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

html {
  scroll-behavior: smooth;
}

@media (hover: hover) and (pointer: fine) {
  html {
    scrollbar-width: thin;
    scrollbar-color: var(--scrollbar-thumb) var(--scrollbar-track);
  }

  html::-webkit-scrollbar {
    width: 7px;
    height: 7px;
  }

  html::-webkit-scrollbar-track {
    background: var(--scrollbar-track);
    border-radius: 999px;
  }

  html::-webkit-scrollbar-thumb {
    background: var(--scrollbar-thumb);
    border-radius: 999px;
    border: 2px solid var(--scrollbar-track);
    background-clip: padding-box;
    transition: background-color 0.2s ease, border-color 0.2s ease;
  }

  html::-webkit-scrollbar-thumb:hover {
    background: var(--scrollbar-thumb-hover);
    border-color: var(--scrollbar-track);
  }

  html::-webkit-scrollbar-corner {
    background: var(--scrollbar-track);
  }
}

body {
  margin: 0;
  font-family: var(--font);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  transition: background-color 0.28s ease, color 0.28s ease;
}

body.nav-open {
  overflow: hidden;
}

body.modal-open {
  overflow: hidden;
}

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

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

.container {
  width: min(1120px, 100% - 2.5rem);
  margin-inline: auto;
}

section[id]:not(#hero) {
  scroll-margin-top: calc(var(--header-h) + 0.75rem);
}

.section {
  padding: var(--space-section) 0;
}

.section__title {
  margin: 0 0 0.75rem;
  font-size: clamp(1.65rem, 3vw, 2rem);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.section__lead {
  margin: 0 0 2.5rem;
  max-width: 48ch;
  color: var(--text-muted);
  font-size: 1rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.35rem;
  font-family: inherit;
  font-size: 0.92rem;
  font-weight: 600;
  border-radius: 999px;
  border: none;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition),
    background var(--transition), border-color var(--transition),
    color var(--transition);
}

.btn--primary {
  background: linear-gradient(145deg, var(--green) 0%, var(--green-soft) 100%);
  color: var(--btn-primary-fg);
  box-shadow: 0 4px 24px var(--green-glow);
}

.btn--block {
  width: 100%;
}

.btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 32px var(--green-glow);
}

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

.btn--outline:hover {
  border-color: var(--green);
  color: var(--green);
  background: var(--green-muted);
}

.btn--large {
  padding: 0.95rem 1.6rem;
  font-size: 1rem;
}

.btn--cv {
  box-shadow: 0 4px 20px var(--green-glow);
}

.back-to-top {
  position: fixed;
  z-index: 44;
  right: max(1rem, env(safe-area-inset-right, 0px));
  bottom: max(1rem, env(safe-area-inset-bottom, 0px));
  width: 46px;
  height: 46px;
  padding: 0;
  display: grid;
  place-items: center;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  color: var(--btn-primary-fg);
  background: linear-gradient(145deg, var(--green) 0%, var(--green-soft) 100%);
  box-shadow: 0 4px 18px rgba(0, 0, 0, 0.22), 0 0 0 1px color-mix(in srgb, var(--green) 35%, transparent);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateY(10px);
  transition: opacity 0.28s ease, visibility 0.28s ease, transform 0.28s ease,
    box-shadow var(--transition), filter var(--transition);
}

.back-to-top--visible {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translateY(0);
}

.back-to-top--visible:hover {
  filter: brightness(1.08);
  transform: translateY(-2px);
  box-shadow: 0 8px 28px var(--green-glow), 0 0 0 1px color-mix(in srgb, var(--green) 45%, transparent);
}

.back-to-top:focus-visible {
  outline: 2px solid var(--green);
  outline-offset: 3px;
}

.back-to-top__icon {
  display: grid;
  place-items: center;
  width: 1.15rem;
  height: 1.15rem;
}

.back-to-top__icon svg {
  width: 100%;
  height: 100%;
  display: block;
}

@media (max-width: 480px) {
  .back-to-top {
    width: 44px;
    height: 44px;
    right: max(0.75rem, env(safe-area-inset-right, 0px));
    bottom: max(0.85rem, env(safe-area-inset-bottom, 0px));
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  body {
    transition: none;
  }

  .modal__panel {
    animation: none;
  }

  .btn,
  .project-card,
  .skills__group,
  .timeline__card,
  .nav a,
  .contact-icon,
  .theme-toggle,
  .theme-toggle__icon,
  .nav-toggle__bar,
  .nav,
  .nav-backdrop,
  .header {
    transition: none;
  }

  .btn--primary:hover,
  .project-card:hover,
  .project-card:focus-visible,
  .theme-toggle:hover,
  .contact-icon:hover {
    transform: none;
  }

  .project-card:hover .project-card__image,
  .project-card:focus-visible .project-card__image {
    transform: none;
    opacity: 1;
  }

  .hero__scroll {
    animation: none;
  }

  .hero__scroll:hover {
    transform: none;
  }

  .back-to-top {
    transition: none;
  }

  .back-to-top:hover,
  .back-to-top--visible:hover {
    transform: none;
    filter: none;
  }
}