/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Noto Sans SC', sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

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

/* 头部导航 */
.header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 1rem 0;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.8rem;
    font-weight: 700;
    color: #4a90e2;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
}

.nav {
    display: flex;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: #666;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 25px;
    transition: all 0.3s ease;
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: #4a90e2;
    background: rgba(74, 144, 226, 0.1);
    transform: translateY(-2px);
}

/* 主要内容区域 */
main {
    margin-top: 80px;
}

/* 英雄区域 */
.hero {
    padding: 4rem 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
    max-width: 1000px;
    margin: 0 auto;
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.hero-subtitle {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.main-illustration {
    max-width: 100%;
    height: auto;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    transition: transform 0.3s ease;
}

.main-illustration:hover {
    transform: scale(1.05);
}

/* 按钮样式 */
.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 25px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-block;
    text-align: center;
}

.btn-primary {
    background: linear-gradient(45deg, #ff6b6b, #ee5a24);
    color: white;
    box-shadow: 0 4px 15px rgba(255, 107, 107, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(255, 107, 107, 0.6);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.3);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.btn-game {
    background: linear-gradient(45deg, #4ecdc4, #44a08d);
    color: white;
    box-shadow: 0 4px 15px rgba(78, 205, 196, 0.4);
}

.btn-game:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(78, 205, 196, 0.6);
}

/* 概念学习区域 */
.concept-section {
    padding: 4rem 0;
    background: white;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 3rem;
    color: #333;
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: linear-gradient(45deg, #ff6b6b, #ee5a24);
    border-radius: 2px;
}

.concept-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.concept-card {
    background: white;
    border-radius: 20px;
    padding: 2rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    border: 1px solid #f0f0f0;
}

.concept-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.15);
}

.concept-image {
    text-align: center;
    margin-bottom: 1.5rem;
}

.concept-illustration {
    max-width: 200px;
    height: auto;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.concept-content h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #4a90e2;
}

.concept-content p {
    margin-bottom: 1rem;
    color: #666;
}

.multiples-example {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    justify-content: center;
    max-width: 100%;
}

.multiple {
    background: linear-gradient(45deg, #ff6b6b, #ee5a24);
    color: white;
    padding: 8px 16px;
    border-radius: 20px;
    font-weight: 600;
    font-size: 0.9rem;
    box-shadow: 0 2px 8px rgba(255, 107, 107, 0.3);
    transition: transform 0.2s ease;
    cursor: pointer;
    user-select: none;
}

.multiple:hover {
    transform: scale(1.1);
    box-shadow: 0 4px 12px rgba(255, 107, 107, 0.5);
}

.multiple:active {
    transform: scale(0.95);
}

/* 练习区域 */
.practice-section {
    padding: 4rem 0;
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    color: white;
}

.practice-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.practice-card {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 2rem;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.practice-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    text-align: center;
}

.practice-content {
    text-align: center;
}

.number-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 0.5rem;
    margin: 1rem 0;
    max-width: 300px;
    margin-left: auto;
    margin-right: auto;
}

.number-item {
    background: rgba(255, 255, 255, 0.2);
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 10px;
    padding: 1rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 600;
    font-size: 1.2rem;
}

.number-item:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.05);
}

.number-item.selected {
    background: #4ecdc4;
    border-color: #4ecdc4;
    transform: scale(1.1);
}

.relationship-example {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin: 1.5rem 0;
    flex-wrap: wrap;
}

.radish-group {
    text-align: center;
}

.radish-example {
    max-width: 80px;
    height: auto;
    border-radius: 10px;
    margin-bottom: 0.5rem;
}

.group-label {
    font-size: 0.9rem;
    opacity: 0.8;
}

.multiply-symbol,
.equals-symbol {
    font-size: 2rem;
    font-weight: bold;
    color: #4ecdc4;
}

.number-input input {
    width: 60px;
    height: 60px;
    border: none;
    border-radius: 10px;
    text-align: center;
    font-size: 1.5rem;
    font-weight: bold;
    background: rgba(255, 255, 255, 0.2);
    color: white;
}

.result-display {
    width: 60px;
    height: 60px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: bold;
    color: #4ecdc4;
}

/* 游戏区域 */
.games-section {
    padding: 4rem 0;
    background: white;
}

/* 游戏类型选择器 */
.game-type-selector {
    text-align: center;
    margin-bottom: 3rem;
}

.game-type-title {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: #333;
}

.game-type-buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.btn-type {
    background: rgba(74, 144, 226, 0.1);
    color: #4a90e2;
    border: 2px solid #4a90e2;
    padding: 10px 20px;
    border-radius: 25px;
    font-weight: 500;
    transition: all 0.3s ease;
}

.btn-type:hover,
.btn-type.active {
    background: #4a90e2;
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(74, 144, 226, 0.4);
}

.games-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.game-card {
    background: white;
    border-radius: 20px;
    padding: 2rem;
    text-align: center;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    border: 1px solid #f0f0f0;
}

.game-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.15);
}

.game-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: #4a90e2;
}

.game-card p {
    margin-bottom: 1.5rem;
    color: #666;
}

/* 页脚 */
.footer {
    background: #333;
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: 2rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .nav {
        gap: 1rem;
    }
    
    .concept-grid,
    .practice-container,
    .games-grid {
        grid-template-columns: 1fr;
    }
    
    .relationship-example {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .number-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .hero-title {
        font-size: 1.8rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .btn {
        padding: 10px 20px;
        font-size: 0.9rem;
    }
}

/* 动画效果 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.concept-card,
.practice-card,
.game-card {
    animation: fadeInUp 0.6s ease-out;
}

/* 倍数关系模态框 */
.relationship-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 10000;
    animation: fadeIn 0.3s ease-out;
}

.relationship-content {
    background: white;
    border-radius: 20px;
    padding: 2rem;
    max-width: 600px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.relationship-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid #f0f0f0;
}

.relationship-header h3 {
    color: #4a90e2;
    font-size: 1.5rem;
    font-weight: 700;
    margin: 0;
}

.close-btn {
    background: none;
    border: none;
    font-size: 2rem;
    color: #999;
    cursor: pointer;
    padding: 0;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.close-btn:hover {
    background: #f0f0f0;
    color: #333;
}

.relationship-visual {
    text-align: center;
}

.radish-groups {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1rem;
    margin: 1.5rem 0;
}

.radish-group-item {
    background: #f8f9fa;
    border-radius: 15px;
    padding: 1rem;
    border: 2px solid #e9ecef;
    transition: all 0.3s ease;
    min-width: 120px;
}

.radish-group-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    border-color: #4a90e2;
}

.group-label {
    font-size: 0.9rem;
    color: #666;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.radish-pair {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    margin: 0.5rem 0;
}

.radish-small {
    width: 40px;
    height: auto;
    border-radius: 8px;
}

.group-count {
    font-size: 0.8rem;
    color: #4a90e2;
    font-weight: 600;
    margin-top: 0.5rem;
}

.relationship-text {
    margin-top: 1.5rem;
    padding: 1rem;
    background: #f8f9fa;
    border-radius: 10px;
    border-left: 4px solid #4a90e2;
}

.relationship-text p {
    margin: 0.5rem 0;
    color: #333;
    font-size: 1rem;
    line-height: 1.5;
}

/* 动画效果 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

@keyframes pulse {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.1);
    }
    100% {
        transform: scale(1);
    }
}

/* 滚动平滑 */
html {
    scroll-behavior: smooth;
} 

    .challenge-timer {
        font-size: 1.2rem;
        font-weight: bold;
        color: #ff6b6b;
        margin-top: 1rem;
    }
    
    .game-result-modal {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: rgba(0, 0, 0, 0.8);
        display: flex;
        justify-content: center;
        align-items: center;
        z-index: 10001;
        animation: fadeIn 0.3s ease-out;
    }
    
    .result-content {
        background: white;
        border-radius: 20px;
        padding: 2rem;
        max-width: 400px;
        width: 90%;
        text-align: center;
        box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    }
    
    .result-content h3 {
        color: #4ecdc4;
        font-size: 1.8rem;
        margin-bottom: 1rem;
    }
    
    .result-content p {
        color: #666;
        margin-bottom: 1rem;
        font-size: 1.1rem;
    }
    
    .result-stats {
        background: #f8f9fa;
        border-radius: 10px;
        padding: 1rem;
        margin: 1.5rem 0;
        border-left: 4px solid #4ecdc4;
    }
    
    .result-stats p {
        margin: 0.5rem 0;
        color: #333;
        font-weight: 500;
    }