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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: 'Hiragino Kaku Gothic ProN', 'Hiragino Sans', 'Meiryo', sans-serif;
  color: #222;
  background: #fff;
  line-height: 1.6;
}

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

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

/* ===========================
   UTILITY
   =========================== */
.container {
  width: 100%;
  max-width: 960px;
  margin-inline: auto;
  padding-inline: 16px;
}

/* ===========================
   BUTTONS
   =========================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border-radius: 50px;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, opacity 0.2s ease;
  white-space: nowrap;
}

.btn--line {
  background: #06c755;
  color: #fff;
  box-shadow: 0 4px 12px rgba(6, 199, 85, 0.4);
}

.btn--line:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(6, 199, 85, 0.5);
  opacity: 0.95;
}

.btn--sm {
  padding: 8px 20px;
  font-size: 0.85rem;
}

.btn--lg {
  padding: 14px 36px;
  font-size: 1.1rem;
}

.btn--xl {
  padding: 18px 48px;
  font-size: 1.3rem;
}

.btn__icon {
  width: 20px;
  height: 20px;
  object-fit: contain;
  border-radius: 4px;
}

/* ===========================
   HEADER
   =========================== */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: #fff;
  border-bottom: 2px solid #e8e8e8;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
  transition: box-shadow 0.3s ease;
}

.header--scrolled {
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.14);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1200px;
  margin-inline: auto;
  padding: 12px 20px;
}

.header__logo {
  font-size: 1rem;
  font-weight: 700;
  color: #222;
}

.header__logo span {
  color: #06c755;
}

/* ===========================
   HERO
   =========================== */
.hero {
  width: 100%;
  overflow: hidden;
}

.hero__img {
  width: 100%;
  height: auto;
  object-fit: cover;
}

/* ===========================
   BENEFITS BANNER
   =========================== */
.benefits {
  width: 100%;
  overflow: hidden;
  margin-bottom: 100px;
}

.benefits__img {
  width: 100%;
  height: auto;
}

/* ===========================
   WHY UPGRADE
   =========================== */
.why {
  padding: 64px 0;
  background: #f9f9f9;
}

.why__heading {
  font-size: 1.6rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 40px;
  color: #222;
  position: relative;
}

.why__heading::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: #e00;
  border-radius: 2px;
  margin: 12px auto 0;
}

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

.why__card {
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.why__card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.14);
}

.why__card-img {
  width: 100%;
  height: auto;
}

.why__cta {
  text-align: center;
  margin-top: 40px;
}

/* ===========================
   4 STEPS
   =========================== */
.steps {
  padding: 0;
  background: #fff;
}

.steps__heading {
  text-align: center;
 
}

.steps__heading-img {
  max-width: 800px;
  width: 100%;
  margin-inline: auto;
}

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

.step-card {
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 2px 16px rgba(0, 0, 0, 0.08);
  border: 2px solid #e8e8e8;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.step-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.13);
  border-color: #06c755;
}

.step-card__img {
  width: 100%;
  height: auto;
}

.steps__pc {
  display: flex;
  justify-content: center;
  margin-bottom: 40px;
}

.steps__pc-img {
  max-width: 560px;
  width: 100%;
  border-radius: 16px;
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.1);
}

.steps__cta {
  text-align: center;
  margin-top: 48px;
}

/* ===========================
   DIY OPTION
   =========================== */
.diy {
  padding: 48px 0;
  background: #f0faf4;
}

.diy__inner {
  display: flex;
  justify-content: center;
}

.diy__img {
  max-width: 640px;
  width: 100%;
  border-radius: 16px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

/* ===========================
   PRICING
   =========================== */
.pricing {
  padding: 64px 0;
  background: #fff;
}

.pricing__heading {
  font-size: 1.6rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 40px;
  color: #222;
  position: relative;
}

.pricing__heading::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: #06c755;
  border-radius: 2px;
  margin: 12px auto 0;
}

.pricing__img {
  max-width: 700px;
  width: 100%;
  margin-inline: auto;
  border-radius: 16px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

/* ===========================
   PAYMENT
   =========================== */
.payment {
  padding: 64px 0;
  background: #f0f6ff;
}

.payment__heading {
  font-size: 1.6rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 40px;
  color: #222;
  position: relative;
}

.payment__heading::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: #1a3f9e;
  border-radius: 2px;
  margin: 12px auto 0;
}

.payment__cards {
  display: grid;
  gap: 24px;
  grid-template-columns: 1fr;
  max-width: 700px;
  margin-inline: auto;
}

.payment__img {
  width: 100%;
  border-radius: 16px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

/* ===========================
   CONTACT / CTA
   =========================== */
.contact {
  padding: 72px 0;
  background: linear-gradient(135deg, #f0faf4 0%, #e8f5e9 100%);
}

.contact__inner {
  text-align: center;
}

.contact__heading {
  font-size: 1.6rem;
  font-weight: 700;
  margin-bottom: 36px;
  color: #222;
}

.contact__img {
  max-width: 640px;
  width: 100%;
  margin-inline: auto;
  margin-bottom: 36px;
  border-radius: 16px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.contact__note {
  margin-top: 16px;
  font-size: 0.9rem;
  color: #666;
}

/* ===========================
   FOOTER
   =========================== */
.footer {
  background: #d4f0e0;
  padding: 40px 0;
}

.footer__inner {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 32px;
}

.footer__nav {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer__link {
  font-size: 11px;
  color: #222;
  transition: color 0.2s ease;
}

.footer__link:hover {
  color: #06c755;
}

.footer__icons {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.footer__icon {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.footer__icon:hover {
  transform: scale(1.1);
  opacity: 0.85;
}

/* ===========================
   FLOATING LINE BUTTON
   =========================== */
.float-line {
  position: fixed;
  bottom: 24px;
  right: 20px;
  z-index: 200;
  display: flex;
  align-items: center;
  gap: 8px;
  background: #06c755;
  color: #fff;
  font-weight: 700;
  font-size: 0.9rem;
  padding: 12px 20px;
  border-radius: 50px;
  box-shadow: 0 4px 16px rgba(6, 199, 85, 0.5);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  animation: float-pulse 3s ease-in-out infinite;
}

.float-line:hover {
  transform: translateY(-3px) scale(1.04);
  box-shadow: 0 8px 24px rgba(6, 199, 85, 0.6);
}

.float-line img {
  width: 24px;
  height: 24px;
  object-fit: contain;
  border-radius: 4px;
}

@keyframes float-pulse {
  0%, 100% { box-shadow: 0 4px 16px rgba(6, 199, 85, 0.5); }
  50% { box-shadow: 0 6px 24px rgba(6, 199, 85, 0.75); }
}

/* ===========================
   SCROLL ANIMATIONS
   =========================== */
.reveal {
  opacity: 0;
  transform: translateY(32px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===========================
   RESPONSIVE — TABLET 640px+
   =========================== */
@media (min-width: 640px) {
  .why__cards {
    grid-template-columns: 1fr 1fr;
  }

  .why__cards .why__card:first-child {
    grid-column: 1 / -1;
  }

  .steps__grid {
    grid-template-columns: 1fr 1fr;
  }

  .payment__cards {
    grid-template-columns: 1fr 1fr;
  }
}

/* ===========================
   RESPONSIVE — DESKTOP 960px+
   =========================== */
@media (min-width: 960px) {
  .why__cards {
    grid-template-columns: 1fr 1fr 1fr;
  }

  .why__cards .why__card:first-child {
    grid-column: 1 / -1;
  }

  .steps__grid {
    grid-template-columns: 1fr 1fr;
  }

  .why__heading {
    font-size: 2rem;
  }

  .pricing__heading,
  .payment__heading,
  .contact__heading {
    font-size: 2rem;
  }
}