/* ===================================================================
   ひとひら — ウェブサイト共通スタイルシート
   =================================================================== */

/* --- Google Fonts --- */
@import url('https://fonts.googleapis.com/css2?family=Zen+Maru+Gothic:wght@300;400;500;700&display=swap');

/* --- CSS Custom Properties (Design Tokens) --- */
:root {
  /* Colors */
  --color-primary: #D4839F;
  --color-primary-hover: #c27290;
  --color-primary-light: #f0d4df;
  --color-bg: #FDF8F5;
  --color-bg-subtle: #FAF0EB;
  --color-text: #4A3B3B;
  --color-text-light: #8B7A7A;
  --color-text-lighter: #B0A0A0;
  --color-white: #FFFFFF;
  --color-border: #F0E0D8;

  /* Typography */
  --font-family: 'Zen Maru Gothic', 'Hiragino Maru Gothic ProN', 'BIZ UDGothic', sans-serif;

  /* Spacing */
  --section-gap: 100px;
  --section-gap-mobile: 64px;
  --content-max-width: 760px;
  --content-padding: 24px;

  /* Border Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;

  /* Header */
  --header-height: 60px;

  /* Transitions */
  --transition-base: 0.3s ease;
}

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

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

body {
  font-family: var(--font-family);
  font-weight: 400;
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-base);
}

a:hover {
  color: var(--color-primary-hover);
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

ul, ol {
  list-style: none;
}

/* --- Utility: Screen Reader Only --- */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* --- Container --- */
.container {
  max-width: var(--content-max-width);
  margin: 0 auto;
  padding: 0 var(--content-padding);
}

/* ===================================================================
   Header
   =================================================================== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-height);
  background: rgba(253, 248, 245, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(240, 224, 216, 0.5);
  transition: background var(--transition-base);
}

.site-header__inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 var(--content-padding);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-header__logo {
  display: flex;
  align-items: center;
  height: 100%;
}

.site-header__logo img {
  height: 32px;
  width: auto;
}

.site-header__nav {
  display: flex;
  align-items: center;
  gap: 24px;
}

.site-header__nav-link {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text);
  transition: color var(--transition-base);
}

.site-header__nav-link:hover {
  color: var(--color-primary);
}

.site-header__cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 6px 20px;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--color-white);
  background-color: var(--color-primary);
  border-radius: var(--radius-full);
  transition: background-color var(--transition-base), transform var(--transition-base);
}

.site-header__cta:hover {
  background-color: var(--color-primary-hover);
  color: var(--color-white);
  transform: scale(1.03);
}

/* ===================================================================
   Main
   =================================================================== */
main {
  padding-top: var(--header-height);
}

/* ===================================================================
   Section Base
   =================================================================== */
.section {
  padding: var(--section-gap) 0;
}

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

.section__heading {
  font-size: 1.5rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 16px;
  color: var(--color-text);
}

.section__lead {
  text-align: center;
  color: var(--color-text-light);
  font-size: 0.9375rem;
  margin-bottom: 48px;
}

/* ===================================================================
   CTA Button (shared)
   =================================================================== */
.cta-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 48px;
  font-size: 1rem;
  font-weight: 500;
  color: var(--color-white);
  background-color: var(--color-primary);
  border-radius: var(--radius-full);
  transition: background-color var(--transition-base), transform 0.2s ease, box-shadow var(--transition-base);
  box-shadow: 0 4px 16px rgba(212, 131, 159, 0.25);
}

.cta-button:hover {
  background-color: var(--color-primary-hover);
  color: var(--color-white);
  transform: translateY(-2px) scale(1.02);
  box-shadow: 0 6px 24px rgba(212, 131, 159, 0.35);
}

.cta-button:active {
  transform: translateY(0) scale(0.99);
}

/* ===================================================================
   Hero (Top Page)
   =================================================================== */
.hero {
  position: relative;
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 80px var(--content-padding) 60px;
  overflow: hidden;
  /* Gradient background */
  background: linear-gradient(
    180deg,
    var(--color-bg) 0%,
    #fdf5f0 40%,
    #fae8e0 70%,
    #f5d9cf 100%
  );
}

/* Floating petals */
.hero__petal {
  position: absolute;
  width: 18px;
  height: 24px;
  opacity: 0.35;
  pointer-events: none;
  will-change: transform;
}

.hero__petal svg {
  width: 100%;
  height: 100%;
}

.hero__petal--1 {
  top: 12%;
  left: 18%;
  animation: petalFloat1 14s ease-in-out infinite;
}

.hero__petal--2 {
  top: 30%;
  right: 15%;
  width: 14px;
  height: 18px;
  animation: petalFloat2 18s ease-in-out infinite;
  animation-delay: -4s;
}

.hero__petal--3 {
  bottom: 25%;
  left: 30%;
  width: 12px;
  height: 16px;
  animation: petalFloat3 16s ease-in-out infinite;
  animation-delay: -8s;
}

@keyframes petalFloat1 {
  0%, 100% { transform: translate(0, 0) rotate(0deg); }
  25% { transform: translate(30px, 40px) rotate(15deg); }
  50% { transform: translate(-10px, 80px) rotate(-10deg); }
  75% { transform: translate(20px, 40px) rotate(20deg); }
}

@keyframes petalFloat2 {
  0%, 100% { transform: translate(0, 0) rotate(0deg); }
  25% { transform: translate(-25px, 35px) rotate(-20deg); }
  50% { transform: translate(15px, 70px) rotate(15deg); }
  75% { transform: translate(-10px, 35px) rotate(-5deg); }
}

@keyframes petalFloat3 {
  0%, 100% { transform: translate(0, 0) rotate(0deg); }
  33% { transform: translate(20px, -30px) rotate(25deg); }
  66% { transform: translate(-15px, 20px) rotate(-15deg); }
}

/* Hero content */
.hero__content {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0;
}

.hero__logo {
  width: 220px;
  height: auto;
  margin-bottom: 32px;
  opacity: 0;
  animation: fadeInUp 0.8s ease forwards;
  animation-delay: 0.2s;
}

.hero__tagline {
  font-size: 2.5rem;
  font-weight: 500;
  line-height: 1.5;
  color: var(--color-text);
  margin-bottom: 16px;
  opacity: 0;
  animation: fadeInUp 0.8s ease forwards;
  animation-delay: 0.4s;
}

.hero__subcopy {
  font-size: 1.0625rem;
  font-weight: 400;
  color: var(--color-text-light);
  margin-bottom: 48px;
  opacity: 0;
  animation: fadeInUp 0.8s ease forwards;
  animation-delay: 0.55s;
}

.hero__cta {
  opacity: 0;
  animation: fadeInUp 0.8s ease forwards;
  animation-delay: 0.7s;
}

/* Scroll indicator */
.hero__scroll-indicator {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  opacity: 0;
  animation: fadeIn 1s ease forwards;
  animation-delay: 1.2s;
}

.hero__scroll-indicator span {
  font-size: 0.6875rem;
  color: var(--color-text-lighter);
  letter-spacing: 0.1em;
}

.hero__scroll-arrow {
  width: 16px;
  height: 16px;
  border-right: 1.5px solid var(--color-text-lighter);
  border-bottom: 1.5px solid var(--color-text-lighter);
  transform: rotate(45deg);
  animation: scrollBounce 2s ease-in-out infinite;
}

@keyframes scrollBounce {
  0%, 100% { transform: rotate(45deg) translateY(0); }
  50% { transform: rotate(45deg) translateY(6px); }
}

/* ===================================================================
   Concept Section (Top Page)
   =================================================================== */
.concept {
  text-align: center;
  padding: var(--section-gap) var(--content-padding);
}

.concept__inner {
  max-width: 600px;
  margin: 0 auto;
}

.concept__lines {
  margin-bottom: 48px;
}

.concept__line {
  font-size: 1.125rem;
  font-weight: 400;
  line-height: 2.2;
  color: var(--color-text);
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.concept__line.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.concept__line--accent {
  color: var(--color-primary);
  font-weight: 500;
}

.concept__description {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  line-height: 2;
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.8s ease 0.3s, transform 0.8s ease 0.3s;
}

.concept__description.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===================================================================
   Highlights Section (Top Page)
   =================================================================== */
.highlights {
  padding: var(--section-gap) var(--content-padding);
}

.highlights__inner {
  max-width: 480px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 80px;
}

.highlight-block {
  text-align: center;
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.highlight-block.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.highlight-block__catchphrase {
  font-size: 1.25rem;
  font-weight: 500;
  color: var(--color-text);
  margin-bottom: 24px;
}

.highlight-block__visual {
  width: 100%;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 8px 40px rgba(74, 59, 59, 0.08);
}

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

/* Mockup placeholder */
.mockup-placeholder {
  background: linear-gradient(135deg, var(--color-bg-subtle), var(--color-primary-light));
  aspect-ratio: 9 / 16;
  max-height: 480px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-lg);
  box-shadow: 0 8px 40px rgba(74, 59, 59, 0.08);
}

.mockup-placeholder__text {
  font-size: 0.875rem;
  color: var(--color-text-light);
  font-weight: 400;
}

/* ===================================================================
   Features Summary (Top Page)
   =================================================================== */
.features {
  padding: var(--section-gap) var(--content-padding);
  background-color: var(--color-bg-subtle);
}

.features__inner {
  max-width: var(--content-max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}

.feature-item {
  text-align: center;
  padding: 24px 8px;
}

.feature-item__icon {
  font-size: 2rem;
  margin-bottom: 12px;
  line-height: 1;
}

.feature-item__label {
  font-size: 1rem;
  font-weight: 500;
  color: var(--color-text);
  margin-bottom: 6px;
}

.feature-item__note {
  font-size: 0.8125rem;
  color: var(--color-text-light);
  font-weight: 300;
}

/* ===================================================================
   Closing CTA (shared)
   =================================================================== */
.closing-cta {
  text-align: center;
  padding: var(--section-gap) var(--content-padding);
}

.closing-cta__copy {
  font-size: 1.375rem;
  font-weight: 500;
  color: var(--color-text);
  margin-bottom: 32px;
}

.closing-cta__sub {
  font-size: 0.875rem;
  color: var(--color-text-light);
  margin-top: 16px;
}

.closing-cta__sublink {
  display: inline-block;
  margin-top: 20px;
  font-size: 0.875rem;
  font-weight: 400;
  color: var(--color-primary);
}

.closing-cta__sublink:hover {
  color: var(--color-primary-hover);
}

/* ===================================================================
   Footer
   =================================================================== */
.site-footer {
  background-color: var(--color-bg-subtle);
  padding: 40px var(--content-padding);
  text-align: center;
  border-top: 1px solid var(--color-border);
}

.site-footer__inner {
  max-width: var(--content-max-width);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}

.site-footer__logo img {
  height: 24px;
  width: auto;
  opacity: 0.7;
}

.site-footer__nav {
  display: flex;
  gap: 24px;
}

.site-footer__nav a {
  font-size: 0.8125rem;
  color: var(--color-text-light);
  font-weight: 400;
}

.site-footer__nav a:hover {
  color: var(--color-primary);
}

.site-footer__copyright {
  font-size: 0.75rem;
  color: var(--color-text-lighter);
  font-weight: 300;
}

/* ===================================================================
   How-To-Use Page
   =================================================================== */

/* Page Header */
.page-header {
  text-align: center;
  padding: 80px var(--content-padding) 40px;
}

.page-header__title {
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 16px;
}

.page-header__lead {
  font-size: 1rem;
  color: var(--color-text-light);
  font-weight: 400;
}

/* How-to Section */
.howto-section {
  padding: var(--section-gap) var(--content-padding);
}

.howto-section:nth-child(even) {
  background-color: var(--color-bg-subtle);
}

.howto-section__inner {
  max-width: var(--content-max-width);
  margin: 0 auto;
}

.howto-section__heading {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 32px;
  text-align: center;
}

.howto-section__text {
  font-size: 0.9375rem;
  line-height: 2;
  color: var(--color-text);
  margin-bottom: 32px;
}

.howto-section__text + .howto-section__text {
  margin-top: -16px;
}

/* Steps */
.steps {
  display: flex;
  flex-direction: column;
  gap: 24px;
  margin-bottom: 40px;
}

.step {
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

.step__number {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--color-primary);
  color: var(--color-white);
  font-size: 0.875rem;
  font-weight: 700;
  border-radius: 50%;
}

.step__content {
  padding-top: 6px;
  font-size: 0.9375rem;
  line-height: 1.7;
}

/* Supplemental note */
.note-box {
  background-color: var(--color-bg-subtle);
  border-left: 3px solid var(--color-primary-light);
  padding: 20px 24px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin-bottom: 40px;
}

.note-box p {
  font-size: 0.875rem;
  line-height: 1.8;
  color: var(--color-text-light);
}

.note-box p + p {
  margin-top: 8px;
}

/* Category Table */
.category-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-bottom: 40px;
}

.category-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 16px 20px;
  background: var(--color-white);
  border-radius: var(--radius-md);
  box-shadow: 0 2px 12px rgba(74, 59, 59, 0.04);
}

.category-item__icon {
  font-size: 1.5rem;
  line-height: 1;
  flex-shrink: 0;
  margin-top: 2px;
}

.category-item__body {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.category-item__name {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-text);
}

.category-item__desc {
  font-size: 0.8125rem;
  color: var(--color-text-light);
  font-weight: 300;
}

/* Reaction list */
.reaction-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin: 24px 0 40px;
}

.reaction-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  background: var(--color-white);
  border-radius: var(--radius-md);
  box-shadow: 0 2px 12px rgba(74, 59, 59, 0.04);
}

.reaction-item__emoji {
  font-size: 1.25rem;
  flex-shrink: 0;
}

.reaction-item__label {
  font-size: 0.875rem;
  color: var(--color-text);
  font-weight: 400;
}

/* Title Growth Table */
.growth-flow {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  gap: 8px;
  margin-bottom: 40px;
  flex-wrap: wrap;
}

.growth-stage {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  width: 110px;
  padding: 16px 8px;
  position: relative;
}

.growth-stage__icon {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-bg-subtle), var(--color-primary-light));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 10px;
}

.growth-stage__title {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-text);
  margin-bottom: 2px;
}

.growth-stage__days {
  font-size: 0.6875rem;
  color: var(--color-text-lighter);
}

.growth-stage__note {
  font-size: 0.75rem;
  color: var(--color-text-light);
  font-weight: 300;
  margin-top: 6px;
}

/* Arrow between growth stages */
.growth-arrow {
  display: flex;
  align-items: center;
  padding-top: 28px;
  color: var(--color-text-lighter);
  font-size: 1rem;
}

/* Mockup grid */
.mockup-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
  margin: 32px 0 40px;
}

.mockup-grid .mockup-placeholder {
  aspect-ratio: 9 / 16;
  max-height: 360px;
}

/* Subsection heading */
.howto-section__subheading {
  font-size: 1.125rem;
  font-weight: 500;
  color: var(--color-text);
  margin-bottom: 16px;
  margin-top: 48px;
}

.howto-section__subheading:first-child {
  margin-top: 0;
}

/* Closing message */
.closing-message {
  margin-top: 40px;
  padding: 32px 24px;
  background: linear-gradient(135deg, var(--color-bg), var(--color-primary-light));
  border-radius: var(--radius-lg);
  text-align: center;
}

.closing-message p {
  font-size: 0.9375rem;
  font-weight: 400;
  line-height: 2;
  color: var(--color-text);
}

/* ===================================================================
   Animations
   =================================================================== */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* Intersection observer animation triggers */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.animate-on-scroll.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===================================================================
   Responsive
   =================================================================== */

/* Mobile: ~480px */
@media (max-width: 480px) {
  :root {
    --section-gap: 64px;
    --content-padding: 20px;
  }

  .hero__tagline {
    font-size: 1.75rem;
  }

  .hero__subcopy {
    font-size: 0.9375rem;
    margin-bottom: 36px;
  }

  .hero__logo {
    width: 180px;
  }

  .concept__line {
    font-size: 1rem;
  }

  .features__inner {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
  }

  .section__heading,
  .howto-section__heading {
    font-size: 1.3rem;
  }

  .page-header__title {
    font-size: 1.6rem;
  }

  .reaction-list {
    grid-template-columns: 1fr;
  }

  .growth-flow {
    gap: 4px;
  }

  .growth-stage {
    width: 90px;
  }

  .growth-arrow {
    display: none;
  }

  .mockup-grid {
    grid-template-columns: 1fr;
    max-width: 280px;
    margin-left: auto;
    margin-right: auto;
  }

  .closing-cta__copy {
    font-size: 1.2rem;
  }
}

/* Tablet: 481px ~ 768px */
@media (min-width: 481px) and (max-width: 768px) {
  :root {
    --section-gap: 80px;
  }

  .hero__tagline {
    font-size: 2rem;
  }

  .features__inner {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
  }

  .mockup-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* Desktop: 769px~ */
@media (min-width: 769px) {
  .highlights__inner {
    gap: 100px;
  }

  .howto-section__inner {
    padding: 0 20px;
  }
}

/* Reduced motion preference */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .hero__logo,
  .hero__tagline,
  .hero__subcopy,
  .hero__cta,
  .hero__scroll-indicator {
    opacity: 1;
    animation: none;
  }

  .concept__line,
  .concept__description,
  .highlight-block,
  .animate-on-scroll {
    opacity: 1;
    transform: none;
  }
}