/* ===================================
   クラシテク サービスLP 共通CSS
   Design System: DESIGN_RULES.md準拠
   =================================== */

/* --- Google Fonts --- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=Noto+Sans+JP:wght@400;500;700&display=swap');

/* --- CSS Custom Properties --- */
:root {
  /* Brand */
  --brand-50: #EEF4FF;
  --brand-100: #D9E5FF;
  --brand-200: #B6CBFF;
  --brand-500: #3B6BF5;
  --brand-600: #2550DC;
  --brand-700: #1C3FB0;
  --brand-900: #0B1B4A;

  /* Accent */
  --accent-500: #00C2B2;

  /* Neutral */
  --neutral-0: #FFFFFF;
  --neutral-50: #F7F8FA;
  --neutral-100: #EEF0F4;
  --neutral-200: #E2E5EC;
  --neutral-500: #6B7280;
  --neutral-700: #374151;
  --neutral-900: #0F172A;

  /* Semantic */
  --success: #10B981;
  --warning: #F59E0B;
  --danger: #EF4444;

  /* Spacing */
  --section-py-sp: 64px;
  --section-py-pc: 120px;
  --container-max: 1280px;

  /* Shadow */
  --shadow-sm: 0 1px 2px 0 rgb(15 23 42 / 0.04);
  --shadow-md: 0 4px 12px -2px rgb(15 23 42 / 0.08);
  --shadow-lg: 0 12px 32px -8px rgb(15 23 42 / 0.12);
  --shadow-xl: 0 24px 56px -12px rgb(11 27 74 / 0.18);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: 'Inter', 'Noto Sans JP', sans-serif;
  color: var(--neutral-700);
  background: var(--neutral-0);
  line-height: 1.8;
}

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

a {
  color: var(--brand-600);
  text-decoration: none;
  transition: color 0.2s ease-out;
}
a:hover { color: var(--brand-700); }

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  color: var(--neutral-900);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

h1 { font-size: 36px; line-height: 1.15; letter-spacing: -0.03em; }
h2 { font-size: 28px; line-height: 1.25; }
h3 { font-size: 22px; line-height: 1.35; }
h4 { font-size: 18px; font-weight: 600; line-height: 1.45; }

.eyebrow {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--brand-600);
  line-height: 1.2;
}

/* --- Layout --- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 16px;
}

.section {
  padding: var(--section-py-sp) 0;
}

.section--alt {
  background: var(--neutral-50);
}

.section--dark {
  background: var(--brand-900);
  color: var(--neutral-0);
}
.section--dark h2,
.section--dark h3,
.section--dark h4 {
  color: var(--neutral-0);
}

/* --- Section Heading --- */
.section-heading {
  text-align: center;
  margin-bottom: 64px;
}
.section-heading .eyebrow {
  margin-bottom: 12px;
  display: block;
}
.section-heading h2 {
  margin-bottom: 16px;
}
.section-heading p {
  max-width: 640px;
  margin: 0 auto;
  color: var(--neutral-500);
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  font-size: 16px;
  font-weight: 600;
  border-radius: 12px;
  border: none;
  cursor: pointer;
  transition: all 0.2s ease-out;
  text-decoration: none;
  line-height: 1.5;
}
.btn:focus-visible {
  outline: none;
  box-shadow: 0 0 0 2px var(--brand-500), 0 0 0 4px rgba(59,107,245,0.2);
}

.btn--primary {
  background: linear-gradient(135deg, #3B6BF5, #2550DC);
  color: #fff;
}
.btn--primary:hover {
  background: var(--brand-700);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn--secondary {
  background: var(--neutral-0);
  color: var(--brand-600);
  border: 1px solid var(--brand-600);
}
.btn--secondary:hover {
  background: var(--brand-50);
  color: var(--brand-700);
}

.btn--white {
  background: var(--neutral-0);
  color: var(--brand-700);
}
.btn--white:hover {
  background: var(--neutral-50);
  transform: translateY(-2px);
}

.btn--lg {
  padding: 16px 32px;
  font-size: 18px;
  border-radius: 16px;
}

.btn-arrow::after {
  content: '\2192';
  font-size: 1.1em;
}

/* --- Cards --- */
.card {
  background: var(--neutral-0);
  border: 1px solid var(--neutral-200);
  border-radius: 16px;
  padding: 32px;
  box-shadow: var(--shadow-md);
  transition: all 0.3s ease-out;
}
.card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-6px);
}

.card__icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--brand-50), var(--brand-100));
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  color: var(--brand-600);
  font-size: 24px;
}

.card__title {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--neutral-900);
}

.card__text {
  font-size: 15px;
  color: var(--neutral-700);
  line-height: 1.7;
}

/* --- Grid --- */
.grid {
  display: grid;
  gap: 24px;
}
.grid--2 { grid-template-columns: 1fr; }
.grid--3 { grid-template-columns: 1fr; }
.grid--4 { grid-template-columns: 1fr; }

/* --- Header --- */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  height: 72px;
  display: flex;
  align-items: center;
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--neutral-200);
  transition: background 0.2s;
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 16px;
}

.header__logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  font-weight: 700;
  color: var(--neutral-900);
  text-decoration: none;
}
.header__logo-mark {
  width: 36px;
  height: 36px;
  background: var(--brand-600);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 14px;
  font-weight: 700;
}

.header__nav {
  display: none;
  gap: 32px;
  list-style: none;
}
.header__nav a {
  font-size: 14px;
  font-weight: 500;
  color: var(--neutral-700);
}
.header__nav a:hover {
  color: var(--brand-600);
}

.header__cta {
  display: none;
}

.header__menu-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--neutral-700);
}

/* Mobile Nav Overlay */
.mobile-nav {
  display: none;
  position: fixed;
  top: 72px;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--neutral-0);
  z-index: 40;
  padding: 24px 16px;
}
.mobile-nav.is-open { display: block; }
.mobile-nav ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.mobile-nav a {
  font-size: 18px;
  font-weight: 500;
  color: var(--neutral-900);
  display: block;
  padding: 8px 0;
}
.mobile-nav .btn {
  width: 100%;
  margin-top: 24px;
  text-align: center;
}

/* --- Hero --- */
.hero {
  padding: 120px 0 64px;
  background: linear-gradient(135deg, var(--brand-50) 0%, var(--neutral-0) 50%, var(--brand-100) 100%);
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(circle at 70% 30%, rgba(59,107,245,0.12) 0%, transparent 50%);
  pointer-events: none;
}

.hero__inner {
  display: grid;
  gap: 48px;
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--brand-50);
  color: var(--brand-700);
  font-size: 13px;
  font-weight: 600;
  padding: 6px 14px;
  border-radius: 9999px;
  margin-bottom: 16px;
}

.hero h1 {
  margin-bottom: 20px;
}

.hero__sub {
  font-size: 16px;
  color: var(--neutral-700);
  line-height: 1.8;
  margin-bottom: 32px;
  max-width: 540px;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.hero__visual {
  position: relative;
}
.hero__visual-placeholder {
  background: linear-gradient(135deg, var(--brand-100), var(--brand-200));
  border-radius: 24px;
  aspect-ratio: 4/3;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-xl);
  border: 1px solid var(--neutral-200);
  overflow: hidden;
}
.hero__visual-placeholder svg {
  width: 80px;
  height: 80px;
  color: var(--brand-600);
  opacity: 0.4;
}

/* --- Problem Section --- */
.problems .card__icon {
  background: rgba(239,68,68,0.08);
  color: var(--danger);
}

/* --- Steps --- */
.steps {
  display: grid;
  gap: 32px;
  counter-reset: step;
}
.step {
  display: flex;
  gap: 20px;
  align-items: flex-start;
}
.step__number {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--brand-600);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  font-weight: 700;
}
.step__content h4 {
  margin-bottom: 4px;
}
.step__content p {
  font-size: 15px;
  color: var(--neutral-500);
}

/* --- Services Grid --- */
.services-grid {
  display: grid;
  gap: 16px;
}
.service-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 20px;
  background: var(--neutral-0);
  border: 1px solid var(--neutral-200);
  border-radius: 12px;
  transition: all 0.2s;
}
.service-item:hover {
  border-color: var(--brand-200);
  background: var(--brand-50);
}
.service-item__check {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  background: var(--accent-500);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 14px;
}
.service-item__text {
  font-size: 15px;
  font-weight: 500;
  color: var(--neutral-900);
}

/* --- FAQ --- */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.faq-item {
  border: 1px solid var(--neutral-200);
  border-radius: 12px;
  overflow: hidden;
}
.faq-item__q {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  background: var(--neutral-0);
  cursor: pointer;
  font-weight: 600;
  font-size: 15px;
  color: var(--neutral-900);
  border: none;
  width: 100%;
  text-align: left;
  transition: background 0.2s;
}
.faq-item__q:hover {
  background: var(--neutral-50);
}
.faq-item__q-icon {
  font-size: 20px;
  color: var(--brand-600);
  transition: transform 0.3s;
  flex-shrink: 0;
  margin-left: 16px;
}
.faq-item.is-open .faq-item__q-icon {
  transform: rotate(45deg);
}
.faq-item__a {
  display: none;
  padding: 0 24px 20px;
  font-size: 15px;
  color: var(--neutral-700);
  line-height: 1.7;
}
.faq-item.is-open .faq-item__a {
  display: block;
}

/* --- CTA Banner --- */
.cta-banner {
  background: var(--brand-900);
  border-radius: 32px;
  padding: 56px 24px;
  text-align: center;
  color: var(--neutral-0);
}
.cta-banner h2 {
  color: var(--neutral-0);
  margin-bottom: 12px;
}
.cta-banner p {
  margin-bottom: 32px;
  color: rgba(255,255,255,0.7);
}
.cta-banner__actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 16px;
}
.cta-banner__actions .btn {
  min-width: 200px;
}
.cta-banner__actions .btn:not(.btn--white):hover {
  background: rgba(255,255,255,0.12);
  transform: translateY(-2px);
}

/* --- Footer --- */
.footer {
  background: var(--neutral-900);
  color: rgba(255,255,255,0.6);
  padding: 48px 0 24px;
}
.footer__inner {
  display: flex;
  flex-direction: column;
  gap: 32px;
}
.footer__brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 16px;
  font-weight: 700;
  color: var(--neutral-0);
}
.footer__links {
  display: flex;
  flex-wrap: wrap;
  gap: 24px;
  list-style: none;
}
.footer__links a {
  color: rgba(255,255,255,0.6);
  font-size: 14px;
}
.footer__links a:hover {
  color: var(--neutral-0);
}
.footer__copy {
  font-size: 13px;
  padding-top: 24px;
  border-top: 1px solid rgba(255,255,255,0.1);
}

/* --- Staging Badge --- */
.staging-badge {
  position: fixed;
  top: 80px;
  right: 16px;
  z-index: 100;
  background: var(--warning);
  color: var(--neutral-900);
  padding: 4px 12px;
  border-radius: 8px;
  font-size: 12px;
  font-weight: 700;
  box-shadow: var(--shadow-md);
}

/* --- Animations --- */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s cubic-bezier(0.16,1,0.3,1), transform 0.7s cubic-bezier(0.16,1,0.3,1);
}
.fade-in.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation: none !important;
    transition: none !important;
  }
}

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

@media (min-width: 640px) {
  .container { padding: 0 24px; }
  .grid--2 { grid-template-columns: repeat(2, 1fr); }
  .grid--4 { grid-template-columns: repeat(2, 1fr); }
  .services-grid { grid-template-columns: repeat(2, 1fr); }
  h1 { font-size: 42px; }
}

@media (min-width: 768px) {
  .grid--3 { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 1024px) {
  .container { padding: 0 32px; }

  .section { padding: var(--section-py-pc) 0; }

  h1 { font-size: 68px; line-height: 1.08; }
  h2 { font-size: 48px; line-height: 1.15; letter-spacing: -0.03em; }
  h3 { font-size: 28px; line-height: 1.3; }
  h4 { font-size: 20px; line-height: 1.4; font-weight: 600; }

  .hero {
    padding: 180px 0 104px;
  }
  .hero__inner {
    grid-template-columns: 7fr 5fr;
    gap: 64px;
  }
  .hero__sub {
    font-size: 18px;
  }

  .header__nav {
    display: flex;
  }
  .header__cta {
    display: inline-flex;
  }
  .header__menu-btn {
    display: none;
  }

  .grid--2 { grid-template-columns: repeat(2, 1fr); }
  .grid--3 { grid-template-columns: repeat(3, 1fr); gap: 32px; }
  .grid--4 { grid-template-columns: repeat(4, 1fr); gap: 32px; }

  .card { padding: 40px; }

  .services-grid { grid-template-columns: repeat(3, 1fr); }

  .steps { grid-template-columns: repeat(4, 1fr); }
  .step { flex-direction: column; text-align: center; align-items: center; }

  .cta-banner {
    padding: 96px 64px;
  }

  .footer__inner {
    flex-direction: row;
    justify-content: space-between;
    align-items: flex-start;
  }
}