* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.6;
  color: var(--text-color);
  background-color: var(--body-color);
  transition: var(--transition);
}
.logo {
  display: inline-block;
  padding: 0.5rem 1rem;
  background: linear-gradient(135deg, #22de1f, #6366f1); /* 紫〜青のグラデ */
  border-radius: 1.25rem;
  cursor: pointer;
  box-shadow: 0 12px 30px -5px rgba(19, 185, 44, 0.5);
  transition: transform 0.25s ease, filter 0.25s ease;
  text-align: center;
}
a {
  text-decoration: none;
  color: var(--primary-color);
  transition: var(--transition);
}

a:hover {
  color: #3a57d0;
}

ul {
  list-style: none;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}
section {
  padding: 100px 0;
}

/* Base Styles */
:root {
  --primary-color: #4a6cf7;
  --secondary-color: #6c757d;
  --dark-color: #212529;
  --light-color: #f8f9fa;
  --success-color: #28a745;
  --danger-color: #dc3545;
  --body-color: #f9f9f9;
  --text-color: #333;
  --border-color: #e9ecef;
  --transition: all 0.3s ease;
  --box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
  --border-radius: 8px;
}

.dark {
  --primary-color: #6d8dff;
  --secondary-color: #adb5bd;
  --dark-color: #f8f9fa;
  --light-color: #212529;
  --body-color: #121212;
  --text-color: #f8f9fa;
  --border-color: #343a40;
}

.section-header {
  text-align: center;
  margin-bottom: 60px;
}

.section-header h2 {
  font-size: 2.5rem;
  margin-bottom: 15px;
  color: var(--dark-color);
}

.underline {
  height: 4px;
  width: 70px;
  background-color: var(--primary-color);
  margin: 0 auto;
}

.btn {
  display: inline-block;
  padding: 12px 30px;
  border-radius: 50px;
  font-weight: 600;
  text-align: center;
  cursor: pointer;
  transition: var(--transition);
  border: none;
}

.primary-btn {
  background-color: var(--primary-color);
  color: white;
}

.primary-btn:hover {
  background-color: #3a57d0;
  color: white;
}

.secondary-btn {
  background-color: transparent;
  color: var(--primary-color);
  border: 2px solid var(--primary-color);
}

.secondary-btn:hover {
  background-color: var(--primary-color);
  color: white;
}

/* Header */
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background-color: var(--body-color);
  box-shadow: var(--box-shadow);
  z-index: 1000;
  transition: var(--transition);
}
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px;
}

.logo h1 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--dark-color);
}

.logo span {
  color: var(--primary-color);
}

nav {
  display: flex;
  align-items: center;
}

.nav-links {
  display: flex;
}

.nav-links li {
  margin-left: 30px;
}

.nav-links a {
  color: var(--dark-color);
  font-weight: 500;
  position: relative;
}

.nav-links a::after {
  content: "";
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--primary-color);
  transition: var(--transition);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}
/* Hero Section */
.hero {
  padding-top: 150px;
  padding-bottom: 100px;
  background-color: var(--body-color);
}

.hero .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.hero-content {
  flex: 1;
}

.hero-content h1 {
  font-size: 2rem;
  margin-bottom: 15px;
  color: var(--primary-color);
}

.hero-content h1 span {
  color: var(--primary-color);
}

.hero-content h2 {
  font-size: 25px;
  margin-bottom: 20px;
  color: #080cecde;
  cursor: pointer;
}

.hero-content p {
  font-size: 1.1rem;
  margin-bottom: 30px;
  max-width: 500px;
  color: #0c30bf;
}

.hero-buttons {
  display: flex;
  gap: 15px;
  margin-bottom: 30px;
}

.social-icons {
  display: flex;
  gap: 60px;
}

.social-icons a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 95px;
  height: 45px;
  border-radius: 50%;
  background-color: var(--light-color);
  color: #310ecd;
  transition: var(--transition);
}

.social-icons a:hover {
  background-color: var(--primary-color);
  color: white;
}

.hero-image {
  flex: 1;
  text-align: right;
}

.hero-image img {
  max-width: 80%;
  border-radius: 20px;
  box-shadow: var(--box-shadow);
  margin-left: auto;
}

/* About Section */
.about h2 {
  color: #c813e0;
  font-style: normal;
  border-radius: 4px solid black;
}
.about-content {
  display: flex;
  align-items: center;
  gap: 50px;
}

.about-image {
  flex: 1;
}

.about-image img {
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
}

.about-text {
  flex: 3;
  margin-bottom: 40px;
}

.about-text h3 {
  font-size: 1.8rem;
  font-weight: bold;
  margin-bottom: 20px;
  color: #551ae0;
}
.about-text p {
  margin-bottom: 20px;
  color: #551ae0;
}

.about-details {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  margin-bottom: 30px;
}

.detail {
  display: flex;
  align-items: center;
  gap: 15px;
}

.detail i {
  font-size: 1.5rem;
  color: var(--primary-color);
}

.detail h4 {
  font-size: 1.1rem;
  margin-bottom: 5px;
  color: var(--dark-color);
}

/* Skills Section */
.skills h2{
  color: #310ecd;
}
.skills-content {
  display: flex;
  flex-direction: column;
  gap: 50px;
}

.skill-category h3 {
  font-size: 1.8rem;
  margin-bottom: 30px;
  color: #258ee3;
  text-align: center;
}

.skills-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 30px;
}

.skill-item {
  background-color: var(--light-color);
  padding: 30px;
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  text-align: center;
  transition: var(--transition);
}

.skill-item:hover {
  transform: translateY(-10px);
}

.skill-icon {
  font-size: 2.5rem;
  color: var(--primary-color);
  margin-bottom: 15px;
}

.skill-item h4 {
  font-size: 1.2rem;
  margin-bottom: 15px;
  color: var(--dark-color);
}

.progress-bar {
  height: 8px;
  background-color: var(--border-color);
  border-radius: 10px;
  margin-bottom: 10px;
  overflow: hidden;
}

.progress {
  height: 100%;
  background-color: var(--primary-color);
  border-radius: 10px;
}

.percentage {
  font-weight: 600;
  color: var(--primary-color);
}

/* Projects Section */


/* Contact Section */
.contact-content {
  display: flex;
  gap: 50px;
}

.contact-info,
.contact-form {
  flex: 1;
}

.contact-info h3,
.contact-form h3 {
  font-size: 1.8rem;
  margin-bottom: 20px;
  color: var(--dark-color);
}

.contact-info p {
  margin-bottom: 30px;
}

.contact-details {
  margin-bottom: 30px;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 15px;
  margin-bottom: 20px;
}

.contact-item i {
  font-size: 1.5rem;
  color: var(--primary-color);
}

.contact-item h4 {
  font-size: 1.1rem;
  margin-bottom: 5px;
  color: var(--dark-color);
}

.form-group {
  margin-bottom: 20px;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 12px 15px;
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  background-color: var(--light-color);
  color: var(--text-color);
  transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary-color);
}

.form-group textarea {
  height: 150px;
  resize: none;
}

/* Footer */
footer {
  background-color: var(--light-color);
  padding: 30px 0;
  text-align: center;
  position: relative;
}

.back-to-top {
  position: absolute;
  right: 30px;
  top: 50%;
  transform: translateY(-50%);
}

.back-to-top a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background-color: var(--primary-color);
  color: white;
  transition: var(--transition);
}

.back-to-top a:hover {
  background-color: var(--dark-color);
}

/* Responsive Styles */
@media (max-width: 992px) {
  .hero-content h1 {
    font-size: 3rem;
  }

  .hero-content h2 {
    font-size: 1.8rem;
  }

  .skills-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .about-content {
    flex-direction: column;
  }

  .about-image {
    margin-bottom: 30px;
  }

  .contact-content {
    flex-direction: column;
  }

  .contact-info {
    margin-bottom: 50px;
  }
}

@media (max-width: 768px) {
  .hamburger {
    display: block;
  }

  .nav-links {
    position: fixed;
    top: 80px;
    left: -100%;
    width: 100%;
    height: calc(100vh - 80px);
    background-color: var(--body-color);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 30px;
    transition: var(--transition);
  }

  .nav-links.active {
    left: 0;
  }

  .hero .container {
    flex-direction: column;
    text-align: center;
  }

  .hero-content {
    margin-bottom: 50px;
  }

  .hero-content p {
    margin: 0 auto 30px;
  }

  .hero-buttons {
    justify-content: center;
  }

  .social-icons {
    justify-content: center;
  }

  .hero-image img {
    margin: 0 auto;
  }

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

  .about-details {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 576px) {
  .section-header h2 {
    font-size: 2rem;
  }

  .hero-content h1 {
    font-size: 2.5rem;
  }

  .hero-content h2 {
    font-size: 1.5rem;
  }

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

  .project-filters {
    flex-wrap: wrap;
  }
}