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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background: #F5F5F5;
    height: 100dvh;
    display: flex;
    justify-content: center;
    align-items: stretch;
    transition: background 0.3s, color 0.3s;
}

body.dark {
    background: #1A1A1A;
    color: #E0E0E0;
}

.container {
    background: #FFFFFF;
    width: 100%;
    max-width: 800px;
    height: 100%;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    transition: background 0.3s;
}

body.dark .container { background: #2C2C2C; }

/* ============ 主题变量 ============ */
:root {
    --bg-primary: #F5F5F5;
    --bg-secondary: #FFFFFF;
    --bg-my-message: #95EC69;
    --bg-their-message: #FFFFFF;
    --text-primary: #333333;
    --text-secondary: #999999;
    --border-color: #E0E0E0;
    --accent-color: #07C160;
}

body.dark {
    --bg-primary: #1A1A1A;
    --bg-secondary: #2C2C2C;
    --bg-my-message: #2B7A0B;
    --bg-their-message: #3A3A3A;
    --text-primary: #E0E0E0;
    --text-secondary: #AAAAAA;
    --border-color: #444444;
    --accent-color: #07C160;
}