/* 公共样式 - 减少重复加载，提升性能 */

/* CSS变量定义 */
:root {
    --primary-green: #7ED321;
    --secondary-green: #9FE870;
    --accent-yellow: #F5D544;
    --dark-gray: #2C3E50;
    --light-gray: #F8F9FA;
    --white: #FFFFFF;
    --shadow-light: rgba(126, 211, 33, 0.1);
    --shadow-medium: rgba(126, 211, 33, 0.2);
    --shadow-heavy: rgba(0, 0, 0, 0.1);
    --gradient-primary: linear-gradient(135deg, var(--primary-green) 0%, var(--secondary-green) 100%);
    --gradient-secondary: linear-gradient(135deg, var(--accent-yellow) 0%, #FFE066 100%);
    --gradient-background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-parent: linear-gradient(135deg, #FF6B6B 0%, #FF8E8E 100%);
    --gradient-teacher: linear-gradient(135deg, #4ECDC4 0%, #6EDDD6 100%);
    --gradient-admin: linear-gradient(135deg, #A8E6CF 0%, #C8F7C5 100%);
}

/* 全局重置 - 使用更高效的重置方式 */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* 基础样式 */
body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--gradient-background);
    min-height: 100vh;
    overflow-x: hidden;
    /* 启用硬件加速 */
    transform: translateZ(0);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* 页面过渡动画 */
.page-transition {
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.3s ease-out;
}

.page-transition.loaded {
    opacity: 1;
    transform: translateY(0);
}

/* 背景装饰 - 优化动画性能 */
.background-decoration {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 0;
    /* 使用will-change优化动画性能 */
    will-change: transform;
}

.floating-shape {
    position: absolute;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    /* 优化动画性能 */
    will-change: transform;
    animation: float 6s ease-in-out infinite;
}

/* 使用transform代替top/left提升性能 */
@keyframes float {
    0%, 100% { 
        transform: translateY(0px) rotate(0deg) translateZ(0); 
    }
    50% { 
        transform: translateY(-20px) rotate(180deg) translateZ(0); 
    }
}

/* 主容器 */
.login-container {
    display: flex;
    min-height: 100vh;
    position: relative;
    z-index: 1;
}

/* 左侧装饰区域 */
.decoration-section {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(20px);
}

/* 右侧登录区域 */
.login-section {
    flex: 0 0 480px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
}

/* 登录卡片 */
.login-card {
    width: 100%;
    max-width: 400px;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    border-radius: 24px;
    padding: 2.5rem;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.3);
    position: relative;
    /* 优化渲染性能 */
    transform: translateZ(0);
}

/* 按钮通用样式 */
.btn-primary {
    width: 100%;
    height: 50px;
    border-radius: 12px;
    border: none;
    font-size: 1rem;
    font-weight: 600;
    transition: all 0.3s ease;
    cursor: pointer;
    /* 硬件加速 */
    transform: translateZ(0);
}

.btn-primary:hover {
    transform: translateY(-2px) translateZ(0);
}

/* 输入框通用样式 */
.input-field {
    width: 100%;
    height: 50px;
    border-radius: 12px;
    border: 2px solid #E8ECF0;
    font-size: 0.95rem;
    transition: all 0.3s ease;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    padding: 0 15px;
}

.input-field:focus {
    border-color: var(--primary-green);
    box-shadow: 0 0 0 3px var(--shadow-light);
    outline: none;
}

/* 加载动画优化 */
.loading-spinner {
    width: 20px;
    height: 20px;
    border: 2px solid transparent;
    border-top: 2px solid currentColor;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    /* 硬件加速 */
    transform: translateZ(0);
}

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

/* 响应式优化 */
@media (max-width: 768px) {
    .login-container {
        flex-direction: column;
    }
    
    .decoration-section {
        flex: none;
        min-height: 40vh;
        padding: 1rem;
    }
    
    .login-section {
        flex: none;
        padding: 1rem;
    }
    
    .login-card {
        padding: 2rem 1.5rem;
    }
}

/* 预加载关键字体 */
@font-face {
    font-family: 'Inter';
    font-display: swap;
    src: url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');
}

/* 图片懒加载优化 */
img {
    loading: lazy;
    decoding: async;
}

/* 减少重绘和回流 */
.no-select {
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

/* 滚动优化 */
.smooth-scroll {
    scroll-behavior: smooth;
    -webkit-overflow-scrolling: touch;
}

/* 内容可见性优化 */
.content-visibility-auto {
    content-visibility: auto;
    contain-intrinsic-size: 200px;
}