;
}
.contact-card__info {
  display: flex;
  flex-direction: column;
}
.contact-card__label {
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-muted);
}
.contact-card__value {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--color-text);
  font-family: var(--font-mono);
}

/* ===== Footer ===== */
.footer {
  background: var(--color-accent);
  color: rgba(255,255,255,0.6);
  padding: 28px 0;
  border-top: 1px solid rgba(255,255,255,0.08);
}
.footer__inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.footer__name {
  font-weight: 700;
  font-size: 1rem;
  color: #fff;
  letter-spacing: -0.01em;
}
.footer__copy {
  font-size: 0.82rem;
}

/* ===== Scroll reveal ===== */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  :root { --nav-h: 60px; }

  .nav__links {
    position: fixed;
    top: var(--nav-h);
    left: 0;
    right: 0;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    gap: 0;
    padding: 8px 0 16px;
    box-shadow: var(--shadow-md);
    transform: translateY(-110%);
    transition: transform 0.3s ease;
  }
  .nav__links.open { transform: translateY(0); }
  .nav__links a {
    display: block;
    padding: 12px 24px;
    font-size: 1rem;
  }
  .nav__links a::after { display: none; }
  .nav__toggle { display: flex; }

  .hero__inner { max-width: 100%; }
  .hero__scroll-hint { display: none; }

  .about__grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

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

  .project-card__links { opacity: 1; }

  .section { padding: 72px 0; }

  .footer__inner {
    flex-direction: column;
    gap: 6px;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .hero__cta { flex-direction: column; align-items: flex-start; }
  .btn { width: 100%; justify-content: center; }
}