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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
}

/* 导航栏样式 */
.header {
    background-color: #fff;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
}

.nav {
    max-width: 1200px;
    margin: 0 auto;
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
}

.nav-logo a {
    font-size: 1.5rem;
    font-weight: bold;
    color: #2196f3;
    text-decoration: none;
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    color: #666;
    cursor: pointer;
}

.nav-menu ul {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
}

.nav-menu li {
    margin: 0 1rem;
}

.nav-menu a {
    color: #666;
    text-decoration: none;
    transition: color 0.3s;
}

.nav-menu a:hover {
    color: #2196f3;
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.login-btn, .register-btn {
    padding: 0.5rem 1rem;
    border-radius: 4px;
    text-decoration: none;
    transition: all 0.3s;
}

.login-btn {
    color: #666;
}

.register-btn {
    background-color: #2196f3;
    color: #fff;
}

.register-btn:hover {
    background-color: #1976d2;
}

/* 主要内容区样式 */
main {
    margin-top: 60px;
    padding: 2rem 0;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 1rem;
}

h1 {
    text-align: center;
    color: #2196f3;
    margin-bottom: 1rem;
}

.subtitle {
    text-align: center;
    color: #666;
    margin-bottom: 2rem;
}

.calculator-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    background: #fff;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.input-section {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.search-box {
    position: relative;
}

.search-box input {
    width: 100%;
    padding: 0.8rem;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 1rem;
}

.search-results {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: #fff;
    border: 1px solid #ddd;
    border-top: none;
    border-radius: 0 0 4px 4px;
    max-height: 200px;
    overflow-y: auto;
    display: none;
}

.search-result-item {
    padding: 0.5rem 1rem;
    cursor: pointer;
}

.search-result-item:hover {
    background: #f5f5f5;
}

.selected-food {
    background: #f9f9f9;
    padding: 1rem;
    border-radius: 4px;
}

.selected-food-list {
    margin-top: 1rem;
}

.food-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem;
    border-bottom: 1px solid #eee;
}

.food-item-info {
    flex: 1;
}

.food-item-actions {
    display: flex;
    gap: 0.5rem;
}

.daily-summary {
    background: #f0f7ff;
    padding: 1rem;
    border-radius: 4px;
}

.summary-content {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
    margin-top: 1rem;
}

.summary-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 0.5rem;
    background: #fff;
    border-radius: 4px;
}

.chart-section {
    padding: 1rem;
    background: #fff;
    border-radius: 4px;
}

.tips-section {
    margin-top: 2rem;
    padding: 2rem;
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.tips-content {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    margin-top: 1.5rem;
}

.tip {
    padding: 1rem;
    background: #f9f9f9;
    border-radius: 4px;
}

.tip h4 {
    color: #2196f3;
    margin-bottom: 0.5rem;
}

/* 广告容器样式 */
.ad-container {
    width: 100%;
    max-width: 1000px;
    margin: 20px auto;
    padding: 0 15px;
}

.ad-content {
    border: 1px dashed #ccc;
    padding: 40px;
    border-radius: 4px;
    text-align: center;
    color: #666;
    font-size: 14px;
    background-color: #fff;
}

/* 底部版权样式 */
.footer {
    background-color: #fff;
    padding: 1rem;
    text-align: center;
    box-shadow: 0 -2px 4px rgba(0,0,0,0.1);
    margin-top: 2rem;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
}

.footer p {
    margin: 0.5rem 0;
    color: #666;
}

.footer a {
    color: #666;
    text-decoration: none;
}

.footer a:hover {
    color: #2196f3;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .calculator-container {
        grid-template-columns: 1fr;
    }

    .tips-content {
        grid-template-columns: 1fr;
    }

    .menu-toggle {
        display: block;
    }

    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: #fff;
        padding: 1rem;
        box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    }

    .nav-menu.active {
        display: block;
    }

    .nav-menu ul {
        flex-direction: column;
    }

    .nav-menu li {
        margin: 0.5rem 0;
    }
}