/* ============================================
   MiMicroResearch — Corporate Site
   ============================================ */

:root {
  --color-bg: #fafafa;
  --color-bg-alt: #f3f4f6;
  --color-text: #0f172a;
  --color-text-muted: #475569;
  --color-accent: #1e3a5f;
  --color-accent-light: #2d5a8e;
  --color-border: #e2e8f0;
  --color-card: #ffffff;
  --font-sans: 'Inter', 'Noto Sans JP', system-ui, -apple-system, 'Hiragino Kaku Gothic ProN', 'Meiryo', sans-serif;
  --max-width: 960px;
  --nav-height: 64px;
}

/* Reset */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
}

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

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

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

ul, ol {
  list-style: none;
}

/* Container */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---- Navigation ---- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--nav-height);
  background: rgba(250, 250, 250, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s, background 0.3s;
}

.nav--scrolled {
  border-bottom-color: var(--color-border);
  background: rgba(255, 255, 255, 0.95);
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-size: 1.1rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--color-accent);
}

.nav-links {
  display: flex;
  gap: 32px;
}

.nav-links a {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-muted);
  transition: color 0.2s;
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-accent);
  transition: width 0.25s ease;
}

.nav-links a:hover,
.nav-links a:focus-visible {
  color: var(--color-accent);
}

.nav-links a:hover::after,
.nav-links a:focus-visible::after {
  width: 100%;
}

/* Mobile menu toggle */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  width: 32px;
  height: 24px;
  position: relative;
}

.nav-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--color-text);
  position: absolute;
  left: 0;
  transition: transform 0.3s, opacity 0.3s;
}

.nav-toggle span:nth-child(1) { top: 2px; }
.nav-toggle span:nth-child(2) { top: 11px; }
.nav-toggle span:nth-child(3) { top: 20px; }

/* ---- Hero ---- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: calc(var(--nav-height) + 40px) 24px 80px;
}

.hero-content {
  max-width: 720px;
}

.hero-logo {
  margin: 0 auto 32px;
  width: min(80vw, 560px);
  height: auto;
}

.hero-tagline {
  font-size: clamp(0.95rem, 2vw, 1.15rem);
  font-weight: 500;
  color: var(--color-text-muted);
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

/* ---- Sections ---- */
.section {
  padding: 96px 0;
}

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

.section-title {
  font-size: clamp(1.4rem, 3vw, 1.75rem);
  font-weight: 700;
  text-align: center;
  margin-bottom: 48px;
  color: var(--color-text);
  letter-spacing: 0.02em;
}

.section-title::after {
  content: '';
  display: block;
  width: 40px;
  height: 3px;
  background: var(--color-accent);
  margin: 16px auto 0;
  border-radius: 2px;
}

/* ---- About ---- */
.about-card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 40px;
  max-width: 640px;
  margin: 0 auto;
}

.about-table {
  width: 100%;
  border-collapse: collapse;
}

.about-table th,
.about-table td {
  padding: 14px 0;
  font-size: 0.95rem;
  border-bottom: 1px solid var(--color-border);
  text-align: left;
  vertical-align: top;
}

.about-table tr:last-child th,
.about-table tr:last-child td {
  border-bottom: none;
}

.about-table th {
  width: 120px;
  font-weight: 600;
  color: var(--color-accent);
  white-space: nowrap;
  padding-right: 24px;
}

.about-table td {
  color: var(--color-text);
}

/* ---- Business ---- */
.business-list {
  max-width: 720px;
  margin: 0 auto;
  counter-reset: none;
}

.business-item {
  display: flex;
  align-items: flex-start;
  gap: 20px;
  padding: 24px 0;
  border-bottom: 1px solid var(--color-border);
}

.business-item:last-child {
  border-bottom: none;
}

.business-num {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-accent);
  opacity: 0.3;
  line-height: 1.4;
  flex-shrink: 0;
  width: 40px;
  font-variant-numeric: tabular-nums;
}

.business-item p {
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--color-text);
}

/* ---- Contact ---- */
.contact-card {
  text-align: center;
  max-width: 480px;
  margin: 0 auto;
}

.contact-text {
  font-size: 0.95rem;
  color: var(--color-text-muted);
  margin-bottom: 16px;
}

.contact-email {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-accent);
  letter-spacing: 0.02em;
}

.contact-email .at {
  font-size: 0.85em;
  color: var(--color-text-muted);
  margin: 0 2px;
}

/* ---- Footer ---- */
.footer {
  background: var(--color-text);
  color: rgba(255, 255, 255, 0.7);
  padding: 40px 0;
  text-align: center;
}

.footer-invoice {
  font-size: 0.8rem;
  margin-bottom: 8px;
  opacity: 0.6;
}

.footer-copy {
  font-size: 0.8rem;
}

.footer-counter {
  font-size: 0.75rem;
  margin-top: 12px;
  opacity: 0.5;
  letter-spacing: 0.04em;
}

/* ---- Announcement table thead ---- */
.about-table thead th {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-accent);
  padding: 10px 0;
  border-bottom: 2px solid var(--color-accent);
  white-space: nowrap;
}

/* ---- Active nav link ---- */
.nav-current {
  color: var(--color-accent) !important;
}

/* ---- Screen reader only ---- */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ---- Fade-in animation ---- */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---- Focus visible ---- */
:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 4px;
}

/* ---- Mobile ---- */
@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.98);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 40px;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s;
  }

  .nav-links a {
    font-size: 1.2rem;
  }

  .nav-toggle {
    display: block;
  }

  .menu-open .nav-links {
    opacity: 1;
    pointer-events: auto;
  }

  .menu-open .nav-toggle span:nth-child(1) {
    transform: translateY(9px) rotate(45deg);
  }

  .menu-open .nav-toggle span:nth-child(2) {
    opacity: 0;
  }

  .menu-open .nav-toggle span:nth-child(3) {
    transform: translateY(-9px) rotate(-45deg);
  }

  .hero {
    min-height: 80vh;
    padding-bottom: 60px;
  }

  .hero-logo {
    width: min(85vw, 400px);
  }

  .section {
    padding: 64px 0;
  }

  .about-card {
    padding: 24px 20px;
  }

  .about-table th {
    width: 90px;
    padding-right: 16px;
    font-size: 0.85rem;
  }

  .about-table td {
    font-size: 0.85rem;
  }

  .business-item {
    padding: 18px 0;
  }

  .business-num {
    font-size: 1.2rem;
    width: 32px;
  }

  .business-item p {
    font-size: 0.875rem;
  }
}

@media (max-width: 480px) {
  .about-table th,
  .about-table td {
    display: block;
    width: 100%;
    padding-right: 0;
  }

  .about-table th {
    padding-bottom: 2px;
    border-bottom: none;
  }

  .about-table td {
    padding-top: 0;
  }
}