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

body {
  font-family: "Noto Sans JP", sans-serif;
  background-color: #1a1a1a;
  color: #ffffff;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Header Styles */
header {
  background-color: #1a1a1a;
  border-bottom: 1px solid #333333;
  padding: 1rem 2rem;
  position: sticky;
  top: 0;
  z-index: 1000;
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: block;
  line-height: 0;
}

.logo img {
  height: 40px;
  width: auto;
  display: block;
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  color: #ffffff;
  text-decoration: none;
  font-weight: 500;
  padding: 0.5rem 1rem;
  transition: all 0.3s ease;
  position: relative;
}

.nav-links a::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background-color: #ffffff;
  transition: all 0.3s ease;
  transform: translateX(-50%);
}

.nav-links a:hover::after {
  width: 80%;
}

.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 0.5rem;
  background: none;
  border: none;
}

.hamburger span {
  width: 25px;
  height: 2px;
  background-color: #ffffff;
  transition: all 0.3s ease;
  display: block;
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(7px, 7px);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
}

.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(7px, -7px);
}

/* Hero section */
.hero {
  max-width: 900px;
  margin: 3rem auto 3rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 2.8rem; 
}

/* logo */
.hero-icon {
  width: 300px;
  height: 300px;
  display: flex;
  align-items: center;
  justify-content: center;
  object-position: center;
  opacity: 0.95;            /* 白を少しだけ落ち着かせる */
}

.hero-icon img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  object-position: center;
}

/* catchphrase */
.hero-catchphrase {
  margin: -4rem auto 2rem;
  font-family: "Shippori Mincho B1", serif;
  font-size: 2rem;
  font-weight: 400;
  letter-spacing: 0.13em;
  line-height: 1.3;
  color: #f4f4f4;
}

.hero-catchphrase span {
  display: block;
  margin-bottom: 0.1rem;
}

/* PCでは少しだけ拡大 */
@media (min-width: 768px) {
  .hero {
    margin-top: 4rem;
    gap: 2rem;
  }

  .hero-icon {
    width: 340px;
    height: 340px;
    object-fit: contain;
    object-position: center;
  }

  .hero-catchphrase {
    font-size: 2.5rem;
  }
}

/* About section */
.about {
  max-width: 800px;
  margin: 0 auto 10rem;
  text-align: center;
}

.about p {
  font-size: 1.1rem;
  line-height: 1.8;
  color: #cccccc;
}

.about a {
  color: #ffffff;
  text-decoration: underline;
  transition: color 0.3s ease;
}

.about a:hover {
  color: #999999;
}

/* ARG section */
.arg-section {
  max-width: 1200px;
  margin: 0 auto 6rem;
}

.arg-section h2 {
  font-size: 2rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 3rem;
  letter-spacing: 0.1em;
}

/* 幅を維持して2枚表示に */
.arg-cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
  margin-bottom: 3rem;
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

.arg-card {
  background-color: #252525;
  border: 1px solid #333333;
  text-decoration: none;
  color: #ffffff;
  transition: all 0.3s ease;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.arg-card:hover {
  border-color: #666666;
  transform: translateY(-4px);
}

/* クリック不可 */
.arg-card-no-link {
  cursor: default;
}

.arg-card-no-link:hover {
  transform: none;
}

.card-image {
  width: 100%;
  height: 200px;
  overflow: hidden;
  background-color: #1a1a1a;
}

.card-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s ease;
}

.arg-card:hover .card-image img {
  transform: scale(1.05);
}

.arg-card-no-link:hover .card-image img {
  transform: none;
}

.card-title {
  font-size: 1.2rem;
  font-weight: 600;
  padding: 1.5rem 1.5rem 0.5rem;
}

.card-description {
  font-size: 0.9rem;
  line-height: 1.6;
  color: #cccccc;
  padding: 0 1.5rem 1.5rem;
}

/* Button styles */
.section-button {
  text-align: center;
}

.btn {
  display: inline-block;
  padding: 1rem 3rem;
  background-color: #ffffff;
  color: #1a1a1a;
  text-decoration: none;
  font-weight: 600;
  font-size: 1rem;
  transition: all 0.3s ease;
  border: 2px solid #ffffff;
}

.btn:hover {
  background-color: #1a1a1a;
  color: #ffffff;
}

/* Member section */
.member-section {
  max-width: 800px;
  margin: 0 auto 4rem;
  text-align: center;
}

.member-section h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  letter-spacing: 0.1em;
}

.member-section p {
  font-size: 1rem;
  line-height: 1.8;
  color: #cccccc;
}

.member-section a {
  color: #ffffff;
  text-decoration: underline;
  transition: color 0.3s ease;
}

.member-section a:hover {
  color: #999999;
}

/* Footer Styles */
footer {
  background-color: #0f0f0f;
  border-top: 1px solid #333333;
  padding: 3rem 2rem 1rem;
  margin-top: auto;
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  gap: 3rem;
  margin-bottom: 2rem;
}

.footer-section {
  flex: 1;
}

.footer-section h3 {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: #999999;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.footer-links a {
  color: #ffffff;
  text-decoration: none;
  font-size: 0.9rem;
  transition: all 0.3s ease;
  display: inline-block;
}

.footer-links a:hover {
  color: #cccccc;
  transform: translateX(4px);
}

.footer-icon {
  width: 80px;
  height: 80px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
}

.footer-icon img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.copyright {
  text-align: center;
  padding: 1rem 0;
  color: #666666;
  font-size: 0.9rem;
  border-top: 1px solid #333333;
}

/* 404 */
.error-page {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
  padding: 6rem 2rem;
}

.error-page h1 {
  font-size: 3rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  letter-spacing: 0.1em;
}

.error-page p {
  font-size: 1.2rem;
  color: #cccccc;
  line-height: 1.8;
}

/* Mobile Styles */
@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: 73px;
    left: 0;
    right: 0;
    background-color: #1a1a1a;
    flex-direction: column;
    padding: 2rem;
    gap: 1rem;
    border-bottom: 1px solid #333333;
    transform: translateY(-100%);
    opacity: 0;
    transition: transform 0.4s ease, opacity 0.4s ease;
    pointer-events: none;
  }

  .nav-links.active {
    transform: translateY(0);
    opacity: 1;
    pointer-events: all;
  }

  .nav-links a::after {
    display: none;
  }

  .hamburger {
    display: flex;
  }

  .hero-content {
    flex-direction: column;
    gap: 2rem;
  }

  .hero-icon {
    width: 200px;
    height: 200px;
  }

  .hero-catchphrase {
    font-size: 1.8rem;
    text-align: center;
  }

  .arg-cards {
    grid-template-columns: 1fr;
  }

  .footer-content {
    flex-direction: column;
    gap: 2rem;
  }
}