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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 1rem;
  font-weight: 400;
  line-height: 1.6;
  color: #333333;
  background-color: #ffffff;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
  margin-top: 0;
  margin-bottom: 1.5rem;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-weight: 700;
  line-height: 1.2;
  color: #2c3e50;
}

h1 {
  font-size: 2.5rem;
}

h2 {
  font-size: 2rem;
}

h3 {
  font-size: 1.5rem;
}

p {
  margin-top: 0;
  margin-bottom: 1.5rem;
}

ul, ol {
  margin-top: 0;
  margin-bottom: 1.5rem;
  padding-left: 2rem;
}

li {
  margin-bottom: 0.5rem;
}

a {
  color: #3498db;
  text-decoration: none;
  transition: color 0.3s ease-in-out;
}
a:hover, a:focus {
  color: #1d6fa5;
}
a:focus {
  outline: 2px solid #3498db;
  outline-offset: 2px;
}
@media (prefers-reduced-motion: reduce) {
  a {
    transition: none;
  }
}

button {
  font-family: inherit;
  cursor: pointer;
}
button:focus {
  outline: 2px solid #3498db;
  outline-offset: 2px;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  top: -100px;
  left: 1rem;
  z-index: 9999;
  padding: 1rem 1.5rem;
  background-color: #2c3e50;
  color: #ffffff;
  font-weight: 700;
  border-radius: 8px;
}
.skip-link:focus {
  top: 1rem;
}

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

:focus-visible {
  outline: 2px solid #3498db;
  outline-offset: 2px;
}

.hero {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: 2rem 1rem;
  background-color: #f8f9fa;
  text-align: center;
}
@media (min-width: 768px) {
  .hero {
    padding: 4rem 2rem;
  }
}
.hero__container {
  max-width: 800px;
  width: 100%;
}
.hero__title {
  margin-bottom: 1.5rem;
  font-size: clamp(2rem, 5vw, 2.5rem);
}
@media (min-width: 768px) {
  .hero__title {
    font-size: 3rem;
  }
}
.hero__intro {
  margin-bottom: 3rem;
  font-size: 1.125rem;
  color: #666666;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}
.hero__cta {
  display: inline-block;
  padding: 1rem 2rem;
  background-color: #3498db;
  color: #ffffff;
  font-weight: 500;
  border-radius: 8px;
  transition: background-color 0.3s ease-in-out, transform 0.3s ease-in-out;
}
.hero__cta:hover, .hero__cta:focus {
  background-color: #2177b3;
  transform: translateY(-2px);
}
.hero__cta:active {
  transform: translateY(0);
}
@media (prefers-reduced-motion: reduce) {
  .hero__cta {
    transition: background-color 0.3s ease-in-out;
  }
  .hero__cta:hover {
    transform: none;
  }
}

.projects {
  padding: 4rem 1rem;
  max-width: 1200px;
  margin: 0 auto;
}
@media (min-width: 768px) {
  .projects {
    padding: 5rem 2rem;
  }
}

.project {
  margin-bottom: 4rem;
}
.project:last-child {
  margin-bottom: 0;
}
@media (min-width: 768px) {
  .project {
    margin-bottom: 5rem;
  }
}
.project__container {
  max-width: 800px;
  margin: 0 auto;
}
.project__title {
  margin-bottom: 1.5rem;
  color: #2c3e50;
}
.project__description {
  font-size: 1.125rem;
  color: #333333;
  margin-bottom: 2rem;
}

.footer {
  padding: 2rem 1rem;
  background-color: #f8f9fa;
  text-align: center;
  border-top: 1px solid #e1e8ed;
}
.footer__text {
  margin: 0;
  font-size: 0.875rem;
  color: #666666;
}

.project__details {
  margin-top: 2rem;
}
.project__details summary {
  list-style: none;
}
.project__details summary::-webkit-details-marker {
  display: none;
}

.project__summary {
  display: inline-flex;
  align-items: center;
  padding: 1rem 1.5rem;
  background-color: #f8f9fa;
  color: #3498db;
  font-weight: 500;
  border: 2px solid #e1e8ed;
  border-radius: 8px;
  cursor: pointer;
  transition: background-color 0.3s ease-in-out, border-color 0.3s ease-in-out, transform 0.15s ease-in-out;
  user-select: none;
}
.project__summary::before {
  content: "";
  display: inline-block;
  width: 0;
  height: 0;
  margin-right: 0.5rem;
  border-left: 6px solid transparent;
  border-right: 6px solid transparent;
  border-top: 8px solid currentColor;
  transition: transform 0.3s ease-in-out;
}
details[open] .project__summary::before {
  transform: rotate(180deg);
}
.project__summary:hover {
  background-color: #eff1f3;
  border-color: #3498db;
}
.project__summary:focus {
  outline: 2px solid #3498db;
  outline-offset: 2px;
  border-color: #3498db;
}
.project__summary:active {
  transform: scale(0.98);
}
@media (prefers-reduced-motion: reduce) {
  .project__summary {
    transition: background-color 0.3s ease-in-out, border-color 0.3s ease-in-out;
  }
  .project__summary::before {
    transition: none;
  }
  .project__summary:active {
    transform: none;
  }
}

.project__expanded {
  margin-top: 2rem;
  padding: 2rem;
  background-color: #f8f9fa;
  border-radius: 8px;
  border: 1px solid #e1e8ed;
  animation: fadeIn 0.3s ease-in-out;
}
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}
@media (prefers-reduced-motion: reduce) {
  .project__expanded {
    animation: none;
  }
}
.project__expanded p:last-child {
  margin-bottom: 0;
}

.project__features {
  margin: 1.5rem 0 0;
  padding-left: 2rem;
}
.project__features li {
  position: relative;
  margin-bottom: 1rem;
  color: #333333;
}
.project__features li::marker {
  color: #3498db;
}
.project__features li:last-child {
  margin-bottom: 0;
}