:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --danger: #dc2626;
    --success: #16a34a;
    --sidebar-bg: #ffffff;
    --main-bg: #f1f5f9;
    --text-main: #1e293b;
    --text-sub: #64748b;
    --border-color: #e2e8f0;
}

* { box-sizing: border-box; }
body { margin: 0; font-family: "PingFang SC", "Microsoft YaHei", sans-serif; color: var(--text-main); background: var(--main-bg); overflow: hidden; }
li { line-height: 1.8em; list-style-type: none; }
#app-container { display: flex; height: 100vh; }
.sub-label { padding-top: 15px; padding-bottom: 5px; display: block; font-weight: 600; font-size: 0.85rem; }

.sidebar { width: 340px; background: var(--sidebar-bg); border-right: 1px solid var(--border-color); display: flex; flex-direction: column; z-index: 100; box-shadow: 4px 0 10px rgba(0,0,0,0.02); }
.sidebar-header { border-bottom: 1px solid var(--border-color); padding: 20px; }
.sidebar-header h1 { margin: 0; font-size: 1.2rem; color: var(--primary); }
.sidebar-header p { font-size: 0.8rem; color: var(--text-sub); margin-top: 10px; margin-bottom: 15px; }

.template-select { width: 100%; padding: 10px; border: 1px solid var(--border-color); border-radius: 6px; font-size: 0.9rem; color: var(--text-main); outline: none; background-color: #f8fafc; cursor: pointer; }
.template-select:focus { border-color: var(--primary); }

.scroll-area { flex: 1; padding: 15px; overflow-y: auto; }

/* 卡片 */
.card { background: #f8fafc; border: 1px solid var(--border-color);  margin-bottom: 15px; }
.card-title { padding: 10px 15px; background: #fff; border-bottom: 1px solid var(--border-color); font-weight: 600; font-size: 0.85rem; display: flex; align-items: center; gap: 8px; justify-content: space-between; }
.card-body { padding: 12px; }

.btn-group-vertical { display: flex; flex-direction: column; gap: 10px; }
.btn-upload-label { display: flex; align-items: center; justify-content: center; gap: 8px; background: var(--primary); color: white; padding: 10px; border-radius: 6px; cursor: pointer; font-size: 0.9rem; transition: 0.2s; text-align: center; }
.btn-upload-label:hover { background: var(--primary-dark); }
.btn-upload-label.secondary { background: #64748b; } 
.btn-upload-label.secondary:hover { background: #475569; }

.input-group { display: flex; gap: 5px; margin-bottom: 10px; }
.input-group input { flex: 1; padding: 8px; border: 1px solid var(--border-color); border-radius: 6px; outline: none; font-size: 0.9rem; }
.btn-add { background: var(--text-main); color: white; border: none; padding: 0 12px; border-radius: 6px; cursor: pointer; }

/* 属性行 */
.property-row { margin-top: 10px; display: flex; align-items: center; gap: 8px; font-size: 0.8rem; }
.property-row label { width: 35px; color: var(--text-sub); flex-shrink: 0; }
.property-row input[type="range"] { flex: 1; cursor: pointer; }
.property-row span { width: 45px; text-align: right; color: var(--primary); font-weight: bold; }
#text-color-hex { width: 70px; border: none; background: transparent; color: var(--text-sub); font-family: monospace; }

/* 字体选择器美化 */
.font-select {
    flex: 1;
    padding: 6px 8px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 0.85rem;
    color: var(--text-main);
    background-color: #fff;
    outline: none;
    cursor: pointer;
    transition: border-color 0.2s;
}
.font-select:focus {
    border-color: var(--primary);
}

/* 说明区域 */
.help-content ul { padding-left: 18px; margin: 0; font-size: 0.8rem; color: var(--text-sub); line-height: 1.6; }
.help-content kbd { background: #eee; border-radius: 3px; border: 1px solid #ccc; padding: 1px 4px; font-size: 0.75rem; }

/* 底部按钮区 */
.sidebar-footer { display: flex; flex-direction: column; gap: 8px; padding: 15px; border-top: 1px solid var(--border-color); }
.btn-main { border: none; border-radius: 6px; font-weight: 400; cursor: pointer; display: flex; align-items: center; justify-content: center; gap: 8px; font-size: 0.95rem; padding: 10px; transition: 0.2s; }
.btn-save-config { background-color: #f1f5f9; color: var(--text-main); border: 1px solid var(--border-color); font-size: 0.85rem; }
.btn-save-config:hover { background-color: #e2e8f0; }
.btn-success { color: white; background-color: #000000; }
.btn-success:disabled { opacity: 0.5; cursor: not-allowed; }
.btn-danger { background: #fff; color: var(--danger); border: 1px solid var(--danger); }

/* 预览区修改：支持原图滚动 */
.preview-container { 
    flex: 1; 
    padding: 20px; 
    overflow: auto; /* 关键：允许滚动 */
    background-color: #e5e5e5; 
    display: flex;
    /* 默认居中，但如果图片大则靠左上 */
    align-items: flex-start; 
    justify-content: center;
}

#main-canvas { 
    /* 关键：取消最大宽度限制，让画布撑开 */
    max-width: none; 
    max-height: none; 
    box-shadow: 0 10px 30px rgba(0,0,0,0.15); 
    background: white;
}

.empty-state { text-align: center; cursor: pointer; color: var(--text-sub); margin-top: 20%; }
.icon-box { font-size: 50px; margin-bottom: 15px; }
.hidden { display: none !important; }