/* ============================================
   DENTECH OTUKI - Style Sheet
   OkusuriTecho Design Inheritance
   ============================================ */

/* ========== CSS Variables ========== */
:root {
  /* Colors - OkusuriTecho Design */
  --color-primary: #4A90E2;
  --color-secondary: #7ED321;
  --color-primary-dark: #357ABD;
  --color-secondary-dark: #6BB81D;
  --color-text: #333333;
  --color-text-light: #666666;
  --color-bg: #FFFFFF;
  --color-bg-light: #F8F9FA;
  --color-border: #E0E0E0;
  --color-success: #7ED321;
  --color-error: #E74C3C;

  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  --space-xxl: 4rem;

  /* Typography */
  --font-base: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans JP", sans-serif;
  --font-size-base: 16px;
  --font-size-sm: 0.875rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.5rem;
  --font-size-xxl: 2rem;
  --font-size-xxxl: 2.5rem;

  /* Breakpoints */
  --bp-mobile: 360px;
  --bp-tablet: 768px;
  --bp-desktop: 1280px;

  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;

  /* Shadows */
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.15);
  --shadow-lg: 0 8px 16px rgba(0, 0, 0, 0.2);

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

/* ========== Reset & Base Styles ========== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: var(--font-size-base);
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-base);
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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-dark);
}

/* ========== Container ========== */
.container {
  width: 100%;
  max-width: var(--bp-desktop);
  margin: 0 auto;
  padding: 0 var(--space-sm);
}

@media (min-width: 768px) {
  .container {
    padding: 0 var(--space-md);
  }
}

@media (min-width: 1280px) {
  .container {
    padding: 0 var(--space-lg);
  }
}

/* ========== Typography ========== */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: var(--space-sm);
}

h1 {
  font-size: var(--font-size-xxxl);
}

h2 {
  font-size: var(--font-size-xxl);
}

h3 {
  font-size: var(--font-size-xl);
}

h4 {
  font-size: var(--font-size-lg);
}

p {
  margin-bottom: var(--space-sm);
}

/* ========== Header & Navigation ========== */
.site-header {
  background-color: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: var(--shadow-sm);
}

.site-header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: var(--space-sm);
  padding-bottom: var(--space-sm);
}

.site-logo {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-primary);
  display: flex;
  align-items: center;
}

.site-logo:hover {
  color: var(--color-primary-dark);
  opacity: 0.9;
}

.site-logo-container {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.logo-img {
  height: 40px;
  width: auto;
  display: block;
}

.site-tagline {
  font-size: 0.7rem;
  color: var(--color-text-light);
  margin: 0;
  line-height: 1;
}

@media (min-width: 768px) {
  .logo-img {
    height: 50px;
  }

  .site-tagline {
    font-size: 0.75rem;
  }
}

.main-nav {
  display: none;
}

.main-nav ul {
  display: flex;
  list-style: none;
  gap: var(--space-lg);
}

.main-nav a {
  font-weight: 500;
  color: var(--color-text);
  transition: color var(--transition-base);
}

.main-nav a:hover,
.main-nav a.active {
  color: var(--color-primary);
}

/* Hamburger Menu */
.hamburger {
  display: flex;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: var(--space-xs);
  background: none;
  border: none;
}

.hamburger span {
  display: block;
  width: 25px;
  height: 3px;
  background-color: var(--color-text);
  transition: transform var(--transition-base), opacity var(--transition-base);
}

.hamburger.active span:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
}

.hamburger.active span:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

.mobile-nav {
  display: none;
  background-color: var(--color-bg);
  border-top: 1px solid var(--color-border);
  box-shadow: var(--shadow-md);
}

.mobile-nav.active {
  display: block;
}

.mobile-nav ul {
  list-style: none;
  padding: var(--space-sm);
}

.mobile-nav li {
  border-bottom: 1px solid var(--color-border);
}

.mobile-nav a {
  display: block;
  padding: var(--space-sm);
  color: var(--color-text);
  font-weight: 500;
}

.mobile-nav a:hover,
.mobile-nav a.active {
  color: var(--color-primary);
  background-color: var(--color-bg-light);
}

@media (min-width: 768px) {
  .main-nav {
    display: block;
  }

  .hamburger,
  .mobile-nav {
    display: none !important;
  }
}

/* ========== Hero Section ========== */
.hero {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: white;
  padding: var(--space-xxl) 0;
  text-align: center;
}

.hero h1 {
  margin-bottom: var(--space-md);
}

.hero p {
  font-size: var(--font-size-lg);
  margin-bottom: var(--space-lg);
  opacity: 0.95;
}

.hero-brand {
  font-size: 3rem;
  font-weight: 700;
  margin-bottom: var(--space-sm);
  letter-spacing: 0.05em;
}

.hero-company {
  font-size: 1rem;
  margin-bottom: var(--space-lg);
  opacity: 0.9;
}

@media (min-width: 768px) {
  .hero {
    padding: 6rem 0;
  }
}

/* ========== About Section ========== */
.about-logo {
  text-align: center;
  margin-bottom: var(--space-xl);
}

.about-logo-img {
  max-width: 200px;
  height: auto;
  margin: 0 auto;
}

.brand-story {
  max-width: 800px;
  margin: var(--space-xl) auto 0;
  display: grid;
  gap: var(--space-xl);
}

.brand-meaning,
.brand-identity {
  background-color: white;
  padding: var(--space-lg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.brand-meaning h3,
.brand-identity h3 {
  color: var(--color-primary);
  font-size: 1.5rem;
  margin-bottom: var(--space-md);
  text-align: center;
}

.brand-meaning ul {
  list-style: none;
  padding-left: 0;
  margin: var(--space-md) 0;
}

.brand-meaning li {
  padding: var(--space-xs) 0;
  font-size: 1.1rem;
}

.brand-definition {
  margin-top: var(--space-md);
  padding: var(--space-md);
  background-color: var(--color-bg-light);
  border-left: 4px solid var(--color-primary);
  border-radius: var(--radius-sm);
  font-size: 1.1rem;
}

.brand-tagline {
  font-size: 1.5rem;
  text-align: center;
  color: var(--color-primary);
  margin: var(--space-md) 0;
}

.brand-subtitle {
  font-size: 1.2rem;
  text-align: center;
  color: var(--color-text);
  font-weight: 600;
}

@media (min-width: 768px) {
  .brand-story {
    grid-template-columns: 1fr 1fr;
  }
}

/* ========== Sections ========== */
.section {
  padding: var(--space-xxl) 0;
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-xl);
}

.section-title {
  color: var(--color-primary);
  margin-bottom: var(--space-sm);
}

.section-subtitle {
  color: var(--color-text-light);
  font-size: var(--font-size-lg);
}

/* ========== Utility Classes: Buttons ========== */
.btn {
  display: inline-block;
  padding: var(--space-sm) var(--space-lg);
  font-size: var(--font-size-base);
  font-weight: 600;
  text-align: center;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
}

.btn-primary {
  background-color: var(--color-primary);
  color: white;
}

.btn-primary:hover {
  background-color: var(--color-primary-dark);
  color: white;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background-color: var(--color-secondary);
  color: white;
}

.btn-secondary:hover {
  background-color: var(--color-secondary-dark);
  color: white;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-outline {
  background-color: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

.btn-outline:hover {
  background-color: var(--color-primary);
  color: white;
}

.btn-large {
  padding: var(--space-md) var(--space-xl);
  font-size: var(--font-size-lg);
}

/* ========== Utility Classes: Card ========== */
.card {
  background-color: var(--color-bg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  padding: var(--space-lg);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.card-header {
  margin-bottom: var(--space-md);
}

.card-title {
  font-size: var(--font-size-xl);
  color: var(--color-text);
  margin-bottom: var(--space-xs);
}

.card-subtitle {
  color: var(--color-text-light);
  font-size: var(--font-size-sm);
}

.card-body {
  margin-bottom: var(--space-md);
}

.card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-sm);
}

.card-footer .btn {
  font-size: 1.1rem;
  padding: 0.75rem 1.5rem;
  white-space: nowrap;
}

.card-img {
  width: 100%;
  max-height: 150px;
  object-fit: contain;
  border-radius: var(--radius-md);
  margin-bottom: var(--space-md);
}

/* ========== Utility Classes: Grid ========== */
.grid {
  display: grid;
  gap: var(--space-lg);
}

.grid-2 {
  grid-template-columns: 1fr;
}

.grid-3 {
  grid-template-columns: 1fr;
}

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

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

@media (min-width: 1280px) {
  .grid-3 {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* ========== Badge ========== */
.badge {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  font-size: var(--font-size-sm);
  font-weight: 600;
  border-radius: var(--radius-sm);
  background-color: var(--color-bg-light);
  color: var(--color-text);
}

.badge-primary {
  background-color: var(--color-primary);
  color: white;
}

.badge-secondary {
  background-color: var(--color-secondary);
  color: white;
}

.badge-featured {
  background-color: #FFD700;
  color: #333;
}

/* ========== Tags ========== */
.tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
  margin-bottom: var(--space-sm);
}

.tag {
  padding: 0.25rem 0.5rem;
  font-size: var(--font-size-sm);
  background-color: var(--color-bg-light);
  border-radius: var(--radius-sm);
  color: var(--color-text-light);
}

/* ========== FAQ / Accordion ========== */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  margin-bottom: var(--space-sm);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.faq-question {
  width: 100%;
  padding: var(--space-md);
  background-color: var(--color-bg-light);
  border: none;
  text-align: left;
  font-size: var(--font-size-base);
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: background-color var(--transition-base);
}

.faq-question:hover {
  background-color: var(--color-border);
}

.faq-question::after {
  content: '+';
  font-size: var(--font-size-xl);
  color: var(--color-primary);
  transition: transform var(--transition-base);
}

.faq-question.active::after {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-base);
}

.faq-answer-content {
  padding: var(--space-md);
  background-color: var(--color-bg);
}

.faq-question.active + .faq-answer {
  max-height: 500px;
}

/* ========== Filter Bar ========== */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-bottom: var(--space-lg);
  padding: var(--space-md);
  background-color: var(--color-bg-light);
  border-radius: var(--radius-md);
}

.filter-btn {
  padding: var(--space-xs) var(--space-md);
  background-color: white;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-base);
  font-size: var(--font-size-sm);
}

.filter-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.filter-btn.active {
  background-color: var(--color-primary);
  color: white;
  border-color: var(--color-primary);
}

/* ========== Product Grid ========== */
.product-grid {
  display: grid;
  gap: var(--space-lg);
  grid-template-columns: 1fr;
}

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

@media (min-width: 1280px) {
  .product-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.product-card {
  position: relative;
}

.product-card .badge-featured {
  position: absolute;
  top: var(--space-sm);
  right: var(--space-sm);
  z-index: 10;
}

.product-price {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-primary);
}

/* ========== Footer ========== */
.site-footer {
  background-color: var(--color-text);
  color: white;
  padding: var(--space-xl) 0 var(--space-md);
  margin-top: var(--space-xxl);
}

.footer-content {
  display: grid;
  gap: var(--space-lg);
  margin-bottom: var(--space-lg);
}

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

.footer-section h3 {
  color: var(--color-secondary);
  margin-bottom: var(--space-md);
}

.footer-section ul {
  list-style: none;
}

.footer-section li {
  margin-bottom: var(--space-xs);
}

.footer-section a {
  color: rgba(255, 255, 255, 0.8);
}

.footer-section a:hover {
  color: white;
}

.footer-bottom {
  text-align: center;
  padding-top: var(--space-md);
  border-top: 1px solid rgba(255, 255, 255, 0.2);
  color: rgba(255, 255, 255, 0.6);
}

/* ========== Loading State ========== */
.loading {
  text-align: center;
  padding: var(--space-xxl);
  color: var(--color-text-light);
}

.loading::after {
  content: '...';
  animation: dots 1.5s infinite;
}

@keyframes dots {
  0%, 20% { content: '.'; }
  40% { content: '..'; }
  60%, 100% { content: '...'; }
}

/* ========== Utility Classes ========== */
.text-center {
  text-align: center;
}

.text-primary {
  color: var(--color-primary);
}

.text-secondary {
  color: var(--color-secondary);
}

.text-muted {
  color: var(--color-text-light);
}

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--space-xs); }
.mt-2 { margin-top: var(--space-sm); }
.mt-3 { margin-top: var(--space-md); }
.mt-4 { margin-top: var(--space-lg); }

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--space-xs); }
.mb-2 { margin-bottom: var(--space-sm); }
.mb-3 { margin-bottom: var(--space-md); }
.mb-4 { margin-bottom: var(--space-lg); }

.hidden {
  display: none;
}