/* 基础样式 - Base Styles */
:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --text-color: #333;
    --light-color: #f8f9fa;
    --dark-color: #343a40;
    --gray-color: #6c757d;
    --border-color: #dee2e6;
    --footer-color: #1a252f;
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Helvetica Neue', Arial, sans-serif;
    color: var(--text-color);
    line-height: 1.6;
    overflow-x: hidden;
}

ul {
    list-style: none;
}

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

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

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 8px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    font-weight: 600;
    border: none;
    font-size: 16px;
    position: relative;
    overflow: hidden;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.primary-btn {
    background: linear-gradient(45deg, #3498db, #2980b9);
    color: white;
    border: none;
}

.primary-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(45deg, #2980b9, #1f6391);
    opacity: 0;
    transition: opacity 0.3s ease;
    z-index: -1;
}

.primary-btn:hover {
    transform: translateY(-3px) scale(1.05);
    box-shadow: 0 8px 25px rgba(52, 152, 219, 0.4);
}

.primary-btn:hover::before {
    opacity: 1;
}

.secondary-btn {
    background: transparent;
    border: 2px solid var(--secondary-color);
    color: var(--secondary-color);
    position: relative;
    z-index: 1;
}

.secondary-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 0;
    height: 100%;
    background: var(--secondary-color);
    transition: width 0.3s ease;
    z-index: -1;
}

.secondary-btn:hover {
    color: white;
    transform: translateY(-3px) scale(1.05);
    box-shadow: 0 8px 25px rgba(52, 152, 219, 0.3);
}

.secondary-btn:hover::before {
    width: 100%;
}

.small-btn {
    padding: 10px 20px;
    font-size: 14px;
}

.download-btn {
    background: linear-gradient(45deg, var(--primary-color), #1a252f);
    color: white;
    width: 100%;
    position: relative;
    overflow: hidden;
}

.download-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(45deg, #1a252f, #0f1419);
    opacity: 0;
    transition: opacity 0.3s ease;
    z-index: -1;
}

.download-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(44, 62, 80, 0.4);
}

.download-btn:hover::before {
    opacity: 1;
}

/* 通用区域标题 */
.section-title {
    text-align: center;
    margin-bottom: 50px;
    font-size: 2.5rem;
    color: var(--primary-color);
    position: relative;
}

.section-title:after {
    content: '';
    display: block;
    width: 80px;
    height: 4px;
    background-color: var(--secondary-color);
    margin: 15px auto 0;
}

/* 兼容性样式 */
.noselect {
    user-select: none;
    -webkit-user-select: none;
}

.max-content-width {
    width: max-content;
}