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

:root {
    /* 主色调 - 红桃红 */
    --primary: #d32f2f;
    --primary-light: #ff6659;
    --primary-dark: #9a0007;
    --primary-gradient: linear-gradient(135deg, #d32f2f 0%, #ff8a80 50%, #d32f2f 100%);
    --secondary-gradient: linear-gradient(135deg, #0d47a1, #1976d2, #42a5f5);
    --accent-gradient: linear-gradient(135deg, #ff6f00, #ffab00, #ffd54f);

    /* 背景与文本 */
    --bg: #fafafa;
    --bg-card: rgba(255, 255, 255, 0.85);
    --bg-glass: rgba(255, 255, 255, 0.2);
    --text: #212121;
    --text-secondary: #616161;
    --text-light: #9e9e9e;
    --border: #e0e0e0;
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.08);
    --shadow-hover: 0 12px 40px rgba(0, 0, 0, 0.15);

    /* 暗色模式变量 */
    --dark-bg: #121212;
    --dark-bg-card: rgba(30, 30, 30, 0.9);
    --dark-bg-glass: rgba(255, 255, 255, 0.05);
    --dark-text: #e0e0e0;
    --dark-text-secondary: #b0b0b0;
    --dark-border: #333;

    /* 圆角 */
    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 24px;
    --radius-xl: 32px;

    /* 字体 */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

    /* 间距 */
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    --space-2xl: 48px;
    --space-3xl: 64px;

    /* 过渡 */
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-sans);
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    transition: background var(--transition-normal), color var(--transition-normal);
    overflow-x: hidden;
}

/* ===== 暗色模式 ===== */
body.dark-mode {
    --bg: #121212;
    --bg-card: rgba(30, 30, 30, 0.9);
    --bg-glass: rgba(255, 255, 255, 0.05);
    --text: #e0e0e0;
    --text-secondary: #b0b0b0;
    --text-light: #757575;
    --border: #333;
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
    --shadow-hover: 0 12px 40px rgba(0, 0, 0, 0.6);
}

/* ===== 滚动条 ===== */
::-webkit-scrollbar {
    width: 8px;
}
::-webkit-scrollbar-track {
    background: transparent;
}
::-webkit-scrollbar-thumb {
    background: var(--primary-light);
    border-radius: 4px;
    transition: background var(--transition-fast);
}
::-webkit-scrollbar-thumb:hover {
    background: var(--primary);
}

/* ===== 通用 ===== */
a {
    color: var(--primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}
a:hover {
    color: var(--primary-light);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

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);
    margin-bottom: var(--space-lg);
}
h3 {
    font-size: clamp(1.1rem, 2.5vw, 1.5rem);
    margin-bottom: var(--space-sm);
}

p {
    margin-bottom: var(--space-md);
    color: var(--text-secondary);
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* ===== 按钮 ===== */
.btn-primary {
    display: inline-block;
    padding: 14px 36px;
    background: var(--primary-gradient);
    color: #fff;
    font-weight: 600;
    font-size: 1rem;
    border-radius: 50px;
    border: none;
    cursor: pointer;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast), filter var(--transition-fast);
    box-shadow: 0 4px 20px rgba(211, 47, 47, 0.3);
    text-align: center;
}
.btn-primary:hover {
    transform: translateY(-2px) scale(1.02);
    box-shadow: 0 8px 30px rgba(211, 47, 47, 0.4);
    filter: brightness(1.1);
    color: #fff;
}
.btn-primary:active {
    transform: translateY(0) scale(0.98);
}

/* ===== 卡片 ===== */
.card {
    background: var(--bg-card);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-radius: var(--radius-md);
    padding: var(--space-lg);
    box-shadow: var(--shadow);
    border: 1px solid rgba(255, 255, 255, 0.2);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}
.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}

/* ===== 毛玻璃 ===== */
.glass {
    background: var(--bg-glass);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: var(--radius-md);
}

/* ===== 滚动动画 ===== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(40px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInLeft {
    from {
        opacity: 0;
        transform: translateX(-40px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes fadeInRight {
    from {
        opacity: 0;
        transform: translateX(40px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

@keyframes shimmer {
    0% {
        background-position: -200% center;
    }
    100% {
        background-position: 200% center;
    }
}

.animate-on-scroll {
    opacity: 0;
    animation-fill-mode: forwards;
    animation-duration: 0.8s;
    animation-timing-function: cubic-bezier(0.4, 0, 0.2, 1);
}

.animate-on-scroll.visible {
    animation-name: fadeInUp;
}

.animate-on-scroll.visible-left {
    animation-name: fadeInLeft;
}

.animate-on-scroll.visible-right {
    animation-name: fadeInRight;
}

.animate-on-scroll.visible-scale {
    animation-name: scaleIn;
}

/* ===== Header & Nav ===== */
header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: var(--bg-glass);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    transition: background var(--transition-normal);
}

body.dark-mode header {
    background: rgba(18, 18, 18, 0.8);
    border-bottom-color: rgba(255, 255, 255, 0.05);
}

nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--space-sm) var(--space-lg);
    gap: var(--space-md);
}

nav > a {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-weight: 700;
    font-size: 1.2rem;
    color: var(--text);
    text-decoration: none;
    transition: color var(--transition-fast);
}
nav > a:hover {
    color: var(--primary);
}
nav > a svg {
    flex-shrink: 0;
}

nav ul {
    display: flex;
    list-style: none;
    gap: var(--space-sm);
    flex-wrap: wrap;
}

nav ul li a {
    padding: var(--space-sm) var(--space-md);
    border-radius: 50px;
    font-weight: 500;
    color: var(--text-secondary);
    transition: background var(--transition-fast), color var(--transition-fast);
    font-size: 0.9rem;
}
nav ul li a:hover {
    background: var(--primary);
    color: #fff;
}

nav form {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    background: var(--bg-card);
    border-radius: 50px;
    padding: 4px 4px 4px 16px;
    border: 1px solid var(--border);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}
nav form:focus-within {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(211, 47, 47, 0.15);
}
nav form input {
    border: none;
    background: transparent;
    outline: none;
    font-size: 0.9rem;
    color: var(--text);
    width: 140px;
    transition: width var(--transition-normal);
}
nav form input:focus {
    width: 200px;
}
nav form input::placeholder {
    color: var(--text-light);
}
nav form button {
    background: var(--primary);
    color: #fff;
    border: none;
    padding: 8px 16px;
    border-radius: 50px;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.85rem;
    transition: background var(--transition-fast), transform var(--transition-fast);
}
nav form button:hover {
    background: var(--primary-dark);
    transform: scale(1.05);
}

#theme-toggle {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 1.2rem;
    transition: background var(--transition-fast), transform var(--transition-fast);
}
#theme-toggle:hover {
    background: var(--primary);
    color: #fff;
    transform: rotate(20deg);
}

#menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.8rem;
    cursor: pointer;
    color: var(--text);
    padding: var(--space-xs);
}

/* ===== Hero ===== */
#hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary-gradient);
    overflow: hidden;
    padding-top: 80px;
}

#hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at 20% 50%, rgba(255,255,255,0.15) 0%, transparent 70%),
                radial-gradient(ellipse at 80% 20%, rgba(255,255,255,0.1) 0%, transparent 50%);
    pointer-events: none;
}

.hero-slider {
    position: relative;
    width: 100%;
    max-width: 800px;
    text-align: center;
    padding: var(--space-2xl) var(--space-lg);
    z-index: 1;
}

.slide {
    display: none;
    animation: fadeInUp 0.8s ease forwards;
}
.slide.active {
    display: block;
}

.slide h1 {
    color: #fff;
    text-shadow: 0 2px 20px rgba(0,0,0,0.2);
    margin-bottom: var(--space-md);
    font-size: clamp(1.8rem, 5vw, 3.2rem);
}

.slide p {
    color: rgba(255,255,255,0.9);
    font-size: 1.1rem;
    max-width: 600px;
    margin: 0 auto var(--space-lg);
}

.slide .btn-primary {
    background: #fff;
    color: var(--primary);
    box-shadow: 0 4px 20px rgba(0,0,0,0.15);
}
.slide .btn-primary:hover {
    background: var(--primary);
    color: #fff;
}

.slider-controls {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    align-items: center;
    gap: var(--space-md);
    z-index: 2;
}

.slider-controls .prev,
.slider-controls .next {
    background: rgba(255,255,255,0.2);
    backdrop-filter: blur(8px);
    border: 1px solid rgba(255,255,255,0.3);
    color: #fff;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    font-size: 1.5rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background var(--transition-fast), transform var(--transition-fast);
}
.slider-controls .prev:hover,
.slider-controls .next:hover {
    background: rgba(255,255,255,0.4);
    transform: scale(1.1);
}

.dots {
    display: flex;
    gap: var(--space-sm);
}
.dots span {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255,255,255,0.4);
    cursor: pointer;
    transition: background var(--transition-fast), transform var(--transition-fast);
    border: 2px solid transparent;
}
.dots span[aria-selected="true"] {
    background: #fff;
    transform: scale(1.3);
    border-color: rgba(255,255,255,0.6);
}

/* ===== Sections ===== */
main section {
    padding: var(--space-3xl) var(--space-lg);
    max-width: 1200px;
    margin: 0 auto;
}

section:nth-child(even) {
    background: var(--bg);
}

body.dark-mode section:nth-child(even) {
    background: #1a1a1a;
}

/* ===== About ===== */
#about > div {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-xl);
}

#about h3 {
    color: var(--primary);
    margin-top: var(--space-md);
}

/* ===== Services ===== */
#services > div {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--space-lg);
    margin-bottom: var(--space-2xl);
}

#services h3 {
    color: var(--primary);
    position: relative;
    padding-left: var(--space-lg);
}
#services h3::before {
    content: '▶';
    position: absolute;
    left: 0;
    color: var(--primary);
    font-size: 0.8rem;
    top: 4px;
}

#services ul {
    list-style: none;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-sm);
}
#services ul li {
    padding: var(--space-sm) var(--space-md);
    background: var(--bg-card);
    border-radius: var(--radius-sm);
    border-left: 4px solid var(--primary);
    font-weight: 500;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}
#services ul li:hover {
    transform: translateX(4px);
    box-shadow: var(--shadow);
}

/* ===== Solutions ===== */
#solutions > div {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-lg);
    margin-bottom: var(--space-2xl);
}

#solutions h3 {
    color: var(--primary);
}

/* ===== Cases ===== */
#cases > div {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-xl);
    margin-bottom: var(--space-2xl);
}

#cases h3 {
    color: var(--primary);
}

#cases p {
    padding: var(--space-md);
    background: var(--bg-card);
    border-radius: var(--radius-sm);
    border-left: 4px solid var(--primary);
    margin-bottom: var(--space-md);
    transition: transform var(--transition-fast);
}
#cases p:hover {
    transform: translateX(4px);
}

/* ===== Articles ===== */
#articles > div {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--space-lg);
}

#articles article {
    background: var(--bg-card);
    backdrop-filter: blur(12px);
    border-radius: var(--radius-md);
    padding: var(--space-lg);
    box-shadow: var(--shadow);
    border: 1px solid rgba(255,255,255,0.1);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
    display: flex;
    flex-direction: column;
}
#articles article:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-hover);
}

#articles article h3 {
    color: var(--text);
    margin-bottom: var(--space-sm);
    font-size: 1.2rem;
}

#articles article time {
    font-size: 0.85rem;
    color: var(--text-light);
    margin-bottom: var(--space-sm);
}

#articles article p {
    flex: 1;
    font-size: 0.95rem;
}

#articles article a {
    align-self: flex-start;
    margin-top: var(--space-md);
    font-weight: 600;
    color: var(--primary);
    transition: gap var(--transition-fast);
    display: inline-flex;
    align-items: center;
    gap: 4px;
}
#articles article a:hover {
    gap: 8px;
}

/* ===== FAQ ===== */
#faq > div {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

#faq details {
    background: var(--bg-card);
    backdrop-filter: blur(8px);
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    overflow: hidden;
    transition: box-shadow var(--transition-fast);
}
#faq details:hover {
    box-shadow: var(--shadow);
}

#faq details[open] {
    box-shadow: var(--shadow);
}

#faq summary {
    padding: var(--space-md) var(--space-lg);
    cursor: pointer;
    font-weight: 600;
    font-size: 1rem;
    list-style: none;
    display: flex;
    align-items: center;
    justify-content: space-between;
    transition: background var(--transition-fast), color var(--transition-fast);
}
#faq summary::-webkit-details-marker {
    display: none;
}
#faq summary::after {
    content: '+';
    font-size: 1.4rem;
    font-weight: 300;
    transition: transform var(--transition-fast);
    color: var(--primary);
}
#faq details[open] summary::after {
    content: '−';
    transform: rotate(180deg);
}
#faq summary:hover {
    background: rgba(211, 47, 47, 0.05);
}

#faq details p {
    padding: 0 var(--space-lg) var(--space-lg);
    margin: 0;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ===== HowTo ===== */
#howto ol {
    counter-reset: step;
    list-style: none;
    display: grid;
    gap: var(--space-md);
    margin: var(--space-lg) 0;
}

#howto ol li {
    counter-increment: step;
    padding: var(--space-md) var(--space-lg);
    background: var(--bg-card);
    border-radius: var(--radius-sm);
    border-left: 4px solid var(--primary);
    position: relative;
    padding-left: 60px;
    transition: transform var(--transition-fast);
}
#howto ol li:hover {
    transform: translateX(4px);
}

#howto ol li::before {
    content: counter(step);
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    width: 32px;
    height: 32px;
    background: var(--primary-gradient);
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.9rem;
}

#howto p {
    margin-bottom: var(--space-sm);
}

/* ===== Contact ===== */
#contact > div {
    background: var(--primary-gradient);
    border-radius: var(--radius-lg);
    padding: var(--space-2xl);
    color: #fff;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-md);
}

#contact > div p {
    color: rgba(255,255,255,0.9);
    margin-bottom: var(--space-sm);
}
#contact > div p strong {
    font-size: 1.3rem;
}

/* ===== Footer ===== */
footer {
    background: #1a1a1a;
    color: #ccc;
    padding: var(--space-2xl) var(--space-lg);
}

body.dark-mode footer {
    background: #0a0a0a;
}

footer nav h2,
footer div h2 {
    color: #fff;
    font-size: 1.1rem;
    margin-bottom: var(--space-md);
}

footer nav ul,
footer div ul {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm) var(--space-md);
}

footer nav ul li a,
footer div ul li a {
    color: #aaa;
    font-size: 0.9rem;
    transition: color var(--transition-fast);
}
footer nav ul li a:hover,
footer div ul li a:hover {
    color: var(--primary-light);
}

footer > div:last-child {
    margin-top: var(--space-2xl);
    padding-top: var(--space-lg);
    border-top: 1px solid #333;
    text-align: center;
    font-size: 0.85rem;
    color: #888;
}

footer > div:last-child p {
    margin-bottom: var(--space-xs);
    color: #888;
}

/* ===== Back to Top ===== */
#back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary-gradient);
    color: #fff;
    border: none;
    border-radius: 50%;
    font-size: 1.5rem;
    cursor: pointer;
    box-shadow: 0 4px 20px rgba(211, 47, 47, 0.3);
    transition: transform var(--transition-fast), opacity var(--transition-fast);
    opacity: 0;
    transform: translateY(20px);
    pointer-events: none;
    z-index: 999;
}
#back-to-top.visible {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
}
#back-to-top:hover {
    transform: translateY(-4px) scale(1.1);
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
    nav ul {
        gap: 4px;
    }
    nav ul li a {
        padding: 6px 12px;
        font-size: 0.85rem;
    }
    nav form input {
        width: 100px;
    }
    nav form input:focus {
        width: 140px;
    }

    #about > div,
    #cases > div {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    :root {
        --space-3xl: 48px;
    }

    nav ul {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--bg-glass);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: var(--space-md);
        gap: var(--space-xs);
        border-bottom: 1px solid var(--border);
    }
    nav ul.open {
        display: flex;
    }
    nav ul li a {
        padding: 12px 16px;
        font-size: 1rem;
        border-radius: var(--radius-sm);
    }

    #menu-toggle {
        display: block;
    }

    nav form {
        display: none;
    }

    #hero {
        min-height: 70vh;
        padding-top: 70px;
    }

    .slide h1 {
        font-size: 1.8rem;
    }
    .slide p {
        font-size: 1rem;
    }

    #services > div,
    #solutions > div {
        grid-template-columns: 1fr;
    }

    #services ul {
        grid-template-columns: 1fr;
    }

    #articles > div {
        grid-template-columns: 1fr;
    }

    #contact > div {
        grid-template-columns: 1fr;
        padding: var(--space-lg);
    }

    .slider-controls {
        bottom: 20px;
    }

    footer nav ul,
    footer div ul {
        flex-direction: column;
        gap: var(--space-xs);
    }
}

@media (max-width: 480px) {
    nav {
        padding: var(--space-sm) var(--space-md);
    }

    #hero {
        min-height: 60vh;
    }

    .slide h1 {
        font-size: 1.5rem;
    }

    .btn-primary {
        padding: 12px 28px;
        font-size: 0.9rem;
    }

    section {
        padding: var(--space-2xl) var(--space-md);
    }
}

/* ===== 暗色模式下的卡片与毛玻璃微调 ===== */
body.dark-mode .card,
body.dark-mode #services ul li,
body.dark-mode #cases p,
body.dark-mode #articles article,
body.dark-mode #faq details,
body.dark-mode #howto ol li {
    border-color: var(--dark-border);
}

body.dark-mode nav form {
    background: rgba(255,255,255,0.05);
    border-color: var(--dark-border);
}
body.dark-mode nav form input {
    color: var(--dark-text);
}
body.dark-mode nav form input::placeholder {
    color: var(--dark-text-secondary);
}

/* ===== 打印样式 ===== */
@media print {
    header,
    #back-to-top,
    .slider-controls,
    #theme-toggle,
    #menu-toggle {
        display: none;
    }
    body {
        background: #fff;
        color: #000;
    }
    section {
        page-break-inside: avoid;
    }
}