/* 基础样式 */
:root {
    --primary-color: #1a365d;
    --secondary-color: #2d3748;
    --accent-color: #e53e3e;
    --light-bg: #f7fafc;
    --text-dark: #2d3748;
    --text-light: #718096;
    --white: #ffffff;
    --black: #000000;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--white);
    padding-top: 70px; /* 为固定导航栏留出空间 */
}

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

/* 语言切换 - 整合到导航栏内 */
.language-switcher {
    display: flex;
    gap: 10px;
    margin-left: auto;
    align-items: center;
}

.lang-btn {
    background: none;
    border: 1px solid var(--primary-color);
    color: var(--primary-color);
    padding: 5px 10px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
    transition: var(--transition);
    height: 32px;
    box-sizing: border-box;
    display: flex;
    align-items: center;
    justify-content: center;
}

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

/* 导航栏 - 修复固定定位和布局 */
header {
    background-color: var(--white);
    box-shadow: var(--shadow);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
    max-width: 1200px;
    margin: 0 auto;
}

.logo {
    font-size: 24px;
    font-weight: bold;
    color: var(--primary-color);
}

.nav-menu {
    display: flex;
    list-style: none;
    align-items: center;
}

.nav-menu li {
    margin-left: 20px;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: var(--transition);
    white-space: nowrap;
}

.nav-menu a:hover {
    color: var(--accent-color);
}

.hamburger {
    display: none;
    cursor: pointer;
    font-size: 1.5rem;
}

/* 英雄区域 */
.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: var(--white);
    padding: 100px 0 80px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('../images/hero-bg.jpg');
    background-size: cover;
    background-position: center;
    opacity: 0.2;
    z-index: -1;
}

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

.hero p {
    font-size: 1.2rem;
    max-width: 700px;
    margin: 0 auto 30px;
    opacity: 0.9;
}

.cta-button {
    display: inline-block;
    background-color: var(--white);
    color: var(--text-dark);
    padding: 12px 30px;
    border-radius: 30px;
    text-decoration: none;
    font-weight: bold;
    transition: var(--transition);
    
}

.cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
}

/* 内容区域 */
section {
    padding: 80px 0;
}

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

.section-title h2 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.section-title p {
    color: var(--text-light);
    max-width: 600px;
    margin: 0 auto;
}

/* 卡片布局 */
.cards-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.card {
    background-color: var(--white);
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
}

.card-header {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 20px;
}

.card-body {
    padding: 25px;
}

.card-body ul {
    list-style: none;
}

.card-body li {
    margin-bottom: 12px;
    padding-left: 20px;
    position: relative;
}

.card-body li:before {
    content: "○";
    position: absolute;
    left: 0;
    color: var(--accent-color);
}

/* 图片卡片 */
.image-card {
    position: relative;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
    height: 100%;
}

.image-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
}

.image-card img {
    width: 100%;
    height: 250px;
    object-fit: cover;
    display: block;
}

.image-card .content {
    padding: 25px;
    background-color: var(--white);
}

.image-card .content h3 {
    color: var(--primary-color);
    margin-bottom: 15px;
}

.image-card .content p {
    color: var(--text-light);
    line-height: 1.6;
}

/* 学生收获部分 */
.student-gains {
    background-color: var(--light-bg);
}

.benefits-list {
    max-width: 800px;
    margin: 0 auto;
}

.benefit-item {
    background-color: var(--white);
    padding: 25px;
    border-radius: 10px;
    margin-bottom: 20px;
    box-shadow: var(--shadow);
}

.benefit-item h3 {
    color: var(--primary-color);
    margin-bottom: 15px;
}

/* 关于我部分 */
.about-section {
    display: flex;
    align-items: center;
    gap: 40px;
}

.about-text {
    flex: 1;
}

.about-image {
    flex: 1;
    min-height: 300px;
    background-color: var(--light-bg);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-light);
    position: relative;
    overflow: hidden;
}

.about-image::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('../images/about-bg.jpg');
    background-size: cover;
    background-position: center;
    opacity: 0.3;
}

.about-image-content {
    position: relative;
    z-index: 1;
    text-align: center;
    padding: 20px;
}

/* 口碑部分 */
.testimonials {
    background-color: var(--light-bg);
    padding: 80px 0;
}

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

.testimonials .section-title h2 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.testimonial-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.testimonial-item {
    background-color: var(--white);
    padding: 30px;
    border-radius: 10px;
    box-shadow: var(--shadow);
    position: relative;
    transition: var(--transition);
}

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

.testimonial-text {
    font-style: italic;
    margin-bottom: 20px;
    position: relative;
    z-index: 1;
    color: var(--text-dark);
    line-height: 1.7;
}

.testimonial-text::before {
    content: '"';
    font-size: 4rem;
    color: var(--accent-color);
    opacity: 0.2;
    position: absolute;
    top: -20px;
    left: -10px;
    font-family: Georgia, serif;
}

.testimonial-author {
    font-weight: 600;
    color: var(--primary-color);
    border-top: 1px solid #e2e8f0;
    padding-top: 15px;
    margin-top: 15px;
}

/* 视频部分 */
.video-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.video-placeholder {
    background-color: var(--light-bg);
    height: 200px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-light);
    position: relative;
    overflow: hidden;
}

.video-placeholder::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('../images/video-bg.jpg');
    background-size: cover;
    background-position: center;
    opacity: 0.2;
}

.video-placeholder-content {
    position: relative;
    z-index: 1;
    text-align: center;
}

/* 课程板块专用布局 - 两行两列 */
#courses .cards-container {
    grid-template-columns: repeat(2, 1fr);
    max-width: 1000px;
    margin: 0 auto;
}

/* 课程图片卡片 */
#courses .image-card {
    display: flex;
    flex-direction: column;
}

#courses .image-card .content {
    flex: 1;
    display: flex;
    flex-direction: column;
}

#courses .image-card .content .card-text {
    flex: 1;
}

/* 响应式设计 */
@media (max-width: 1024px) {
    .nav-menu {
        flex-wrap: wrap;
        justify-content: flex-end;
    }
    
    .nav-menu li {
        margin-left: 15px;
    }
    
    .about-section {
        flex-direction: column;
    }
}

@media (max-width: 768px) {
    body {
        padding-top: 70px;
    }
    
    .header-container {
        flex-wrap: wrap;
        padding: 10px 20px;
    }
    
    .logo {
        font-size: 20px;
    }
    
    .nav-menu {
        position: fixed;
        top: 60px;
        left: 0;
        right: 0;
        flex-direction: column;
        background-color: var(--white);
        height: auto;
        padding: 15px 20px;
        transition: var(--transition);
        box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-menu li {
        margin: 10px 0;
        width: 100%;
    }
    
    .nav-menu a {
        display: block;
        padding: 10px 0;
        border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    }
    
    .language-switcher {
        margin-left: 0;
        margin-top: 15px;
        justify-content: center;
        width: 100%;
        border-top: 1px solid rgba(0, 0, 0, 0.05);
        padding-top: 15px;
    }
    
    .hamburger {
        display: block;
    }
    
    .hero {
        padding: 80px 0 60px;
    }
    
    .hero h1 {
        font-size: 2.2rem;
    }
    
    .hero p {
        font-size: 1rem;
    }
    
    .section-title h2 {
        font-size: 2rem;
    }
    
    section {
        padding: 60px 0;
    }
    
    .testimonial-container {
        grid-template-columns: 1fr;
        padding: 0 15px;
    }
    
    .testimonials {
        padding: 60px 0;
    }
}

@media (max-width: 480px) {
    body {
        padding-top: 60px;
    }
    
    .header-container {
        padding: 8px 15px;
    }
    
    .logo {
        font-size: 18px;
    }
    
    .nav-menu {
        top: 50px;
    }
    
    .hero {
        padding: 60px 0 40px;
    }
    
    .hero h1 {
        font-size: 1.8rem;
    }
}

/* 语言切换效果 - 默认英文 */
/* 修复语言显示问题 */
body:not(.chinese) .lang-zh {
    display: none !important;
}

body.chinese .lang-en {
    display: none !important;
}

/* 语言标志样式 */
.lang-flag {
    margin-right: 5px;
}

/* 联系表单样式 */
.contact-container .card {
    border: 1px solid #e2e8f0;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.contact-container .card-header {
    background-color: var(--primary-color);
    color: white;
    padding: 15px 20px;
    border-radius: 8px 8px 0 0;
}

.contact-container .card-body {
    padding: 20px;
}

.contact-container .form-label {
    font-weight: 500;
    margin-bottom: 5px;
    display: block;
}

.contact-container .form-control {
    width: 100%;
    padding: 10px;
    border: 1px solid #cbd5e0;
    border-radius: 4px;
    margin-bottom: 15px;
    font-size: 16px;
}

.contact-container .form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(26, 54, 93, 0.1);
}

.contact-container textarea.form-control {
    resize: vertical;
    min-height: 100px;
}

.contact-container .btn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
    font-weight: 500;
    transition: background-color 0.2s;
    width: 100%;
}

.contact-container .btn:hover {
    background-color: #2c5282;
}

.contact-container .btn:disabled {
    background-color: #a0aec0;
    cursor: not-allowed;
}

.form-message {
    padding: 10px;
    border-radius: 4px;
    margin-top: 15px;
}

.form-message.success {
    background-color: #c6f6d5;
    color: #22543d;
    border: 1px solid #9ae6b4;
}

.form-message.error {
    background-color: #fed7d7;
    color: #742a2a;
    border: 1px solid #feb2b2;
}

.form-message.info {
    background-color: #bee3f8;
    color: #2a4365;
    border: 1px solid #90cdf4;
}

/* 页脚样式 */
footer {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 50px 0 20px;
}

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

.footer-column h3 {
    margin-bottom: 20px;
    font-size: 1.2rem;
}

.footer-column ul {
    list-style: none;
}

.footer-column li {
    margin-bottom: 10px;
}

.footer-column a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: var(--transition);
}

.footer-column a:hover {
    color: var(--white);
}

.copyright {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.6);
}

/* 课程 */
#courses {
    background-color: var(--white);
}

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

#courses .section-title {
    text-align: center;
    margin-bottom: 50px;
}

#courses .section-title h2 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 15px;
}

#courses .section-title p {
    color: var(--text-light);
    max-width: 600px;
    margin: 0 auto;
}

/* 卡片布局 - 修改为两行两列 */
#courses .cards-container {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
    max-width: 1000px;
    margin: 0 auto;
}

#courses .card {
    background-color: var(--white);
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid #e2e8f0;
}

#courses .card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
}

#courses .card-header {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 20px;
    text-align: center;
}

#courses .card-body {
    padding: 25px;
}

#courses .card-body h4 {
    color: var(--primary-color);
    margin: 15px 0 10px 0;
}

#courses .card-body p {
    margin-bottom: 15px;
    line-height: 1.6;
}

#courses .card-body ul {
    list-style: none;
    padding-left: 0;
}

#courses .card-body li {
    margin-bottom: 12px;
    padding-left: 20px;
    position: relative;
}

#courses .card-body li:before {
    content: "○";
    position: absolute;
    left: 0;
    color: var(--accent-color);
}

/* 响应式设计 - 课程板块 */
@media (max-width: 768px) {
    #courses .cards-container {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    #courses .card-header {
        padding: 15px;
    }
    
    #courses .card-body {
        padding: 20px;
    }
    
    #courses {
        padding: 60px 0;
    }
}

/* 口碑部分 */
.testimonials {
    background-color: var(--light-bg);
    padding: 80px 0;
}

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

.testimonials .section-title h2 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.testimonial-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.testimonial-item {
    background-color: var(--white);
    padding: 30px;
    border-radius: 10px;
    box-shadow: var(--shadow);
    position: relative;
    transition: var(--transition);
}

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

.testimonial-text {
    font-style: italic;
    margin-bottom: 20px;
    position: relative;
    z-index: 1;
    color: var(--text-dark);
    line-height: 1.7;
}

.testimonial-text::before {
    content: '"';
    font-size: 4rem;
    color: var(--accent-color);
    opacity: 0.2;
    position: absolute;
    top: -20px;
    left: -10px;
    font-family: Georgia, serif;
}

.testimonial-author {
    font-weight: 600;
    color: var(--primary-color);
    border-top: 1px solid #e2e8f0;
    padding-top: 15px;
    margin-top: 15px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .testimonial-container {
        grid-template-columns: 1fr;
        padding: 0 15px;
    }
    
    .testimonials {
        padding: 60px 0;
    }
}

/* 视频部分 */
.video-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.video-placeholder {
    background-color: var(--light-bg);
    height: 200px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-light);
}

/* 课程板块专用布局 - 两行两列 */
#courses .cards-container {
    grid-template-columns: repeat(2, 1fr);
    max-width: 1000px;
    margin: 0 auto;
}

/* 响应式设计 */
@media (max-width: 1024px) {
    .nav-menu {
        flex-wrap: wrap;
        justify-content: flex-end;
    }
    
    .nav-menu li {
        margin-left: 15px;
    }
    
    .about-section {
        flex-direction: column;
    }
}

@media (max-width: 768px) {
    body {
        padding-top: 70px;
    }
    
    .header-container {
        flex-wrap: wrap;
        padding: 10px 20px; /* 减少顶部和底部内边距 */
    }
    
    .logo {
        font-size: 20px; /* 减小logo字体 */
    }
    
    .nav-menu {
        position: fixed;
        top: 60px; /* 将菜单直接放在导航栏下方 */
        left: 0;
        right: 0;
        flex-direction: column;
        background-color: var(--white);
        height: auto; /* 自动高度，不占用整个屏幕 */
        padding: 15px 20px;
        transition: var(--transition);
        box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-menu li {
        margin: 10px 0;
        width: 100%;
    }
    
    .nav-menu a {
        display: block;
        padding: 10px 0;
        border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    }
    
    .language-switcher {
        margin-left: 0;
        margin-top: 15px;
        justify-content: center;
        width: 100%;
        border-top: 1px solid rgba(0, 0, 0, 0.05);
        padding-top: 15px;
    }
    
    .hamburger {
        display: block;
    }
    
    .hero {
        padding: 80px 0 60px;
    }
    
    .hero h1 {
        font-size: 2.2rem;
    }
    
    .hero p {
        font-size: 1rem;
    }
    
    .section-title h2 {
        font-size: 2rem;
    }
    
    section {
        padding: 60px 0;
    }
}

@media (max-width: 480px) {
    body {
        padding-top: 60px;
    }
    
    .header-container {
        padding: 8px 15px;
    }
    
    .logo {
        font-size: 18px;
    }
    
    .nav-menu {
        top: 50px; /* 进一步减少顶部间距 */
    }
    
    .hero {
        padding: 60px 0 40px;
    }
    
    .hero h1 {
        font-size: 1.8rem;
    }
}

/* 语言切换效果 - 默认英文 */
/* 修复语言显示问题 */
body:not(.chinese) .lang-zh {
    display: none !important;
}

body.chinese .lang-en {
    display: none !important;
}

/* 语言标志样式 */
.lang-flag {
    margin-right: 5px;
}

/* 联系表单样式 */
.contact-container .card {
    border: 1px solid #e2e8f0;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.contact-container .card-header {
    background-color: var(--primary-color);
    color: white;
    padding: 15px 20px;
    border-radius: 8px 8px 0 0;
}

.contact-container .card-body {
    padding: 20px;
}

.contact-container .form-label {
    font-weight: 500;
    margin-bottom: 5px;
    display: block;
}

.contact-container .form-control {
    width: 100%;
    padding: 10px;
    border: 1px solid #cbd5e0;
    border-radius: 4px;
    margin-bottom: 15px;
    font-size: 16px;
}

.contact-container .form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(26, 54, 93, 0.1);
}

.contact-container textarea.form-control {
    resize: vertical;
    min-height: 100px;
}

.contact-container .btn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
    font-weight: 500;
    transition: background-color 0.2s;
    width: 100%;
}

.contact-container .btn:hover {
    background-color: #2c5282;
}

.contact-container .btn:disabled {
    background-color: #a0aec0;
    cursor: not-allowed;
}

.form-message {
    padding: 10px;
    border-radius: 4px;
    margin-top: 15px;
}

.form-message.success {
    background-color: #c6f6d5;
    color: #22543d;
    border: 1px solid #9ae6b4;
}

.form-message.error {
    background-color: #fed7d7;
    color: #742a2a;
    border: 1px solid #feb2b2;
}

.form-message.info {
    background-color: #bee3f8;
    color: #2a4365;
    border: 1px solid #90cdf4;
}

/* 页脚样式 */
footer {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 50px 0 20px;
}

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

.footer-column h3 {
    margin-bottom: 20px;
    font-size: 1.2rem;
}

.footer-column ul {
    list-style: none;
}

.footer-column li {
    margin-bottom: 10px;
}

.footer-column a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: var(--transition);
}

.footer-column a:hover {
    color: var(--white);
}

.copyright {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.6);
}

.contact-container .card-header {
    background-color: var(--primary-color);
    color: white;
    padding: 15px 20px;
    border-radius: 8px 8px 0 0;
}

.contact-container .card-body {
    padding: 20px;
}

.contact-container .form-label {
    font-weight: 500;
    margin-bottom: 5px;
    display: block;
}

.contact-container .form-control {
    width: 100%;
    padding: 10px;
    border: 1px solid #cbd5e0;
    border-radius: 4px;
    margin-bottom: 15px;
    font-size: 16px;
}

.contact-container .form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(26, 54, 93, 0.1);
}

.contact-container textarea.form-control {
    resize: vertical;
    min-height: 100px;
}

.contact-container .btn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
    font-weight: 500;
    transition: background-color 0.2s;
    width: 100%;
}

.contact-container .btn:hover {
    background-color: #2c5282;
}

.contact-container .btn:disabled {
    background-color: #a0aec0;
    cursor: not-allowed;
}

.form-message {
    padding: 10px;
    border-radius: 4px;
    margin-top: 15px;
}

.form-message.success {
    background-color: #c6f6d5;
    color: #22543d;
    border: 1px solid #9ae6b4;
}

.form-message.error {
    background-color: #fed7d7;
    color: #742a2a;
    border: 1px solid #feb2b2;
}

.form-message.info {
    background-color: #bee3f8;
    color: #2a4365;
    border: 1px solid #90cdf4;
}

/* 卡片布局 - 修改为两行两列 */
#courses .cards-container {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
    max-width: 1000px;
    margin: 0 auto;
}

#courses .card {
    background-color: var(--white);
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid #e2e8f0;
}

#courses .card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
}

#courses .card-header {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 20px;
    text-align: center;
}

#courses .card-body {
    padding: 25px;
}

#courses .card-body ul {
    list-style: none;
}

#courses .card-body li {
    margin-bottom: 12px;
    padding-left: 20px;
    position: relative;
}

#courses .card-body li:before {
    content: "○";
    position: absolute;
    left: 0;
    color: var(--accent-color);
}

/* 响应式设计 - 课程板块 */
@media (max-width: 768px) {
    #courses .cards-container {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    #courses .card-header {
        padding: 15px;
    }
    
    #courses .card-body {
        padding: 20px;
    }
}