@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+JP:wght@500;700;900&display=swap');

:root {
  --bg: #F5F5F0;
  --surface: #FFFFFF;
  --ink: #000000;
  --accent-red: #E4002B;
  --accent-blue: #0057B8;
  --warn: #FFD400;

  --boat-1: #FFFFFF;
  --boat-2: #000000;
  --boat-3: #E4002B;
  --boat-4: #0057B8;
  --boat-5: #FFD400;
  --boat-6: #00A550;

  --border-w: 3px;
  --shadow-off: 6px;
  --shadow: var(--shadow-off) var(--shadow-off) 0 var(--ink);
  --shadow-sm: 4px 4px 0 var(--ink);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: 'Noto Sans JP', sans-serif;
  font-weight: 500;
  line-height: 1.7;
}

h1, h2, h3, h4 {
  font-weight: 900;
  line-height: 1.4;
  margin: 0 0 0.6em;
}

a {
  color: inherit;
}

img {
  max-width: 100%;
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--surface);
  border-bottom: var(--border-w) solid var(--ink);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 14px;
  padding-bottom: 14px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.25rem;
  font-weight: 900;
  text-decoration: none;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  background: var(--accent-red);
  color: #fff;
  border: var(--border-w) solid var(--ink);
  box-shadow: var(--shadow-sm);
  font-size: 1rem;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-block;
  padding: 12px 24px;
  border: var(--border-w) solid var(--ink);
  background: var(--surface);
  color: var(--ink);
  font-weight: 700;
  text-decoration: none;
  box-shadow: var(--shadow-sm);
  transition: transform 0.08s ease, box-shadow 0.08s ease;
  cursor: pointer;
}

.btn:hover {
  transform: translate(2px, 2px);
  box-shadow: 2px 2px 0 var(--ink);
}

.btn:active {
  transform: translate(4px, 4px);
  box-shadow: 0 0 0 var(--ink);
}

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

.btn-secondary {
  background: var(--accent-blue);
  color: #fff;
}

.btn-sm {
  padding: 8px 16px;
  font-size: 0.9rem;
}

.btn-disabled {
  background: var(--surface);
  color: #999;
  border-color: #999;
  box-shadow: none;
  cursor: not-allowed;
  pointer-events: none;
}

/* ---------- Hero ---------- */
.hero {
  border-bottom: var(--border-w) solid var(--ink);
  background: var(--surface);
  overflow: hidden;
}

.hero .container {
  padding-top: 64px;
  padding-bottom: 64px;
}

.hero-tag {
  display: inline-block;
  background: var(--ink);
  color: var(--warn);
  padding: 6px 14px;
  font-weight: 700;
  font-size: 0.85rem;
  margin-bottom: 20px;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3.2rem);
  max-width: 16ch;
}

.hero h1 span {
  background: linear-gradient(transparent 60%, var(--warn) 60%);
}

.hero p.lead {
  max-width: 60ch;
  font-size: 1.1rem;
  font-weight: 500;
}

.hero-ctas {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  margin-top: 28px;
}

.hero-note {
  margin-top: 16px;
  font-size: 0.85rem;
  color: #444;
}

/* ---------- Section base ---------- */
section {
  padding: 64px 0;
  border-bottom: var(--border-w) solid var(--ink);
}

section:last-of-type {
  border-bottom: none;
}

.section-head {
  margin-bottom: 40px;
  max-width: 70ch;
}

.section-eyebrow {
  display: inline-block;
  border: 2px solid var(--ink);
  padding: 3px 10px;
  font-size: 0.8rem;
  font-weight: 700;
  margin-bottom: 12px;
  background: var(--warn);
}

/* ---------- 12 factors grid ---------- */
.factors {
  background: var(--bg);
}

.factor-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 18px;
}

.factor-card {
  background: var(--surface);
  border: var(--border-w) solid var(--ink);
  box-shadow: var(--shadow-sm);
  padding: 18px;
  display: flex;
  gap: 12px;
  align-items: flex-start;
}

.factor-num {
  flex: none;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--ink);
  color: #fff;
  font-weight: 900;
  font-size: 0.9rem;
}

.factor-card h3 {
  font-size: 1rem;
  margin-bottom: 4px;
}

.factor-card p {
  margin: 0;
  font-size: 0.88rem;
  color: #333;
}

/* ---------- Boat number legend ---------- */
.boat-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 28px;
}

.boat-chip {
  display: flex;
  align-items: center;
  gap: 8px;
  border: 2px solid var(--ink);
  padding: 6px 12px;
  background: var(--surface);
  font-size: 0.85rem;
  font-weight: 700;
}

.boat-swatch {
  width: 16px;
  height: 16px;
  border: 2px solid var(--ink);
  display: inline-block;
}

/* ---------- Two-layer / how it works ---------- */
.layers {
  background: var(--surface);
}

.layer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}

.layer-card {
  border: var(--border-w) solid var(--ink);
  box-shadow: var(--shadow);
  padding: 26px;
  position: relative;
}

.layer-card .layer-label {
  position: absolute;
  top: -14px;
  left: 20px;
  padding: 4px 12px;
  font-weight: 900;
  color: #fff;
  font-size: 0.85rem;
}

.layer-card.rule .layer-label {
  background: var(--accent-blue);
}

.layer-card.ai .layer-label {
  background: var(--accent-red);
}

.layer-card ul {
  padding-left: 1.2em;
  margin: 12px 0 0;
}

.layer-card li {
  margin-bottom: 6px;
  font-size: 0.92rem;
}

/* ---------- Accuracy verification ---------- */
.verify {
  background: var(--ink);
  color: #fff;
}

.verify .section-eyebrow {
  background: var(--warn);
  color: var(--ink);
}

.verify-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 18px;
}

.verify-card {
  border: var(--border-w) solid #fff;
  padding: 20px;
  background: #111;
}

.verify-card .metric {
  font-size: 1.6rem;
  font-weight: 900;
  color: var(--warn);
  display: block;
  margin-bottom: 6px;
}

.verify-card p {
  margin: 0;
  font-size: 0.88rem;
  color: #ddd;
}

/* ---------- Disclaimer ---------- */
.disclaimer {
  background: var(--warn);
}

.disclaimer-box {
  border: var(--border-w) solid var(--ink);
  background: var(--surface);
  box-shadow: var(--shadow);
  padding: 28px;
}

.disclaimer-box h2 {
  font-size: 1.3rem;
}

.disclaimer-list {
  margin: 16px 0 0;
  padding-left: 1.2em;
}

.disclaimer-list li {
  margin-bottom: 10px;
  font-weight: 700;
}

.disclaimer-list li span {
  font-weight: 500;
  display: block;
  font-size: 0.88rem;
  color: #333;
}

/* ---------- CTA band ---------- */
.cta-band {
  background: var(--accent-blue);
  color: #fff;
  text-align: center;
  border-bottom: none;
}

.cta-band h2 {
  color: #fff;
}

.cta-band .btn-primary {
  background: var(--warn);
  color: var(--ink);
}

.cta-band .signup-note {
  margin-top: 14px;
  font-size: 0.85rem;
  color: #eee;
}

/* ---------- Footer ---------- */
.site-footer {
  background: var(--ink);
  color: #ccc;
  padding: 32px 0;
  font-size: 0.85rem;
}

.site-footer p {
  margin: 0 0 8px;
}

.site-footer a {
  color: #fff;
  text-decoration: underline;
}

@media (max-width: 640px) {
  .hero-ctas {
    flex-direction: column;
  }
  .btn {
    text-align: center;
  }
}