/* ============ RESET & BASE ============ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --color-bg: #ffffff;
  --color-bg-alt: #f8f9fb;
  --color-text: #1a1a1a;
  --color-muted: #6b7280;
  --color-accent: #d4a017;
  --color-primary: #0a2540;
  --color-success: #047857;
  --color-danger: #b91c1c;
  --color-border: #e5e7eb;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 10px 30px rgba(0,0,0,0.12);
  --radius: 8px;
  --max-width: 1100px;
}

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Kaku Gothic ProN", "Yu Gothic", "Meiryo", sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  font-size: 16px;
}

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

h1, h2, h3 { color: var(--color-primary); font-weight: 700; line-height: 1.3; }
a { color: var(--color-primary); text-decoration: none; }
a:hover { opacity: 0.7; }

/* ============ HEADER ============ */
header {
  background: white;
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(8px);
}

.nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 64px;
}

.logo {
  font-weight: 800;
  font-size: 18px;
  color: var(--color-primary);
  letter-spacing: -0.5px;
}

header nav {
  display: flex;
  gap: 32px;
  align-items: center;
}

header nav a {
  font-size: 14px;
  font-weight: 500;
  color: var(--color-muted);
}

header nav a:hover {
  color: var(--color-primary);
  opacity: 1;
}

.btn-small {
  background: var(--color-primary);
  color: white !important;
  padding: 8px 16px;
  border-radius: var(--radius);
  font-size: 14px;
}

.btn-small:hover {
  background: #0c3057;
  opacity: 1 !important;
}

/* ============ HERO ============ */
.hero {
  background: linear-gradient(135deg, #0a2540 0%, #1a3a5e 100%);
  color: white;
  padding: 100px 0 120px;
  text-align: center;
}

.hero h1 {
  font-size: clamp(28px, 5vw, 48px);
  color: white;
  margin-bottom: 24px;
  letter-spacing: -1px;
}

.hero h1 .accent {
  color: var(--color-accent);
}

.hero .lead {
  font-size: clamp(15px, 2vw, 18px);
  opacity: 0.92;
  margin-bottom: 40px;
  line-height: 1.8;
}

.hero-cta {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn-primary, .btn-secondary {
  display: inline-block;
  padding: 14px 32px;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 15px;
  transition: all 0.2s;
  border: 2px solid transparent;
}

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

.btn-primary:hover {
  background: #c69517;
  opacity: 1;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background: transparent;
  color: white;
  border-color: rgba(255,255,255,0.4);
}

.btn-secondary:hover {
  background: rgba(255,255,255,0.1);
  border-color: white;
  opacity: 1;
}

.btn-primary-large {
  display: inline-block;
  padding: 18px 48px;
  background: var(--color-accent);
  color: var(--color-primary) !important;
  border-radius: var(--radius);
  font-weight: 700;
  font-size: 18px;
  transition: all 0.2s;
  box-shadow: var(--shadow-md);
}

.btn-primary-large:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  opacity: 1;
}

/* ============ SECTION ============ */
.section {
  padding: 100px 0;
}

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

.section-dark {
  background: var(--color-primary);
  color: white;
  text-align: center;
}

.section h2 {
  font-size: clamp(24px, 4vw, 36px);
  margin-bottom: 8px;
  text-align: center;
  letter-spacing: -0.5px;
}

.section h2.white {
  color: white;
}

.section-sub {
  text-align: center;
  color: var(--color-muted);
  font-size: 15px;
  margin-bottom: 48px;
}

.lead-white {
  color: rgba(255,255,255,0.92);
  font-size: 18px;
  margin-bottom: 40px;
  line-height: 1.8;
}

/* ============ VIDEO PLAYER ============ */
.lang-tabs {
  display: flex;
  gap: 8px;
  justify-content: center;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.lang-tab {
  padding: 10px 20px;
  background: white;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 14px;
  font-weight: 500;
  color: var(--color-muted);
  transition: all 0.2s;
}

.lang-tab:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.lang-tab.active {
  background: var(--color-primary);
  color: white;
  border-color: var(--color-primary);
}

.video-wrapper {
  position: relative;
  width: 100%;
  max-width: 960px;
  margin: 0 auto;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  background: #000;
}

.video-placeholder {
  aspect-ratio: 16/9;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #1f2937 0%, #374151 100%);
  color: white;
}

.placeholder-content {
  text-align: center;
}

.placeholder-icon {
  font-size: 64px;
  opacity: 0.5;
  margin-bottom: 16px;
}

.placeholder-text {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
  opacity: 0.9;
}

.placeholder-sub {
  font-size: 14px;
  opacity: 0.6;
}

.video-wrapper iframe {
  width: 100%;
  aspect-ratio: 16/9;
  border: none;
  display: block;
}

.video-meta {
  text-align: center;
  color: var(--color-muted);
  font-size: 13px;
  margin-top: 16px;
}

/* ============ COMPARE TABLE ============ */
.compare-table {
  width: 100%;
  max-width: 800px;
  margin: 0 auto;
  border-collapse: collapse;
  background: white;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.compare-table th, .compare-table td {
  padding: 16px 24px;
  text-align: center;
  border-bottom: 1px solid var(--color-border);
}

.compare-table th {
  background: var(--color-primary);
  color: white;
  font-weight: 600;
  font-size: 14px;
}

.compare-table th.us {
  background: var(--color-accent);
  color: var(--color-primary);
}

.compare-table tbody tr:last-child td {
  border-bottom: none;
}

.compare-table td:first-child {
  text-align: left;
  font-weight: 500;
}

.compare-table td.them {
  color: var(--color-muted);
}

.compare-table td.us {
  background: #fffbeb;
  color: var(--color-primary);
}

.compare-table td.us strong {
  color: var(--color-danger);
}

/* ============ FEATURES ============ */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 32px;
}

.feature-card {
  background: white;
  padding: 40px 32px;
  border-radius: var(--radius);
  text-align: center;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border);
  transition: transform 0.2s, box-shadow 0.2s;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.feature-icon {
  font-size: 48px;
  margin-bottom: 16px;
}

.feature-card h3 {
  font-size: 20px;
  margin-bottom: 12px;
}

.feature-card p {
  color: var(--color-muted);
  font-size: 14px;
  line-height: 1.7;
}

/* ============ CASE STUDY ============ */
.case-card {
  background: white;
  padding: 48px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
  max-width: 800px;
  margin: 0 auto;
  border-top: 4px solid var(--color-accent);
}

.case-badge {
  display: inline-block;
  background: var(--color-primary);
  color: white;
  padding: 6px 14px;
  border-radius: 4px;
  font-size: 12px;
  font-weight: 600;
  margin-bottom: 16px;
  letter-spacing: 0.5px;
}

.case-card h3 {
  font-size: 24px;
  margin-bottom: 8px;
}

.case-summary {
  color: var(--color-muted);
  margin-bottom: 24px;
  font-size: 15px;
}

.case-details {
  display: grid;
  grid-template-columns: 100px 1fr;
  gap: 12px 24px;
  margin-bottom: 24px;
  font-size: 14px;
}

.case-details dt {
  font-weight: 600;
  color: var(--color-primary);
}

.case-details dd {
  color: var(--color-text);
}

.case-note {
  padding: 16px;
  background: var(--color-bg-alt);
  border-left: 3px solid var(--color-accent);
  border-radius: 4px;
  font-size: 13px;
  color: var(--color-muted);
}

/* ============ ROI CALCULATOR ============ */
.roi-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  max-width: 900px;
  margin: 0 auto;
}

.roi-input {
  background: white;
  padding: 32px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border);
}

.roi-input label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 8px;
  margin-top: 16px;
}

.roi-input label:first-child {
  margin-top: 0;
}

.roi-input input {
  width: 100%;
  padding: 12px 16px;
  font-size: 16px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  font-family: inherit;
}

.roi-input input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(10, 37, 64, 0.1);
}

.roi-result {
  background: var(--color-primary);
  color: white;
  padding: 32px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
}

.roi-result h3 {
  color: white;
  font-size: 18px;
  margin-bottom: 24px;
  border-bottom: 1px solid rgba(255,255,255,0.2);
  padding-bottom: 12px;
}

.roi-number {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 20px;
  padding-bottom: 16px;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}

.roi-number:last-of-type {
  border-bottom: none;
}

.roi-label {
  font-size: 13px;
  opacity: 0.8;
}

.roi-value {
  font-size: 24px;
  font-weight: 700;
  color: var(--color-accent);
}

.roi-value.secondary {
  color: rgba(255,255,255,0.7);
  font-size: 18px;
}

.roi-note {
  font-size: 11px;
  opacity: 0.6;
  margin-top: 16px;
  line-height: 1.5;
}

/* ============ CONTACT ============ */
.contact-cta {
  margin-top: 16px;
}

/* ============ FOOTER ============ */
footer {
  background: #050d18;
  color: rgba(255,255,255,0.6);
  padding: 40px 0;
  text-align: center;
  font-size: 13px;
}

footer p {
  margin-bottom: 8px;
}

.footer-note {
  opacity: 0.5;
  font-size: 11px;
}

/* ============ RESPONSIVE ============ */
@media (max-width: 768px) {
  header nav {
    gap: 16px;
  }

  header nav a:not(.btn-small) {
    display: none;
  }

  .hero {
    padding: 60px 0 80px;
  }

  .section {
    padding: 60px 0;
  }

  .roi-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .compare-table {
    font-size: 13px;
  }

  .compare-table th, .compare-table td {
    padding: 10px 12px;
  }

  .case-card {
    padding: 32px 24px;
  }

  .case-details {
    grid-template-columns: 80px 1fr;
  }
}