:root {
  --color-bg: #f5f7fa;
  --color-bg-alt: #ffffff;
  --color-primary: #0f4c81;
  --color-accent: #4da1a9;
  --color-text: #222222;
  --color-text-muted: #6b7280;
  --color-border: #e2e8f0;
  --radius-lg: 18px;
  --radius-sm: 10px;
  --shadow-soft: 0 10px 25px rgba(15, 76, 129, 0.08);
  --shadow-card: 0 4px 14px rgba(15, 76, 129, 0.06);
  --max-width: 1120px;
}

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

html {
  font-family: -apple-system, BlinkMacSystemFont, "Noto Sans JP", "Segoe UI",
    "Helvetica Neue", Arial, "ヒラギノ角ゴ ProN W3", "Hiragino Kaku Gothic ProN",
    "メイリオ", Meiryo, sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

body {
  margin: 0;
}

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

a {
  color: inherit;
  text-decoration: none;
}

ul,
ol {
  margin: 0;
  padding-left: 1.2rem;
}

p {
  margin: 0 0 0.75rem;
}

h1,
h2,
h3,
h4 {
  margin: 0 0 0.5rem;
  font-weight: 600;
}

/* LAYOUT */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section {
  padding: 3.5rem 0;
}

.section-alt {
  background: var(--color-bg);
}

.page-hero {
  background: linear-gradient(135deg, #ffffff, #e5edf6);
  padding: 3.5rem 0 2.5rem;
  border-bottom: 1px solid var(--color-border);
}

.page-hero h1 {
  font-size: 1.9rem;
  margin-bottom: 0.5rem;
}

.page-hero p {
  color: var(--color-text-muted);
}

/* HEADER */
.site-header {
  background: rgba(255, 255, 255, 0.92);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(226, 232, 240, 0.7);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.7rem 0;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.logo img {
  width: 40px;
  height: 40px;
}

.logo-text {
  font-weight: 700;
  letter-spacing: 0.08em;
  font-size: 1rem;
}

.logo-subtext {
  display: block;
  font-size: 0.7rem;
  color: var(--color-text-muted);
}

/* NAV */
.site-nav ul {
  display: flex;
  list-style: none;
  gap: 1.5rem;
  padding: 0;
  margin: 0;
  font-size: 0.9rem;
}

.site-nav a {
  position: relative;
  padding-bottom: 0.2rem;
  color: var(--color-text-muted);
}

.site-nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -0.2rem;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: width 0.2s ease;
}

.site-nav a:hover::after,
.site-nav a.active::after {
  width: 100%;
}

.site-nav a.active {
  color: var(--color-primary);
}

/* NAV TOGGLE (SP) */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  border: none;
  background: none;
  padding: 0;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  height: 2px;
  width: 100%;
  background: var(--color-text);
  border-radius: 999px;
}

/* HERO */
.hero {
  padding: 3.5rem 0 3rem;
  background: radial-gradient(circle at top left, #e6f0ff, #f5f7fa 55%);
}

.hero-inner {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 2.5rem;
  align-items: center;
}

.hero h1 {
  font-size: 2.1rem;
  line-height: 1.3;
  margin-bottom: 1rem;
}

.hero p {
  color: var(--color-text-muted);
  max-width: 32rem;
}

.hero-actions {
  margin-top: 1.5rem;
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.hero-visual {
  text-align: center;
}

.hero-image-stack {
  display: grid;
  gap: 0.75rem;
}

.hero-image-stack img {
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
}

.hero-caption {
  margin-top: 0.5rem;
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

/* BUTTONS */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.6rem 1.4rem;
  border-radius: 999px;
  border: 1px solid transparent;
  font-size: 0.9rem;
  cursor: pointer;
  transition: background 0.15s ease, color 0.15s ease, box-shadow 0.15s ease,
    border-color 0.15s ease, transform 0.1s ease;
  text-decoration: none;
}

.btn.primary {
  background: var(--color-primary);
  color: #fff;
  box-shadow: 0 6px 18px rgba(15, 76, 129, 0.35);
}

.btn.primary:hover {
  background: #0b3a63;
  transform: translateY(-1px);
}

.btn.ghost {
  background: #ffffff;
  color: var(--color-primary);
  border-color: rgba(15, 76, 129, 0.3);
}

.btn.ghost:hover {
  background: #f3f6fb;
}

.btn.text-link {
  padding: 0;
  border-radius: 0;
  border: none;
  color: var(--color-primary);
}

/* GRID / CARDS */
.grid {
  display: grid;
  gap: 1.5rem;
}

.grid-2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.grid-3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.grid-4 {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.card {
  background: var(--color-bg-alt);
  border-radius: var(--radius-lg);
  padding: 1.4rem 1.5rem;
  box-shadow: var(--shadow-card);
  border: 1px solid rgba(226, 232, 240, 0.7);
}

.card.minimal {
  box-shadow: none;
  border-radius: var(--radius-sm);
}

.card-icon {
  width: 44px;
  margin-bottom: 0.8rem;
  border-radius: 8px;
}

/* SECTION HEADER */
.section-header {
  text-align: left;
  margin-bottom: 1.8rem;
}

.section-header h2 {
  font-size: 1.5rem;
}

.section-header p {
  color: var(--color-text-muted);
}

/* STRENGTHS */
.strengths h3 {
  font-size: 1.05rem;
  margin-bottom: 0.3rem;
}

.strengths p {
  font-size: 0.9rem;
}

/* SOLUTION CARDS */
.solution-cards p {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

.card-link {
  display: inline-flex;
  margin-top: 0.4rem;
  font-size: 0.83rem;
  color: var(--color-primary);
}

/* CASES ON HOME */
.case-highlight .case-card {
  max-width: 640px;
  margin: 0 auto;
}

.case-meta {
  font-size: 0.8rem;
  color: var(--color-text-muted);
  margin-bottom: 0.5rem;
}

/* CLIENT LOGOS */
.client-logos {
  margin-top: 2.5rem;
  text-align: center;
}

.client-logos p {
  font-size: 0.75rem;
  color: var(--color-text-muted);
  margin-bottom: 0.6rem;
}

.client-logos-row {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 1.2rem;
}

/* CTA */
.section-cta {
  background: linear-gradient(135deg, #0f4c81, #4da1a9);
  color: #ffffff;
}

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

.section-cta p {
  opacity: 0.9;
}

/* SERVICE DETAIL */
.service-detail .service-block + .service-block {
  margin-top: 2.5rem;
  padding-top: 2.5rem;
  border-top: 1px dashed var(--color-border);
}

.service-block h2 {
  margin-bottom: 0.6rem;
}

.service-block p {
  color: var(--color-text-muted);
  max-width: 40rem;
}

/* CASE LIST */
.case-list .case-card + .case-card {
  margin-top: 2rem;
}

/* TECH PAGE */
.tech-content {
  display: grid;
  gap: 1.5rem;
}

/* CONTACT */
.contact-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
  gap: 1.5rem;
}

.company-table {
  margin: 0 0 1.5rem;
}

.company-table div {
  display: grid;
  grid-template-columns: 90px 1fr;
  gap: 0.5rem 0.75rem;
  padding: 0.4rem 0;
  border-bottom: 1px dashed var(--color-border);
}

.company-table dt {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

.company-table dd {
  margin: 0;
  font-size: 0.9rem;
}

.contact-form form {
  display: grid;
  gap: 0.9rem;
}

.contact-form label {
  display: grid;
  gap: 0.25rem;
  font-size: 0.85rem;
}

.contact-form input,
.contact-form select,
.contact-form textarea {
  padding: 0.55rem 0.7rem;
  border-radius: 10px;
  border: 1px solid var(--color-border);
  font: inherit;
  background: #ffffff;
}

.contact-form input:focus,
.contact-form select:focus,
.contact-form textarea:focus {
  outline: 2px solid rgba(13, 148, 136, 0.25);
  border-color: var(--color-accent);
}

.required {
  color: #dc2626;
  font-size: 0.78rem;
  margin-left: 0.25rem;
}

.small {
  font-size: 0.78rem;
  color: var(--color-text-muted);
}

/* FOOTER */
.site-footer {
  margin-top: 2.5rem;
  padding-top: 1.8rem;
  border-top: 1px solid var(--color-border);
  background: #ffffff;
}

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

.footer-logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.9rem;
}

.footer-logo img {
  width: 32px;
  height: 32px;
}

.footer-text {
  font-size: 0.8rem;
  color: var(--color-text-muted);
  margin-top: 0.4rem;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.8rem;
}

.footer-links a {
  color: var(--color-text-muted);
}

.footer-bottom {
  text-align: center;
  padding: 0.8rem 0 1.3rem;
  font-size: 0.75rem;
  color: var(--color-text-muted);
}

/* RESPONSIVE */
@media (max-width: 960px) {
  .hero-inner {
    grid-template-columns: 1fr;
  }
  .grid-3 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .grid-4 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .contact-layout {
    grid-template-columns: 1fr;
  }
  .cta-inner {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 720px) {
  .header-inner {
    padding: 0.5rem 0;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: fixed;
    inset: 56px 0 auto 0;
    background: rgba(255, 255, 255, 0.98);
    border-bottom: 1px solid var(--color-border);
    transform: translateY(-100%);
    transition: transform 0.2s ease;
  }

  .site-nav.open {
    transform: translateY(0);
  }

  .site-nav ul {
    flex-direction: column;
    padding: 0.75rem 1.5rem 1rem;
    gap: 0.75rem;
  }

  .hero {
    padding-top: 2.4rem;
  }

  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }

  .section {
    padding: 3rem 0 2.5rem;
  }

  .page-hero {
    padding: 2.6rem 0 1.8rem;
  }

  .footer-inner {
    flex-direction: column;
    align-items: flex-start;
  }
}

.cta-btn {
  white-space: nowrap;
  min-width: 220px;
}