/* ============================================================
   INDENT LP — style.css
   ============================================================ */

/* ---------- CSS Custom Properties ---------- */
:root {
  --color-bg:        #0d0d0d;
  --color-bg-light:  #161616;
  --color-bg-card:   #1a1a1a;
  --color-footer:    #080808;
  --color-accent:    #F5A623;
  --color-accent-hover: #e6991a;
  --color-text:      #e8e8e8;
  --color-text-sub:  #a0a0a0;
  --color-border:    #2a2a2a;
  --font-family:     "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
  --max-width:       1080px;
  --section-padding: 100px 24px;
  --radius:          12px;
  --transition:      0.3s ease;
}

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

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

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

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

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

/* ---------- Utility ---------- */
.section-inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

.section-title {
  text-align: center;
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 56px;
  letter-spacing: 0.04em;
  position: relative;
}

.section-title::after {
  content: "";
  display: block;
  width: 48px;
  height: 3px;
  background: var(--color-accent);
  margin: 16px auto 0;
  border-radius: 2px;
}

/* ---------- CTA Button ---------- */
.btn-cta {
  display: inline-block;
  padding: 16px 40px;
  background: var(--color-accent);
  color: #0d0d0d;
  font-size: 1rem;
  font-weight: 700;
  border-radius: 60px;
  letter-spacing: 0.04em;
  transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
  box-shadow: 0 4px 20px rgba(245, 166, 35, 0.25);
}

.btn-cta:hover {
  background: var(--color-accent-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 28px rgba(245, 166, 35, 0.35);
}

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

/* ============================================================
   HEADER
   ============================================================ */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(13, 13, 13, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  transition: background var(--transition);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 24px;
}

.header-logo img {
  width: 110px;
  height: auto;
}

.header-cta {
  font-size: 0.85rem;
  font-weight: 600;
  padding: 8px 20px;
  border: 1.5px solid var(--color-accent);
  border-radius: 60px;
  color: var(--color-accent);
  transition: background var(--transition), color var(--transition);
}

.header-cta:hover {
  background: var(--color-accent);
  color: #0d0d0d;
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: 120px 24px 80px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

/* 背景のグロー演出 */
.hero::before {
  content: "";
  position: absolute;
  top: 30%;
  left: 50%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(245, 166, 35, 0.08) 0%, transparent 70%);
  transform: translate(-50%, -50%);
  pointer-events: none;
}

.hero-inner {
  position: relative;
  z-index: 1;
}

.hero-logo {
  width: 280px;
  margin: 0 auto 36px;
}

.hero-catch {
  font-size: 2rem;
  font-weight: 700;
  line-height: 1.6;
  margin-bottom: 20px;
  letter-spacing: 0.03em;
}

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

/* ============================================================
   FEATURES
   ============================================================ */
.features {
  padding: var(--section-padding);
  background: var(--color-bg-light);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 36px 28px;
  text-align: center;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
  /* アニメーション初期状態 */
  opacity: 0;
  transform: translateY(30px);
}

.feature-card.is-visible {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 0.6s ease, transform 0.6s ease, box-shadow var(--transition), border-color var(--transition);
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.4);
  border-color: var(--color-accent);
}

.feature-card.is-visible:hover {
  transform: translateY(-4px);
}

.feature-icon {
  color: var(--color-accent);
  margin-bottom: 20px;
}

.feature-icon svg {
  width: 48px;
  height: 48px;
}

.feature-heading {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 12px;
  letter-spacing: 0.02em;
}

.feature-text {
  font-size: 0.9rem;
  color: var(--color-text-sub);
  line-height: 1.8;
}

/* ============================================================
   HOW-TO (STEPS)
   ============================================================ */
.howto {
  padding: var(--section-padding);
}

.steps {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0;
}

.step-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 40px 36px;
  text-align: center;
  max-width: 520px;
  width: 100%;
  position: relative;
  /* アニメーション初期状態 */
  opacity: 0;
  transform: translateY(30px);
}

.step-card.is-visible {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.step-connector {
  display: flex;
  justify-content: center;
  padding: 4px 0;
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--color-accent);
  color: #0d0d0d;
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.step-icon {
  color: var(--color-accent);
  margin-bottom: 16px;
}

.step-icon svg {
  width: 44px;
  height: 44px;
}

.step-heading {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.step-text {
  font-size: 0.9rem;
  color: var(--color-text-sub);
  line-height: 1.8;
}

.howto-cta {
  text-align: center;
  margin-top: 56px;
}

/* ============================================================
   FOOTER
   ============================================================ */
.footer {
  background: var(--color-footer);
  border-top: 1px solid var(--color-border);
  padding: 40px 24px;
  text-align: center;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

.footer-app-link {
  display: inline-block;
  font-size: 0.9rem;
  color: var(--color-accent);
  margin-bottom: 16px;
  transition: opacity var(--transition);
}

.footer-app-link:hover {
  opacity: 0.7;
}

.footer-copy {
  font-size: 0.8rem;
  color: var(--color-text-sub);
}

/* ============================================================
   RESPONSIVE — タブレット (≤ 900px)
   ============================================================ */
@media (max-width: 900px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .hero-catch {
    font-size: 1.7rem;
  }

  .hero-logo {
    width: 240px;
  }
}

/* ============================================================
   RESPONSIVE — スマートフォン (≤ 600px)
   ============================================================ */
@media (max-width: 600px) {
  :root {
    --section-padding: 72px 16px;
  }

  .section-title {
    font-size: 1.4rem;
    margin-bottom: 40px;
  }

  /* Header */
  .header-inner {
    padding: 12px 16px;
  }

  .header-logo img {
    width: 90px;
  }

  .header-cta {
    font-size: 0.78rem;
    padding: 7px 14px;
  }

  /* Hero */
  .hero {
    min-height: auto;
    padding: 120px 16px 64px;
  }

  .hero-logo {
    width: 200px;
    margin-bottom: 28px;
  }

  .hero-catch {
    font-size: 1.35rem;
  }

  .hero-sub {
    font-size: 0.9rem;
  }

  .btn-cta {
    padding: 14px 32px;
    font-size: 0.95rem;
  }

  /* Features */
  .features-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .feature-card {
    padding: 28px 20px;
  }

  /* Steps */
  .step-card {
    padding: 28px 20px;
  }
}