/* 专利费用期限提醒系统 - 专业商业软件官网 */
/* 简洁、专业、稳重的商务风格 */

:root {
    /* 主色调 - 稳重的商务蓝 */
    --primary-dark: #1a365d;
    --primary: #2c5282;
    --primary-light: #4299e1;
    
    /* 辅助色 */
    --accent: #3182ce;
    --accent-hover: #2b6cb0;
    
    /* 中性色 */
    --text-dark: #1a202c;
    --text: #4a5568;
    --text-light: #718096;
    --text-muted: #a0aec0;
    --bg-white: #ffffff;
    --bg-light: #f7fafc;
    --bg-gray: #edf2f7;
    --border: #e2e8f0;
    
    /* 功能色 */
    --success: #38a169;
    --warning: #d69e2e;
    
    /* 阴影 */
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
    --shadow: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-md: 0 10px 15px rgba(0,0,0,0.1);
    --shadow-lg: 0 20px 25px rgba(0,0,0,0.12);
    
    /* 圆角 */
    --radius-sm: 4px;
    --radius: 8px;
    --radius-lg: 12px;
    
    /* 过渡 */
    --transition: all 0.25s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    line-height: 1.7;
    color: var(--text);
    background: var(--bg-white);
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ========== 导航栏 ========== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: var(--bg-white);
    box-shadow: var(--shadow-sm);
    border-bottom: 1px solid var(--border);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 18px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-dark);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 35px;
    align-items: center;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text);
    font-weight: 500;
    font-size: 0.95rem;
    transition: var(--transition);
}

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

.btn-nav {
    background: var(--primary);
    color: white !important;
    padding: 10px 24px !important;
    border-radius: var(--radius);
    transition: var(--transition);
}

.btn-nav:hover {
    background: var(--accent-hover);
}

/* ========== 首页横幅 ========== */
.hero {
    background: linear-gradient(180deg, var(--bg-light) 0%, var(--bg-white) 100%);
    padding: 160px 20px 100px;
    text-align: center;
    border-bottom: 1px solid var(--border);
}

.hero-content {
    max-width: 850px;
    margin: 0 auto;
}

.hero-title {
    font-size: 2.8rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 20px;
    line-height: 1.3;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--primary);
    margin-bottom: 20px;
    font-weight: 500;
}

.hero-description {
    font-size: 1.1rem;
    color: var(--text-light);
    margin-bottom: 40px;
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin-bottom: 60px;
}

.btn-primary {
    display: inline-block;
    background: var(--primary);
    color: white;
    padding: 14px 40px;
    border-radius: var(--radius);
    text-decoration: none;
    font-weight: 600;
    font-size: 1.05rem;
    transition: var(--transition);
}

.btn-primary:hover {
    background: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    display: inline-block;
    background: transparent;
    color: var(--primary);
    padding: 14px 40px;
    border-radius: var(--radius);
    text-decoration: none;
    font-weight: 600;
    font-size: 1.05rem;
    border: 2px solid var(--primary);
    transition: var(--transition);
}

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

.hero-stats {
    display: flex;
    gap: 60px;
    justify-content: center;
}

.stat-item {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-dark);
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-top: 5px;
    display: block;
}

/* ========== 通用区块样式 ========== */
.section {
    padding: 100px 0;
}

.section-title {
    text-align: center;
    font-size: 2.2rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 15px;
}

.section-subtitle {
    text-align: center;
    font-size: 1.1rem;
    color: var(--text-light);
    margin-bottom: 60px;
}

/* ========== 功能区块 ========== */
.features {
    background: var(--bg-white);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
    gap: 30px;
}

.feature-card {
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 35px;
    transition: var(--transition);
}

.feature-card:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow-md);
    transform: translateY(-4px);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 20px;
    display: block;
}

.feature-card h3 {
    font-size: 1.35rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 15px;
}

.feature-card p {
    color: var(--text-light);
    margin-bottom: 20px;
    line-height: 1.7;
}

.feature-list {
    list-style: none;
}

.feature-list li {
    padding: 6px 0;
    color: var(--text);
    font-size: 0.95rem;
    padding-left: 22px;
    position: relative;
}

.feature-list li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--primary);
    font-weight: bold;
}

/* ========== 优势区块 ========== */
.advantages {
    background: var(--bg-light);
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
}

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 40px;
}

.advantage-item {
    display: flex;
    gap: 20px;
}

.advantage-icon {
    width: 36px;
    height: 36px;
    background: var(--success);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.1rem;
    flex-shrink: 0;
}

.advantage-item h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 10px;
}

.advantage-item p {
    color: var(--text-light);
    line-height: 1.7;
    font-size: 0.98rem;
}

/* ========== 展示区块 ========== */
.showcase {
    background: var(--bg-white);
}

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

.showcase-item {
    background: var(--bg-light);
    border-radius: var(--radius-lg);
    padding: 35px;
    border: 1px solid var(--border);
}

.showcase-item h3 {
    font-size: 1.35rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 15px;
    padding-bottom: 15px;
    border-bottom: 2px solid var(--primary);
}

.showcase-item p {
    color: var(--text-light);
    margin-bottom: 20px;
    line-height: 1.7;
}

.showcase-item ul {
    list-style: none;
}

.showcase-item li {
    padding: 8px 0;
    color: var(--text);
    padding-left: 20px;
    position: relative;
}

.showcase-item li::before {
    content: '›';
    position: absolute;
    left: 0;
    color: var(--primary);
    font-weight: bold;
    font-size: 1.2rem;
}

/* ========== 教程区块 ========== */
.tutorial {
    background: var(--bg-light);
    border-top: 1px solid var(--border);
}

.tutorial-box {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: start;
}

.tutorial-info {
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 40px;
}

.tutorial-info h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 15px;
}

.tutorial-info p {
    color: var(--text-light);
    margin-bottom: 25px;
    line-height: 1.7;
}

.btn-tutorial {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: var(--primary);
    color: white;
    padding: 14px 30px;
    border-radius: var(--radius);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
}

.btn-tutorial:hover {
    background: var(--accent-hover);
}

.btn-tutorial span {
    font-size: 1.2rem;
}

.tutorial-steps {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.step-item {
    display: flex;
    gap: 18px;
    padding: 20px;
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
}

.step-num {
    width: 36px;
    height: 36px;
    background: var(--primary);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1rem;
    flex-shrink: 0;
}

.step-item h4 {
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 5px;
}

.step-item p {
    color: var(--text-light);
    font-size: 0.95rem;
}

/* ========== 下载区块 ========== */
.download {
    background: var(--bg-white);
}

.download-content {
    background: var(--bg-light);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 45px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: center;
    margin-bottom: 50px;
}

.download-info h3 {
    font-size: 1.6rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 10px;
}

.version {
    color: var(--text-muted);
    margin-bottom: 25px;
    font-size: 0.95rem;
}

.requirements {
    list-style: none;
}

.requirements li {
    padding: 10px 0;
    color: var(--text);
    font-size: 0.95rem;
    padding-left: 25px;
    position: relative;
}

.requirements li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--primary);
}

.download-buttons {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.btn-download {
    display: flex;
    align-items: center;
    gap: 15px;
    background: var(--bg-white);
    border: 2px solid var(--border);
    border-radius: var(--radius);
    padding: 18px 25px;
    text-decoration: none;
    transition: var(--transition);
}

.btn-download:hover {
    border-color: var(--primary);
    background: var(--bg-light);
}

.btn-icon {
    font-size: 2rem;
}

.btn-download strong {
    display: block;
    color: var(--text-dark);
    font-size: 1rem;
    margin-bottom: 3px;
}

.btn-download span {
    color: var(--text-muted);
    font-size: 0.85rem;
}

/* ========== 会员区块 ========== */
.membership-section {
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 100%);
    border-radius: var(--radius-lg);
    padding: 45px;
    color: white;
}

.membership-section h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 30px;
    text-align: center;
}

.membership-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-bottom: 30px;
}

.member-item {
    display: flex;
    align-items: center;
    gap: 12px;
    background: rgba(255,255,255,0.1);
    padding: 15px 18px;
    border-radius: var(--radius);
    font-size: 0.95rem;
}

.member-check {
    width: 24px;
    height: 24px;
    background: var(--success);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.85rem;
    flex-shrink: 0;
}

.membership-contact {
    text-align: center;
    color: rgba(255,255,255,0.9);
    font-size: 1rem;
}

.membership-contact strong {
    color: white;
    font-size: 1.15rem;
}

/* ========== 页脚 ========== */
.footer {
    background: var(--primary-dark);
    color: rgba(255,255,255,0.8);
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-section h4 {
    font-size: 1.1rem;
    font-weight: 600;
    color: white;
    margin-bottom: 18px;
}

.footer-section p {
    line-height: 1.8;
    font-size: 0.95rem;
}

.footer-section a {
    display: block;
    color: rgba(255,255,255,0.7);
    text-decoration: none;
    padding: 8px 0;
    transition: var(--transition);
    font-size: 0.95rem;
}

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

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255,255,255,0.1);
}

.footer-bottom p {
    font-size: 0.88rem;
    color: rgba(255,255,255,0.6);
    margin: 5px 0;
}

/* ========== 响应式设计 ========== */
@media (max-width: 968px) {
    .nav-menu {
        gap: 20px;
    }
    
    .hero-title {
        font-size: 2.2rem;
    }
    
    .hero-stats {
        gap: 30px;
    }
    
    .tutorial-box,
    .download-content {
        grid-template-columns: 1fr;
    }
    
    .advantages-grid {
        grid-template-columns: 1fr;
    }
    
    .membership-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-container {
        flex-direction: column;
        gap: 15px;
    }
    
    .nav-menu {
        flex-wrap: wrap;
        justify-content: center;
        gap: 15px;
    }
    
    .hero {
        padding: 140px 20px 80px;
    }
    
    .hero-title {
        font-size: 1.9rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 20px;
    }
    
    .section {
        padding: 70px 0;
    }
    
    .section-title {
        font-size: 1.8rem;
    }
    
    .features-grid,
    .showcase-grid {
        grid-template-columns: 1fr;
    }
    
    .download-buttons {
        flex-direction: column;
    }
    
    .membership-grid {
        grid-template-columns: 1fr;
    }
}