/* ===== 极简设计 - 无容器版本 ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* ===== 色彩系统 ===== */
:root {
    --background-primary: #ffffff; /* 纯白背景 */
    --text-primary: #1a1a1a; /* 深灰文字 */
    --text-secondary: #666666; /* 中灰文字 */
    --text-tertiary: #999999; /* 浅灰文字 */
    --accent-primary: #2563eb; /* 蓝色强调色 */
}

/* ===== 基础排版 ===== */
body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--background-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    min-height: 100vh;
}

/* ===== 布局 ===== */
.container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: space-between;
    padding: 0;
}

/* ===== 主内容区域 ===== */
.main-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    flex-grow: 1;
    text-align: center;
    max-width: 600px;
    width: 100%;
    padding: 2rem 1rem;
    /* 移除白色容器样式 */
}

.logo {
    margin-bottom: 2rem;
}

.logo-symbol {
    font-size: 4rem;
    font-weight: 300;
    color: var(--text-secondary);
    display: block;
    line-height: 1;
}

.main-title {
    font-size: 3rem;
    font-weight: 400;
    margin-bottom: 1rem;
    color: var(--text-primary);
    line-height: 1.2;
}

.ai-highlight {
    color: var(--accent-primary);
    font-weight: 600;
}

.subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    font-weight: 400;
    line-height: 1.5;
    max-width: 500px;
}

/* ===== 页脚 ===== */
.footer {
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    padding: 2rem 1rem;
    border-top: 1px solid #f0f0f0; /* 极细分割线 */
}

.footer-links {
    display: flex;
    gap: 2rem;
}

.footer-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.875rem;
    transition: color 0.2s ease;
}

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

.footer-copyright {
    font-size: 0.75rem;
    color: var(--text-tertiary);
}

/* ===== 响应式设计 ===== */

/* 平板 */
@media (max-width: 768px) {
    .main-title {
        font-size: 2.5rem;
    }

    .logo-symbol {
        font-size: 3.5rem;
    }

    .subtitle {
        font-size: 1.1rem;
    }

    .footer-links {
        gap: 1.5rem;
    }
}

/* 手机 */
@media (max-width: 480px) {
    .main-content {
        padding: 1.5rem 1rem;
    }

    .main-title {
        font-size: 2rem;
    }

    .logo-symbol {
        font-size: 3rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    .footer {
        padding: 1.5rem 1rem;
    }

    .footer-links {
        flex-direction: column;
        gap: 0.75rem;
        text-align: center;
    }
}

/* 大屏幕 */
@media (min-width: 1200px) {
    .main-content {
        padding: 3rem 2rem;
    }
}

/* ===== 可访问性 ===== */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* 高对比度模式 */
@media (prefers-contrast: high) {
    :root {
        --background-primary: #ffffff;
        --text-primary: #000000;
        --text-secondary: #333333;
        --accent-primary: #0000ff;
    }
}

/* 暗色模式支持 */
@media (prefers-color-scheme: dark) {
    :root {
        --background-primary: #000000;
        --text-primary: #ffffff;
        --text-secondary: #cccccc;
        --text-tertiary: #999999;
        --accent-primary: #3b82f6;
    }

    .footer {
        border-top-color: #333333;
    }
}