/* ===== 全局重置 & 基础 ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    color: #1a1a2e;
    line-height: 1.6;
    transition: background 0.3s, color 0.3s;
}

body.dark-mode {
    background: linear-gradient(135deg, #0f0f1a 0%, #1a1a2e 100%);
    color: #e0e0e0;
}

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

/* ===== 玻璃拟态通用 ===== */
.glass {
    background: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

.dark-mode .glass {
    background: rgba(20, 20, 40, 0.7);
    border-color: rgba(255, 255, 255, 0.1);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.5);
}

/* ===== 导航栏 ===== */
header {
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    transition: background 0.3s, box-shadow 0.3s;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(15px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.dark-mode header {
    background: rgba(15, 15, 26, 0.8);
    border-color: rgba(255, 255, 255, 0.05);
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: inherit;
}

.logo svg {
    width: 48px;
    height: 48px;
}

.logo-text {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, #ff6b35, #f7c948);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

.nav-links a {
    text-decoration: none;
    color: #1a1a2e;
    font-weight: 500;
    transition: color 0.3s;
    position: relative;
}

.dark-mode .nav-links a {
    color: #e0e0e0;
}

.nav-links a:hover {
    color: #ff6b35;
}

.nav-links a.active {
    color: #ff6b35;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: #ff6b35;
    transition: width 0.3s;
}

.nav-links a:hover::after,
.nav-links a.active::after {
    width: 100%;
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 20px;
}

.search-box {
    display: flex;
    align-items: center;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 30px;
    padding: 5px 15px;
    border: 1px solid rgba(0, 0, 0, 0.1);
}

.dark-mode .search-box {
    border-color: rgba(255, 255, 255, 0.1);
}

.search-box input {
    border: none;
    background: transparent;
    outline: none;
    padding: 8px 10px;
    font-size: 0.9rem;
    color: inherit;
    width: 180px;
}

.search-box button {
    background: none;
    border: none;
    cursor: pointer;
    color: #ff6b35;
    font-size: 1.2rem;
}

.dark-toggle {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: inherit;
    transition: transform 0.3s;
}

.dark-toggle:hover {
    transform: rotate(20deg);
}

.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    background: none;
    border: none;
}

.hamburger span {
    width: 28px;
    height: 3px;
    background: #1a1a2e;
    border-radius: 5px;
    transition: 0.3s;
}

.dark-mode .hamburger span {
    background: #e0e0e0;
}

/* ===== 移动端菜单 ===== */
.mobile-menu {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 999;
}

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

.mobile-menu-content {
    position: absolute;
    top: 0;
    right: 0;
    width: 300px;
    height: 100%;
    background: white;
    padding: 80px 30px 30px;
    box-shadow: -10px 0 30px rgba(0, 0, 0, 0.1);
    transform: translateX(100%);
    transition: transform 0.4s;
}

.dark-mode .mobile-menu-content {
    background: #1a1a2e;
}

.mobile-menu.active .mobile-menu-content {
    transform: translateX(0);
}

.mobile-menu-content a {
    display: block;
    padding: 15px 0;
    font-size: 1.1rem;
    color: #1a1a2e;
    text-decoration: none;
    border-bottom: 1px solid #eee;
}

.dark-mode .mobile-menu-content a {
    color: #e0e0e0;
    border-color: #333;
}

.mobile-menu-close {
    position: absolute;
    top: 20px;
    right: 20px;
    font-size: 2rem;
    background: none;
    border: none;
    cursor: pointer;
    color: #1a1a2e;
}

.dark-mode .mobile-menu-close {
    color: #e0e0e0;
}

/* ===== 主内容区 ===== */
main {
    margin-top: 80px;
}

section {
    padding: 80px 0;
}

/* ===== Banner ===== */
.banner {
    position: relative;
    height: 600px;
    overflow: hidden;
    border-radius: 0 0 50px 50px;
    margin-bottom: 40px;
}

.banner-slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 1s ease;
}

.banner-slide.active {
    opacity: 1;
}

.banner-content {
    text-align: center;
    color: white;
    z-index: 2;
    padding: 40px;
    background: rgba(0, 0, 0, 0.3);
    backdrop-filter: blur(5px);
    border-radius: 30px;
    max-width: 700px;
}

.banner-content h1 {
    font-size: 3rem;
    margin-bottom: 20px;
    text-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
}

.banner-content p {
    font-size: 1.2rem;
    margin-bottom: 30px;
}

.btn {
    display: inline-block;
    padding: 15px 40px;
    background: linear-gradient(135deg, #ff6b35, #f7c948);
    color: white;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: transform 0.3s, box-shadow 0.3s;
    border: none;
    cursor: pointer;
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(255, 107, 53, 0.4);
}

.banner-indicators {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 12px;
    z-index: 3;
}

.banner-indicators button {
    width: 14px;
    height: 14px;
    border-radius: 50%;
    border: 2px solid white;
    background: transparent;
    cursor: pointer;
    transition: 0.3s;
}

.banner-indicators button.active {
    background: white;
    transform: scale(1.2);
}

/* ===== 卡片通用 ===== */
.card {
    background: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(15px);
    border-radius: 24px;
    padding: 30px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.08);
    transition: transform 0.3s, box-shadow 0.3s;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.dark-mode .card {
    background: rgba(20, 20, 40, 0.7);
    border-color: rgba(255, 255, 255, 0.1);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
}

.card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.15);
}

.grid-2,
.grid-3,
.grid-4 {
    display: grid;
    gap: 30px;
}

.grid-2 {
    grid-template-columns: repeat(2, 1fr);
}

.grid-3 {
    grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
    grid-template-columns: repeat(4, 1fr);
}

@media (max-width: 768px) {
    .grid-2,
    .grid-3,
    .grid-4 {
        grid-template-columns: 1fr;
    }
}

/* ===== 标题 ===== */
h2 {
    font-size: 2.2rem;
    margin-bottom: 40px;
    text-align: center;
    position: relative;
}

h2::after {
    content: '';
    display: block;
    width: 80px;
    height: 4px;
    background: linear-gradient(135deg, #ff6b35, #f7c948);
    margin: 15px auto 0;
    border-radius: 5px;
}

h3 {
    font-size: 1.5rem;
    margin-bottom: 20px;
}

/* ===== 面包屑 ===== */
.breadcrumb {
    padding: 20px 0;
    font-size: 0.9rem;
    color: #666;
}

.dark-mode .breadcrumb {
    color: #aaa;
}

.breadcrumb a {
    color: #ff6b35;
    text-decoration: none;
}

/* ===== 文章卡片 ===== */
.article-card svg {
    width: 100%;
    height: 200px;
    border-radius: 16px;
    margin-bottom: 15px;
}

.article-card h3 {
    font-size: 1.3rem;
}

.article-card .date {
    color: #888;
    font-size: 0.85rem;
}

/* ===== FAQ ===== */
.faq-item {
    margin-bottom: 15px;
    border-radius: 16px;
    overflow: hidden;
}

.faq-question {
    width: 100%;
    padding: 20px 25px;
    background: rgba(255, 255, 255, 0.5);
    border: none;
    text-align: left;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: inherit;
    transition: background 0.3s;
}

.dark-mode .faq-question {
    background: rgba(255, 255, 255, 0.05);
}

.faq-question:hover {
    background: rgba(255, 107, 53, 0.1);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.5s ease, padding 0.3s;
    padding: 0 25px;
    background: rgba(255, 255, 255, 0.2);
}

.dark-mode .faq-answer {
    background: rgba(0, 0, 0, 0.2);
}

.faq-item.active .faq-answer {
    max-height: 400px;
    padding: 20px 25px;
}

.faq-answer p {
    margin-bottom: 10px;
}

/* ===== 数字动画 ===== */
.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, #ff6b35, #f7c948);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ===== 页脚 ===== */
footer {
    background: rgba(0, 0, 0, 0.05);
    padding: 60px 0 30px;
    margin-top: 60px;
}

.dark-mode footer {
    background: rgba(0, 0, 0, 0.3);
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 40px;
    margin-bottom: 40px;
}

@media (max-width: 768px) {
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
}

.footer-grid h4 {
    margin-bottom: 20px;
    font-size: 1.1rem;
}

.footer-grid a {
    display: block;
    color: #666;
    text-decoration: none;
    margin-bottom: 10px;
    transition: color 0.3s;
}

.dark-mode .footer-grid a {
    color: #aaa;
}

.footer-grid a:hover {
    color: #ff6b35;
}

.copyright {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(0, 0, 0, 0.1);
    font-size: 0.9rem;
    color: #888;
}

.dark-mode .copyright {
    border-color: rgba(255, 255, 255, 0.1);
}

/* ===== 返回顶部 ===== */
.back-top {
    position: fixed;
    bottom: 40px;
    right: 40px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: linear-gradient(135deg, #ff6b35, #f7c948);
    color: white;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: 0.3s;
    z-index: 100;
    box-shadow: 0 5px 20px rgba(255, 107, 53, 0.4);
}

.back-top.visible {
    opacity: 1;
    visibility: visible;
}

/* ===== 动画类 ===== */
.fade-up {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.fade-up.visible {
    opacity: 1;
    transform: translateY(0);
}

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

    .hamburger {
        display: flex;
    }

    .search-box input {
        width: 100px;
    }

    .banner {
        height: 400px;
    }

    .banner-content h1 {
        font-size: 2rem;
    }

    section {
        padding: 50px 0;
    }

    .mobile-menu {
        display: block;
    }
}

@media (max-width: 480px) {
    .banner {
        height: 300px;
    }

    .banner-content h1 {
        font-size: 1.5rem;
    }

    .banner-content p {
        font-size: 1rem;
    }
}

/* ===== HowTo样式 ===== */
.howto-step {
    display: flex;
    gap: 20px;
    margin-bottom: 25px;
    align-items: flex-start;
}

.howto-step .step-number {
    background: linear-gradient(135deg, #ff6b35, #f7c948);
    color: white;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    flex-shrink: 0;
}