/* 理论力学 - 个性化学习平台 公共样式 */

* {
    font-family: 'Inter', sans-serif;
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    background: #0a0f1c;
    color: white;
    min-height: 100vh;
}

/* 渐变文字 */
.gradient-text {
    background: linear-gradient(135deg, #00d4ff, #0099cc);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* 卡片悬停效果 */
.card-hover {
    transition: all 0.3s ease;
}

.card-hover:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 40px rgba(0, 212, 255, 0.2);
    border-color: #00d4ff;
}

/* 粒子动画 */
.particle {
    position: absolute;
    width: 4px;
    height: 4px;
    background: rgba(0, 212, 255, 0.5);
    border-radius: 50%;
    animation: float 20s infinite;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0) translateX(0);
        opacity: 0;
    }
    10% {
        opacity: 1;
    }
    90% {
        opacity: 1;
    }
    100% {
        transform: translateY(-100vh) translateX(100px);
        opacity: 0;
    }
}

/* 滚动条样式 */
.scrollbar::-webkit-scrollbar {
    width: 8px;
}

.scrollbar::-webkit-scrollbar-track {
    background: rgba(30, 58, 95, 0.3);
}

.scrollbar::-webkit-scrollbar-thumb {
    background: rgba(0, 212, 255, 0.3);
    border-radius: 4px;
}

.scrollbar::-webkit-scrollbar-thumb:hover {
    background: rgba(0, 212, 255, 0.5);
}

/* 图片样式 */
.section-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: 12px;
    margin-bottom: 1rem;
}

.content-image {
    width: 100%;
    height: 300px;
    object-fit: cover;
    border-radius: 16px;
    margin: 1.5rem 0;
}

.hero-image {
    width: 100%;
    height: 400px;
    object-fit: cover;
    border-radius: 20px;
    margin: 2rem 0;
}

/* 按钮样式 */
.btn-primary {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    background: linear-gradient(135deg, #00d4ff, #0099cc);
    color: #0a0f1c;
    font-weight: 600;
    border-radius: 0.5rem;
    text-decoration: none;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 212, 255, 0.3);
}

.btn-secondary {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    background: rgba(0, 212, 255, 0.1);
    color: #00d4ff;
    font-weight: 600;
    border-radius: 0.5rem;
    text-decoration: none;
    transition: all 0.3s ease;
    border: 1px solid rgba(0, 212, 255, 0.3);
    cursor: pointer;
}

.btn-secondary:hover {
    background: rgba(0, 212, 255, 0.2);
    border-color: #00d4ff;
}

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 50;
    background: rgba(10, 15, 28, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0, 212, 255, 0.1);
    padding: 1rem 2rem;
}

.navbar-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.navbar-brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: white;
    text-decoration: none;
}

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

.navbar-nav a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: color 0.3s ease;
}

.navbar-nav a:hover {
    color: #00d4ff;
}

/* 页面内容区域 */
.page-content {
    padding-top: 80px;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* 课程卡片 */
.course-card {
    background: rgba(30, 58, 95, 0.3);
    border: 1px solid rgba(0, 212, 255, 0.2);
    border-radius: 16px;
    padding: 1.5rem;
    transition: all 0.3s ease;
}

.course-card:hover {
    border-color: #00d4ff;
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(0, 212, 255, 0.15);
}

.course-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: white;
}

.course-card p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

/* 章节样式 */
.section {
    margin-bottom: 3rem;
}

.section-title {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: white;
}

.section-content {
    background: rgba(30, 58, 95, 0.2);
    border-radius: 16px;
    padding: 2rem;
    border: 1px solid rgba(0, 212, 255, 0.1);
}

/* 案例研究框 */
.case-study {
    background: rgba(0, 212, 255, 0.1);
    border-left: 4px solid #00d4ff;
    border-radius: 0 12px 12px 0;
    padding: 1.5rem;
    margin-top: 1.5rem;
}

.case-study h4 {
    color: #00d4ff;
    font-size: 1.1rem;
    margin-bottom: 0.75rem;
}

.case-study ul {
    list-style: none;
    padding-left: 0;
}

.case-study li {
    padding: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
    color: rgba(255, 255, 255, 0.8);
}

.case-study li::before {
    content: "▸";
    position: absolute;
    left: 0;
    color: #00d4ff;
}

/* 页脚 */
.footer {
    background: rgba(0, 0, 0, 0.3);
    border-top: 1px solid rgba(0, 212, 255, 0.1);
    padding: 2rem;
    text-align: center;
    color: rgba(255, 255, 255, 0.5);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .navbar-nav {
        display: none;
    }
    
    .page-content {
        padding-top: 60px;
    }
    
    .hero-image {
        height: 250px;
    }
    
    .section-content {
        padding: 1.5rem;
    }
}