/* ===========================
   现代化帮助中心设计系统
   =========================== */

:root {
    /* 主色调系统 - 蓝色渐变主题 */
    --primary-50: #eff6ff;
    --primary-100: #dbeafe;
    --primary-200: #bfdbfe;
    --primary-300: #93c5fd;
    --primary-400: #60a5fa;
    --primary-500: #3b82f6;
    --primary-600: #2563eb;
    --primary-700: #1d4ed8;
    --primary-800: #1e40af;
    --primary-900: #1e3a8a;

    /* 中性色系统 */
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;

    /* 蓝色系统 */
    --blue-50: #eff6ff;
    --blue-500: #3b82f6;
    --blue-600: #2563eb;
    --blue-700: #1d4ed8;

    /* 绿色系统 */
    --green-50: #f0fdf4;
    --green-500: #22c55e;
    --green-600: #16a34a;

    /* 橙色系统 */
    --orange-50: #fff7ed;
    --orange-500: #f97316;
    --orange-600: #ea580c;

    /* 现代化渐变色 */
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-success: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --gradient-warning: linear-gradient(135deg, #feca57 0%, #ff9ff3 100%);
    --gradient-hero: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    --gradient-card: linear-gradient(145deg, #ffffff 0%, #f8fafc 100%);

    /* 阴影系统 */
    --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);

    /* 间距系统 */
    --space-1: 0.25rem; /* 4px */
    --space-2: 0.5rem; /* 8px */
    --space-3: 0.75rem; /* 12px */
    --space-4: 1rem; /* 16px */
    --space-5: 1.25rem; /* 20px */
    --space-6: 1.5rem; /* 24px */
    --space-8: 2rem; /* 32px */
    --space-10: 2.5rem; /* 40px */
    --space-12: 3rem; /* 48px */
    --space-16: 4rem; /* 64px */
    --space-20: 5rem; /* 80px */
    --space-24: 6rem; /* 96px */
    --space-32: 8rem; /* 128px */

    /* 字体系统 */
    --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-serif: ui-serif, Georgia, Cambria, serif;
    --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Consolas, monospace;

    /* 字体大小 */
    --text-xs: 0.75rem; /* 12px */
    --text-sm: 0.875rem; /* 14px */
    --text-base: 1rem; /* 16px */
    --text-lg: 1.125rem; /* 18px */
    --text-xl: 1.25rem; /* 20px */
    --text-2xl: 1.5rem; /* 24px */
    --text-3xl: 1.875rem; /* 30px */
    --text-4xl: 2.25rem; /* 36px */
    --text-5xl: 3rem; /* 48px */
    --text-6xl: 3.75rem; /* 60px */

    /* 行高 */
    --leading-tight: 1.25;
    --leading-normal: 1.5;
    --leading-relaxed: 1.625;

    /* 圆角 */
    --rounded-sm: 0.125rem; /* 2px */
    --rounded: 0.25rem; /* 4px */
    --rounded-md: 0.375rem; /* 6px */
    --rounded-lg: 0.5rem; /* 8px */
    --rounded-xl: 0.75rem; /* 12px */
    --rounded-2xl: 1rem; /* 16px */
    --rounded-3xl: 1.5rem; /* 24px */
    --rounded-full: 9999px;

    /* 动画 */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
    --transition-slow: 350ms ease;
    --ease-in-out: cubic-bezier(0.4, 0, 0.2, 1);
    --ease-bounce: cubic-bezier(0.68, -0.55, 0.265, 1.55);

    /* 容器最大宽度 */
    --container-sm: 640px;
    --container-md: 768px;
    --container-lg: 1024px;
    --container-xl: 1280px;
    --container-2xl: 1536px;
}

/* ===========================
   基础重置和全局样式
   =========================== */

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font-sans);
    font-size: var(--text-base);
    line-height: var(--leading-normal);
    color: var(--gray-800);
    background-color: var(--gray-50);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ===========================
   容器系统
   =========================== */

.container {
    width: 100%;
    max-width: var(--container-xl);
    margin: 0 auto;
    padding: 0 var(--space-6);
}

.container-sm {
    max-width: var(--container-sm);
}
.container-md {
    max-width: var(--container-md);
}
.container-lg {
    max-width: var(--container-lg);
}
.container-xl {
    max-width: var(--container-xl);
}
.container-2xl {
    max-width: var(--container-2xl);
}

/* ===========================
   超现代化渐变导航栏
   =========================== */

.modern-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 50;
    background: linear-gradient(
        135deg,
        rgba(99, 102, 241, 0.1) 0%,
        rgba(139, 92, 246, 0.1) 25%,
        rgba(59, 130, 246, 0.1) 50%,
        rgba(139, 92, 246, 0.1) 75%,
        rgba(99, 102, 241, 0.1) 100%
    );
    backdrop-filter: blur(20px) saturate(180%);
    border-bottom: 1px solid rgba(255, 255, 255, 0.18);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    animation: navGradientShift 8s ease-in-out infinite;
}

@keyframes navGradientShift {
    0%,
    100% {
        background: linear-gradient(
            135deg,
            rgba(99, 102, 241, 0.1) 0%,
            rgba(139, 92, 246, 0.1) 25%,
            rgba(59, 130, 246, 0.1) 50%,
            rgba(139, 92, 246, 0.1) 75%,
            rgba(99, 102, 241, 0.1) 100%
        );
    }
    50% {
        background: linear-gradient(
            135deg,
            rgba(59, 130, 246, 0.15) 0%,
            rgba(99, 102, 241, 0.15) 25%,
            rgba(139, 92, 246, 0.15) 50%,
            rgba(59, 130, 246, 0.15) 75%,
            rgba(99, 102, 241, 0.15) 100%
        );
    }
}

.modern-nav.scrolled {
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.95) 0%, rgba(248, 250, 252, 0.95) 100%);
    backdrop-filter: blur(25px) saturate(200%);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.15);
    border-bottom: 1px solid rgba(99, 102, 241, 0.2);
    animation: none;
}

.modern-nav::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(90deg, transparent 0%, rgba(255, 255, 255, 0.1) 50%, transparent 100%);
    transform: translateX(-100%);
    transition: transform 0.6s ease;
}

.modern-nav:hover::before {
    transform: translateX(100%);
}

.nav-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 4rem;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    font-weight: 700;
    font-size: var(--text-lg);
    color: transparent;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    background-clip: text;
    text-decoration: none;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    padding: var(--space-2) var(--space-4);
    border-radius: var(--rounded-xl);
}

.nav-logo::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.1), rgba(118, 75, 162, 0.1));
    border-radius: var(--rounded-xl);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.nav-logo:hover {
    transform: scale(1.05) translateY(-2px);
    filter: drop-shadow(0 10px 20px rgba(102, 126, 234, 0.3));
}

.nav-logo:hover::before {
    opacity: 1;
}

.nav-logo img {
    height: 2.5rem;
    width: auto;
    transition: all 0.3s ease;
    filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.1));
}

.nav-logo:hover img {
    transform: rotate(5deg) scale(1.1);
    filter: drop-shadow(0 8px 16px rgba(102, 126, 234, 0.4));
}

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--space-8);
}

.nav-link {
    position: relative;
    color: var(--gray-700);
    text-decoration: none;
    font-weight: 600;
    font-size: var(--text-sm);
    padding: var(--space-3) var(--space-5);
    border-radius: var(--rounded-full);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    overflow: hidden;
    backdrop-filter: blur(10px);
}

.nav-link::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.1) 0%, rgba(118, 75, 162, 0.1) 100%);
    transform: scale(0);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    border-radius: var(--rounded-full);
}

.nav-link::after {
    content: "";
    position: absolute;
    bottom: -2px;
    left: 50%;
    width: 0;
    height: 3px;
    background: linear-gradient(90deg, #667eea, #764ba2, #f093fb);
    border-radius: var(--rounded-full);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    transform: translateX(-50%);
    box-shadow: 0 0 10px rgba(102, 126, 234, 0.5);
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-700);
    transform: translateY(-2px);
    text-shadow: 0 2px 8px rgba(102, 126, 234, 0.3);
}

.nav-link:hover::before,
.nav-link.active::before {
    transform: scale(1);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
    animation: linkGlow 2s ease-in-out infinite;
}

@keyframes linkGlow {
    0%,
    100% {
        box-shadow: 0 0 10px rgba(102, 126, 234, 0.5);
    }
    50% {
        box-shadow: 0 0 20px rgba(102, 126, 234, 0.8), 0 0 30px rgba(118, 75, 162, 0.6);
    }
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: var(--space-4);
}

/* ===========================
   现代化语言切换器
   =========================== */

.language-switch {
    position: relative;
    display: inline-block;
}

.dropdown-trigger {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-3);
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--rounded-lg);
    color: var(--gray-700);
    cursor: pointer;
    transition: all var(--transition-fast);
    font-size: var(--text-sm);
    font-weight: 500;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    min-width: 100px;
}

.dropdown-trigger:hover {
    background: rgba(255, 255, 255, 0.15);
    border-color: rgba(255, 255, 255, 0.3);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.dropdown-trigger .fa-globe {
    color: var(--primary-600);
    font-size: var(--text-base);
}

.dropdown-trigger .fa-chevron-down {
    font-size: var(--text-xs);
    transition: transform var(--transition-fast);
    margin-left: auto;
}

.language-switch.show .fa-chevron-down {
    transform: rotate(180deg);
}

.dropdown-content {
    position: absolute;
    top: 100%;
    right: 0;
    min-width: 150px;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    border: 1px solid rgba(0, 0, 0, 0.1);
    border-radius: var(--rounded-xl);
    box-shadow: var(--shadow-xl);
    margin-top: var(--space-2);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all var(--transition-fast);
    z-index: 1000;
    overflow: hidden;
}

.language-switch.show .dropdown-content {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-content a {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3) var(--space-4);
    color: var(--gray-700);
    text-decoration: none;
    transition: all var(--transition-fast);
    font-size: var(--text-sm);
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.dropdown-content a:last-child {
    border-bottom: none;
}

.dropdown-content a:hover {
    background: rgba(99, 102, 241, 0.05);
    color: var(--primary-600);
    transform: translateX(2px);
}

.dropdown-content a.active {
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary-600);
    font-weight: 600;
}

.dropdown-content .lang-flag {
    font-size: var(--text-base);
    width: 20px;
    text-align: center;
}

/* 移动端适配 */
@media (max-width: 768px) {
    .dropdown-trigger {
        padding: var(--space-2);
        min-width: 80px;
        font-size: var(--text-xs);
    }

    .dropdown-content {
        min-width: 120px;
        right: -10px;
    }

    .dropdown-content a {
        padding: var(--space-2) var(--space-3);
        font-size: var(--text-xs);
    }
}

/* ===========================
   现代化按钮系统
   =========================== */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: var(--space-3) var(--space-6);
    border: none;
    border-radius: var(--rounded-lg);
    font-weight: 600;
    font-size: var(--text-sm);
    text-decoration: none;
    cursor: pointer;
    transition: all var(--transition-fast);
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: "";
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    transition: all var(--transition-normal);
    transform: translate(-50%, -50%);
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: white;
    color: var(--gray-700);
    border: 1px solid var(--gray-300);
}

.btn-secondary:hover {
    background: var(--gray-50);
    border-color: var(--primary-300);
    color: var(--primary-600);
}

.btn-ghost {
    background: transparent;
    color: var(--gray-600);
}

.btn-ghost:hover {
    background: var(--gray-100);
    color: var(--gray-900);
}

/* ===========================
   现代化英雄区域
   =========================== */

.hero-modern {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    background: linear-gradient(135deg, var(--gray-50) 0%, #fefefe 100%);
    overflow: hidden;
}

.hero-modern::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at 20% 50%, rgba(59, 130, 246, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(239, 68, 68, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 40% 80%, rgba(34, 197, 94, 0.1) 0%, transparent 50%);
    z-index: 0;
}

.hero-content {
    position: relative;
    z-index: 1;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-16);
    align-items: center;
    padding: var(--space-20) 0;
}

.hero-text {
    max-width: 600px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    background: linear-gradient(135deg, var(--primary-50), var(--blue-50));
    border: 1px solid var(--primary-200);
    border-radius: var(--rounded-full);
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--primary-700);
    margin-bottom: var(--space-6);
}

.hero-title {
    font-size: var(--text-6xl);
    font-weight: 800;
    line-height: var(--leading-tight);
    color: var(--gray-900);
    margin-bottom: var(--space-6);
}

.hero-title .highlight {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-description {
    font-size: var(--text-xl);
    line-height: var(--leading-relaxed);
    color: var(--gray-600);
    margin-bottom: var(--space-8);
}

.hero-actions {
    display: flex;
    align-items: center;
    gap: var(--space-4);
    margin-bottom: var(--space-12);
}

.hero-stats {
    display: flex;
    gap: var(--space-8);
}

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

.hero-stat-number {
    font-size: var(--text-3xl);
    font-weight: 700;
    color: var(--gray-900);
    display: block;
}

.hero-stat-label {
    font-size: var(--text-sm);
    color: var(--gray-500);
    margin-top: var(--space-1);
}

.hero-visual {
    position: relative;
    height: 600px;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* ===========================
   现代化卡片系统
   =========================== */

.card-modern {
    background: white;
    border-radius: var(--rounded-2xl);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--gray-200);
    overflow: hidden;
    transition: all var(--transition-normal);
}

.card-modern:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-200);
}

.card-header {
    padding: var(--space-6);
    border-bottom: 1px solid var(--gray-100);
}

.card-body {
    padding: var(--space-6);
}

.card-footer {
    padding: var(--space-6);
    border-top: 1px solid var(--gray-100);
    background: var(--gray-50);
}

/* ===========================
   功能网格系统
   =========================== */

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--space-8);
    margin-top: var(--space-16);
}

.feature-card {
    position: relative;
    background: white;
    border-radius: var(--rounded-2xl);
    padding: var(--space-8);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--gray-200);
    transition: all var(--transition-normal);
    overflow: hidden;
}

.feature-card::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-primary);
    transform: scaleX(0);
    transition: transform var(--transition-normal);
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-2xl);
}

.feature-card:hover::before {
    transform: scaleX(1);
}

.feature-icon {
    width: 3rem;
    height: 3rem;
    background: var(--gradient-primary);
    border-radius: var(--rounded-xl);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: var(--text-xl);
    margin-bottom: var(--space-4);
}

.feature-title {
    font-size: var(--text-xl);
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: var(--space-3);
}

.feature-description {
    color: var(--gray-600);
    line-height: var(--leading-relaxed);
}

/* ===========================
   响应式设计
   =========================== */

@media (max-width: 768px) {
    .modern-nav {
        backdrop-filter: blur(15px) saturate(150%);
        animation: none;
        background: linear-gradient(135deg, rgba(255, 255, 255, 0.9) 0%, rgba(248, 250, 252, 0.9) 100%);
    }

    .nav-links {
        display: none;
    }

    .nav-logo {
        padding: var(--space-1) var(--space-3);
    }

    .nav-logo img {
        height: 2rem;
    }

    .hero-content {
        grid-template-columns: 1fr;
        gap: var(--space-8);
        text-align: center;
    }

    .hero-title {
        font-size: var(--text-4xl);
    }

    .hero-actions {
        justify-content: center;
    }

    .features-grid {
        grid-template-columns: 1fr;
        gap: var(--space-6);
    }

    .container {
        padding: 0 var(--space-4);
    }
}

@media (max-width: 640px) {
    .hero-title {
        font-size: var(--text-3xl);
    }

    .hero-description {
        font-size: var(--text-lg);
    }

    .hero-actions {
        flex-direction: column;
        gap: var(--space-3);
    }

    .hero-stats {
        justify-content: center;
        gap: var(--space-6);
    }
}

/* ===========================
   动画系统
   =========================== */

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes fadeInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes pulse {
    0%,
    100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

.animate-fade-in-up {
    animation: fadeInUp 0.6s ease-out;
}

.animate-fade-in-left {
    animation: fadeInLeft 0.6s ease-out;
}

.animate-fade-in-right {
    animation: fadeInRight 0.6s ease-out;
}

.animate-pulse {
    animation: pulse 2s infinite;
}

/* ===========================
   演示面板样式
   =========================== */

.dashboard-demo {
    position: relative;
    z-index: 1;
}

.demo-window {
    background: white;
    border-radius: var(--rounded-2xl);
    box-shadow: var(--shadow-2xl);
    border: 1px solid var(--gray-200);
    overflow: hidden;
    max-width: 500px;
    margin: 0 auto;
}

.demo-header {
    background: var(--gray-100);
    padding: var(--space-4) var(--space-6);
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid var(--gray-200);
}

.demo-controls {
    display: flex;
    gap: var(--space-2);
}

.demo-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.demo-dot.red {
    background-color: #ff5f57;
}
.demo-dot.yellow {
    background-color: #ffbd2e;
}
.demo-dot.green {
    background-color: #28ca42;
}

.demo-title {
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--gray-700);
}

.demo-content {
    padding: var(--space-6);
}

.demo-metrics {
    display: grid;
    gap: var(--space-4);
    margin-bottom: var(--space-6);
}

.metric-card {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-4);
    background: var(--gray-50);
    border-radius: var(--rounded-lg);
    border: 1px solid var(--gray-200);
}

.metric-card.orders .metric-icon {
    background: var(--gradient-blue);
}
.metric-card.inventory .metric-icon {
    background: var(--gradient-purple);
}
.metric-card.revenue .metric-icon {
    background: linear-gradient(135deg, var(--green-500), var(--green-600));
}

.metric-icon {
    width: 2.5rem;
    height: 2.5rem;
    background: var(--gradient-primary);
    border-radius: var(--rounded-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: var(--text-sm);
}

.metric-data {
    flex: 1;
}

.metric-number {
    font-size: var(--text-lg);
    font-weight: 700;
    color: var(--gray-900);
    line-height: 1.2;
}

.metric-label {
    font-size: var(--text-xs);
    color: var(--gray-500);
    margin-top: var(--space-1);
}

.metric-trend {
    font-size: var(--text-xs);
    font-weight: 600;
    margin-top: var(--space-1);
}

.metric-trend.positive {
    color: var(--green-600);
}

.demo-chart {
    background: var(--gray-50);
    border-radius: var(--rounded-lg);
    padding: var(--space-4);
    border: 1px solid var(--gray-200);
}

.chart-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--space-4);
}

.chart-header span:first-child {
    font-weight: 600;
    color: var(--gray-900);
    font-size: var(--text-sm);
}

.chart-period {
    font-size: var(--text-xs);
    color: var(--gray-500);
}

.chart-bars {
    display: flex;
    align-items: end;
    gap: var(--space-2);
    height: 60px;
}

.chart-bar {
    flex: 1;
    background: var(--gray-300);
    border-radius: var(--rounded-sm);
    min-height: 8px;
    transition: all var(--transition-normal);
}

.chart-bar.active {
    background: var(--gradient-primary);
    box-shadow: 0 0 0 2px rgba(239, 68, 68, 0.2);
}

.chart-bar:hover {
    background: var(--gradient-primary);
    opacity: 0.8;
}

/* 按钮大小变体 */
.btn-lg {
    padding: var(--space-4) var(--space-8);
    font-size: var(--text-lg);
}

.btn-sm {
    padding: var(--space-2) var(--space-4);
    font-size: var(--text-sm);
}

/* 网格系统 */
.grid {
    display: grid;
}

.grid-cols-1 {
    grid-template-columns: repeat(1, minmax(0, 1fr));
}
.grid-cols-2 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
}
.grid-cols-3 {
    grid-template-columns: repeat(3, minmax(0, 1fr));
}

@media (min-width: 768px) {
    .md\\:grid-cols-2 {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
    .md\\:grid-cols-3 {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
}

@media (min-width: 640px) {
    .sm\\:flex-row {
        flex-direction: row;
    }
}

.max-w-2xl {
    max-width: 42rem;
}
.max-w-3xl {
    max-width: 48rem;
}
.max-w-4xl {
    max-width: 56rem;
}

.mx-auto {
    margin-left: auto;
    margin-right: auto;
}

.space-y-2 > * + * {
    margin-top: var(--space-2);
}
.space-y-4 > * + * {
    margin-top: var(--space-4);
}

.flex-wrap {
    flex-wrap: wrap;
}
.flex-col {
    flex-direction: column;
}

/* ===========================
   工具类
   =========================== */

.text-center {
    text-align: center;
}
.text-left {
    text-align: left;
}
.text-right {
    text-align: right;
}

.font-thin {
    font-weight: 100;
}
.font-light {
    font-weight: 300;
}
.font-normal {
    font-weight: 400;
}
.font-medium {
    font-weight: 500;
}
.font-semibold {
    font-weight: 600;
}
.font-bold {
    font-weight: 700;
}
.font-extrabold {
    font-weight: 800;
}
.font-black {
    font-weight: 900;
}

.text-xs {
    font-size: var(--text-xs);
}
.text-sm {
    font-size: var(--text-sm);
}
.text-base {
    font-size: var(--text-base);
}
.text-lg {
    font-size: var(--text-lg);
}
.text-xl {
    font-size: var(--text-xl);
}
.text-2xl {
    font-size: var(--text-2xl);
}
.text-3xl {
    font-size: var(--text-3xl);
}
.text-4xl {
    font-size: var(--text-4xl);
}
.text-5xl {
    font-size: var(--text-5xl);
}
.text-6xl {
    font-size: var(--text-6xl);
}

.text-primary {
    color: var(--primary-600);
}
.text-gray-500 {
    color: var(--gray-500);
}
.text-gray-600 {
    color: var(--gray-600);
}
.text-gray-700 {
    color: var(--gray-700);
}
.text-gray-800 {
    color: var(--gray-800);
}
.text-gray-900 {
    color: var(--gray-900);
}

.bg-white {
    background-color: white;
}
.bg-gray-50 {
    background-color: var(--gray-50);
}
.bg-gray-100 {
    background-color: var(--gray-100);
}
.bg-primary {
    background: var(--gradient-primary);
}

.rounded {
    border-radius: var(--rounded);
}
.rounded-md {
    border-radius: var(--rounded-md);
}
.rounded-lg {
    border-radius: var(--rounded-lg);
}
.rounded-xl {
    border-radius: var(--rounded-xl);
}
.rounded-2xl {
    border-radius: var(--rounded-2xl);
}
.rounded-full {
    border-radius: var(--rounded-full);
}

.shadow-sm {
    box-shadow: var(--shadow-sm);
}
.shadow-md {
    box-shadow: var(--shadow-md);
}
.shadow-lg {
    box-shadow: var(--shadow-lg);
}
.shadow-xl {
    box-shadow: var(--shadow-xl);
}

.transition {
    transition: all var(--transition-normal);
}
.transition-fast {
    transition: all var(--transition-fast);
}
.transition-slow {
    transition: all var(--transition-slow);
}

.mb-2 {
    margin-bottom: var(--space-2);
}
.mb-4 {
    margin-bottom: var(--space-4);
}
.mb-6 {
    margin-bottom: var(--space-6);
}
.mb-8 {
    margin-bottom: var(--space-8);
}
.mb-12 {
    margin-bottom: var(--space-12);
}
.mb-16 {
    margin-bottom: var(--space-16);
}

.mt-2 {
    margin-top: var(--space-2);
}
.mt-4 {
    margin-top: var(--space-4);
}
.mt-6 {
    margin-top: var(--space-6);
}
.mt-8 {
    margin-top: var(--space-8);
}
.mt-12 {
    margin-top: var(--space-12);
}
.mt-16 {
    margin-top: var(--space-16);
}

.p-4 {
    padding: var(--space-4);
}
.p-6 {
    padding: var(--space-6);
}
.p-8 {
    padding: var(--space-8);
}

.px-4 {
    padding-left: var(--space-4);
    padding-right: var(--space-4);
}
.px-6 {
    padding-left: var(--space-6);
    padding-right: var(--space-6);
}
.py-4 {
    padding-top: var(--space-4);
    padding-bottom: var(--space-4);
}
.py-6 {
    padding-top: var(--space-6);
    padding-bottom: var(--space-6);
}

.flex {
    display: flex;
}
.grid {
    display: grid;
}
.hidden {
    display: none;
}
.block {
    display: block;
}
.inline-block {
    display: inline-block;
}

.items-center {
    align-items: center;
}
.justify-center {
    justify-content: center;
}
.justify-between {
    justify-content: space-between;
}

.gap-2 {
    gap: var(--space-2);
}
.gap-4 {
    gap: var(--space-4);
}
.gap-6 {
    gap: var(--space-6);
}
.gap-8 {
    gap: var(--space-8);
}

.relative {
    position: relative;
}
.absolute {
    position: absolute;
}
.fixed {
    position: fixed;
}

.overflow-hidden {
    overflow: hidden;
}
.z-10 {
    z-index: 10;
}
.z-20 {
    z-index: 20;
}
.z-50 {
    z-index: 50;
}

/* ===========================
   现代化帮助中心专用样式
   =========================== */

/* 帮助中心主容器 */
.help-main {
    margin-top: 4rem;
    padding: 0;
    min-height: 100vh;
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
}

.help-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--space-6);
}

/* 现代化页面标题区域 */
.help-header-modern {
    text-align: center;
    margin: var(--space-12) 0;
    padding: var(--space-16) 0;
    background: var(--gradient-card);
    border-radius: var(--rounded-3xl);
    box-shadow: var(--shadow-lg);
    position: relative;
    overflow: hidden;
}

.help-header-modern::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 100'%3E%3Cdefs%3E%3Cpattern id='grid' width='10' height='10' patternUnits='userSpaceOnUse'%3E%3Cpath d='M 10 0 L 0 0 0 10' fill='none' stroke='%23f1f5f9' stroke-width='0.5'/%3E%3C/pattern%3E%3C/defs%3E%3Crect width='100' height='100' fill='url(%23grid)'/%3E%3C/svg%3E")
        repeat;
    opacity: 0.3;
}

.help-header-modern > * {
    position: relative;
    z-index: 1;
}

.help-title-modern {
    font-size: var(--text-5xl);
    font-weight: 800;
    margin-bottom: var(--space-6);
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.help-subtitle-modern {
    font-size: var(--text-xl);
    color: var(--gray-600);
    margin-bottom: var(--space-8);
    line-height: var(--leading-relaxed);
}

/* 现代化搜索框 */
.search-container-modern {
    position: relative;
    max-width: 500px;
    margin: 0 auto;
}

.search-input-modern {
    width: 100%;
    padding: var(--space-4) var(--space-6) var(--space-4) var(--space-12);
    border: 2px solid var(--gray-200);
    border-radius: var(--rounded-full);
    font-size: var(--text-lg);
    background: white;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
}

.search-input-modern:focus {
    outline: none;
    border-color: var(--primary-500);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.search-icon-modern {
    position: absolute;
    left: var(--space-4);
    top: 50%;
    transform: translateY(-50%);
    color: var(--gray-400);
    font-size: var(--text-lg);
}

.search-button-modern {
    position: absolute;
    right: var(--space-1);
    top: 50%;
    transform: translateY(-50%);
    background: var(--gradient-primary);
    border: none;
    border-radius: var(--rounded-full);
    width: 2.5rem;
    height: 2.5rem;
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

.search-button-modern:hover {
    transform: translateY(-50%) scale(1.05);
    box-shadow: var(--shadow-md);
}

/* 内容区域现代化网格布局 */
.help-content-grid {
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: var(--space-8);
    margin-top: var(--space-12);
}

.help-main-content {
    background: white;
    border-radius: var(--rounded-2xl);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
}

.help-sidebar {
    display: flex;
    flex-direction: column;
    gap: var(--space-6);
}

/* 现代化区域标题 */
.section-header-modern {
    text-align: center;
    margin: var(--space-20) 0 var(--space-12);
    position: relative;
}

.section-badge-modern {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    background: var(--primary-50);
    color: var(--primary-700);
    border-radius: var(--rounded-full);
    font-size: var(--text-sm);
    font-weight: 600;
    margin-bottom: var(--space-4);
}

.section-title-modern {
    font-size: var(--text-4xl);
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: var(--space-4);
    position: relative;
}

.section-title-modern::after {
    content: "";
    position: absolute;
    bottom: -var(--space-2);
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: var(--gradient-primary);
    border-radius: var(--rounded-full);
}

.section-description-modern {
    font-size: var(--text-lg);
    color: var(--gray-600);
    line-height: var(--leading-relaxed);
}

/* 热门文章轮播区域 */
.featured-articles-modern {
    background: var(--gradient-hero);
    border-radius: var(--rounded-3xl);
    padding: var(--space-12);
    margin: var(--space-12) 0;
    position: relative;
    overflow: hidden;
}

.featured-articles-modern::before {
    content: "";
    position: absolute;
    top: -50px;
    right: -50px;
    width: 200px;
    height: 200px;
    background: var(--gradient-primary);
    border-radius: 50%;
    opacity: 0.1;
}

.featured-card-modern {
    background: white;
    border-radius: var(--rounded-2xl);
    padding: var(--space-8);
    box-shadow: var(--shadow-lg);
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-8);
    align-items: center;
    position: relative;
    z-index: 1;
}

.featured-content-modern h3 {
    font-size: var(--text-2xl);
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: var(--space-4);
}

.featured-content-modern p {
    color: var(--gray-600);
    line-height: var(--leading-relaxed);
    margin-bottom: var(--space-6);
}

.featured-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    background: var(--gradient-primary);
    color: white;
    padding: var(--space-2) var(--space-4);
    border-radius: var(--rounded-full);
    font-size: var(--text-sm);
    font-weight: 600;
    margin-bottom: var(--space-4);
}

.featured-meta {
    display: flex;
    align-items: center;
    gap: var(--space-4);
    font-size: var(--text-sm);
    color: var(--gray-500);
}

.btn-featured {
    background: var(--gradient-primary);
    color: white;
    padding: var(--space-3) var(--space-6);
    border: none;
    border-radius: var(--rounded-lg);
    font-weight: 600;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    transition: all var(--transition-fast);
}

.btn-featured:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.featured-visual-modern {
    background: var(--gradient-card);
    border-radius: var(--rounded-xl);
    padding: var(--space-6);
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 200px;
    position: relative;
}

.featured-icon-modern {
    font-size: 4rem;
    color: var(--primary-500);
    animation: pulse 2s infinite;
}

/* 时间线布局现代化 */
.timeline-section-modern {
    background: white;
    border-radius: var(--rounded-3xl);
    padding: var(--space-16);
    margin: var(--space-12) 0;
    position: relative;
}

.timeline-container-modern {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}

.timeline-line {
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 4px;
    background: var(--gradient-primary);
    transform: translateX(-50%);
    border-radius: var(--rounded-full);
}

.timeline-item-modern {
    display: flex;
    align-items: center;
    margin-bottom: var(--space-16);
    position: relative;
}

.timeline-item-modern:nth-child(even) .timeline-content {
    text-align: right;
    padding-right: var(--space-8);
}

.timeline-item-modern:nth-child(odd) .timeline-content {
    text-align: left;
    padding-left: var(--space-8);
}

.timeline-content {
    flex: 1;
    background: var(--gradient-card);
    border-radius: var(--rounded-2xl);
    padding: var(--space-6);
    box-shadow: var(--shadow-md);
    position: relative;
}

.timeline-content::before {
    content: "";
    position: absolute;
    top: var(--space-6);
    width: 0;
    height: 0;
    border: 15px solid transparent;
}

.timeline-item-modern:nth-child(odd) .timeline-content::before {
    right: -15px;
    border-left-color: white;
}

.timeline-item-modern:nth-child(even) .timeline-content::before {
    left: -15px;
    border-right-color: white;
}

.timeline-icon {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 60px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: var(--text-xl);
    box-shadow: var(--shadow-lg);
    z-index: 2;
}

.step-badge {
    background: var(--gradient-secondary);
    color: white;
    padding: var(--space-1) var(--space-3);
    border-radius: var(--rounded-full);
    font-size: var(--text-xs);
    font-weight: 600;
    display: inline-block;
    margin-bottom: var(--space-3);
}

.timeline-content h3 {
    font-size: var(--text-xl);
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: var(--space-3);
}

.timeline-content p {
    color: var(--gray-600);
    line-height: var(--leading-relaxed);
    margin-bottom: var(--space-4);
}

/* 功能网格现代化 */
.features-grid-modern {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-6);
    margin: var(--space-12) 0;
}

.feature-card-modern {
    background: white;
    border-radius: var(--rounded-2xl);
    padding: var(--space-6);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--gray-200);
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.feature-card-modern::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-primary);
    transform: scaleX(0);
    transition: transform var(--transition-normal);
}

.feature-card-modern:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.feature-card-modern:hover::before {
    transform: scaleX(1);
}

.feature-icon-modern {
    width: 60px;
    height: 60px;
    background: var(--gradient-primary);
    border-radius: var(--rounded-xl);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: var(--text-2xl);
    margin-bottom: var(--space-4);
}

.feature-title-modern {
    font-size: var(--text-xl);
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: var(--space-3);
}

.feature-description-modern {
    color: var(--gray-600);
    line-height: var(--leading-relaxed);
}

/* 侧边栏现代化 */
.sidebar-card-modern {
    background: white;
    border-radius: var(--rounded-2xl);
    padding: var(--space-6);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--gray-200);
}

.sidebar-header-modern {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    margin-bottom: var(--space-4);
    color: var(--gray-900);
    font-size: var(--text-lg);
    font-weight: 700;
}

.sidebar-header-modern i {
    color: var(--primary-500);
}

.tag-cloud {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
}

.tag-modern {
    background: var(--gradient-primary);
    color: white;
    padding: var(--space-2) var(--space-3);
    border-radius: var(--rounded-full);
    font-size: var(--text-xs);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.tag-modern:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-sm);
}

.sidebar-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.sidebar-list li {
    padding: var(--space-3) 0;
    border-bottom: 1px solid var(--gray-100);
}

.sidebar-list li:last-child {
    border-bottom: none;
}

.sidebar-list h5 {
    color: var(--gray-900);
    font-weight: 600;
    margin-bottom: var(--space-1);
}

.sidebar-list p {
    color: var(--gray-500);
    font-size: var(--text-sm);
    margin: 0;
}

/* 快速链接卡片 */
.quick-links-card {
    background: var(--gradient-primary);
    color: white;
    border-radius: var(--rounded-2xl);
    padding: var(--space-6);
}

.quick-links-card h4 {
    margin-bottom: var(--space-4);
    font-size: var(--text-lg);
    font-weight: 700;
}

.quick-link {
    display: block;
    color: rgba(255, 255, 255, 0.9);
    text-decoration: none;
    padding: var(--space-3) 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
    transition: all var(--transition-fast);
}

.quick-link:hover {
    color: white;
    padding-left: var(--space-2);
}

.quick-link:last-child {
    border-bottom: none;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .help-content-grid {
        grid-template-columns: 1fr;
        gap: var(--space-6);
    }

    .help-sidebar {
        order: -1;
    }

    .featured-card-modern {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .timeline-line {
        left: var(--space-8);
    }

    .timeline-item-modern {
        flex-direction: column;
        align-items: flex-start;
    }

    .timeline-content {
        margin-left: var(--space-16);
        text-align: left !important;
        padding-left: var(--space-6) !important;
        padding-right: var(--space-6) !important;
    }

    .timeline-content::before {
        left: -15px !important;
        right: auto !important;
        border-right-color: white !important;
        border-left-color: transparent !important;
    }

    .timeline-icon {
        left: var(--space-8);
    }

    .help-title-modern {
        font-size: var(--text-3xl);
    }

    .section-title-modern {
        font-size: var(--text-2xl);
    }
}

@media (max-width: 640px) {
    .help-container {
        padding: var(--space-4);
    }

    .help-header-modern {
        padding: var(--space-8) var(--space-4);
        margin: var(--space-6) 0;
    }

    .features-grid-modern {
        grid-template-columns: 1fr;
    }

    .search-input-modern {
        font-size: var(--text-base);
        padding: var(--space-3) var(--space-5) var(--space-3) var(--space-10);
    }
}