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

:root {
    --primary-color: #4a90e2;
    --primary-dark: #357abd;
    --secondary-color: #2c3e50;
    --accent-color: #f39c12;
    --bg-color: #f8f9fa;
    --white: #ffffff;
    --text-dark: #333333;
    --text-light: #666666;
    --border-color: #e1e8ed;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.15);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica', 'Arial', sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-color);
}

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

/* 导航栏 */
.navbar {
    background-color: var(--white);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 15px 0;
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 15px;
}

.logo-img {
    height: 80px;
    width: auto;
    object-fit: contain;
}

.logo h2 {
    color: var(--primary-color);
    font-size: 28px;
    font-weight: bold;
}

.lang-switcher {
    display: flex;
    gap: 5px;
    border: 1px solid var(--border-color);
    border-radius: 5px;
    overflow: hidden;
}

.lang-btn {
    padding: 6px 12px;
    background: var(--bg-color);
    border: none;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.3s ease;
}

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

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

.nav-links {
    display: flex;
    list-style: none;
    gap: 30px;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: color 0.3s ease;
}

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

.auth-buttons {
    display: flex;
    gap: 10px;
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 10px 24px;
    border-radius: 5px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    cursor: pointer;
    border: 2px solid transparent;
}

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

.btn-primary:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
}

.btn-outline {
    background-color: transparent;
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.btn-outline:hover {
    background-color: var(--primary-color);
    color: var(--white);
    transform: translateY(-2px);
}

.btn-large {
    padding: 14px 32px;
    font-size: 16px;
}

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

.hero-content h1 {
    font-size: 48px;
    margin-bottom: 20px;
    font-weight: bold;
}

.hero-content p {
    font-size: 20px;
    margin-bottom: 30px;
    opacity: 0.95;
}

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

/* 功能特点 */
.features {
    padding: 80px 0;
    background-color: var(--white);
}

.section-title {
    text-align: center;
    font-size: 32px;
    margin-bottom: 50px;
    color: var(--secondary-color);
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.feature-card {
    background: var(--bg-color);
    padding: 30px;
    border-radius: 10px;
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.feature-icon {
    font-size: 48px;
    margin-bottom: 20px;
}

.feature-card h3 {
    margin-bottom: 15px;
    color: var(--secondary-color);
}

/* 公司介绍 */
.business {
    padding: 80px 0;
    background-color: var(--white);
}

.company-intro-card {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--white);
    padding: 50px;
    border-radius: 15px;
    text-align: center;
    margin-bottom: 50px;
}

.company-icon {
    font-size: 80px;
    margin-bottom: 30px;
}

.company-intro-card h3 {
    font-size: 32px;
    margin-bottom: 20px;
}

.company-intro-card p {
    font-size: 18px;
    line-height: 1.8;
    margin-bottom: 40px;
    opacity: 0.95;
}

.company-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.stat-number {
    font-size: 36px;
    font-weight: bold;
    margin-bottom: 10px;
}

.stat-label {
    font-size: 16px;
    opacity: 0.9;
}

/* 业务介绍 */
.services {
    padding: 80px 0;
    background-color: var(--bg-color);
}

.service-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 30px;
}

.service-card {
    background: var(--white);
    padding: 40px 30px;
    border-radius: 10px;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.service-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.service-icon {
    font-size: 60px;
    margin-bottom: 25px;
    text-align: center;
}

.service-card h3 {
    margin-bottom: 15px;
    color: var(--secondary-color);
    font-size: 24px;
    text-align: center;
}

.service-card p {
    color: var(--text-light);
    margin-bottom: 25px;
    line-height: 1.6;
}

.service-features {
    list-style: none;
    padding: 0;
}

.service-features li {
    padding: 8px 0;
    padding-left: 25px;
    position: relative;
    color: var(--text-dark);
    border-bottom: 1px solid var(--border-color);
}

.service-features li:before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

.service-features li:last-child {
    border-bottom: none;
}

/* 用户信息栏 */
.user-info-bar {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: var(--white);
    padding: 30px 0;
}

.user-info-content {
    display: flex;
    align-items: center;
    gap: 30px;
}

.user-avatar {
    width: 80px;
    height: 80px;
    background: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 40px;
}

.user-details h3 {
    font-size: 24px;
    margin-bottom: 5px;
}

.user-details p {
    opacity: 0.9;
    font-size: 14px;
}

.user-stats {
    display: flex;
    gap: 40px;
    margin-left: auto;
}

.user-stat {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.user-stat .stat-number {
    font-size: 28px;
    font-weight: bold;
    margin-bottom: 5px;
}

.user-stat .stat-label {
    font-size: 14px;
    opacity: 0.9;
}

/* 项目筛选 */
.project-filters {
    display: flex;
    gap: 10px;
    margin-bottom: 40px;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 10px 20px;
    background: var(--white);
    border: 2px solid var(--border-color);
    border-radius: 20px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.3s ease;
    color: var(--text-dark);
}

.filter-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

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

/* 项目展示（用于dashboard页面） */
.projects {
    padding: 80px 0;
    background-color: var(--bg-color);
}

.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 30px;
}

.project-card {
    background: var(--white);
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    cursor: pointer;
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.project-image {
    height: 180px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.placeholder-image {
    color: var(--white);
    font-size: 48px;
    font-weight: bold;
}

.project-info {
    padding: 20px;
}

.project-info h3 {
    margin-bottom: 10px;
    color: var(--secondary-color);
}

.project-info p {
    color: var(--text-light);
    margin-bottom: 15px;
    font-size: 14px;
}

.project-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.badge {
    display: inline-block;
    padding: 4px 12px;
    background-color: var(--primary-color);
    color: var(--white);
    border-radius: 15px;
    font-size: 12px;
    font-weight: 600;
}

.badge.completed {
    background-color: #52c41a;
}

.badge.available {
    background-color: #faad14;
}

.reward {
    color: var(--accent-color);
    font-weight: bold;
}

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

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    margin-bottom: 30px;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 20px;
}

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

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

.footer-section a {
    color: var(--white);
    text-decoration: none;
    opacity: 0.8;
    transition: opacity 0.3s ease;
}

.footer-section a:hover {
    opacity: 1;
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    opacity: 0.7;
}

/* 表单页面样式 */
.auth-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    padding: 40px 20px;
}

.auth-container {
    background: var(--white);
    padding: 40px;
    border-radius: 10px;
    box-shadow: var(--shadow-hover);
    max-width: 450px;
    width: 100%;
}

.auth-container h1 {
    text-align: center;
    margin-bottom: 30px;
    color: var(--secondary-color);
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text-dark);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 5px;
    font-size: 16px;
    transition: border-color 0.3s ease;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.auth-submit {
    width: 100%;
    padding: 14px;
    background-color: var(--primary-color);
    color: var(--white);
    border: none;
    border-radius: 5px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.auth-submit:hover {
    background-color: var(--primary-dark);
}

.auth-submit:disabled {
    background-color: #ccc;
    cursor: not-allowed;
    opacity: 0.5;
}

.auth-footer {
    text-align: center;
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
}

.auth-footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

.auth-footer a:hover {
    text-decoration: underline;
}

/* 条款页面 */
.terms-page {
    max-width: 800px;
    margin: 40px auto;
    padding: 40px;
    background: var(--white);
    border-radius: 10px;
    box-shadow: var(--shadow);
}

.terms-page h1 {
    margin-bottom: 30px;
    color: var(--secondary-color);
}

.terms-page h2 {
    margin: 30px 0 15px;
    color: var(--secondary-color);
}

.terms-page h3 {
    margin: 20px 0 10px;
    color: var(--text-dark);
}

.terms-page p {
    margin-bottom: 15px;
    color: var(--text-light);
    line-height: 1.8;
}

.terms-page ul {
    margin: 15px 0 15px 30px;
}

.terms-page li {
    margin-bottom: 10px;
    color: var(--text-light);
}

.terms-page .update-date {
    color: var(--text-light);
    font-style: italic;
    margin-bottom: 30px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

    .hero-content h1 {
        font-size: 32px;
    }

    .hero-content p {
        font-size: 16px;
    }

    .hero-buttons {
        flex-direction: column;
    }

    .section-title {
        font-size: 24px;
    }
}