/* 瑞士国际主义风格 - 株式会社RCA官网样式表 */
/* 基于设计令牌的系统化样式 */

/* ======================================
   CSS 变量 - Design Tokens
   ====================================== */
:root {
  /* 色彩系统 */
  --color-primary-500: #DC143C;
  --color-primary-700: #A01028;
  --color-black: #000000;
  --color-charcoal: #1A1A1A;
  --color-gray-900: #333333;
  --color-gray-600: #666666;
  --color-gray-400: #999999;
  --color-gray-300: #CCCCCC;
  --color-gray-100: #E5E5E5;
  --color-gray-50: #F5F5F5;
  --color-white: #FFFFFF;

  /* 字体系统 */
  --font-primary: 'Yu Gothic', '游ゴシック体', 'YuGothic', 'Hiragino Kaku Gothic ProN', 'Hiragino Sans', Helvetica, Arial, sans-serif;
  
  /* 字号系统 */
  --font-size-display: 64px;
  --font-size-h1: 48px;
  --font-size-h2: 32px;
  --font-size-h3: 24px;
  --font-size-body-large: 20px;
  --font-size-body: 16px;
  --font-size-small: 14px;
  --font-size-caption: 12px;

  /* 字重系统 */
  --font-weight-regular: 400;
  --font-weight-medium: 500;
  --font-weight-bold: 700;

  /* 行高系统 */
  --line-height-tight: 1.1;
  --line-height-snug: 1.2;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.6;

  /* 间距系统（8px网格） */
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --space-12: 96px;
  --space-16: 128px;

  /* 圆角系统 */
  --radius-none: 0px;
  --radius-sm: 2px;

  /* 阴影系统 */
  --shadow-none: none;
  --shadow-minimal: 0 1px 3px rgba(0, 0, 0, 0.12);

  /* 动画系统 */
  --duration-fast: 150ms;
  --duration-base: 200ms;
  --easing-linear: linear;
  --easing-out: ease-out;
}

/* ======================================
   基础重置和设置
   ====================================== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: var(--font-primary);
  font-size: var(--font-size-body);
  font-weight: var(--font-weight-regular);
  line-height: var(--line-height-normal);
  color: var(--color-gray-900);
  background-color: var(--color-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ======================================
   容器和网格系统
   ====================================== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-6);
}

/* 12列网格系统 */
.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: var(--space-3);
}

.grid-6 {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: var(--space-3);
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-3);
}

/* ======================================
   排版系统
   ====================================== */
h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-weight-bold);
  color: var(--color-black);
  margin-bottom: var(--space-3);
}

h1 {
  font-size: var(--font-size-display);
  line-height: var(--line-height-tight);
  letter-spacing: -0.02em;
  margin-bottom: var(--space-4);
}

h2 {
  font-size: var(--font-size-h1);
  line-height: var(--line-height-snug);
  letter-spacing: -0.01em;
  margin-bottom: var(--space-4);
}

h3 {
  font-size: var(--font-size-h2);
  font-weight: var(--font-weight-medium);
  line-height: var(--line-height-normal);
  margin-bottom: var(--space-2);
}

p {
  margin-bottom: var(--space-3);
  line-height: var(--line-height-relaxed);
}

/* ======================================
   Site Header
   ====================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: saturate(140%) blur(8px);
  background: rgba(255, 255, 255, 0.85);
  border-bottom: 1px solid var(--color-gray-300);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 72px;
  gap: var(--space-3);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  text-decoration: none;
}

.brand-mark {
  display: inline-grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border: 1px solid var(--color-black);
  color: var(--color-black);
  font-weight: var(--font-weight-bold);
  line-height: 1;
}

.brand-name {
  font-size: var(--font-size-h3);
  font-weight: var(--font-weight-bold);
  font-family: 'Stack Sans Notch', var(--font-primary), sans-serif;
  color: var(--color-black);
  letter-spacing: -0.01em;
}

/* SVG brand logo */
.brand-logo {
  width: 36px;
  height: 36px;
  display: block;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.nav-list {
  list-style: none;
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.nav-item a {
  text-decoration: none;
  color: var(--color-gray-900);
  font-weight: var(--font-weight-medium);
  line-height: 1;
  padding: 10px 6px;
  border-bottom: 2px solid transparent;
}

.nav-item a:hover {
  color: var(--color-black);
  border-bottom-color: var(--color-black);
}

.nav-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 16px;
  border: 1px solid transparent;
  color: var(--color-black);
  text-decoration: none;
  font-weight: var(--font-weight-medium);
}

.nav-cta:hover {
  background: var(--color-black);
  color: var(--color-white);
}

/* Only show border when focused explicitly, and avoid double outline */
.nav-cta:focus {
  outline: none;
  border-color: var(--color-black);
}

/* ======================================
   Hero Section
   ====================================== */
.hero-section {
  min-height: 560px;
  display: flex;
  align-items: center;
  background-color: var(--color-white);
  /* MUJI-like minimal hero: soft overlay on photo */
  background-image:
    linear-gradient(rgba(0,0,0,0.35), rgba(0,0,0,0.35)),
    url('../images/image.png');
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  border-bottom: 1px solid var(--color-gray-300);
  padding: var(--space-12) 0;
}

.hero-content {
  text-align: left;
  max-width: 600px;
}

.hero-title {
  font-size: var(--font-size-display);
  font-weight: var(--font-weight-bold);
  font-family: 'Stack Sans Notch', var(--font-primary), sans-serif;
  color: var(--color-white);
  line-height: var(--line-height-tight);
  letter-spacing: -0.02em;
  margin-bottom: var(--space-3);
}

/* Hero title font variants */
.hero-title.font-stack {
  font-family: 'Stack Sans Notch', var(--font-primary), sans-serif;
}

.hero-title.font-alternate {
  /* font-family: 'Jersey 20 Charted', cursive;
  font-weight: 400;
  letter-spacing: 0; */
  font-family: 'Stack Sans Notch', var(--font-primary), sans-serif;
}

/* Hero title aligned layout: prefix at left, words stacked at right */
.hero-title-grid {
  display: inline-grid;
  grid-template-columns: auto 1fr;
  column-gap: 0.5ch;
  align-items: start;
}

.hero-title-prefix {
  white-space: nowrap;
}

.hero-title-words {
  display: flex;
  flex-direction: column;
}

.hero-title-word {
  display: block;
}

.hero-subtitle {
  font-size: var(--font-size-body-large);
  font-weight: var(--font-weight-regular);
  color: rgba(255,255,255,0.85);
  line-height: var(--line-height-relaxed);
}

/* ======================================
   Section 通用样式
   ====================================== */
section {
  padding: var(--space-12) 0;
}

.section-title {
  font-size: var(--font-size-h1);
  font-weight: var(--font-weight-bold);
  color: var(--color-black);
  line-height: var(--line-height-snug);
  letter-spacing: -0.01em;
}

.section-description {
  font-size: var(--font-size-body-large);
  color: var(--color-gray-600);
  line-height: var(--line-height-relaxed);
  margin-top: var(--space-3);
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-8);
}

/* ======================================
   Company Overview Section
   ====================================== */
.company-overview {
  background-color: var(--color-gray-50);
  border-top: 1px solid var(--color-gray-300);
  border-bottom: 1px solid var(--color-gray-300);
}

.overview-grid {
  display: grid;
  grid-template-columns: 6fr 6fr;
  gap: var(--space-6);
  align-items: start;
}

.overview-left {
  padding-right: var(--space-4);
}

.overview-right {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.info-item {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  padding: var(--space-3) 0;
  border-bottom: 1px solid var(--color-gray-300);
}

.info-item:last-child {
  border-bottom: none;
}

.info-label {
  font-size: var(--font-size-small);
  font-weight: var(--font-weight-medium);
  color: var(--color-gray-600);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.info-value {
  font-size: var(--font-size-body);
  font-weight: var(--font-weight-regular);
  color: var(--color-gray-900);
}

/* ======================================
   Business Services Section
   ====================================== */
.business-services {
  background-color: var(--color-white);
}

.business-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-3);
  margin-top: var(--space-8);
}

.business-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-gray-300);
  border-radius: var(--radius-none);
  padding: var(--space-4);
  transition: border-color var(--duration-fast) var(--easing-linear);
}

.business-card:hover {
  border-color: var(--color-gray-600);
}

/* Highlighted primary business card spanning a full row */
.business-card--highlight {
  grid-column: 1 / -1; /* span all columns */
  background: linear-gradient(180deg, rgba(220,20,60,0.08), rgba(220,20,60,0.02)); /* subtle crimson tint */
  border-color: var(--color-primary-500);
}

.business-card--highlight .card-number,
.business-card--highlight .card-title,
.business-card--highlight .card-description {
  color: var(--color-charcoal);
}

.business-card--highlight:hover {
  border-color: var(--color-primary-700);
}

/* Subtle varied tints for other business cards (avoid clutter) */
.business-grid .business-card:not(.business-card--highlight):nth-child(1) {
  background: linear-gradient(180deg, rgba(220,20,60,0.04), rgba(220,20,60,0.01));
}

.business-grid .business-card:not(.business-card--highlight):nth-child(2) {
  background: linear-gradient(180deg, rgba(0,0,0,0.03), rgba(0,0,0,0.01));
}

.business-grid .business-card:not(.business-card--highlight):nth-child(3) {
  background: linear-gradient(180deg, rgba(220,20,60,0.03), rgba(220,20,60,0.01));
}

.business-grid .business-card:not(.business-card--highlight):nth-child(4) {
  background: linear-gradient(180deg, rgba(0,0,0,0.025), rgba(0,0,0,0.01));
}

.business-grid .business-card:not(.business-card--highlight):nth-child(5) {
  background: linear-gradient(180deg, rgba(220,20,60,0.025), rgba(220,20,60,0.01));
}

.business-grid .business-card:not(.business-card--highlight):nth-child(6) {
  background: linear-gradient(180deg, rgba(0,0,0,0.02), rgba(0,0,0,0.01));
}

.card-number {
  font-size: var(--font-size-h3);
  font-weight: var(--font-weight-medium);
  color: var(--color-black);
  margin-bottom: var(--space-2);
  line-height: var(--line-height-tight);
}

.card-title {
  font-size: var(--font-size-body);
  font-weight: var(--font-weight-medium);
  color: var(--color-gray-900);
  line-height: var(--line-height-normal);
  margin-bottom: var(--space-2);
}

.card-description {
  font-size: var(--font-size-body);
  font-weight: var(--font-weight-regular);
  color: var(--color-gray-600);
  line-height: var(--line-height-relaxed);
}

/* ======================================
   Contact Section
   ====================================== */
.contact-section {
  background-color: var(--color-gray-50);
  border-top: 1px solid var(--color-gray-300);
}

.contact-grid {
  display: grid;
  grid-template-columns: 6fr 6fr;
  gap: var(--space-6);
  align-items: start;
}

.contact-left {
  padding-right: var(--space-4);
}

.contact-right {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.contact-item {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.contact-label {
  font-size: var(--font-size-small);
  font-weight: var(--font-weight-medium);
  color: var(--color-gray-600);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-1);
}

.contact-info {
  font-size: var(--font-size-body);
  font-weight: var(--font-weight-regular);
  color: var(--color-gray-900);
  line-height: var(--line-height-relaxed);
}

/* ======================================
   Footer
   ====================================== */
.footer {
  background-color: var(--color-white);
  border-top: 1px solid var(--color-gray-300);
  padding: var(--space-6) 0;
  text-align: center;
}

.footer-content {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.footer-text {
  font-size: var(--font-size-caption);
  font-weight: var(--font-weight-regular);
  color: var(--color-gray-600);
  line-height: var(--line-height-normal);
}

.footer-japanese {
  font-size: var(--font-size-caption);
  font-weight: var(--font-weight-regular);
  color: var(--color-gray-400);
  line-height: var(--line-height-normal);
}

/* ======================================
   响应式设计
   ====================================== */

/* 平板设备 (768px - 1024px) */
@media (max-width: 1024px) {
  :root {
    --font-size-display: 48px;
    --font-size-h1: 32px;
    --font-size-h2: 24px;
    --space-12: 64px;
    --space-8: 48px;
  }
  
  .container {
    padding: 0 var(--space-4);
  }
  
  .header-inner {
    min-height: 64px;
  }

  .hero-section {
    min-height: 440px;
    padding: var(--space-8) 0;
  }
  
  .business-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .overview-grid,
  .contact-grid {
    grid-template-columns: 1fr;
    gap: var(--space-4);
  }
  
  .overview-left,
  .contact-left {
    padding-right: 0;
  }
  
  .business-card--highlight {
    grid-column: 1 / -1; /* span all columns */
  }
}

/* 移动设备 (< 768px) */
@media (max-width: 768px) {
  :root {
    --font-size-display: 40px;
    --font-size-h1: 32px;
    --font-size-h2: 24px;
    --space-12: 48px;
    --space-8: 32px;
  }
  
  .container {
    padding: 0 var(--space-3);
  }
  
  .brand-name {
    font-size: 18px;
  }

  .nav-list {
    gap: var(--space-2);
  }

  .nav-cta {
    display: none;
  }

  .hero-section {
    min-height: 360px;
    padding: var(--space-6) 0;
  }
  
  .business-grid {
    grid-template-columns: 1fr;
    gap: var(--space-2);
  }
  
  .business-card {
    padding: var(--space-3);
  }
  
  .business-card--highlight {
    grid-column: 1 / -1; /* span all columns */
  }
  
  section {
    padding: var(--space-8) 0;
  }
  
  .section-header {
    margin-bottom: var(--space-6);
  }
  
  .footer {
    padding: var(--space-4) 0;
  }
  
  .footer-content {
    gap: var(--space-1);
  }
}

/* ======================================
   可访问性优化
   ====================================== */

/* 减少动画偏好 */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

/* 高对比度模式支持 */
@media (prefers-contrast: high) {
  :root {
    --color-gray-600: var(--color-black);
    --color-gray-400: var(--color-black);
  }
}

/* 焦点样式 */
:focus {
  outline: 2px solid var(--color-black);
  outline-offset: 2px;
}

/* 按钮和链接 */
button, a {
  cursor: pointer;
  transition: all var(--duration-fast) var(--easing-linear);
}

/* 选择文本样式 */
::selection {
  background-color: var(--color-gray-300);
  color: var(--color-black);
}

/* 滚动条样式 */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background-color: var(--color-gray-50);
}

::-webkit-scrollbar-thumb {
  background-color: var(--color-gray-300);
  border-radius: var(--radius-sm);
}

::-webkit-scrollbar-thumb:hover {
  background-color: var(--color-gray-400);
}