/* 全局重置与基础样式 */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --primary: #1a1a2e;
    --primary-light: #2d2d4a;
    --accent: #f5c518;
    --accent-hover: #e0b414;
    --accent-soft: rgba(245, 197, 24, 0.15);
    --text: #e0e0e0;
    --text-muted: #a0a0b0;
    --bg: #0f0f1a;
    --bg-card: rgba(26, 26, 46, 0.8);
    --bg-glass: rgba(15, 15, 26, 0.7);
    --border: rgba(245, 197, 24, 0.2);
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
    --radius: 16px;
    --radius-sm: 10px;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --font: 'Segoe UI', system-ui, -apple-system, sans-serif;
}

/* 暗色主题（默认） */
html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    line-height: 1.7;
    min-height: 100vh;
    overflow-x: hidden;
}

/* 滚动条 */
::-webkit-scrollbar {
    width: 8px;
}
::-webkit-scrollbar-track {
    background: var(--primary);
}
::-webkit-scrollbar-thumb {
    background: var(--accent);
    border-radius: 4px;
}

/* 链接与交互 */
a {
    color: var(--accent);
    text-decoration: none;
    transition: var(--transition);
}
a:hover, a:focus-visible {
    color: var(--accent-hover);
    text-decoration: underline;
}

/* 标题 */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.3;
    letter-spacing: -0.02em;
}
h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.5rem, 3.5vw, 2.5rem); }
h3 { font-size: clamp(1.2rem, 2.5vw, 1.8rem); }

/* 容器 */
section {
    padding: 4rem 1.5rem;
    max-width: 1200px;
    margin: 0 auto;
}

/* ===== 头部导航 ===== */
header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: var(--bg-glass);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-bottom: 1px solid var(--border);
    transition: var(--transition);
}

header nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.75rem 1.5rem;
    max-width: 1200px;
    margin: 0 auto;
}

header nav > div a {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text);
    font-weight: 700;
    font-size: 1.2rem;
}
header nav > div a:hover {
    color: var(--accent);
    text-decoration: none;
}
header nav > div a svg {
    flex-shrink: 0;
}

header nav ul {
    list-style: none;
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

header nav ul li a {
    color: var(--text-muted);
    font-weight: 500;
    padding: 0.4rem 0.2rem;
    position: relative;
    font-size: 0.95rem;
}
header nav ul li a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: var(--transition);
}
header nav ul li a:hover::after,
header nav ul li a:focus-visible::after {
    width: 100%;
}
header nav ul li a:hover {
    color: var(--accent);
    text-decoration: none;
}

/* ===== Hero 区域（渐变Banner） ===== */
#hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 6rem 1.5rem 4rem;
    position: relative;
    background: linear-gradient(135deg, #0f0f1a 0%, #1a1a2e 40%, #2d1b4e 70%, #1a1a2e 100%);
    overflow: hidden;
}
#hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at 30% 50%, rgba(245, 197, 24, 0.08) 0%, transparent 50%),
                radial-gradient(circle at 70% 30%, rgba(245, 197, 24, 0.05) 0%, transparent 40%);
    animation: heroGlow 15s ease-in-out infinite alternate;
    pointer-events: none;
}
@keyframes heroGlow {
    0% { transform: translate(0, 0) rotate(0deg); }
    100% { transform: translate(5%, 5%) rotate(3deg); }
}

#hero > div {
    position: relative;
    z-index: 1;
    max-width: 800px;
}
#hero h1 {
    color: #fff;
    text-shadow: 0 2px 20px rgba(0,0,0,0.5);
    margin-bottom: 1rem;
}
#hero p {
    font-size: clamp(1rem, 2vw, 1.3rem);
    color: var(--text-muted);
    margin-bottom: 0.5rem;
}
#hero p:first-of-type {
    color: var(--accent);
    font-weight: 600;
    letter-spacing: 0.05em;
}
#hero div:last-of-type {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-top: 2rem;
    flex-wrap: wrap;
}
#hero a {
    display: inline-block;
    padding: 0.85rem 2.5rem;
    border-radius: 50px;
    font-weight: 600;
    transition: var(--transition);
    border: 2px solid transparent;
}
#hero a:first-of-type {
    background: var(--accent);
    color: var(--primary);
    border-color: var(--accent);
}
#hero a:first-of-type:hover {
    background: var(--accent-hover);
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(245, 197, 24, 0.3);
    text-decoration: none;
}
#hero a:last-of-type {
    background: transparent;
    color: #fff;
    border-color: rgba(255,255,255,0.3);
}
#hero a:last-of-type:hover {
    background: rgba(255,255,255,0.1);
    border-color: #fff;
    transform: translateY(-3px);
    text-decoration: none;
}

/* ===== 通用卡片样式（圆角卡片 + 毛玻璃） ===== */
section:not(#hero) {
    background: var(--bg-card);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-radius: var(--radius);
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
    margin: 2rem auto;
    padding: 2.5rem 2rem;
    transition: var(--transition);
    opacity: 0;
    transform: translateY(30px);
    animation: fadeInUp 0.8s ease forwards;
}
section:not(#hero):hover {
    border-color: rgba(245, 197, 24, 0.4);
    box-shadow: 0 12px 40px rgba(0,0,0,0.5);
}

@keyframes fadeInUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 延迟动画 */
#about { animation-delay: 0.1s; }
#story { animation-delay: 0.2s; }
#team { animation-delay: 0.3s; }
#products { animation-delay: 0.4s; }
#services { animation-delay: 0.5s; }
#solutions { animation-delay: 0.6s; }
#industries { animation-delay: 0.7s; }
#features { animation-delay: 0.8s; }
#advantages { animation-delay: 0.9s; }
#testimonials { animation-delay: 1s; }
#case-studies { animation-delay: 1.1s; }
#latest-insights { animation-delay: 1.2s; }
#knowledge-center { animation-delay: 1.3s; }
#faq { animation-delay: 1.4s; }
#howto { animation-delay: 1.5s; }
#contact { animation-delay: 1.6s; }

/* 标题装饰 */
section h2 {
    color: var(--accent);
    margin-bottom: 1.5rem;
    position: relative;
    display: inline-block;
}
section h2::after {
    content: '';
    display: block;
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, var(--accent), transparent);
    margin-top: 0.5rem;
    border-radius: 2px;
}

/* 段落 */
section p {
    margin-bottom: 1rem;
    color: var(--text);
}
section p:last-child {
    margin-bottom: 0;
}

/* 列表 */
section ul, section ol {
    padding-left: 1.5rem;
    margin: 1rem 0;
}
section li {
    margin-bottom: 0.5rem;
    color: var(--text-muted);
}
section li::marker {
    color: var(--accent);
}

/* ===== 产品卡片网格 ===== */
#products > div {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
    margin-top: 1.5rem;
}
#products article {
    background: rgba(255,255,255,0.03);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 1.5rem;
    transition: var(--transition);
    cursor: default;
}
#products article:hover {
    transform: translateY(-5px);
    background: rgba(245, 197, 24, 0.05);
    border-color: var(--accent);
    box-shadow: 0 8px 25px rgba(245, 197, 24, 0.1);
}
#products article h3 {
    color: var(--accent);
    margin-bottom: 0.75rem;
}
#products article p {
    color: var(--text-muted);
    font-size: 0.95rem;
}

/* ===== 用户评价（blockquote） ===== */
#testimonials > div {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-top: 1.5rem;
}
blockquote {
    background: rgba(255,255,255,0.03);
    border-left: 4px solid var(--accent);
    padding: 1.2rem 1.5rem;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    transition: var(--transition);
}
blockquote:hover {
    background: rgba(245, 197, 24, 0.05);
    transform: translateX(5px);
}
blockquote p {
    font-style: italic;
    margin-bottom: 0.5rem;
}
blockquote cite {
    color: var(--accent);
    font-style: normal;
    font-weight: 500;
    font-size: 0.9rem;
}

/* ===== 成功案例 & 资讯 ===== */
#case-studies article,
#latest-insights article,
#knowledge-center article {
    background: rgba(255,255,255,0.02);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 1.2rem 1.5rem;
    margin-top: 1rem;
    transition: var(--transition);
}
#case-studies article:hover,
#latest-insights article:hover,
#knowledge-center article:hover {
    border-color: var(--accent);
    background: rgba(245, 197, 24, 0.03);
    transform: translateY(-3px);
}
#latest-insights time {
    display: block;
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-top: 0.5rem;
}

/* ===== FAQ (details) ===== */
#faq details {
    background: rgba(255,255,255,0.02);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    margin-bottom: 0.75rem;
    padding: 0.75rem 1.2rem;
    transition: var(--transition);
    cursor: pointer;
}
#faq details:hover {
    border-color: var(--accent);
    background: rgba(245, 197, 24, 0.03);
}
#faq details[open] {
    border-color: var(--accent);
    background: rgba(245, 197, 24, 0.05);
}
#faq summary {
    font-weight: 600;
    color: var(--accent);
    cursor: pointer;
    padding: 0.25rem 0;
    outline: none;
}
#faq summary::-webkit-details-marker {
    color: var(--accent);
}
#faq details p {
    padding: 0.75rem 0 0.25rem;
    color: var(--text-muted);
    font-size: 0.95rem;
}

/* ===== 使用指南 ===== */
#howto ol {
    list-style: decimal;
    padding-left: 1.5rem;
}
#howto ol li {
    padding: 0.4rem 0;
    font-weight: 500;
}

/* ===== 联系我们 ===== */
#contact ul {
    list-style: none;
    padding-left: 0;
}
#contact ul li {
    padding: 0.3rem 0;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}
#contact ul li::before {
    content: '✦';
    color: var(--accent);
    font-size: 0.8rem;
}

/* ===== 底部 ===== */
footer {
    background: var(--primary);
    border-top: 1px solid var(--border);
    padding: 2.5rem 1.5rem 1.5rem;
    margin-top: 3rem;
}
footer > div {
    max-width: 1200px;
    margin: 0 auto;
}
footer nav {
    margin-bottom: 1rem;
}
footer nav ul {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 1.2rem;
    justify-content: center;
    padding: 0;
}
footer nav ul li a {
    color: var(--text-muted);
    font-size: 0.9rem;
}
footer nav ul li a:hover {
    color: var(--accent);
}
footer p {
    text-align: center;
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-top: 0.5rem;
}

/* ===== 响应式设计 ===== */
@media (max-width: 768px) {
    header nav {
        flex-direction: column;
        gap: 0.75rem;
        padding: 0.5rem 1rem;
    }
    header nav ul {
        flex-wrap: wrap;
        justify-content: center;
        gap: 1rem;
    }
    header nav ul li a {
        font-size: 0.9rem;
    }

    section {
        padding: 2rem 1rem;
        margin: 1.5rem 1rem;
    }

    #hero {
        padding: 5rem 1rem 3rem;
        min-height: 80vh;
    }
    #hero h1 {
        font-size: 1.8rem;
    }
    #hero div:last-of-type {
        flex-direction: column;
        align-items: center;
    }
    #hero a {
        width: 100%;
        max-width: 280px;
        text-align: center;
    }

    #products > div,
    #testimonials > div {
        grid-template-columns: 1fr;
    }

    footer nav ul {
        flex-direction: column;
        align-items: center;
        gap: 0.5rem;
    }
}

@media (max-width: 480px) {
    html {
        font-size: 14px;
    }
    section {
        padding: 1.5rem 0.8rem;
    }
    #hero h1 {
        font-size: 1.5rem;
    }
}

/* ===== 暗色模式（已内置） ===== */
@media (prefers-color-scheme: light) {
    /* 强制保留暗色风格，符合品牌调性 */
    :root {
        --bg: #0f0f1a;
        --text: #e0e0e0;
        --text-muted: #a0a0b0;
        --bg-card: rgba(26, 26, 46, 0.85);
        --bg-glass: rgba(15, 15, 26, 0.75);
    }
    body {
        background: var(--bg);
    }
}

/* ===== 辅助功能 ===== */
:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

/* 跳过导航（隐式） */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0,0,0,0);
    white-space: nowrap;
    border: 0;
}