:root {
    --primary: #0ea5e9;
    --primary-dark: #0284c7;
    --primary-light: #7dd3fc;
    --primary-solid: #0ea5e9;
    --accent: #2563eb;
    --secondary: #06b6d4;
    --dark: #1e293b;
    --gray: #64748b;
    --light-gray: #f1f5f9;
    --white: #ffffff;
    --blue-light: #e0f2fe;
    --shadow-sm: 0 2px 8px rgba(14, 165, 233, 0.1);
    --shadow-md: 0 4px 20px rgba(14, 165, 233, 0.15);
    --shadow-lg: 0 10px 40px rgba(14, 165, 233, 0.2);
    --blue-glow: 0 0 20px rgba(14, 165, 233, 0.2);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Noto Sans TC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    line-height: 1.7;
    color: var(--dark);
    background: var(--white);
    overflow-x: hidden;
}

/* 統一 Scrollbar 樣式 */
::-webkit-scrollbar {
    width: 12px;
    height: 12px;
}

::-webkit-scrollbar-track {
    background: #f1f5f9;
}

::-webkit-scrollbar-thumb {
    background: linear-gradient(135deg, #0ea5e9 0%, #3b82f6 100%);
    border-radius: 6px;
}

::-webkit-scrollbar-thumb:hover {
    background: linear-gradient(135deg, #0284c7 0%, #2563eb 100%);
}

/* Firefox */
* {
    scrollbar-width: thin;
    scrollbar-color: #0ea5e9 #f1f5f9;
}

/* Back to Top 按鈕 */
#backToTop {
    position: fixed;
    bottom: 30px;
    right: 30px;
    background-color: #002060;
    color: white;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    border: 2px solid white;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.3);
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    z-index: 999;
    transition: all 0.3s ease;
}

#backToTop.show {
    display: flex;
}

#backToTop:hover {
    background-color: white;
    color: #002060;
    border-color: #002060;
    transform: translateY(-5px);
}

@media (max-width: 768px) {
    #backToTop {
        width: 45px;
        height: 45px;
        bottom: 25px;
        right: 25px;
        font-size: 20px;
    }
}