/* =============================================
 * 道得投资 cn_v2 — 共享样式表
 * 从 cnv1.html 迁移 + 多页 SPA 扩展
 * 设计系统遵循 docs/DESIGN.md
 * ============================================= */

/* --- 设计令牌（Design Tokens） --- */
:root {
  /* 核心色彩 — DESIGN.md 矿物色系 */
  --brand: #0d1a2d;            /* 深夜海军蓝主色（权威沉稳，规避绿色下跌联想） */
  --brand-light: #1a3050;      /* 海军蓝浅色（悬浮/聚焦态） */
  --brand-surface: #f8f7f4;    /* 米白背景（宣纸底色） */
  --brand-accent: #a83635;     /* 朱砂红（东方印章色，每屏≤2处） */
  --brand-accent-light: #c94a49; /* 朱砂红浅色（悬浮态） */
  --brand-muted: #717975;      /* 辅助灰文字 */
  --brand-border: #e0ddd8;     /* 极浅分隔色（用于渐变分隔线，非实线） */
  --brand-text: #1b1c1a;       /* 正文色（接近炭灰 #1A1A1A，禁止纯黑） */

  /* 表面阶层 — DESIGN.md 色调叠层 */
  --surface-lowest: #ffffff;
  --surface-low: #fafaf7;
  --surface: #f8f7f4;
  --surface-high: #f0efec;
  --surface-highest: #e8e7e4;

  /* 字体 — DESIGN.md 排版系统 */
  --font-serif: 'Noto Serif SC', Georgia, serif;       /* 标题：衬线体 */
  --font-sans: 'Inter', system-ui, sans-serif;           /* 正文：无衬线体（DESIGN.md 规范） */

  /* 缓动函数 — DESIGN.md 仅允许极慢淡入淡出 */
  --ease-reveal: cubic-bezier(0.16, 1, 0.3, 1);
  --duration-reveal: 0.9s;
  --duration-slow: 1.2s;

  /* 间距 */
  --section-padding: clamp(4rem, 8vw, 8rem);
  --container-max: 1280px;
  --container-padding: clamp(1.5rem, 4vw, 3rem);
}

/* --- 基础重置 --- */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-sans);
  background: var(--brand-surface);
  color: var(--brand-text);
  overflow-x: hidden;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* 文字选中态 — 朱砂红 */
::selection { background: var(--brand-accent); color: white; }

/* Material Icons 基础配置 */
.material-symbols-outlined {
  font-variation-settings: 'FILL' 0, 'wght' 300, 'GRAD' 0, 'opsz' 24;
  vertical-align: middle;
}

/* --- 滚动揭示动效（ScrollReveal） --- */
/* 从下方淡入 */
.reveal {
  opacity: 0; transform: translateY(48px);
  transition: opacity var(--duration-reveal) var(--ease-reveal),
              transform var(--duration-reveal) var(--ease-reveal);
}
.reveal.visible { opacity: 1; transform: translateY(0); }

/* 从左侧淡入 */
.reveal-left {
  opacity: 0; transform: translateX(-48px);
  transition: opacity var(--duration-reveal) var(--ease-reveal),
              transform var(--duration-reveal) var(--ease-reveal);
}
.reveal-left.visible { opacity: 1; transform: translateX(0); }

/* 从右侧淡入 */
.reveal-right {
  opacity: 0; transform: translateX(48px);
  transition: opacity var(--duration-reveal) var(--ease-reveal),
              transform var(--duration-reveal) var(--ease-reveal);
}
.reveal-right.visible { opacity: 1; transform: translateX(0); }

/* 缩放淡入 */
.reveal-scale {
  opacity: 0; transform: scale(0.92);
  transition: opacity var(--duration-reveal) var(--ease-reveal),
              transform var(--duration-reveal) var(--ease-reveal);
}
.reveal-scale.visible { opacity: 1; transform: scale(1); }

/* 交错延迟（列表项依次出现） */
.stagger-1 { transition-delay: 0.08s; }
.stagger-2 { transition-delay: 0.16s; }
.stagger-3 { transition-delay: 0.24s; }
.stagger-4 { transition-delay: 0.32s; }
.stagger-5 { transition-delay: 0.40s; }
.stagger-6 { transition-delay: 0.48s; }
.stagger-7 { transition-delay: 0.56s; }
.stagger-8 { transition-delay: 0.64s; }

/* --- 语言切换淡入动画 --- */
@keyframes textFadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to   { opacity: 1; transform: translateY(0); }
}
.lang-fade { animation: textFadeIn 0.4s ease-out forwards; }

/* --- 路由切换页面淡入 --- */
@keyframes pageFadeIn {
  from { opacity: 0; transform: translateY(24px); }
  to   { opacity: 1; transform: translateY(0); }
}
.page-enter {
  animation: pageFadeIn 0.6s var(--ease-reveal) forwards;
}

/* --- Hero 视差背景 --- */
.hero-bg { transition: transform 0.1s linear; }

/* --- 装饰线条生长动效 --- */
.line-grow {
  width: 0;
  transition: width var(--duration-slow) var(--ease-reveal) 0.3s;
}
.line-grow.visible { width: 100%; }

/* --- 统计数字 --- */
.stat-number { display: inline-block; }

/* --- 卡片悬浮抬升 --- */
.card-lift {
  transition: transform 0.5s var(--ease-reveal),
              box-shadow 0.5s var(--ease-reveal);
}
.card-lift:hover {
  transform: translateY(-8px);
  box-shadow: 0 24px 48px rgba(13, 26, 45, 0.08);
}

/* --- 图片悬浮缩放 --- */
.img-zoom { overflow: hidden; }
.img-zoom img {
  transition: transform 0.7s var(--ease-reveal);
}
.img-zoom:hover img { transform: scale(1.06); }

/* --- 导航栏毛玻璃效果 --- */
.nav-glass {
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  transition: background-color 0.4s ease, box-shadow 0.4s ease;
}
.nav-scrolled {
  background-color: rgba(248, 247, 244, 0.95);
  box-shadow: 0 1px 0 rgba(0, 0, 0, 0.06);
}

/* --- 滚动指示器弹跳 --- */
@keyframes gentleBounce {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(10px); }
}
.scroll-indicator { animation: gentleBounce 2.4s ease-in-out infinite; }

/* --- 语言切换按钮下划线 --- */
.lang-btn {
  position: relative;
  overflow: hidden;
}
.lang-btn::after {
  content: '';
  position: absolute; bottom: 0; left: 0;
  width: 100%; height: 2px;
  background: var(--brand-accent);
  transform: scaleX(0);
  transition: transform 0.3s ease;
  transform-origin: right;
}
.lang-btn.active::after {
  transform: scaleX(1);
  transform-origin: left;
}

/* --- 渐变分隔线（遵循 DESIGN.md 无实线规则） --- */
.section-divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--brand-border) 20%, var(--brand-border) 80%, transparent);
}

/* --- 图片占位 Fallback --- */
.img-fallback {
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--surface-high);
  color: var(--brand-muted);
}

/* --- 页面顶部 Banner --- */
.page-banner {
  position: relative;
  min-height: 320px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-size: cover;
  background-position: center;
  overflow: hidden;
}
.page-banner::before {
  content: '';
  position: absolute; inset: 0;
  background: linear-gradient(135deg, rgba(13, 26, 45, 0.88), rgba(13, 26, 45, 0.62));
}
.page-banner > * { position: relative; z-index: 1; }

/* --- 文章详情页排版 --- */
.article-content {
  line-height: 2;
  font-size: 1.0625rem;
}
.article-content p {
  margin-bottom: 1.5rem;
}
.article-content img {
  max-width: 100%;
  height: auto;
  border-radius: 2px;
  margin: 2rem 0;
}

/* --- 导航下拉菜单 --- */
.nav-dropdown {
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s;
}
.nav-item:hover .nav-dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

/* --- 表单输入框（DESIGN.md 底部边框风格） --- */
.form-input {
  border: none;
  border-bottom: 1px solid var(--brand-border);
  background: transparent;
  padding: 0.75rem 0;
  font-size: 1rem;
  font-family: var(--font-sans);
  color: var(--brand-text);
  transition: border-color 0.3s ease;
  outline: none;
  width: 100%;
}
.form-input:focus {
  border-bottom-color: var(--brand);
}
.form-input::placeholder {
  color: var(--brand-muted);
}

/* --- 水纹装饰纹理（道家水墨意象，极淡波纹叠加于深色区域） --- */
.water-texture::after {
  content: '';
  position: absolute;
  inset: 0;
  opacity: 0.03;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='400' height='200'%3E%3Cpath d='M0 100 Q50 80 100 100 T200 100 T300 100 T400 100' fill='none' stroke='%23fff' stroke-width='0.8'/%3E%3Cpath d='M0 130 Q50 110 100 130 T200 130 T300 130 T400 130' fill='none' stroke='%23fff' stroke-width='0.5'/%3E%3Cpath d='M0 160 Q50 140 100 160 T200 160 T300 160 T400 160' fill='none' stroke='%23fff' stroke-width='0.3'/%3E%3C/svg%3E");
  background-size: 400px 200px;
  pointer-events: none;
}

/* --- 响应式调整 --- */
@media (max-width: 768px) {
  .page-banner { min-height: 240px; }
  :root {
    --section-padding: clamp(3rem, 6vw, 5rem);
    --container-padding: clamp(1rem, 3vw, 1.5rem);
  }
}

@media (max-width: 480px) {
  .page-banner { min-height: 200px; }
}

/* =============================================
 * RTL（阿拉伯语）方向支持
 * 当 <html dir="rtl"> 时自动镜像布局
 * ============================================= */

/* RTL 模式下的字体调整 — 阿拉伯文使用 Noto Naskh Arabic */
[dir="rtl"] {
  --font-serif: 'Noto Naskh Arabic', 'Noto Serif SC', Georgia, serif;
  --font-sans: 'Noto Sans Arabic', 'Inter', system-ui, sans-serif;
  direction: rtl;
  text-align: right;
}

/* RTL 模式下翻转 flex 方向和间距 */
[dir="rtl"] .flex-row-reverse { flex-direction: row; }

/* RTL 模式下翻转 margin/padding 相关的特殊处理 */
[dir="rtl"] .ml-auto { margin-left: unset; margin-right: auto; }
[dir="rtl"] .mr-auto { margin-right: unset; margin-left: auto; }

/* RTL 模式下翻转箭头图标方向 */
[dir="rtl"] .material-symbols-outlined[style*="rotate"] {
  transform: scaleX(-1);
}

/* RTL 模式下翻转滚动揭示动画方向 */
[dir="rtl"] .reveal-left { transform: translateX(40px); }
[dir="rtl"] .reveal-right { transform: translateX(-40px); }
[dir="rtl"] .reveal-left.visible { transform: translateX(0); }
[dir="rtl"] .reveal-right.visible { transform: translateX(0); }