:root {
    /* 明亮商务风格颜色方案 */
    --primary-color: #2563eb; /* 专业蓝色 */
    --secondary-color: #059669; /* 商务绿色 */
    --accent-color: #7c3aed; /* 紫色点缀 */
    --light-bg: #ffffff; /* 白色背景 */
    --card-bg: #ffffff; /* 卡片背景 */
    --text-primary: #1f2937; /* 深灰色主文本 */
    --text-secondary: #6b7280; /* 灰色次要文本 */
    --text-muted: #9ca3af; /* 静音文本 */
    --gradient-primary: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
    --gradient-secondary: linear-gradient(135deg, #059669 0%, #047857 100%);
    --border-color: #e5e7eb;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --font-family-sans-serif: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-family-headings: 'Poppins', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
}

body {
    font-family: var(--font-family-sans-serif);
    color: var(--text-primary);
    padding-top: 70px;
    line-height: 1.7;
    background: var(--light-bg);
    min-height: 100vh;
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6, .fw-bold, .fw-semibold {
    font-family: var(--font-family-headings);
    font-weight: 600;
    color: var(--text-primary);
}

.container {
    max-width: 1140px;
}

/* SVG 和图像基本样式 */
.feature-illustration svg,
.feature-illustration img {
    max-width: 100%;
    height: auto;
    transition: transform 0.2s ease;
    border-radius: 12px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
}

.feature-illustration:hover svg,
.feature-illustration:hover img {
    transform: scale(1.02);
}

/* --- Navigation --- */
.navbar {
    background: rgba(255, 255, 255, 0.95) !important;
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    padding: 1rem 0;
    width: 100%;
    left: 0;
    right: 0;
}

.navbar .container {
    max-width: 100%;
    width: 100%;
    padding-right: 15px;
    padding-left: 15px;
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.98) !important;
    backdrop-filter: blur(15px);
}

.navbar-brand {
    font-family: var(--font-family-headings);
    font-weight: 700;
    color: var(--primary-color) !important;
    font-size: 1.5rem;
    transition: color 0.3s ease;
}

.navbar-brand:hover {
    color: var(--secondary-color) !important;
}

.nav-link {
    font-weight: 500;
    color: var(--text-secondary) !important;
    transition: color 0.3s ease;
    position: relative;
    margin: 0 0.5rem;
}

.nav-link:hover, .nav-link.active {
    color: var(--primary-color) !important;
}

.navbar-toggler {
    border: none;
    color: var(--text-primary);
}

.navbar-toggler:focus {
    box-shadow: 0 0 0 0.25rem rgba(37, 99, 235, 0.25);
}

.dropdown-menu {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    box-shadow: var(--shadow);
}

.dropdown-item {
    color: var(--text-secondary);
    transition: all 0.3s ease;
}

.dropdown-item:hover {
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary-color);
}



/* --- Hero Section (通用基础样式已移动到具体类中) --- */


/* 简单动画 */
@keyframes fade-in-up {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}



.btn-primary {
    background: var(--gradient-primary);
    border: none;
    padding: 15px 40px;
    font-weight: 600;
    border-radius: 8px;
    color: white;
    transition: all 0.3s ease;
    box-shadow: var(--shadow);
    text-transform: uppercase;
    letter-spacing: 1px;
    font-size: 0.9rem;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(37, 99, 235, 0.3);
}

.btn-secondary {
    background: var(--gradient-secondary);
    border: none;
    padding: 15px 40px;
    font-weight: 600;
    border-radius: 8px;
    color: white;
    transition: all 0.3s ease;
    box-shadow: var(--shadow);
    text-transform: uppercase;
    letter-spacing: 1px;
    font-size: 0.9rem;
}

.btn-secondary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(5, 150, 105, 0.3);
}

.btn-outline-light {
    border: 2px solid rgba(255, 255, 255, 0.6);
    color: rgba(255, 255, 255, 0.9);
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    padding: 15px 40px;
    font-weight: 600;
    border-radius: 8px;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-size: 0.9rem;
}

.btn-outline-light:hover {
    background: rgba(255, 255, 255, 0.2);
    border-color: rgba(255, 255, 255, 0.8);
    color: #ffffff;
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(255, 255, 255, 0.2);
}


/* --- Products Section --- */
#products {
    background: var(--light-bg);
    padding: 100px 0;
}

.product-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    padding: 3rem 2.5rem;
    height: 100%;
}

.product-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
}


.product-card .card-title {
    color: var(--text-primary);
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
}

.product-card .card-text {
    color: var(--text-secondary);
    line-height: 1.8;
    font-size: 1.05rem;
}

.product-card .icon-container {
    width: 90px;
    height: 90px;
    margin: 0 auto 2rem;
    background: var(--gradient-primary);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease;
}

.product-card:hover .icon-container {
    transform: scale(1.05);
}

a.product-link {
    text-decoration: none;
    color: inherit;
    display: block;
    position: relative;
}

a.product-link:hover {
    color: inherit;
}


/* --- About Section --- */
#about {
    padding: 100px 0;
    background: #f9fafb;
}

#about img {
    box-shadow: var(--shadow);
    border-radius: 12px;
    border: 1px solid var(--border-color);
    transition: transform 0.3s ease;
}

#about img:hover {
    transform: scale(1.02);
}


#about h2 {
    color: var(--text-primary);
}

#about p {
    color: var(--text-secondary);
    font-size: 1.1rem;
    line-height: 1.8;
}

/* --- Contact Section --- */
#contact {
    padding: 100px 0;
    background: var(--light-bg);
}


#contact h2 {
    color: var(--text-primary);
}

#contact .text-muted {
    color: var(--text-secondary) !important;
}

.contact-form {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    box-shadow: var(--shadow);
    padding: 3rem;
}

#contact .form-control {
    border-radius: 8px;
    padding: 18px 20px;
    border: 1px solid var(--border-color);
    background: white;
    color: var(--text-primary);
    font-size: 1rem;
    transition: all 0.3s ease;
}

#contact .form-control::placeholder {
    color: var(--text-muted);
}

#contact .form-control:focus {
    box-shadow: 0 0 0 0.25rem rgba(37, 99, 235, 0.25);
    border-color: var(--primary-color);
    outline: none;
}

.form-group {
    margin-bottom: 2rem;
    position: relative;
}

.form-group:last-child {
    margin-bottom: 0;
}

#contact button {
    padding: 18px 50px;
    font-weight: 600;
    margin-top: 1rem;
}

/* --- Footer --- */
footer {
    background: #1f2937;
    border-top: 1px solid var(--border-color);
}

footer p {
    color: #9ca3af;
    margin: 0;
    font-size: 0.95rem;
}

/* 加载动画 */
.loading-spinner {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid rgba(37, 99, 235, 0.3);
    border-radius: 50%;
    border-top-color: var(--primary-color);
    animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* --- Responsive Styles --- */
@media (max-width: 992px) {
    .product-card {
        margin-bottom: 2rem;
    }
    .navbar {
        padding: 0.8rem 0;
    }
}

@media (max-width: 768px) {
    body {
        padding-top: 70px;
    }
    
    .navbar {
        padding: 0.6rem 0;
    }
    
    .navbar-brand {
        font-size: 1.3rem;
    }
    
    .navbar-toggler {
        padding: 0.25rem 0.5rem;
        font-size: 1rem;
    }
    #products, #about, #contact {
        padding: 80px 0;
    }
    .product-card {
        padding: 2rem 1.5rem;
        margin-bottom: 2rem;
    }
    .product-card .icon-container {
        width: 80px;
        height: 80px;
    }
    .contact-form {
        padding: 2rem 1.5rem;
    }
    .btn-primary, .btn-secondary {
        padding: 15px 30px;
        font-size: 0.85rem;
    }
    .navbar-brand {
        font-size: 1.3rem;
    }
}

@media (max-width: 576px) {
    .navbar {
        padding: 0.5rem 0;
    }
    
    .navbar-brand {
        font-size: 1.2rem;
    }
    
    .navbar-nav {
        text-align: center;
        padding: 1rem 0;
    }
    
    .navbar-toggler {
        padding: 0.2rem 0.4rem;
        font-size: 0.9rem;
    }
    
    .dropdown-menu {
        width: 100%;
        text-align: center;
    }
    .product-card {
        padding: 2rem 1rem;
    }
    .product-card .icon-container {
        width: 70px;
        height: 70px;
    }
    .product-card .card-title {
        font-size: 1.3rem;
    }
    .contact-form {
        padding: 1.5rem 1rem;
    }
    .btn-primary, .btn-secondary {
        padding: 12px 25px;
        font-size: 0.8rem;
    }
    #products, #about, #contact {
        padding: 60px 0;
    }
    .navbar-brand {
        font-size: 1.2rem;
    }
    
    /* Download badges stack vertically on small screens */
    .hero-accunote .d-flex.justify-content-center {
        flex-direction: column;
        align-items: center;
    }
    .hero-accunote .mx-3 {
        margin: 0.5rem 0 !important;
    }
}

.error-message {
    color: #ff6b6b;
    font-size: 0.875em;
    margin-top: .5rem;
    text-shadow: 0 1px 3px rgba(255, 107, 107, 0.3);
    animation: fade-in-up 0.3s ease;
}

.form-control.is-invalid {
    border-color: #ff6b6b;
    box-shadow: 
        0 0 0 0.25rem rgba(255, 107, 107, 0.25),
        inset 0 1px 0 rgba(255, 255, 255, 0.05);
    background: rgba(255, 107, 107, 0.05);
    animation: shake 0.5s ease-in-out;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    75% { transform: translateX(5px); }
}

/* 性能优化 */
.hero-section-tech,
.hero-accunote,
.hero-api,
.hero-custom {
    will-change: background-position;
    transform: translateZ(0);
}

.hero-section-tech::before,
.hero-section-tech::after,
.hero-accunote::before,
.hero-accunote::after,
.hero-api::before,
.hero-api::after,
.hero-custom::before,
.hero-custom::after {
    will-change: transform, opacity;
    transform: translateZ(0);
}

/* 降低动效 - 保持背景但禁用动画 */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
    
    .hero-section-tech,
    .hero-accunote,
    .hero-api,
    .hero-custom {
        animation: none !important;
    }
    
    .hero-section-tech::before,
    .hero-section-tech::after,
    .hero-accunote::before,
    .hero-accunote::after,
    .hero-api::before,
    .hero-api::after,
    .hero-custom::before,
    .hero-custom::after {
        animation: none !important;
    }
}

/* 基本交互效果 */
.btn-primary:focus,
.btn-secondary:focus {
    outline: none;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.4);
}

/* 可访问性改进 */
.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;
}

/* 最终的响应式优化 */
@media (max-width: 320px) {
    .navbar {
        padding: 0.4rem 0;
    }
    
    .navbar-brand {
        font-size: 1.1rem;
    }
    
    .navbar .container {
        padding-right: 10px;
        padding-left: 10px;
    }
    
    .hero-section-tech h1 {
        font-size: 1.8rem;
    }
    
    .product-card {
        padding: 1.5rem 1rem;
    }
    
    .btn-primary, .btn-secondary {
        padding: 10px 20px;
        font-size: 0.75rem;
    }
    
    /* Download badges responsive */
    .hero-accunote img[src*="app-store"], 
    .hero-accunote img[src*="google-play"] {
        height: 36px !important;
        max-width: 120px !important;
    }
}

/* --- Hero Section Animations --- */
@keyframes wave-animation {
    0% { transform: translateX(-100px) translateY(0px); }
    50% { transform: translateX(50px) translateY(-20px); }
    100% { transform: translateX(-100px) translateY(0px); }
}

@keyframes floating-elements {
    0%, 100% { transform: translateY(0px) rotate(0deg); }
    25% { transform: translateY(-20px) rotate(1deg); }
    75% { transform: translateY(-10px) rotate(-1deg); }
}

@keyframes pulse-glow {
    0%, 100% { opacity: 0.3; }
    50% { opacity: 0.8; }
}

@keyframes gradient-shift {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

/* --- 首页 Hero Section (活泼现代渐变) --- */
.hero-section-tech {
    color: #ffffff;
    padding: 150px 0;
    min-height: 90vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    background: 
        linear-gradient(135deg, #667eea 0%, #764ba2 50%, #4ecdc4 100%);
    background-size: 100% 100%;
    /* animation: gradient-shift 12s ease infinite; 动态特效已关闭 */
}

.hero-section-tech::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 30% 30%, rgba(102, 126, 234, 0.4) 0%, transparent 50%),
        radial-gradient(circle at 70% 70%, rgba(240, 147, 251, 0.3) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 80%, rgba(78, 205, 196, 0.3) 0%, transparent 60%);
    /* animation: pulse-glow 8s ease-in-out infinite; 动态特效已关闭 */
    z-index: 1;
}

.hero-section-tech::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        repeating-linear-gradient(
            45deg,
            transparent,
            transparent 2px,
            rgba(255,255,255,0.06) 2px,
            rgba(255,255,255,0.06) 4px
        ),
        repeating-conic-gradient(
            from 0deg at 25% 75%,
            transparent 0deg,
            rgba(102, 126, 234, 0.08) 60deg,
            transparent 120deg,
            rgba(240, 147, 251, 0.06) 180deg,
            transparent 240deg
        );
    /* animation: wave-animation 22s linear infinite; 动态特效已关闭 */
    z-index: 1;
}

/* --- AccuNote 产品页 Hero (清新蓝绿渐变 - 智能笔记) --- */
.hero-accunote {
    color: #ffffff;
    padding: 150px 0;
    min-height: 90vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    background: 
        linear-gradient(135deg, #4facfe 0%, #00f2fe 35%, #43e97b 70%, #38f9d7 100%);
    background-size: 100% 100%;
    /* animation: gradient-shift 15s ease infinite; 动态特效已关闭 */
}

.hero-accunote::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 20% 80%, rgba(79, 172, 254, 0.4) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(67, 233, 123, 0.5) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 50%, rgba(56, 249, 215, 0.3) 0%, transparent 60%);
    /* animation: floating-elements 10s ease-in-out infinite; 动态特效已关闭 */
    z-index: 1;
}

.hero-accunote::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        repeating-linear-gradient(
            60deg,
            transparent,
            transparent 2px,
            rgba(255,255,255,0.08) 2px,
            rgba(255,255,255,0.08) 4px
        ),
        repeating-radial-gradient(
            circle at 30% 70%,
            transparent 15px,
            rgba(79, 172, 254, 0.06) 17px,
            rgba(79, 172, 254, 0.06) 20px,
            transparent 22px
        );
    /* animation: wave-animation 18s linear infinite; 动态特效已关闭 */
    z-index: 1;
}

/* --- AccuNote API 产品页 Hero (现代青绿科技风 - API服务) --- */
.hero-api {
    color: #ffffff;
    padding: 150px 0;
    min-height: 90vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    background: 
        linear-gradient(135deg, #00d2ff 0%, #3a7bd5 30%, #00d2ff 60%, #3a7bd5 100%);
    background-size: 100% 100%;
    /* animation: gradient-shift 18s ease infinite; 动态特效已关闭 */
}

.hero-api::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 20% 80%, rgba(0, 210, 255, 0.4) 0%, transparent 40%),
        radial-gradient(circle at 80% 20%, rgba(58, 123, 213, 0.5) 0%, transparent 50%),
        radial-gradient(ellipse at center, rgba(255,255,255,0.15) 0%, transparent 70%);
    /* animation: floating-elements 12s ease-in-out infinite reverse; 动态特效已关闭 */
    z-index: 1;
}

.hero-api::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        repeating-linear-gradient(
            90deg,
            transparent,
            transparent 3px,
            rgba(255,255,255,0.06) 3px,
            rgba(255,255,255,0.06) 6px
        ),
        repeating-linear-gradient(
            45deg,
            transparent,
            transparent 8px,
            rgba(0, 210, 255, 0.08) 8px,
            rgba(0, 210, 255, 0.08) 16px
        );
    /* animation: wave-animation 22s linear infinite; 动态特效已关闭 */
    z-index: 1;
}

/* --- 定制化服务页 Hero (高端紫金渐变 - 企业定制) --- */
.hero-custom {
    color: #ffffff;
    padding: 150px 0;
    min-height: 90vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    background: 
        linear-gradient(135deg, #2c3e50 0%, #3498db 25%, #8e44ad 50%, #2c3e50 75%, #34495e 100%);
    background-size: 100% 100%;
    /* animation: gradient-shift 20s ease infinite; 动态特效已关闭 */
}

.hero-custom::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 30% 30%, rgba(52, 152, 219, 0.4) 0%, transparent 50%),
        radial-gradient(circle at 70% 70%, rgba(142, 68, 173, 0.5) 0%, transparent 60%),
        radial-gradient(ellipse at 50% 80%, rgba(44, 62, 80, 0.3) 0%, transparent 70%);
    /* animation: pulse-glow 14s ease-in-out infinite; 动态特效已关闭 */
    z-index: 1;
}

.hero-custom::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        repeating-linear-gradient(
            0deg,
            transparent,
            transparent 2px,
            rgba(255,255,255,0.04) 2px,
            rgba(255,255,255,0.04) 4px
        ),
        repeating-conic-gradient(
            from 30deg at 25% 75%,
            transparent 0deg,
            rgba(52, 152, 219, 0.06) 60deg,
            transparent 120deg,
            rgba(142, 68, 173, 0.04) 180deg,
            transparent 240deg
        );
    /* animation: wave-animation 28s linear infinite; 动态特效已关闭 */
    z-index: 1;
}

/* --- 通用容器样式 --- */
.hero-section-tech .container,
.hero-accunote .container,
.hero-api .container,
.hero-custom .container {
    position: relative;
    z-index: 2;
}

.hero-section-tech h1,
.hero-section-tech .lead,
.hero-accunote h1,
.hero-accunote .lead,
.hero-api h1,
.hero-api .lead,
.hero-custom h1,
.hero-custom .lead {
    color: #ffffff;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

/* --- 响应式设计 --- */
@media (max-width: 992px) {
    .hero-section-tech,
    .hero-accunote,
    .hero-api,
    .hero-custom {
        padding: 100px 0;
        min-height: 80vh;
    }
    
    .hero-section-tech::after,
    .hero-accunote::after,
    .hero-api::after,
    .hero-custom::after {
        animation-duration: 15s;
    }
}

@media (max-width: 768px) {
    .hero-section-tech,
    .hero-accunote,
    .hero-api,
    .hero-custom {
        padding: 80px 0;
    }
    
    .hero-section-tech::before,
    .hero-accunote::before,
    .hero-api::before,
    .hero-custom::before {
        animation-duration: 6s;
    }
}

@media (max-width: 576px) {
    .hero-section-tech,
    .hero-accunote,
    .hero-api,
    .hero-custom {
        padding: 60px 0;
        min-height: 70vh;
    }
    
    /* 减少动画复杂度以提高性能 */
    .hero-section-tech::after,
    .hero-accunote::after,
    .hero-api::after,
    .hero-custom::after {
        opacity: 0.3;
        animation-duration: 12s;
    }
}