:root {
  color-scheme: light;
}

body {
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  margin: 0;
  padding: 0;
  background-color: #f8f9fa;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

header {
  background: linear-gradient(90deg, #4a90e2, #9013fe);
  color: #fff;
  padding: 20px 40px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
  height: 90px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: sticky;
  top: 0;
  z-index: 1000;
}

h1 {
  margin: 0;
  font-size: 3em;
}

main {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.portfolio {
  padding: 40px 20px;
  max-width: 1400px;
  margin: 0 auto;
}

.app-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 40px;
  padding: 20px;
}

.app-card {
  background: white;
  border-radius: 20px;
  padding: 25px;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.05);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  text-decoration: none;
  cursor: pointer;
  width: 100%;
  box-sizing: border-box;
  aspect-ratio: 0.9;
  justify-content: center;
}

.app-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
}

.app-image {
  width: 120px;
  height: 120px;
  border-radius: 27px;
  margin-bottom: 25px;
  box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
}

.app-details {
  width: 100%;
}

.app-details h3 {
  font-size: 1.5em;
  margin: 10px 0;
  color: #2d3748;
  transition: color 0.3s ease;
}

.app-details p {
  font-size: 0.9em;
  line-height: 1.4;
  color: #4a5568;
  margin-bottom: 0;
  transition: color 0.3s ease;
}

footer {
  text-align: center;
  padding: 30px 0;
  background: #4a4a4a;
  color: rgba(255, 255, 255, 0.8);
  width: 100%;
  box-sizing: border-box;
  letter-spacing: 0.5px;
  font-size: 1em;
}

footer p {
  margin: 8px 0;
  line-height: 1.5;
}

footer a {
  color: rgba(255, 255, 255, 0.8);
  text-decoration: none;
  transition: color 0.3s ease;
}

footer a:hover {
  color: #fff;
}

.contact {
  margin-top: 15px;
  letter-spacing: 0.7px;
}

.copyright {
  margin-top: 15px;
  color: rgba(255, 255, 255, 0.5);
}

@media (max-width: 1200px) {
  .app-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
  }
}

@media (max-width: 900px) {
  .app-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 25px;
  }

  .app-card {
    aspect-ratio: 0.85;
    padding: 20px;
  }

  .app-image,
  .placeholder-circle {
    width: 100px;
    height: 100px;
    border-radius: 22.5px;
    margin-bottom: 20px;
  }

  .app-details h3 {
    font-size: 1.3em;
    margin: 8px 0;
  }

  .app-details p {
    font-size: 0.85em;
    line-height: 1.3;
  }
}

@media (max-width: 768px) {
  .portfolio {
    padding: 20px 10px;
  }

  .app-grid {
    gap: 20px;
    padding: 10px;
  }

  .app-card {
    padding: 20px;
  }

  header {
    padding: 15px 20px;
    gap: 15px;
  }

  .header-logo {
    width: 40px;
    height: 40px;
  }

  h1 {
    font-size: 2.2em;
  }
}

@media (max-width: 480px) {
  .app-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 15px;
    padding: 10px;
  }

  .app-card {
    aspect-ratio: 0.8;
    padding: 15px;
  }

  .app-image,
  .placeholder-circle {
    width: 80px;
    height: 80px;
    border-radius: 18px;
    margin-bottom: 15px;
  }

  .app-details h3 {
    font-size: 1.1em;
    margin: 6px 0;
  }

  .app-details p {
    font-size: 0.75em;
    line-height: 1.2;
    margin: 0 5px;
  }

  .placeholder-circle i {
    font-size: 2em;
  }

  header {
    padding: 10px 15px;
    gap: 10px;
  }

  .header-logo {
    width: 35px;
    height: 35px;
  }

  h1 {
    font-size: 2em;
  }
}

.section-title {
  text-align: center;
  font-size: 2.5em;
  color: #2d3748;
  margin-bottom: 40px;
  font-weight: 600;
}

/* 모바일 대응 */
@media (max-width: 768px) {
  .section-title {
    font-size: 2em;
    margin-bottom: 30px;
  }
}

@media (max-width: 480px) {
  .section-title {
    font-size: 1.8em;
    margin-bottom: 20px;
  }
}

.coming-soon {
  opacity: 0.7;
  cursor: default;
  background: linear-gradient(145deg, #f0f0f0, #e6e6e6);
  border: 2px dashed #ccc;
}

.coming-soon:hover {
  transform: none;
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.05);
}

.placeholder-circle {
  width: 120px;
  height: 120px;
  border-radius: 27px;
  background: #f0f0f0;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 25px;
}

.placeholder-circle i {
  font-size: 3em;
  color: #999;
}