/* === 智能導航 CSS - 最佳化版本 === */

:root {
  /* 顏色系統 */
  --nav-color-primary: #8B4513;
  --nav-color-secondary: #D2691E;
  --nav-color-accent: #F9A825;
  --nav-color-back: #C23B22;
  --nav-color-section: #5D4037;
  --nav-color-home: #2C2416;
  --nav-color-top: #8B4513;
  
  /* 背景和陰影 */
  --nav-bg-light: rgba(255, 255, 255, 0.92);
  --nav-bg-dark: rgba(40, 40, 40, 0.92);
  --nav-shadow: 0 4px 20px rgba(139, 69, 19, 0.15);
  --nav-border: rgba(139, 69, 19, 0.2);
  
  /* 尺寸 */
  --nav-desktop-btn: 58px;
  --nav-desktop-icon: 28px;
  --nav-mobile-core: 68px;
  --nav-mobile-item: 48px;
  --nav-mobile-offset: 75px;
  
  /* 動畫 */
  --nav-transition: 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

@media (prefers-reduced-motion: reduce) {
  :root {
    --nav-transition: 0.1s ease;
  }
}

/* 智能導航容器 - 性能優化 */
.smart-nav-system {
  position: fixed;
  z-index: 99999;
  pointer-events: none;
  contain: layout style paint;
  will-change: transform;
}

.smart-nav-system * {
  pointer-events: auto;
}

/* 性能優化：GPU加速動畫 */
@supports (backdrop-filter: blur(1px)) {
  .smart-nav-desktop-btn,
  .smart-nav-core,
  .smart-nav-item {
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
  }
}

/* === 桌面模式 === */
@media (min-width: 1025px) {
  .smart-nav-desktop {
    position: fixed;
    z-index: 99999;
    isolation: isolate;
  }
  
  .smart-nav-desktop-btn {
    position: absolute;
    width: var(--nav-desktop-btn);
    height: var(--nav-desktop-btn);
    border-radius: 50%;
    background: var(--nav-bg-light);
    border: 1.5px solid var(--nav-border);
    box-shadow: var(--nav-shadow),
                inset 0 1px 0 rgba(255, 255, 255, 0.9);
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    transition: all var(--nav-transition);
    animation: nav-float 4s ease-in-out infinite;
    cursor: pointer;
    padding: 0;
    will-change: transform, box-shadow;
    transform: translateZ(0);
  }
  
  @media (prefers-color-scheme: dark) {
    .smart-nav-desktop-btn {
      background: var(--nav-bg-dark);
      border-color: rgba(249, 168, 37, 0.3);
    }
  }
  
  /* 懸停效果 - 性能優化 */
  .smart-nav-desktop-btn:hover {
    transform: scale(1.12) translateZ(0);
    box-shadow: 0 6px 25px rgba(139, 69, 19, 0.25),
                0 0 0 2px rgba(249, 168, 37, 0.15);
  }
  
  /* 禁用動畫的用戶 */
  @media (prefers-reduced-motion: reduce) {
    .smart-nav-desktop-btn {
      animation: none;
    }
    
    .smart-nav-desktop-btn:hover {
      transform: scale(1.05);
    }
  }
  
  .smart-nav-desktop-btn:active {
    transform: scale(0.95) translateZ(0);
  }
  
  /* 按鈕位置 */
  .smart-nav-back { 
    top: clamp(80px, 10vh, 120px); 
    left: 25px; 
    animation-delay: 0s; 
    border-color: rgba(194, 59, 34, 0.3);
  }
  
  .smart-nav-section { 
    top: calc(clamp(80px, 10vh, 120px) + 68px); 
    left: 25px; 
    animation-delay: 0.2s; 
    border-color: rgba(92, 64, 55, 0.3);
  }
  
  .smart-nav-home { 
    bottom: clamp(70px, 8vh, 90px); 
    left: 25px; 
    animation-delay: 0.4s; 
    border-color: rgba(44, 36, 22, 0.3);
  }
  
  .smart-nav-top { 
    bottom: clamp(70px, 8vh, 90px); 
    right: 25px; 
    animation-delay: 0.6s; 
    border-color: rgba(139, 69, 19, 0.3);
  }
  
  /* 按鈕圖標 */
  .smart-nav-icon {
    width: var(--nav-desktop-icon);
    height: var(--nav-desktop-icon);
    stroke-width: 2.3;
    stroke-linecap: round;
    stroke-linejoin: round;
    fill: none;
    transition: all 0.3s ease;
    will-change: stroke-width;
  }
  
  .smart-nav-desktop-btn:hover .smart-nav-icon {
    stroke-width: 2.6;
  }
  
  /* 按鈕顏色 */
  .smart-nav-back .smart-nav-icon { stroke: var(--nav-color-back); }
  .smart-nav-section .smart-nav-icon { stroke: var(--nav-color-section); }
  .smart-nav-home .smart-nav-icon { stroke: var(--nav-color-home); }
  .smart-nav-top .smart-nav-icon { stroke: var(--nav-color-top); }
  
  /* 按鈕標籤 */
  .smart-nav-label {
    position: absolute;
    left: calc(var(--nav-desktop-btn) + 7px);
    background: rgba(0, 0, 0, 0.85);
    color: white;
    padding: 6px 12px;
    border-radius: 6px;
    font-size: 0.8rem;
    white-space: nowrap;
    opacity: 0;
    transition: all 0.3s ease;
    pointer-events: none;
    font-family: 'Noto Serif TC', serif;
    font-weight: 500;
    z-index: 100000;
    transform: translateX(-5px);
    will-change: opacity, transform;
  }
  
  .smart-nav-desktop-btn:hover .smart-nav-label {
    opacity: 1;
    transform: translateX(0);
  }
  
  /* 減少動畫版本 */
  @media (prefers-reduced-motion: reduce) {
    .smart-nav-label {
      transition: opacity 0.1s ease;
    }
  }
}

/* === 移動模式 === */
@media (max-width: 1024px) {
  .smart-nav-mobile {
    position: fixed;
    bottom: max(20px, env(safe-area-inset-bottom));
    right: max(20px, env(safe-area-inset-right));
    width: var(--nav-mobile-core);
    height: var(--nav-mobile-core);
    z-index: 99999;
    isolation: isolate;
  }
  
  /* 核心按鈕 */
  .smart-nav-core {
    position: absolute;
    width: 100%;
    height: 100%;
    border-radius: 50%;
    background: var(--nav-bg-light);
    border: 2px solid var(--nav-border);
    box-shadow: var(--nav-shadow);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s ease;
    will-change: transform, box-shadow;
    transform: translateZ(0);
  }
  
  @media (prefers-color-scheme: dark) {
    .smart-nav-core {
      background: var(--nav-bg-dark);
    }
  }
  
  .smart-nav-core:hover,
  .smart-nav-core.expanded {
    border-color: var(--nav-color-accent);
    box-shadow: 0 0 0 1px rgba(249, 168, 37, 0.3),
                0 8px 32px rgba(249, 168, 37, 0.2);
  }
  
  /* 核心圖標 */
  .smart-nav-core-icon {
    width: 22px;
    height: 22px;
    stroke: var(--nav-color-primary);
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
    fill: none;
    transition: all 0.3s ease;
    will-change: transform;
  }
  
  .smart-nav-core.expanded .smart-nav-core-icon {
    transform: rotate(45deg);
    stroke: var(--nav-color-accent);
  }
  
  /* 子按鈕 */
  .smart-nav-item {
    position: absolute;
    width: var(--nav-mobile-item);
    height: var(--nav-mobile-item);
    border-radius: 50%;
    background: var(--nav-bg-light);
    border: 1.5px solid var(--nav-border);
    box-shadow: var(--nav-shadow);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    transform: scale(0) translateZ(0);
    transition: all var(--nav-transition);
    will-change: transform, opacity;
  }
  
  @media (prefers-color-scheme: dark) {
    .smart-nav-item {
      background: var(--nav-bg-dark);
    }
  }
  
  .smart-nav-item:hover {
    border-color: var(--nav-color-accent);
    box-shadow: 0 0 0 2px rgba(249, 168, 37, 0.2);
  }
  
  /* 按鈕邊框顏色 */
  .smart-nav-back { border-color: rgba(194, 59, 34, 0.4); }
  .smart-nav-section { border-color: rgba(92, 64, 55, 0.4); }
  .smart-nav-home { border-color: rgba(44, 36, 22, 0.4); }
  .smart-nav-top { border-color: rgba(139, 69, 19, 0.4); }
  
  /* 展開狀態 - 使用 CSS 變數動態控制 */
  .smart-nav-mobile.expanded .smart-nav-item {
    opacity: 1;
    transform: scale(1) translateZ(0);
  }
  
  /* 佈局系統 */
  .smart-nav-mobile[class*="layout-"].expanded .smart-nav-back { 
    transform: scale(1) translate(calc(-1 * var(--nav-mobile-offset)), 0) !important; 
  }
  .smart-nav-mobile[class*="layout-"].expanded .smart-nav-section { 
    transform: scale(1) translate(0, calc(-1 * var(--nav-mobile-offset))) !important; 
  }
  .smart-nav-mobile[class*="layout-"].expanded .smart-nav-home { 
    transform: scale(1) translate(var(--nav-mobile-offset), 0) !important; 
  }
  .smart-nav-mobile[class*="layout-"].expanded .smart-nav-top { 
    transform: scale(1) translate(0, var(--nav-mobile-offset)) !important; 
  }
  
  /* 特定佈局覆蓋 */
  .smart-nav-mobile.layout-single.expanded .smart-nav-top { 
    transform: scale(1) translate(0, calc(-1 * var(--nav-mobile-offset))) !important; 
  }
  
  .smart-nav-mobile.layout-two-back-top.expanded .smart-nav-back { 
    transform: scale(1) translate(calc(-1 * var(--nav-mobile-offset)), calc(-0.3 * var(--nav-mobile-offset))) !important; 
  }
  .smart-nav-mobile.layout-two-back-top.expanded .smart-nav-top { 
    transform: scale(1) translate(calc(-0.3 * var(--nav-mobile-offset)), calc(-1 * var(--nav-mobile-offset))) !important; 
  }
  
  .smart-nav-mobile.layout-three-back-section-top.expanded .smart-nav-back { 
    transform: scale(1) translate(calc(-1 * var(--nav-mobile-offset)), 0) !important; 
  }
  .smart-nav-mobile.layout-three-back-section-top.expanded .smart-nav-section { 
    transform: scale(1) translate(0, calc(-1 * var(--nav-mobile-offset))) !important; 
  }
  .smart-nav-mobile.layout-three-back-section-top.expanded .smart-nav-top { 
    transform: scale(1) translate(var(--nav-mobile-offset), 0) !important; 
  }
  
  /* 子按鈕圖標 */
  .smart-nav-item-icon {
    width: 20px;
    height: 20px;
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
    fill: none;
    will-change: stroke;
  }
  
  /* 按鈕圖標顏色 */
  .smart-nav-back .smart-nav-item-icon { stroke: var(--nav-color-back); }
  .smart-nav-section .smart-nav-item-icon { stroke: var(--nav-color-section); }
  .smart-nav-home .smart-nav-item-icon { stroke: var(--nav-color-home); }
  .smart-nav-top .smart-nav-item-icon { stroke: var(--nav-color-top); }
  
  /* 子按鈕標籤 */
  .smart-nav-item-label {
    position: absolute;
    bottom: -28px;
    background: rgba(0, 0, 0, 0.85);
    color: white;
    padding: 4px 10px;
    border-radius: 5px;
    font-size: 0.7rem;
    white-space: nowrap;
    opacity: 0;
    transition: opacity 0.3s ease;
    pointer-events: none;
    font-family: 'Noto Serif TC', serif;
    font-weight: 500;
    will-change: opacity;
  }
  
  .smart-nav-item:hover .smart-nav-item-label {
    opacity: 1;
  }
  
  /* 觸摸設備優化 */
  @media (hover: none) {
    .smart-nav-core:hover,
    .smart-nav-item:hover {
      border-color: var(--nav-border);
      box-shadow: var(--nav-shadow);
    }
    
    .smart-nav-core:active,
    .smart-nav-item:active {
      border-color: var(--nav-color-accent);
      box-shadow: 0 0 0 2px rgba(249, 168, 37, 0.2);
    }
    
    .smart-nav-item:hover .smart-nav-item-label {
      opacity: 0;
    }
  }
}

/* === 動畫定義 === */
@keyframes nav-float {
  0%, 100% { 
    transform: translateY(0) translateZ(0); 
  }
  50% { 
    transform: translateY(-6px) translateZ(0); 
  }
}

@keyframes nav-ripple {
  0% { 
    transform: scale(0) translateZ(0); 
    opacity: 0.6; 
  }
  100% { 
    transform: scale(2) translateZ(0); 
    opacity: 0; 
  }
}

/* 減少動畫支持 */
@media (prefers-reduced-motion: reduce) {
  @keyframes nav-float {
    0%, 100% { transform: translateY(0) translateZ(0); }
  }
  
  @keyframes nav-ripple {
    0% { opacity: 0; }
    100% { opacity: 0; }
  }
}

/* === 響應式調整 === */
@media (max-width: 768px) {
  :root {
    --nav-shadow: 0 4px 15px rgba(139, 69, 19, 0.12);
    --nav-desktop-btn: 52px;
    --nav-mobile-core: 62px;
    --nav-mobile-item: 44px;
    --nav-mobile-offset: 65px;
  }
  
  .smart-nav-mobile {
    bottom: max(15px, env(safe-area-inset-bottom));
    right: max(15px, env(safe-area-inset-right));
  }
  
  .smart-nav-desktop-btn {
    animation-duration: 6s;
  }
}

@media (max-width: 480px) {
  :root {
    --nav-desktop-btn: 48px;
    --nav-desktop-icon: 24px;
    --nav-mobile-core: 58px;
    --nav-mobile-item: 40px;
    --nav-mobile-offset: 55px;
  }
  
  .smart-nav-mobile {
    bottom: max(10px, env(safe-area-inset-bottom));
    right: max(10px, env(safe-area-inset-right));
  }
  
  .smart-nav-item-icon {
    width: 18px;
    height: 18px;
  }
  
  .smart-nav-label {
    font-size: 0.7rem;
    padding: 4px 8px;
  }
  
  .smart-nav-item-label {
    font-size: 0.65rem;
    bottom: -24px;
  }
}

/* 超大螢幕優化 */
@media (min-width: 1600px) {
  :root {
    --nav-desktop-btn: 64px;
    --nav-desktop-icon: 32px;
  }
  
  .smart-nav-back { left: max(25px, env(safe-area-inset-left)); }
  .smart-nav-section { left: max(25px, env(safe-area-inset-left)); }
  .smart-nav-home { left: max(25px, env(safe-area-inset-left)); }
  .smart-nav-top { right: max(25px, env(safe-area-inset-right)); }
}

/* 隱藏邏輯 */
@media (max-width: 1024px) {
  .smart-nav-desktop {
    display: none !important;
  }
}

@media (min-width: 1025px) {
  .smart-nav-mobile {
    display: none !important;
  }
}

/* 打印樣式 */
@media print {
  .smart-nav-system {
    display: none !important;
  }
}