/* 重置和基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fafafa;
}

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

/* 现代化头部样式 */
.modern-header {
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.95) 0%, rgba(248, 250, 252, 0.9) 100%);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(226, 232, 240, 0.3);
    box-shadow: 0 4px 32px rgba(0, 0, 0, 0.06), 0 2px 16px rgba(0, 0, 0, 0.04);
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.modern-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(59, 130, 246, 0.3), transparent);
}

.header-container {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 2rem;
    position: relative;
}

/* Logo区域样式 */
.brand-section {
    display: flex;
    align-items: center;
    flex-shrink: 0;
}

.logo-wrapper {
    display: flex;
    align-items: center;
    gap: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.logo-wrapper:hover {
    transform: translateY(-1px);
}

.logo-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    box-shadow: 0 4px 16px rgba(59, 130, 246, 0.3);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.logo-icon::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.6s ease;
}

.logo-wrapper:hover .logo-icon::before {
    left: 100%;
}

.logo-wrapper:hover .logo-icon {
    transform: scale(1.05);
    box-shadow: 0 6px 24px rgba(59, 130, 246, 0.4);
}

.brand-text {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.brand-title {
    color: #1e293b;
    font-size: 1.5rem;
    font-weight: 700;
    line-height: 1.2;
    margin: 0;
    transition: color 0.3s ease;
}

.logo-wrapper:hover .brand-title {
    color: #3b82f6;
}

.brand-subtitle {
    color: #64748b;
    font-size: 0.75rem;
    font-weight: 500;
    line-height: 1;
    opacity: 0.8;
    transition: all 0.3s ease;
}

.logo-wrapper:hover .brand-subtitle {
    color: #3b82f6;
    opacity: 1;
}

/* 导航菜单样式 */
.main-navigation {
    display: flex;
    align-items: center;
    flex: 1;
    justify-content: center;
}

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    position: relative;
    text-decoration: none;
    color: #475569;
    font-weight: 600;
    font-size: 1rem;
    padding: 0.75rem 1.25rem;
    border-radius: 10px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    overflow: hidden;
}

.nav-link::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.08) 0%, rgba(37, 99, 235, 0.05) 100%);
    opacity: 0;
    transition: opacity 0.3s ease;
    border-radius: 10px;
}

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

.nav-link:hover {
    color: #3b82f6;
    transform: translateY(-2px);
    box-shadow: 0 4px 16px rgba(59, 130, 246, 0.15);
}

.nav-text {
    position: relative;
    z-index: 1;
}

/* 导航栏谷歌登录按钮样式 */
.google-signin-btn {
    background: none;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    font-family: inherit;
    font-size: 1rem;
    font-weight: 600;
}

.google-signin-btn:hover {
    background: linear-gradient(135deg, rgba(66, 133, 244, 0.1) 0%, rgba(52, 168, 83, 0.05) 100%);
}

.google-signin-btn svg {
    flex-shrink: 0;
}

/* 右侧工具栏样式 */
.header-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-shrink: 0;
}

/* 用户认证样式 */
/* 现代化语言选择器样式 */
.language-selector {
    position: relative;
    display: flex;
    align-items: center;
    margin-right: 15px;
}

.language-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 0.625rem 1rem;
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.9) 0%, rgba(248, 250, 252, 0.8) 100%);
    border: 1px solid rgba(226, 232, 240, 0.6);
    border-radius: 12px;
    color: #475569;
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
    position: relative;
    overflow: hidden;
}

.language-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.05) 0%, rgba(37, 99, 235, 0.03) 100%);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.language-btn:hover::before {
    opacity: 1;
}

.language-btn:hover {
    border-color: rgba(59, 130, 246, 0.3);
    transform: translateY(-1px);
    box-shadow: 0 4px 16px rgba(59, 130, 246, 0.1);
    color: #3b82f6;
}

.language-dropdown {
    position: absolute;
    top: calc(100% + 8px);
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(226, 232, 240, 0.3);
    border-radius: 16px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.08), 0 8px 24px rgba(0, 0, 0, 0.04);
    z-index: 1000;
    max-height: 300px;
    overflow-y: auto;
    display: none;
    overflow: hidden;
}

.language-dropdown::before {
    content: '';
    position: absolute;
    top: -8px;
    left: 16px;
    width: 16px;
    height: 16px;
    background: rgba(255, 255, 255, 0.95);
    border: 1px solid rgba(226, 232, 240, 0.3);
    border-bottom: none;
    border-right: none;
    transform: rotate(45deg);
    backdrop-filter: blur(20px);
}

.language-dropdown.show {
    display: block;
    animation: fadeInUp 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.language-option {
    padding: 0.875rem 1.25rem;
    color: #475569;
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    font-size: 0.875rem;
    font-weight: 500;
    position: relative;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.language-option::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.language-option:last-child {
    border-bottom: none;
}

.language-option:hover {
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.08) 0%, rgba(37, 99, 235, 0.05) 100%);
    color: #3b82f6;
    transform: translateX(4px);
}

.language-option:hover::before {
    opacity: 1;
}

.language-option.active {
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.12) 0%, rgba(37, 99, 235, 0.08) 100%);
    color: #3b82f6;
    font-weight: 600;
}

.language-option.active::before {
    opacity: 1;
}

.user-auth {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-left: 2rem;
}

.google-signin-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    background: white;
    border: 1px solid #dadce0;
    border-radius: 8px;
    padding: 10px 16px;
    cursor: pointer;
    font-weight: 500;
    color: #3c4043;
    transition: all 0.2s ease;
    font-size: 14px;
    min-height: 40px;
    text-decoration: none;
}

.google-signin-btn:hover {
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.12), 0 1px 2px rgba(0, 0, 0, 0.24);
    border-color: #c1c7cd;
    background: #f8f9fa;
}

.google-signin-btn:active {
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.16);
    background: #f1f3f4;
}

.google-icon {
    width: 18px;
    height: 18px;
    flex-shrink: 0;
}

/* 用户信息显示 */
.user-info {
    margin-top: 20px;
    padding: 10px;
    border: 1px solid #eee;
    display: none;
    flex-direction: row;
    align-items: center;
    gap: 10px;
}

.user-info img {
    flex-shrink: 0;
    object-fit: cover;
    border: 2px solid #e5e7eb;
    background-color: #f9fafb;
}

.user-info span {
    font-weight: 500;
    color: #333;
}

.user-info button {
    background: #dc3545;
    color: white;
    border: none;
    padding: 5px 10px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 12px;
}

.user-info button:hover {
    background: #c82333;
}

/* 简化的用户信息样式 */
.user-profile {
    display: flex;
    align-items: center;
    position: relative;
}

.user-avatar-wrapper {
    position: relative;
    cursor: pointer;
}

.user-avatar {
    width: 42px;
    height: 42px;
    border-radius: 50%;
    border: 2px solid transparent;
    background: linear-gradient(white, white) padding-box,
                linear-gradient(135deg, #3b82f6, #8b5cf6, #06b6d4) border-box;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.15);
    position: relative;
    overflow: hidden;
    object-fit: cover;
}

.user-avatar::before {
    content: '';
    position: absolute;
    top: -2px;
    left: -2px;
    right: -2px;
    bottom: -2px;
    background: linear-gradient(135deg, #3b82f6, #8b5cf6, #06b6d4);
    border-radius: 50%;
    z-index: -1;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.user-avatar:hover::before {
    opacity: 1;
}

.user-avatar:hover {
    transform: scale(1.1) translateY(-2px);
    box-shadow: 0 8px 24px rgba(59, 130, 246, 0.25);
}

.online-indicator {
    position: absolute;
    bottom: 2px;
    right: 2px;
    width: 12px;
    height: 12px;
    background: #10b981;
    border: 2px solid white;
    border-radius: 50%;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

/* 付费用户黄冠标识 */
.premium-crown {
    position: absolute;
    top: -8px;
    right: -6px;
    width: 24px;
    height: 24px;
    background: linear-gradient(135deg, #fbbf24 0%, #f59e0b 50%, #d97706 100%);
    border-radius: 50%;
    border: 2px solid white;
    box-shadow: 0 2px 8px rgba(251, 191, 36, 0.4), 0 0 0 1px rgba(251, 191, 36, 0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10;
    animation: crownGlow 2s ease-in-out infinite alternate;
}

.premium-crown::before {
    content: '👑';
    font-size: 12px;
    filter: drop-shadow(0 1px 2px rgba(0, 0, 0, 0.2));
}

@keyframes crownGlow {
    0% {
        box-shadow: 0 2px 8px rgba(251, 191, 36, 0.4), 0 0 0 1px rgba(251, 191, 36, 0.2);
    }
    100% {
        box-shadow: 0 4px 16px rgba(251, 191, 36, 0.6), 0 0 0 2px rgba(251, 191, 36, 0.3);
    }
}

/* 付费用户头像增强效果 */
.user-avatar-wrapper.premium .user-avatar {
    background: linear-gradient(white, white) padding-box,
                linear-gradient(135deg, #fbbf24, #f59e0b, #d97706) border-box;
    box-shadow: 0 4px 16px rgba(251, 191, 36, 0.25), 0 2px 8px rgba(0, 0, 0, 0.1);
}

.user-avatar-wrapper.premium .user-avatar:hover {
    box-shadow: 0 8px 32px rgba(251, 191, 36, 0.4), 0 4px 16px rgba(0, 0, 0, 0.15);
    transform: scale(1.1) translateY(-2px);
}

.sign-out-btn {
    background: #f3f4f6;
    border: 1px solid #d1d5db;
    border-radius: 6px;
    padding: 0.375rem 0.75rem;
    font-size: 0.75rem;
    color: #6b7280;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-left: 0.75rem;
}

.sign-out-btn:hover {
    background: #e5e7eb;
    color: #374151;
}

/* 用户下拉菜单样式 */
.user-dropdown {
    position: absolute;
    top: 100%;
    right: 0;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(24px);
    border: 1px solid rgba(226, 232, 240, 0.3);
    border-radius: 16px;
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.08), 0 4px 16px rgba(0, 0, 0, 0.04);
    min-width: 180px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-12px) scale(0.95);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 1000;
    overflow: hidden;
}

.user-dropdown.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0) scale(1);
}

/* 下拉菜单内容 */
.user-dropdown-menu {
    padding: 8px;
}

/* 退出按钮样式 - 简约时尚设计 */
.user-dropdown-item.logout-btn {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    border-radius: 12px;
    background: transparent;
    border: none;
    color: #64748b;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
    width: 100%;
    text-align: left;
}

.user-dropdown-item.logout-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(239, 68, 68, 0.05) 0%, rgba(220, 38, 38, 0.05) 100%);
    opacity: 0;
    transition: opacity 0.2s ease;
}

.user-dropdown-item.logout-btn:hover {
    color: #ef4444;
    background: rgba(254, 242, 242, 0.8);
    transform: translateX(2px);
}

.user-dropdown-item.logout-btn:hover::before {
    opacity: 1;
}

.user-dropdown-item.logout-btn:active {
    transform: translateX(1px) scale(0.98);
}

/* 退出按钮图标优化 */
.user-dropdown-item.logout-btn svg {
    width: 18px;
    height: 18px;
    stroke-width: 2;
    transition: all 0.2s ease;
    flex-shrink: 0;
}

.user-dropdown-item.logout-btn:hover svg {
    transform: translateX(1px);
    stroke-width: 2.5;
}

/* 主要内容区域 */
.hero {
    padding: 4rem 0;
    text-align: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 3rem;
    opacity: 0.9;
}

/* 转换器样式 */
.converter-box {
    background: white;
    border-radius: 20px;
    padding: 3rem;
    box-shadow: 0 25px 50px rgba(0, 0, 0, 0.15), 0 10px 20px rgba(0, 0, 0, 0.1);
    max-width: 600px;
    margin: 0 auto;
    color: #333;
    border: 1px solid rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
}

.upload-area {
    border: 2px dashed #d1d5db;
    border-radius: 16px;
    padding: 3rem 2rem;
    text-align: center;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
    background: linear-gradient(135deg, #fafafa 0%, #f8fafc 100%);
    position: relative;
    overflow: hidden;
}

.upload-area::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(37, 99, 235, 0.05) 0%, rgba(59, 130, 246, 0.05) 100%);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.upload-area:hover {
    border-color: #2563eb;
    background: linear-gradient(135deg, #f8fafc 0%, #eff6ff 100%);
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(37, 99, 235, 0.1);
}

.upload-area:hover::before {
    opacity: 1;
}

.upload-area.dragover {
    border-color: #2563eb;
    background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
    transform: scale(1.02);
    box-shadow: 0 15px 40px rgba(37, 99, 235, 0.15);
}

.upload-area.dragover::before {
    opacity: 1;
}

.upload-icon {
    color: #6b7280;
    margin-bottom: 1rem;
}

.upload-area h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: #374151;
}

.upload-area p {
    color: #6b7280;
    margin-bottom: 1.5rem;
}

.upload-btn {
    background: linear-gradient(135deg, #2563eb 0%, #3b82f6 100%);
    color: white;
    border: none;
    padding: 0.75rem 2rem;
    border-radius: 12px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3);
    position: relative;
    overflow: hidden;
}

.upload-btn:hover {
    background: linear-gradient(135deg, #1d4ed8 0%, #2563eb 100%);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(37, 99, 235, 0.4);
}

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

/* 转换状态样式 */
.conversion-status {
    text-align: center;
    padding: 2rem;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: #e5e7eb;
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 1rem;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #2563eb, #3b82f6);
    border-radius: 4px;
    transition: width 0.3s ease;
    width: 0%;
}

#statusText {
    color: #6b7280;
    font-weight: 500;
}

/* 下载区域样式 */
.download-area {
    text-align: center;
    padding: 2rem;
}

.success-icon {
    margin-bottom: 1rem;
}

.download-area h3 {
    color: #10b981;
    margin-bottom: 1.5rem;
    font-size: 1.25rem;
}

.download-btn {
    background: linear-gradient(135deg, #10b981 0%, #34d399 100%);
    color: white;
    border: none;
    padding: 0.75rem 2rem;
    border-radius: 12px;
    font-weight: 600;
    cursor: pointer;
    margin-right: 1rem;
    margin-bottom: 0.5rem;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 4px 15px rgba(16, 185, 129, 0.3);
}

.download-btn:hover {
    background: linear-gradient(135deg, #059669 0%, #10b981 100%);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(16, 185, 129, 0.4);
}

.download-btn:active {
    transform: translateY(0);
    box-shadow: 0 2px 10px rgba(16, 185, 129, 0.3);
}

.reset-btn {
    background: linear-gradient(135deg, #6b7280 0%, #9ca3af 100%);
    color: white;
    border: none;
    padding: 0.75rem 2rem;
    border-radius: 12px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 4px 15px rgba(107, 114, 128, 0.3);
}

.reset-btn:hover {
    background: linear-gradient(135deg, #4b5563 0%, #6b7280 100%);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(107, 114, 128, 0.4);
}

.reset-btn:active {
    transform: translateY(0);
    box-shadow: 0 2px 10px rgba(107, 114, 128, 0.3);
}

/* 功能特性样式 */
.features {
    padding: 5rem 0;
    background: white;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.feature-card {
    text-align: center;
    padding: 2rem;
    border-radius: 16px;
    background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
    border: 1px solid rgba(37, 99, 235, 0.1);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.feature-card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: 0 20px 40px rgba(37, 99, 235, 0.15), 0 10px 20px rgba(0, 0, 0, 0.1);
    border-color: rgba(37, 99, 235, 0.2);
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(37, 99, 235, 0.05), transparent);
    transition: left 0.6s ease;
}

.feature-card:hover::before {
    left: 100%;
}

.feature-icon {
    color: #2563eb;
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: #1f2937;
}

.feature-card p {
    color: #6b7280;
    line-height: 1.6;
}

/* 定价样式 */
.pricing {
    padding: 5rem 0;
    background: #f8fafc;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    color: #1f2937;
    margin-bottom: 3rem;
}



.pricing-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    align-items: stretch;
    margin-bottom: 3rem;
    max-width: 1400px;
    margin-left: auto;
    margin-right: auto;
}

.pricing-card {
    background: #ffffff;
    border-radius: 16px;
    padding: 2rem 1.5rem;
    text-align: center;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
    transition: all 0.3s ease;
    position: relative;
    border: 1px solid #e2e8f0;
    overflow: hidden;
    width: 100%;
    max-width: 300px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    min-height: 480px;
}

/* 新订阅方案特殊样式 */
.pricing-card.basic-plan {
    border-color: #e2e8f0;
}

.pricing-card.pro-plan {
    border-color: #3b82f6;
    transform: scale(1.05);
}

.pricing-card.enterprise-plan {
    border-color: #7c3aed;
}

/* 受欢迎标签 */
.popular-badge {
    position: absolute;
    top: -14px;
    left: 50%;
    transform: translateX(-50%);
    background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
    color: white;
    padding: 0.625rem 1.75rem;
    border-radius: 24px;
    font-size: 0.8rem;
    font-weight: 700;
    box-shadow: 0 6px 20px rgba(245, 158, 11, 0.4);
    letter-spacing: 0.5px;
    text-transform: uppercase;
    border: 2px solid rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
}

/* 价格容器 */
.price-container {
    margin: 1.5rem 0;
}

.yearly-price {
    display: none;
}

/* 年付价格显示 */
.annual-price {
    font-size: 1rem;
    color: #059669;
    font-weight: 600;
    margin-top: 0.75rem;
    padding: 0.5rem 1rem;
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.08) 0%, rgba(5, 150, 105, 0.04) 100%);
    border: 1px solid rgba(16, 185, 129, 0.15);
    border-radius: 16px;
    display: inline-block;
    position: relative;
    overflow: hidden;
}

.annual-price::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(16, 185, 129, 0.2), transparent);
}

/* 试用信息 */
.trial-info {
    color: #059669;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 1rem;
    padding: 0.5rem 1rem;
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.1) 0%, rgba(5, 150, 105, 0.05) 100%);
    border: 1px solid rgba(16, 185, 129, 0.2);
    border-radius: 20px;
    display: inline-block;
    position: relative;
    overflow: hidden;
}

.trial-info::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(16, 185, 129, 0.3), transparent);
}

.pricing-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: #e2e8f0;
    transition: all 0.3s ease;
}

.pricing-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    border-color: #3b82f6;
}

.pricing-card:hover::before {
    background: linear-gradient(90deg, #3b82f6, #8b5cf6);
}

.pricing-card.featured {
    border: 2px solid #3b82f6;
    transform: scale(1.02);
    box-shadow: 0 4px 20px rgba(59, 130, 246, 0.12);
    background: linear-gradient(135deg, #fefbff 0%, #f8faff 100%);
}

.pricing-card.featured::before {
    background: linear-gradient(90deg, #3b82f6, #8b5cf6);
    height: 3px;
}

.pricing-card.featured::after {
    content: '推荐';
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background: linear-gradient(135deg, #3b82f6, #8b5cf6);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    z-index: 10;
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
    white-space: nowrap;
    letter-spacing: 0.5px;
}

.pricing-card h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: #1e293b;
    line-height: 1.2;
    font-weight: 600;
    text-align: center;
    letter-spacing: -0.01em;
    position: relative;
}

.pricing-card.featured h3 {
    color: #3b82f6;
}

.price {
    font-size: 1.8rem;
    font-weight: 600;
    color: #2563eb;
    margin: 1rem 0;
    text-align: center;
    line-height: 1;
    letter-spacing: -0.01em;
    position: relative;
}



 .features-list {
     list-style: none;
     margin-bottom: 1.5rem;
     text-align: left;
     padding: 0;
     flex-grow: 1;
 }

.features-list li {
    padding: 0.75rem 0;
    color: #475569;
    position: relative;
    padding-left: 2rem;
    font-size: 0.9rem;
    line-height: 1.5;
    border-bottom: 1px solid #f8fafc;
    transition: color 0.2s ease;
}

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

.features-list li:hover {
    color: #334155;
}

.features-list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    top: 0.875rem;
    width: 18px;
    height: 18px;
    background: #10b981;
    border-radius: 50%;
    color: white;
    font-weight: 600;
    font-size: 0.75rem;
    display: flex;
    align-items: center;
    justify-content: center;
    line-height: 1;
}

.pricing-btn {
    background: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%);
    color: white;
    border: none;
    padding: 1rem 2rem;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    width: 100%;
    transition: all 0.3s ease;
    font-size: 1rem;
    letter-spacing: 0.025em;
    position: relative;
    overflow: hidden;
    margin-top: auto;
    min-height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.pricing-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s;
}

.pricing-btn:hover::before {
    left: 100%;
}

.pricing-btn:hover {
    background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
    transform: translateY(-1px);
    box-shadow: 0 12px 32px rgba(59, 130, 246, 0.3);
}

.pricing-btn:active {
    transform: translateY(0);
    box-shadow: 0 6px 16px rgba(59, 130, 246, 0.25);
}

.pricing-card.featured .pricing-btn {
    background: linear-gradient(135deg, #7c3aed 0%, #5b21b6 100%);
    box-shadow: 0 8px 24px rgba(124, 58, 237, 0.25);
}

.pricing-card.featured .pricing-btn:hover {
    background: linear-gradient(135deg, #6d28d9 0%, #4c1d95 100%);
    box-shadow: 0 12px 32px rgba(124, 58, 237, 0.35);
}

/* 免费方案按钮样式 */
.pricing-card:first-child .pricing-btn,
.pricing-card:nth-child(2) .pricing-btn {
    background: linear-gradient(135deg, #64748b 0%, #475569 100%);
    color: white;
}

.pricing-card:first-child .pricing-btn:hover,
.pricing-card:nth-child(2) .pricing-btn:hover {
    background: linear-gradient(135deg, #475569 0%, #334155 100%);
    box-shadow: 0 12px 32px rgba(100, 116, 139, 0.3);
}

.need-more {
    text-align: center;
    background: white;
    padding: 3rem;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.need-more h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: #1f2937;
}

.need-more p {
    color: #6b7280;
    font-size: 1.1rem;
}

/* 页脚样式 */
.footer {
    background: #1f2937;
    color: white;
    text-align: center;
    padding: 2rem 0;
}

.footer p {
    opacity: 0.8;
}

/* 微动画效果 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.pricing-card {
    animation: fadeInUp 0.6s ease-out;
}

.pricing-card:nth-child(1) {
    animation-delay: 0.1s;
}

.pricing-card:nth-child(2) {
    animation-delay: 0.2s;
}

.pricing-card:nth-child(3) {
    animation-delay: 0.3s;
}

.pricing-card:nth-child(4) {
    animation-delay: 0.4s;
}

/* 响应式设计 */
@media (max-width: 1024px) {
    .pricing-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 1rem;
    }
    
    .pricing-card {
        max-width: 280px;
        min-height: 460px;
    }
}

@media (max-width: 768px) {
    .header .container {
        flex-direction: column;
        gap: 1rem;
    }
    
    .nav {
        gap: 1rem;
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .language-selector {
        margin-right: 0;
        margin-bottom: 10px;
    }
    
    .language-btn {
        font-size: 13px;
        padding: 6px 10px;
    }
    
    .language-dropdown {
        left: -50px;
        right: -50px;
        min-width: 200px;
    }
    
    .user-auth {
        margin-left: 0;
        margin-top: 1rem;
    }
    
    .google-signin-btn {
        font-size: 0.8rem;
        padding: 0.4rem 0.8rem;
    }
    
    .user-profile {
        gap: 0.5rem;
    }
    
    .user-name {
        font-size: 0.8rem;
    }
    
    .sign-out-btn {
        padding: 0.25rem 0.5rem;
        font-size: 0.7rem;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .converter-box {
        padding: 2rem;
        margin: 0 1rem;
    }
    
    .upload-area {
        padding: 2rem 1rem;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .pricing-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
        padding: 0 1rem;
    }
    
    .pricing-card {
        max-width: 100%;
        margin: 0;
        padding: 2rem 1.5rem;
    }
    
    .pricing-card.featured {
        transform: none;
    }
    
    .price {
        font-size: 2.5rem;
    }
    
    .pricing-card h3 {
        font-size: 1.375rem;
    }
    
    .popular-badge {
        font-size: 0.75rem;
        padding: 0.5rem 1.25rem;
    }
    
    .save-badge {
        font-size: 0.7rem;
        padding: 0.375rem 0.75rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .hero {
        padding: 2rem 0;
    }
    
    .hero-title {
        font-size: 1.75rem;
    }
    
    .converter-box {
        padding: 1.5rem;
    }
    
    .download-btn, .reset-btn {
        display: block;
        width: 100%;
        margin: 0.5rem 0;
    }
}

/* 动画效果 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

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

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

.converter-box {
    animation: fadeIn 0.8s ease-out;
}

.feature-card {
    animation: fadeIn 0.6s ease-out;
}

.feature-card:nth-child(odd) {
    animation: slideInLeft 0.8s ease-out;
}

.feature-card:nth-child(even) {
    animation: slideInRight 0.8s ease-out;
}

.pricing-card {
    animation: fadeIn 0.6s ease-out;
}

.pricing-card.featured {
    animation: fadeIn 0.8s ease-out, pulse 2s ease-in-out infinite;
}

.upload-btn, .download-btn, .reset-btn, .pricing-btn {
    position: relative;
    overflow: hidden;
}

.upload-btn::after, .download-btn::after, .reset-btn::after, .pricing-btn::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s ease;
}

.upload-btn:hover::after, .download-btn:hover::after, .reset-btn:hover::after, .pricing-btn:hover::after {
    left: 100%;
}