* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  font-family: "Outfit", "Zen Kaku Gothic New", sans-serif;
  font-weight: 400;
  background: #0a0a0a;
  color: #f5f5f5;
}

header {
  padding: 1.25rem 0;
  border-bottom: 1px solid #262626;
}

.site-inner {
  max-width: 48rem;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.site-logo {
  color: #f5f5f5;
  text-decoration: none;
  font-weight: 700;
  font-size: 0.9375rem;
  letter-spacing: 0.08em;
  flex-shrink: 0;
  transition: color 0.2s ease;
}

.site-logo:hover {
  color: #a3a3a3;
}

nav ul {
  display: flex;
  gap: 1.5rem;
  margin: 0;
  padding: 0;
  list-style: none;
  justify-content: flex-end;
  flex-wrap: wrap;
}

nav a {
  color: #a3a3a3;
  text-decoration: none;
  font-weight: 500;
  letter-spacing: 0.05em;
  transition: color 0.2s ease;
}

nav a.active {
  color: #f5f5f5;
}

nav a:hover {
  color: #f5f5f5;
}

main {
  flex: 1;
  display: grid;
  place-items: center;
  padding: 2rem 1.5rem;
  text-align: center;
}

.hero {
  max-width: 48rem;
}

.hero-eyebrow {
  margin: 0 0 1.25rem;
  color: #737373;
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
}

.hero-title {
  margin: 0;
  font-size: clamp(1.75rem, 5vw, 2.75rem);
  font-weight: 700;
  line-height: 1.6;
  letter-spacing: 0.04em;
}

.hero-subtitle {
  margin: 1.25rem 0 0;
  font-size: clamp(1.125rem, 3vw, 1.5rem);
  font-weight: 500;
  line-height: 1.6;
  letter-spacing: 0.04em;
  color: #a3a3a3;
}

.hero-subtitle .hero-highlight {
  color: #f5f5f5;
}

.hero-detail {
  margin: 1rem 0 0;
  font-size: 0.8125rem;
  line-height: 1.7;
  color: #737373;
  letter-spacing: 0.02em;
}

.hero-accent {
  background: linear-gradient(135deg, #38bdf8, #a78bfa);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-highlight {
  color: #f5f5f5;
  position: relative;
}

.hero-highlight::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0.1em;
  width: 100%;
  height: 0.12em;
  background: linear-gradient(90deg, #38bdf8, #a78bfa);
  opacity: 0.5;
  border-radius: 2px;
}

h2 {
  margin: 0 0 0.5rem;
  font-size: clamp(1.75rem, 5vw, 2.5rem);
  font-weight: 700;
  letter-spacing: 0.05em;
}

footer {
  padding: 1.5rem 0 2rem;
  margin-top: auto;
  border-top: 1px solid #262626;
  color: #737373;
  font-size: 0.875rem;
}

footer p {
  margin: 0;
  text-align: center;
}

/* About / 下層ページ */
main.page {
  display: block;
  padding: 3rem 0 4rem;
  text-align: left;
}

.page-content {
  max-width: 48rem;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.page-eyebrow {
  margin: 0 0 0.75rem;
  color: #737373;
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
}

.page-title {
  margin: 0;
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: 700;
  line-height: 1.5;
  letter-spacing: 0.04em;
}

.page-lead {
  margin: 1.25rem 0 0;
  color: #a3a3a3;
  font-size: 1rem;
  line-height: 1.8;
}

.page-section {
  margin-top: 3rem;
  padding-top: 3rem;
  border-top: 1px solid #262626;
}

.page-section--first {
  margin-top: 2rem;
  padding-top: 0;
  border-top: none;
}

.section-title {
  margin: 0 0 1.5rem;
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: #f5f5f5;
}

.card-list {
  display: grid;
  gap: 1rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

@media (min-width: 640px) {
  .card-list {
    grid-template-columns: repeat(2, 1fr);
  }
}

.card {
  padding: 1.25rem;
  border: 1px solid #262626;
  border-radius: 0.5rem;
  background: #111;
}

.card-title {
  margin: 0 0 0.5rem;
  font-size: 1rem;
  font-weight: 700;
}

.card-text {
  margin: 0;
  color: #a3a3a3;
  font-size: 0.875rem;
  line-height: 1.7;
}

.feature-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.feature-list li {
  display: grid;
  gap: 0.25rem;
  padding: 1rem 0;
  border-bottom: 1px solid #262626;
}

.feature-list li:first-child {
  padding-top: 0;
}

.feature-list strong {
  font-weight: 700;
  color: #f5f5f5;
}

.feature-list span {
  color: #a3a3a3;
  font-size: 0.875rem;
  line-height: 1.7;
}

.plain-list,
.step-list {
  margin: 0;
  padding-left: 1.25rem;
  color: #a3a3a3;
  line-height: 1.8;
}

.step-list {
  display: grid;
  gap: 0.5rem;
}

.page-note {
  margin: 1rem 0 0;
  color: #737373;
  font-size: 0.8125rem;
}

.info-list {
  margin: 0;
}

.info-item {
  display: grid;
  gap: 0.25rem;
  padding: 0.875rem 0;
  border-bottom: 1px solid #262626;
}

@media (min-width: 640px) {
  .info-item {
    grid-template-columns: 7rem 1fr;
    gap: 1rem;
  }
}

.info-item dt {
  color: #737373;
  font-size: 0.875rem;
  font-weight: 500;
}

.info-item dd {
  margin: 0;
  color: #a3a3a3;
  font-size: 0.875rem;
  line-height: 1.7;
}

.text-link {
  color: #38bdf8;
  text-decoration: none;
  transition: color 0.2s ease;
}

.text-link:hover {
  color: #a78bfa;
}

.contact-form {
  display: grid;
  gap: 1.25rem;
}

.form-group {
  display: grid;
  gap: 0.5rem;
}

.form-group label {
  font-size: 0.875rem;
  font-weight: 500;
  color: #f5f5f5;
}

.required {
  margin-left: 0.5rem;
  color: #737373;
  font-size: 0.75rem;
  font-weight: 400;
}

.contact-form input,
.contact-form select,
.contact-form textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid #262626;
  border-radius: 0.375rem;
  background: #111;
  color: #f5f5f5;
  font-family: inherit;
  font-size: 0.875rem;
  line-height: 1.5;
  transition: border-color 0.2s ease;
}

.contact-form input::placeholder,
.contact-form textarea::placeholder {
  color: #525252;
}

.contact-form input:focus,
.contact-form select:focus,
.contact-form textarea:focus {
  outline: none;
  border-color: #38bdf8;
}

.contact-form select {
  cursor: pointer;
}

.contact-form textarea {
  resize: vertical;
  min-height: 9rem;
}

.btn-submit {
  justify-self: start;
  padding: 0.75rem 2rem;
  border: none;
  border-radius: 0.375rem;
  background: linear-gradient(135deg, #38bdf8, #a78bfa);
  color: #0a0a0a;
  font-family: inherit;
  font-size: 0.875rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  cursor: pointer;
  transition: opacity 0.2s ease;
}

.btn-submit:hover {
  opacity: 0.85;
}