/* 全局样式 */
:root {
    --primary: #3b82f6;
    --secondary: #dbeafe;
    --accent: #60a5fa;
    --light: #f0f9ff;
    --dark: #1e40af;
    --text-dark: #1e293b;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
}

body {
    background: linear-gradient(135deg, #e0f2fe 0%, #dbeafe 100%);
    color: var(--text-dark);
    min-height: 100vh;
    overflow-x: hidden;
    display: flex;
    flex-direction: column;
}

/* 头部导航 */
header {
    padding: 1.5rem 5%;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.8rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    color: var(--text-dark);
}

.language-switcher {
    position: relative;
}

.lang-select {
    background: rgba(219, 234, 254, 0.7);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(96, 165, 250, 0.5);
    border-radius: 8px;
    padding: 8px 16px;
    color: var(--text-dark);
    cursor: pointer;
    appearance: none;
    width: 140px;
    padding-right: 40px;
    font-size: 1rem;
}

.lang-select:focus {
    outline: none;
    border-color: var(--accent);
}

.lang-select-wrapper {
    position: relative;
}

.lang-select-wrapper::after {
    content: "▼";
    position: absolute;
    top: 50%;
    right: 15px;
    transform: translateY(-50%);
    color: var(--accent);
    pointer-events: none;
    font-size: 0.8rem;
}

/* 核心内容区 */
.main-container {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 5%;
    text-align: center;
}

h1 {
    font-size: 3.5rem;
    line-height: 1.2;
    margin-bottom: 1.5rem;
    background: linear-gradient(to right, #1e40af, #3b82f6);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.subtitle {
    font-size: 1.5rem;
    max-width: 800px;
    margin: 0 auto 3rem;
    color: #475569;
}

/* 功能卡片 */
.features {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 2rem;
    margin: 4rem 0;
}

.card {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(96, 165, 250, 0.3);
    border-radius: 16px;
    padding: 2.5rem;
    width: 320px;
    transition: transform 0.3s, box-shadow 0.3s;
    opacity: 0;
    transform: translateY(20px);
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

.card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 25px -5px rgba(59, 130, 246, 0.2);
}

.card h3 {
    font-size: 1.8rem;
    margin: 1.5rem 0;
    color: var(--text-dark);
}

.card p {
    color: #475569;
    line-height: 1.7;
}

.icon {
    font-size: 3.5rem;
    color: var(--accent);
}

/* 按钮样式 */
.cta-buttons {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin: 2rem 0;
    flex-wrap: wrap;
}

.btn {
    padding: 1.1rem 2.5rem;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1.1rem;
    text-decoration: none;
    transition: all 0.3s;
    display: inline-flex;
    align-items: center;
    gap: 10px;
}

.btn-primary {
    background: var(--primary);
    color: white;
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.4);
}

.btn-secondary {
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
}

.btn:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 20px rgba(59, 130, 246, 0.5);
}

/* 底部信息区域 */
.bottom-section {
    max-width: 1400px;
    margin: 3rem auto;
    padding: 0 5%;
}

/* 联系信息容器 */
.contact-container {
    display: flex;
    justify-content: center;
    background: rgba(255, 255, 255, 0.6);
    padding: 1.5rem;
    border-radius: 16px;
    border: 1px solid rgba(96, 165, 250, 0.3);
}

/* 承诺盒子容器 */
.promise-container {
    display: flex;
    justify-content: center;
    gap: 2rem;
    width: 100%;
    max-width: 1200px;
}

.promise-box {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.8);
    padding: 1.5rem;
    border-radius: 12px;
    transition: transform 0.3s, box-shadow 0.3s;
    border: 1px solid rgba(96, 165, 250, 0.3);
    width: 100%;
    max-width: 280px;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

.promise-box:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(59, 130, 246, 0.15);
}

.promise-box svg {
    margin-bottom: 12px;
    flex-shrink: 0;
}

.promise-box span {
    font-size: 1.0rem;
    font-weight: 500;
    text-align: center;
    white-space: nowrap;
    color: var(--text-dark);
}

/* 页脚 */
footer {
    text-align: center;
    padding: 2rem;
    border-top: 1px solid rgba(59, 130, 246, 0.2);
    color: #64748b;
    font-size: 0.9rem;
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

/* 响应式设计调整 */
@media (max-width: 1024px) {
    .contact-container {
        padding: 1.5rem;
    }
    
    .promise-container {
        gap: 1.5rem;
    }
}

@media (max-width: 768px) {
    h1 {
        font-size: 2.5rem;
    }
    .subtitle {
        font-size: 1.2rem;
    }
    .card {
        width: 100%;
        max-width: 400px;
    }
    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .promise-container {
        flex-direction: column;
        align-items: center;
        gap: 1rem;
    }
    
    .promise-box {
        max-width: 100%;
        width: 100%;
        flex-direction: row;
        justify-content: flex-start;
        padding: 1rem;
    }
    
    .promise-box svg {
        margin-right: 12px;
        margin-bottom: 0;
    }
}

@media (max-width: 480px) {
    .promise-box span {
        font-size: 0.9rem;
    }
}