/* 全局样式 */
:root {
    --primary: #4a6ee0;
    --primary-dark: #3a56b0;
    --secondary: #ff7043;
    --light: #f5f7fa;
    --dark: #263238;
    --gray: #78909c;
    --success: #43a047;
    --python: #3776ab;
    --java: #e76f00;
    --go: #00add8;
    --mysql: #00758f;
    --html: #e44d26;
    --csharp: #9b4f96;
    --vue: #42b883;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Noto Sans SC', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: #f9f9f9;
    color: #333;
    line-height: 1.6;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

section {
    padding: 60px 0;
}

.section-title {
    text-align: center;
    margin-bottom: 50px;
    position: relative;
}

    .section-title h2 {
        font-size: 2.2rem;
        color: var(--dark);
        margin-bottom: 15px;
    }

    .section-title p {
        color: var(--gray);
        max-width: 700px;
        margin: 0 auto;
        font-size: 1.1rem;
    }

    .section-title::after {
        content: '';
        position: absolute;
        bottom: -15px;
        left: 50%;
        transform: translateX(-50%);
        width: 70px;
        height: 4px;
        background: var(--primary);
        border-radius: 2px;
    }

.btn {
    display: inline-block;
    padding: 12px 30px;
    background: var(--primary);
    color: white;
    border-radius: 30px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

    .btn:hover {
        background: var(--primary-dark);
        transform: translateY(-3px);
        box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    }

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

    .btn-secondary:hover {
        background: #e65100;
    }

/* 导航栏 */
header {
    background-color: white;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
}

.logo {
    display: flex;
    align-items: center;
}

    .logo i {
        font-size: 2rem;
        margin-right: 10px;
        background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
        -webkit-background-clip: text;
        -webkit-text-fill-color: transparent;
    }

    .logo h1 {
        font-size: 1.5rem;
        color: var(--primary);
        font-weight: 700;
    }

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

    .nav-links li {
        margin-left: 30px;
        position: relative;
    }

    .nav-links a {
        text-decoration: none;
        color: var(--dark);
        font-weight: 500;
        font-size: 1.05rem;
        transition: color 0.3s;
        position: relative;
    }

        .nav-links a:hover {
            color: var(--primary);
        }

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

        .nav-links a:hover::after {
            width: 100%;
        }

/* 下拉菜单 */
.dropdown {
    position: relative;
}

.dropdown-content {
    display: none;
    position: absolute;
    background: white;
    min-width: 200px;
    box-shadow: 0 8px 16px rgba(0,0,0,0.1);
    border-radius: 8px;
    z-index: 1;
    top: 100%;
    left: 0;
    padding: 10px 0;
}

.dropdown:hover .dropdown-content {
    display: block;
}

.dropdown-content a {
    display: block;
    padding: 10px 20px;
    color: var(--dark);
    text-decoration: none;
    transition: all 0.2s;
}

    .dropdown-content a:hover {
        background: rgba(74, 110, 224, 0.05);
        color: var(--primary);
    }

/* 英雄区域 */
.hero {
    background: linear-gradient(135deg, rgba(74, 110, 224, 0.9) 0%, rgba(58, 86, 176, 0.9) 100%), url('https://images.unsplash.com/photo-1555066931-4365d14bab8c?ixlib=rb-4.0.3&ixid=M3wxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8fA%3D%3D&auto=format&fit=crop&w=1200&q=80');
    background-size: cover;
    background-position: center;
    color: white;
    padding: 100px 0;
    text-align: center;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 20px;
    font-weight: 800;
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: 30px;
    opacity: 0.9;
}

.hero-buttons {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-top: 30px;
}

/* 功能区域 */
.features {
    background-color: white;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.feature-card {
    background: white;
    border-radius: 10px;
    padding: 30px;
    text-align: center;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
    transition: transform 0.3s ease;
}

    .feature-card:hover {
        transform: translateY(-10px);
    }

.feature-icon {
    width: 80px;
    height: 80px;
    background: rgba(74, 110, 224, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 25px;
    color: var(--primary);
    font-size: 2rem;
}

.feature-card h3 {
    font-size: 1.4rem;
    margin-bottom: 15px;
    color: var(--dark);
}

/* 语言卡片区域 */
.languages {
    background-color: var(--light);
}

.languages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 25px;
    margin-top: 30px;
}

.language-card {
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
    transition: all 0.3s ease;
    text-align: center;
    padding: 30px 20px;
    position: relative;
}

    .language-card:hover {
        transform: translateY(-8px);
        box-shadow: 0 12px 20px rgba(0,0,0,0.1);
    }

.language-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    border-radius: 50%;
    background: rgba(74, 110, 224, 0.1);
    color: var(--primary);
}

.java-icon {
    background: rgba(231, 111, 0, 0.1);
    color: var(--java);
}

.python-icon {
    background: rgba(55, 118, 171, 0.1);
    color: var(--python);
}

.go-icon {
    background: rgba(0, 173, 216, 0.1);
    color: var(--go);
}

.mysql-icon {
    background: rgba(0, 117, 143, 0.1);
    color: var(--mysql);
}

.html-icon {
    background: rgba(228, 77, 38, 0.1);
    color: var(--html);
}

.csharp-icon {
    background: rgba(155, 79, 150, 0.1);
    color: var(--csharp);
}

.vue-icon {
    background: rgba(66, 184, 131, 0.1);
    color: var(--vue);
}

.language-card h3 {
    font-size: 1.3rem;
    margin-bottom: 15px;
}

.language-card p {
    color: var(--gray);
    margin-bottom: 20px;
    font-size: 0.95rem;
}

/* 课程区域 */
.courses {
    background-color: white;
}

.course-categories {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 15px;
    margin-bottom: 40px;
}

.category-btn {
    padding: 10px 25px;
    background: white;
    border: 1px solid #e0e0e0;
    border-radius: 30px;
    cursor: pointer;
    transition: all 0.3s;
    font-weight: 500;
}

    .category-btn.active, .category-btn:hover {
        background: var(--primary);
        color: white;
        border-color: var(--primary);
    }

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 30px;
}

.course-card {
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
    transition: transform 0.3s;
}

    .course-card:hover {
        transform: translateY(-5px);
        box-shadow: 0 10px 25px rgba(0,0,0,0.1);
    }

.course-image {
    height: 200px;
    background-color: #e0e0e0;
    position: relative;
    overflow: hidden;
}

    .course-image img {
        width: 100%;
        height: 100%;
        object-fit: cover;
        transition: transform 0.5s;
    }

.course-card:hover .course-image img {
    transform: scale(1.05);
}

.course-level {
    position: absolute;
    top: 15px;
    right: 15px;
    background: var(--secondary);
    color: white;
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
}

.course-content {
    padding: 25px;
}

    .course-content h3 {
        font-size: 1.3rem;
        margin-bottom: 15px;
        color: var(--dark);
    }

.course-meta {
    display: flex;
    justify-content: space-between;
    margin-top: 20px;
    color: var(--gray);
    font-size: 0.9rem;
}

/* 学习路线区域 */
.learning-path {
    background-color: var(--light);
}

.path-container {
    max-width: 1000px;
    margin: 0 auto;
    background: white;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.08);
    padding: 40px;
    position: relative;
}

.path-steps {
    display: flex;
    flex-direction: column;
    gap: 40px;
    position: relative;
    padding: 20px 0;
}

    .path-steps::before {
        content: '';
        position: absolute;
        top: 0;
        bottom: 0;
        left: 30px;
        width: 4px;
        background: linear-gradient(to bottom, var(--primary), var(--secondary));
        z-index: 1;
    }

.path-step {
    display: flex;
    align-items: flex-start;
    position: relative;
    z-index: 2;
}

.step-number {
    width: 60px;
    height: 60px;
    background: white;
    border: 4px solid var(--primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    flex-shrink: 0;
    margin-right: 30px;
    position: relative;
}

.step-content {
    background: rgba(74, 110, 224, 0.03);
    border-radius: 10px;
    padding: 20px;
    flex-grow: 1;
    border-left: 3px solid var(--primary);
}

    .step-content h3 {
        font-size: 1.4rem;
        color: var(--primary);
        margin-bottom: 15px;
    }

.step-languages {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 15px;
}

.language-tag {
    padding: 5px 15px;
    background: rgba(74, 110, 224, 0.1);
    color: var(--primary);
    border-radius: 20px;
    font-size: 0.85rem;
}

.java-tag {
    background: rgba(231, 111, 0, 0.1);
    color: var(--java);
}

.python-tag {
    background: rgba(55, 118, 171, 0.1);
    color: var(--python);
}

.go-tag {
    background: rgba(0, 173, 216, 0.1);
    color: var(--go);
}

.mysql-tag {
    background: rgba(0, 117, 143, 0.1);
    color: var(--mysql);
}

.html-tag {
    background: rgba(228, 77, 38, 0.1);
    color: var(--html);
}

.csharp-tag {
    background: rgba(155, 79, 150, 0.1);
    color: var(--csharp);
}

.vue-tag {
    background: rgba(66, 184, 131, 0.1);
    color: var(--vue);
}

/* 每日计划 */
.daily-plan {
    background-color: white;
}

.plan-container {
    max-width: 800px;
    margin: 0 auto;
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 10px 25px rgba(0,0,0,0.05);
}

.plan-header {
    background: var(--primary);
    color: white;
    padding: 25px;
    text-align: center;
}

    .plan-header h3 {
        font-size: 1.8rem;
        margin-bottom: 10px;
    }

.plan-body {
    padding: 30px;
}

.plan-grid {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 20px;
}

.time-slot {
    font-weight: 600;
    color: var(--primary);
    display: flex;
    align-items: center;
}

    .time-slot::before {
        content: '';
        display: inline-block;
        width: 12px;
        height: 12px;
        background: var(--primary);
        border-radius: 50%;
        margin-right: 10px;
    }

.activity {
    background: rgba(74, 110, 224, 0.05);
    padding: 15px;
    border-radius: 8px;
    border-left: 3px solid var(--primary);
}

/* 注册区域 */
.cta {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    text-align: center;
    padding: 80px 0;
}

    .cta h2 {
        font-size: 2.5rem;
        margin-bottom: 20px;
    }

    .cta p {
        max-width: 700px;
        margin: 0 auto 30px;
        font-size: 1.1rem;
        opacity: 0.9;
    }

/* 页脚 */
footer {
    background: var(--dark);
    color: white;
    padding: 60px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-col h3 {
    font-size: 1.3rem;
    margin-bottom: 25px;
    position: relative;
    padding-bottom: 10px;
}

    .footer-col h3::after {
        content: '';
        position: absolute;
        bottom: 0;
        left: 0;
        width: 50px;
        height: 2px;
        background: var(--primary);
    }

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

    .footer-links li {
        margin-bottom: 15px;
    }

    .footer-links a {
        color: #b0bec5;
        text-decoration: none;
        transition: color 0.3s;
    }

        .footer-links a:hover {
            color: white;
        }

.social-links {
    display: flex;
    gap: 15px;
    margin-top: 20px;
}

    .social-links a {
        display: inline-flex;
        align-items: center;
        justify-content: center;
        width: 40px;
        height: 40px;
        background: rgba(255,255,255,0.1);
        border-radius: 50%;
        color: white;
        transition: all 0.3s;
    }

        .social-links a:hover {
            background: var(--primary);
            transform: translateY(-3px);
        }

.copyright {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255,255,255,0.1);
    color: #b0bec5;
    font-size: 0.9rem;
}

/* 响应式设计 */
@media (max-width: 992px) {
    .nav-links {
        display: none;
    }

    .menu-toggle {
        display: block;
        font-size: 1.5rem;
        cursor: pointer;
    }
}

@media (max-width: 768px) {
    .hero h1 {
        font-size: 2.3rem;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .section-title h2 {
        font-size: 1.8rem;
    }

    .plan-grid {
        grid-template-columns: 1fr;
        gap: 15px;
    }

    .path-steps::before {
        left: 15px;
    }

    .step-number {
        margin-right: 15px;
        width: 50px;
        height: 50px;
    }
}

/* 移动菜单 */
.menu-toggle {
    display: none;
    font-size: 1.5rem;
    cursor: pointer;
}

.mobile-menu {
    position: fixed;
    top: 0;
    right: -300px;
    width: 280px;
    height: 100%;
    background: white;
    box-shadow: -5px 0 15px rgba(0,0,0,0.1);
    z-index: 1001;
    transition: right 0.3s ease;
    overflow-y: auto;
    padding: 20px;
}

    .mobile-menu.active {
        right: 0;
    }

.mobile-nav-links {
    list-style: none;
    margin-top: 40px;
}

    .mobile-nav-links li {
        margin-bottom: 20px;
    }

    .mobile-nav-links a {
        text-decoration: none;
        color: var(--dark);
        font-size: 1.1rem;
        font-weight: 500;
    }

.mobile-dropdown-content {
    padding-left: 20px;
    margin-top: 10px;
}

    .mobile-dropdown-content a {
        display: block;
        padding: 8px 0;
        color: var(--gray);
    }

.close-menu {
    position: absolute;
    top: 20px;
    right: 20px;
    font-size: 1.5rem;
    cursor: pointer;
}