/* 暗色现代主题样式 */
:root {
    --bg-color: #1a1a1a;
    --text-color: #ffffff;
    --primary-color: #6366f1;
    --secondary-color: #8b5cf6;
    --accent-color: #06b6d4;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    --info-color: #3b82f6;
    --light-gray: #374151;
    --medium-gray: #6b7280;
    --dark-gray: #ffffff;
    --border-radius: 12px;
    --box-shadow: 0 20px 40px rgba(0,0,0,0.3);
    --header-height: 80px;
    --content-padding: 40px;
    --animation-duration: 0.4s;
    --hover-scale: 1.05;
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --heading-font-size: 2.8em;
    --body-font-size: 16px;
    --line-height: 1.7;
    --font-weight-light: 300;
    --font-weight-normal: 400;
    --font-weight-medium: 500;
}

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

body {
    font-family: var(--font-family);
    line-height: var(--line-height);
    color: var(--text-color);
    background: linear-gradient(135deg, #0f0f23 0%, #1a1a2e 50%, #16213e 100%);
    min-height: 100vh;
    transition: all var(--animation-duration) ease;
    font-size: var(--body-font-size);
    font-weight: var(--font-weight-normal);
    position: relative;
    overflow-x: hidden;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 20% 80%, rgba(99, 102, 241, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(139, 92, 246, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(6, 182, 212, 0.05) 0%, transparent 50%);
    pointer-events: none;
    z-index: -1;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    position: relative;
    z-index: 1;
}

/* 头部样式 */
.header {
    text-align: center;
    background: rgba(26, 26, 26, 0.8);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    padding: var(--content-padding);
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    margin-bottom: 30px;
    transition: all var(--animation-duration) ease;
    position: relative;
    overflow: hidden;
}

.header::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.05), transparent);
    transition: left 0.8s ease;
}

.header:hover::before {
    left: 100%;
}

.header:hover {
    transform: translateY(-5px) scale(var(--hover-scale));
    box-shadow: 0 25px 50px rgba(0,0,0,0.4);
    border-color: rgba(99, 102, 241, 0.3);
}

.logo {
    max-height: 60px;
    margin-bottom: 20px;
    transition: transform var(--animation-duration) ease;
    filter: drop-shadow(0 4px 8px rgba(0,0,0,0.3));
}

.logo:hover {
    transform: scale(1.1) rotate(2deg);
}

.header h1 {
    color: var(--text-color);
    font-size: var(--heading-font-size);
    margin-bottom: 10px;
    font-weight: var(--font-weight-light);
    transition: color var(--animation-duration) ease;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: 0 0 30px rgba(99, 102, 241, 0.3);
}

.subtitle {
    color: var(--medium-gray);
    font-size: 1.2em;
    font-weight: var(--font-weight-normal);
    opacity: 0.9;
}

/* 主要内容 */
.main {
    background: rgba(26, 26, 26, 0.8);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    margin-bottom: 30px;
    overflow: hidden;
    transition: all var(--animation-duration) ease;
    position: relative;
}

.main::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color), var(--accent-color));
    opacity: 0;
    transition: opacity var(--animation-duration) ease;
}

.main:hover::before {
    opacity: 1;
}

.main:hover {
    transform: translateY(-5px) scale(var(--hover-scale));
    box-shadow: 0 25px 50px rgba(0,0,0,0.4);
    border-color: rgba(99, 102, 241, 0.3);
}

.welcome {
    padding: var(--content-padding);
    text-align: center;
}

.welcome h2 {
    color: var(--text-color);
    font-size: 2.2em;
    margin-bottom: 20px;
    font-weight: var(--font-weight-medium);
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.welcome > p {
    color: var(--medium-gray);
    font-size: 1.1em;
    margin-bottom: 40px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
    opacity: 0.9;
}

/* 特性展示 */
.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    margin-bottom: 40px;
}

.feature {
    padding: 30px 25px;
    border-radius: var(--border-radius);
    background: rgba(55, 65, 81, 0.3);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    transition: all var(--animation-duration) ease;
    position: relative;
    overflow: hidden;
}

.feature::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(99, 102, 241, 0.1), transparent);
    transition: left 0.6s ease;
}

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

.feature:hover {
    transform: translateY(-8px) scale(var(--hover-scale));
    background: rgba(99, 102, 241, 0.1);
    border-color: rgba(99, 102, 241, 0.3);
    box-shadow: 0 15px 35px rgba(99, 102, 241, 0.2);
}

.feature-icon {
    font-size: 3.5em;
    margin-bottom: 15px;
    display: block;
    transition: transform var(--animation-duration) ease;
    filter: drop-shadow(0 4px 8px rgba(0,0,0,0.3));
}

.feature:hover .feature-icon {
    transform: scale(1.2) rotate(5deg);
}

.feature h3 {
    color: var(--text-color);
    font-size: 1.4em;
    margin-bottom: 10px;
    font-weight: var(--font-weight-medium);
}

.feature p {
    color: var(--medium-gray);
    font-size: 0.95em;
    opacity: 0.9;
}

/* 按钮样式 */
.actions {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    display: inline-block;
    padding: 15px 35px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: var(--font-weight-medium);
    transition: all var(--animation-duration) ease;
    border: none;
    cursor: pointer;
    font-size: 16px;
    position: relative;
    overflow: hidden;
    backdrop-filter: blur(10px);
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

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

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.2);
    box-shadow: 0 8px 25px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
    transform: translateY(-3px) scale(var(--hover-scale));
    box-shadow: 0 15px 35px rgba(99, 102, 241, 0.4);
    background: linear-gradient(135deg, #5856eb, #7c3aed);
}

.btn-secondary {
    background: rgba(107, 114, 128, 0.3);
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.2);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.2);
}

.btn-secondary:hover {
    transform: translateY(-3px) scale(var(--hover-scale));
    background: rgba(107, 114, 128, 0.5);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.3);
}

/* 页脚样式 */
.footer {
    background: rgba(26, 26, 26, 0.8);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    padding: 30px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    transition: all var(--animation-duration) ease;
}

.footer:hover {
    transform: translateY(-5px) scale(var(--hover-scale));
    box-shadow: 0 25px 50px rgba(0,0,0,0.4);
    border-color: rgba(99, 102, 241, 0.3);
}

.footer h3 {
    color: var(--text-color);
    margin-bottom: 15px;
    font-weight: var(--font-weight-medium);
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.footer ul {
    list-style: none;
}

.footer li {
    color: var(--medium-gray);
    margin-bottom: 8px;
    padding-left: 15px;
    position: relative;
    transition: color var(--animation-duration) ease;
    opacity: 0.9;
}

.footer li:hover {
    color: var(--primary-color);
}

.footer li:before {
    content: "•";
    color: var(--primary-color);
    position: absolute;
    left: 0;
    transition: transform var(--animation-duration) ease;
}

.footer li:hover:before {
    transform: scale(1.3);
}

.footer p {
    color: var(--medium-gray);
    margin-bottom: 8px;
    transition: color var(--animation-duration) ease;
    opacity: 0.9;
}

.footer p:hover {
    color: var(--text-color);
}

.footer a {
    color: var(--primary-color);
    text-decoration: none;
    transition: all var(--animation-duration) ease;
}

.footer a:hover {
    text-decoration: underline;
    color: var(--secondary-color);
}

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

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

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

@keyframes glow {
    0%, 100% {
        box-shadow: 0 0 20px rgba(99, 102, 241, 0.3);
    }
    50% {
        box-shadow: 0 0 40px rgba(99, 102, 241, 0.6);
    }
}

/* 滚动动画类 */
.animate-fadeInUp {
    animation: fadeInUp 0.8s ease-out;
}

.animate-fadeInLeft {
    animation: fadeInLeft 0.8s ease-out;
}

.animate-fadeInRight {
    animation: fadeInRight 0.8s ease-out;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        padding: 15px;
    }
    
    .header {
        padding: 30px 20px;
    }
    
    .header h1 {
        font-size: 2.2em;
    }
    
    .welcome {
        padding: 30px 20px;
    }
    
    .features {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .actions {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 300px;
    }
    
    .footer {
        grid-template-columns: 1fr;
        gap: 20px;
        padding: 20px;
    }
}

@media (max-width: 480px) {
    .header h1 {
        font-size: 1.8em;
    }
    
    .subtitle {
        font-size: 1em;
    }
    
    .welcome h2 {
        font-size: 1.8em;
    }
}

/* 主题切换按钮 */
.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    transition: all var(--animation-duration) ease;
    z-index: 1000;
    box-shadow: 0 8px 25px rgba(99, 102, 241, 0.3);
}

.theme-toggle:hover {
    transform: scale(var(--hover-scale)) rotate(180deg);
    box-shadow: 0 15px 35px rgba(99, 102, 241, 0.4);
}

/* 预加载器样式 */
.preloader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--bg-color);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
    transition: opacity var(--animation-duration) ease;
}

.preloader.hidden {
    opacity: 0;
    pointer-events: none;
}

.preloader-spinner {
    width: 60px;
    height: 60px;
    border: 3px solid var(--light-gray);
    border-top: 3px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* 无障碍支持 */
.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;
}

/* 焦点样式 */
.btn:focus,
input:focus,
textarea:focus,
select:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* 减少动画模式 */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* 打印样式 */
@media print {
    body {
        background: white !important;
        color: black !important;
    }
    
    .header, .main, .footer {
        box-shadow: none !important;
        border: 1px solid #ddd;
        background: white !important;
    }
    
    .btn {
        display: none !important;
    }
}