/* ==========================================================================
   sabakuru LP — Style
   ========================================================================== */

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

:root {
  --color-primary: #3b7d8c;
  --color-primary-dark: #2a5f6b;
  --color-primary-light: #e8f4f7;
  --color-accent: #e07b4c;
  --color-accent-hover: #c96a3e;
  --color-text: #2d2d2d;
  --color-text-light: #5a5a5a;
  --color-text-muted: #888;
  --color-bg: #fafaf8;
  --color-white: #fff;
  --color-border: #e5e5e0;
  --color-card-bg: #fff;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.10);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --font-sans: "Noto Sans JP", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --max-width: 960px;
  --section-padding: 80px 24px;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

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

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

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

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

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
}

/* --- CTA Button --- */
.cta-button {
  display: inline-block;
  background: var(--color-accent);
  color: var(--color-white);
  font-size: 1rem;
  font-weight: 700;
  padding: 16px 36px;
  border-radius: 60px;
  border: none;
  cursor: pointer;
  transition: background 0.2s ease, transform 0.15s ease, box-shadow 0.2s ease;
  box-shadow: 0 4px 14px rgba(224, 123, 76, 0.3);
  text-align: center;
  letter-spacing: 0.02em;
}

.cta-button:hover {
  background: var(--color-accent-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(224, 123, 76, 0.4);
}

.cta-button:active {
  transform: translateY(0);
}

/* --- Header / Nav --- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(250, 250, 248, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  transition: box-shadow 0.3s ease;
}

.site-header.scrolled {
  box-shadow: var(--shadow-sm);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.site-logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: 0.04em;
}

.header-cta .cta-button {
  font-size: 0.85rem;
  padding: 10px 22px;
}

/* ==========================================================================
   S1 — Hero
   ========================================================================== */
.hero {
  padding: 140px 24px 80px;
  background: linear-gradient(170deg, var(--color-primary-light) 0%, var(--color-bg) 60%);
  text-align: center;
}

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

.hero-headline {
  font-size: 1.75rem;
  font-weight: 700;
  line-height: 1.5;
  color: var(--color-text);
  margin-bottom: 24px;
}

.hero-sub {
  font-size: 1rem;
  color: var(--color-text-light);
  line-height: 1.9;
  margin-bottom: 40px;
}

.hero .cta-button {
  font-size: 1.05rem;
  padding: 18px 40px;
}

.hero-note {
  margin-top: 16px;
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

/* ==========================================================================
   S2 — Problem / Empathy
   ========================================================================== */
.problem {
  padding: var(--section-padding);
  background: var(--color-white);
}

.problem .container {
  max-width: 720px;
}

.section-label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  margin-bottom: 16px;
}

.section-heading {
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1.5;
  margin-bottom: 32px;
  color: var(--color-text);
}

.problem-list {
  list-style: none;
  margin-bottom: 32px;
}

.problem-list li {
  position: relative;
  padding: 16px 0 16px 28px;
  border-bottom: 1px solid var(--color-border);
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--color-text-light);
}

.problem-list li:last-child {
  border-bottom: none;
}

.problem-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 22px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--color-accent);
  opacity: 0.6;
}

.problem-closing {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--color-text);
  border-left: 3px solid var(--color-accent);
  padding-left: 16px;
}

/* ==========================================================================
   S3 — Solution / Benefits
   ========================================================================== */
.solution {
  padding: var(--section-padding);
  background: var(--color-bg);
}

.solution .section-heading {
  text-align: center;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.solution-desc {
  text-align: center;
  max-width: 620px;
  margin: 0 auto 48px;
  font-size: 0.95rem;
  color: var(--color-text-light);
  line-height: 1.9;
}

.benefit-cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  max-width: 800px;
  margin: 0 auto;
}

.benefit-card {
  background: var(--color-card-bg);
  border-radius: var(--radius-md);
  padding: 32px 28px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.2s ease, transform 0.2s ease;
}

.benefit-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.benefit-step {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--color-primary);
  color: var(--color-white);
  font-size: 0.85rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.benefit-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--color-text);
}

.benefit-text {
  font-size: 0.9rem;
  color: var(--color-text-light);
  line-height: 1.7;
}

/* ==========================================================================
   S4 — Trust / Safety
   ========================================================================== */
.trust {
  padding: var(--section-padding);
  background: var(--color-white);
}

.trust .container {
  max-width: 800px;
}

.trust .section-heading {
  text-align: center;
  margin-bottom: 40px;
}

.principles {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-bottom: 48px;
}

.principle-item {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 20px;
  border-radius: var(--radius-sm);
  background: var(--color-primary-light);
}

.principle-icon {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--color-primary);
  color: var(--color-white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  font-weight: 700;
}

.principle-content h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 4px;
  color: var(--color-text);
}

.principle-content p {
  font-size: 0.88rem;
  color: var(--color-text-light);
  line-height: 1.7;
}

/* App screenshot placeholder */
.app-preview {
  text-align: center;
  margin-top: 16px;
}

.app-preview-placeholder {
  display: inline-block;
  width: 260px;
  height: 460px;
  border-radius: 28px;
  background: linear-gradient(160deg, #e0eff3 0%, #d4e4e9 100%);
  border: 2px dashed var(--color-border);
  position: relative;
  overflow: hidden;
}

.app-preview-placeholder::after {
  content: "App Screenshot";
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 0.85rem;
  color: var(--color-text-muted);
  letter-spacing: 0.04em;
}

/* FAQ */
.faq {
  margin-top: 48px;
}

.faq h3 {
  font-size: 1.1rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 24px;
  color: var(--color-text);
}

.faq-item {
  border-bottom: 1px solid var(--color-border);
  padding: 20px 0;
}

.faq-item:first-of-type {
  border-top: 1px solid var(--color-border);
}

.faq-q {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 8px;
  padding-left: 24px;
  position: relative;
}

.faq-q::before {
  content: "Q";
  position: absolute;
  left: 0;
  color: var(--color-primary);
  font-weight: 700;
}

.faq-a {
  font-size: 0.9rem;
  color: var(--color-text-light);
  line-height: 1.7;
  padding-left: 24px;
}

/* ==========================================================================
   S5 — Final CTA
   ========================================================================== */
.final-cta {
  padding: 80px 24px 96px;
  background: linear-gradient(170deg, var(--color-bg) 0%, var(--color-primary-light) 100%);
  text-align: center;
}

.final-cta .container {
  max-width: 640px;
}

.final-cta .section-heading {
  text-align: center;
  margin-bottom: 16px;
}

.final-cta-desc {
  font-size: 0.95rem;
  color: var(--color-text-light);
  line-height: 1.9;
  margin-bottom: 36px;
}

.final-cta .cta-button {
  font-size: 1.05rem;
  padding: 18px 40px;
}

.final-cta-note {
  margin-top: 16px;
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

.final-cta-safety {
  margin-top: 8px;
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
  padding: 32px 24px;
  background: var(--color-white);
  border-top: 1px solid var(--color-border);
  text-align: center;
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (min-width: 600px) {
  .hero-headline {
    font-size: 2.25rem;
  }

  .section-heading {
    font-size: 1.75rem;
  }

  .benefit-cards {
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
  }

  .principles {
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
  }

  .principle-item {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
}

@media (min-width: 768px) {
  :root {
    --section-padding: 100px 24px;
  }

  .hero {
    padding: 160px 24px 100px;
  }

  .hero-headline {
    font-size: 2.5rem;
  }

  .hero-sub {
    font-size: 1.1rem;
  }
}

/* --- Fade-in animation --- */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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