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

:root {
    /* Color Palette - Modern minimalist theme */
    --primary-color: #3dd9b8;
    --primary-dark: #2bb89a;
    --secondary-color: #1a2332;
    --text-primary: #1a2332;
    --text-secondary: #6b7280;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #e2e8f0;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.12);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.de_iv_adv {
    width: 100%;
    height: auto;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 5px 0;
    background-color: #F8F8F8;
    margin: 10px 0 0px;
}


/* 底部广告位 */

.postionFixed {
    width: 100%;
    min-height: 60px;
    position: fixed;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: #F8F8F8;
    right: 0;
    left: 0;
    bottom: 0;
    z-index: 9999;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

button {
    font-family: inherit;
    border: none;
    cursor: pointer;
    transition: var(--transition);
}

/* ===================================
   Header Styles
   =================================== */
.header {
    position: sticky;
    top: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    box-shadow: var(--shadow-sm);
}

.header-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 2rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

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

.nav {
    display: flex;
    align-items: center;
    gap: 2.5rem;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    font-weight: 500;
    font-size: 0.95rem;
    color: var(--text-secondary);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width 0.3s ease;
}

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

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.search-box {
    position: relative;
    flex: 0 0 300px;
}

.search-input {
    width: 100%;
    padding: 0.75rem 1rem 0.75rem 2.8rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 0.95rem;
    background: var(--bg-secondary);
    transition: var(--transition);
}

.search-input:focus {
    outline: none;
    border-color: var(--primary-color);
    background: var(--bg-primary);
    box-shadow: 0 0 0 3px rgba(61, 217, 184, 0.1);
}

.search-icon {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
    pointer-events: none;
}

.mobile-menu-btn {
    display: none;
    background: transparent;
    font-size: 1.5rem;
    color: var(--text-primary);
}

/* ===================================
   Footer Styles
   =================================== */
.footer {
    background: var(--secondary-color);
    color: #fff;
    margin-top: 6rem;
    padding: 3rem 0 1.5rem;
}

.footer-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 3rem;
    margin-bottom: 2.5rem;
    padding-bottom: 2.5rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-brand {
    max-width: 350px;
}

.footer-logo {
    height: 50px;
    width: auto;
    margin-bottom: 1rem;
}

.footer-description {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.95rem;
    line-height: 1.7;
}

.footer-section h3 {
    font-size: 1.1rem;
    margin-bottom: 1.2rem;
    color: var(--primary-color);
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 0.7rem;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.95rem;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--primary-color);
    padding-left: 5px;
}

.footer-bottom {
    text-align: center;
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.9rem;
}

/* ===================================
   Back to Top Button
   =================================== */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 999;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-3px);
}

/* ===================================
   Utility Classes
   =================================== */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
}

.section {
    padding: 4rem 0;
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 2rem;
    color: var(--text-primary);
}

.btn {
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 0.95rem;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

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

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

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--bg-tertiary);
}

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 1024px) {
    .header-container {
        padding: 1rem 1.5rem;
    }

    .nav-links {
        gap: 1.5rem;
    }

    .search-box {
        flex: 0 0 250px;
    }

    .footer-content {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    .header-container {
        padding: 1rem;
    }

    .nav-link::after {
        bottom: 0;
    }

    .nav {
        position: fixed;
        top: 67px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        align-items: stretch;
        gap: 0;
        padding: 1rem;
        border-top: 1px solid var(--border-color);
        box-shadow: var(--shadow-lg);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
        height: 100vh;
    }

    .nav.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav-links {
        flex-direction: column;
        width: 100%;
        gap: 0;
    }

    .search-icon {
        top: 40%;
        transform: translateY(0);
    }

    .nav-link {
        display: block;
        padding: 1rem;
        border-bottom: 1px solid var(--border-color);
    }

    .search-box {
        display: flex;
        height: fit-content;
        width: 100%;
        padding-top: 1rem;
        flex: 0 0 auto;
    }

    .mobile-menu-btn {
        display: block;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .back-to-top {
        bottom: 1.5rem;
        right: 1.5rem;
        width: 45px;
        height: 45px;
    }

    .container {
        padding: 0 1rem;
    }

    .section {
        padding: 3rem 0;
    }

    .section-title {
        font-size: 1.75rem;
    }
}

@media (max-width: 480px) {
    .logo {
        font-size: 1.25rem;
    }

    .logo img {
        height: 35px;
    }

    .section-title {
        font-size: 1.5rem;
    }

    .back-to-top {
        width: 40px;
        height: 40px;
        font-size: 1.25rem;
    }
}