:root {
    /* 深色主题配色 */
    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --text-main: #f1f5f9;
    --text-sub: #94a3b8;
    --accent-color: #6366f1; /* 主题强调色 (蓝色/紫色) */
    --btn-hover: #4f46e5;
    --border-color: #334155;
    --nav-bg: rgba(30, 41, 59, 0.95);
    
    /* 预设卡片颜色 */
    --safe-color: #10b981;    /* 绿色 */
    --normal-color: #3b82f6;  /* 蓝色 */
    --danger-color: #f59e0b;  /* 黄色 */
    --extreme-color: #ef4444; /* 红色 */
    --doc-color: #0ea5e9;     /* 文档天蓝色 */
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    min-height: 100vh;
}

/* =========================================
   1. 顶部导航栏 (App-Nav) - 结构与样式优化
   ========================================= */
.app-nav {
    width: 100%;
    background: var(--nav-bg);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    padding: 10px 40px; /* 增加左右内边距 */
    display: flex;
    justify-content: space-between; /* 左右分散对齐 */
    align-items: center; /* 垂直居中 */
    position: sticky;
    top: 0;
    z-index: 200;
}

/* 导航链接容器（用于居中链接） */
.nav-links-container {
    display: flex;
    gap: 25px; 
    /* 在桌面端居中链接 */
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    max-width: 80%;
}

.nav-link {
    text-decoration: none;
    color: var(--text-sub);
    padding: 10px 0; /* 垂直留出空间 */
    font-weight: 500;
    transition: 0.2s;
    background: transparent;
    position: relative; 
    font-size: 1.05rem; 
    letter-spacing: 0.5px;
}

.nav-link:hover {
    color: white;
}

/* 重点优化：Active 状态 (底部指示条) */
.nav-link.active {
    color: var(--accent-color); 
    font-weight: bold;
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -10px; /* 定位到链接底部下方 */
    left: 0;
    width: 100%; /* 宽度与链接文字对齐 */
    height: 3px;
    background: var(--accent-color); 
    border-radius: 2px;
}

/* 登出按钮样式 */
.logout-btn {
    background-color: #ef4444;
    color: white;
    border: none;
    padding: 8px 15px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: background-color 0.3s;
    flex-shrink: 0; /* 防止被压缩 */
}

.logout-btn:hover {
    background-color: #dc2626;
}

/* === 页面容器 === */
.page-container {
    width: 100%;
    max-width: 1200px;
    padding: 40px 20px 180px 20px; 
    box-sizing: border-box;
}

h1 {
    text-align: center;
    margin-bottom: 30px;
    font-size: 1.8rem;
    background: linear-gradient(to right, #fbbf24, #f472b6, #60a5fa);
    -webkit-background-clip: text;
    color: transparent;
}

/* =========================================
   2. 预设库页面样式 (Presets)
   ========================================= */
.preset-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 20px;
    margin-top: 30px;
}

.preset-card {
    background: var(--card-bg);
    padding: 30px 20px;
    border-radius: 16px;
    cursor: pointer;
    text-align: center;
    color: white;
    font-weight: bold;
    transition: transform 0.2s, filter 0.2s, box-shadow 0.2s;
    border: 1px solid var(--border-color);
    position: relative;
    overflow: hidden;
}

.preset-card:hover { 
    transform: translateY(-5px); 
    filter: brightness(1.1); 
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
}
.preset-card:active { transform: scale(0.98); }

.preset-card .icon { font-size: 3rem; margin-bottom: 15px; display: block; }
.preset-card .label { font-size: 1.1rem; }

/* 颜色变体 */
.preset-card.safe { border-bottom: 4px solid var(--safe-color); }
.preset-card.normal { border-bottom: 4px solid var(--normal-color); }
.preset-card.danger { border-bottom: 4px solid var(--danger-color); }
.preset-card.extreme { border-bottom: 4px solid var(--extreme-color); }

/* 文档类卡片颜色优化 */
.preset-card.doc {
    border-bottom: 4px solid var(--doc-color); 
    background: linear-gradient(to bottom, var(--card-bg), rgba(14, 165, 233, 0.05));
}

.preset-card.doc:hover {
    border-color: #38bdf8;
    box-shadow: 0 5px 15px rgba(14, 165, 233, 0.2);
}

.preset-hint {
    text-align: center; color: var(--text-sub); margin-top: 30px; font-size: 0.9rem;
}

/* === 分割线样式 === */
.divider {
    display: flex;
    align-items: center;
    text-align: center;
    margin: 50px 0 30px 0;
}
.divider::before, .divider::after {
    content: '';
    flex: 1;
    border-bottom: 1px dashed var(--border-color);
}
.divider span {
    padding: 0 15px;
    font-weight: bold;
    font-size: 1.1rem;
    color: #60a5fa; /* 浅蓝色文字 */
}

/* =========================================
   3. 生成器页面样式 (Generator)
   ========================================= */
.controls-header {
    display: flex;
    justify-content: flex-end;
    gap: 10px;
    margin-bottom: 20px;
}

.ctrl-btn {
    padding: 6px 12px;
    border-radius: 6px;
    border: 1px solid var(--border-color);
    background: var(--card-bg);
    color: var(--text-sub);
    cursor: pointer;
    transition: 0.2s;
}
.ctrl-btn:hover { background: var(--border-color); color: white; }

.gen-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 15px;
}

.gen-card {
    background-color: var(--card-bg);
    border-radius: 12px;
    padding: 15px;
    border: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    gap: 10px;
    opacity: 0.5;
    filter: grayscale(0.8);
    transition: 0.2s;
}

.gen-card.active { opacity: 1; filter: grayscale(0); border-color: var(--card-accent, #6366f1); box-shadow: 0 0 10px -5px var(--card-accent, #6366f1); }

.card-top { display: flex; justify-content: space-between; align-items: center; font-weight: bold; color: var(--card-accent, #fff); }
.card-content { text-align: center; min-height: 50px; display: flex; flex-direction: column; justify-content: center; }
.item-group { font-size: 0.75rem; color: #64748b; margin-bottom: 4px; }
.item-name { font-size: 1.2rem; color: white; font-weight: bold; }
.prompt-preview { font-family: monospace; font-size: 0.75rem; color: #38bdf8; background: #0f172a; padding: 5px; border-radius: 4px; height: 40px; overflow-y: auto; word-break: break-all; }

/* 开关样式 */
.toggle { width: 32px; height: 18px; background: #475569; border-radius: 20px; position: relative; cursor: pointer; margin-right: 8px;}
.toggle::after { content:''; position:absolute; top:2px; left:2px; width:14px; height:14px; background:#fff; border-radius:50%; transition:0.2s; }
.gen-card.active .toggle { background: var(--card-accent); }
.gen-card.active .toggle::after { left: 16px; }

/* 底部固定栏 */
.fixed-bar {
    position: fixed; bottom: 0; left: 0; right: 0;
    background: rgba(15, 23, 42, 0.98);
    border-top: 1px solid var(--border-color);
    padding: 15px 40px; /* 增加左右内边距 */
    z-index: 100;
    display: flex; flex-direction: column; align-items: center; gap: 10px;
}

.bar-row { width: 100%; max-width: 1000px; display: flex; gap: 10px; }
.bar-input { flex: 1; background: #1e293b; border: 1px solid var(--border-color); color: white; padding: 8px 12px; border-radius: 6px; }
.bar-btn { background: var(--accent-color); color: white; border: none; padding: 0 20px; border-radius: 6px; font-weight: bold; cursor: pointer; white-space: nowrap; transition: background-color 0.2s; }
.bar-btn:hover { filter: brightness(1.1); }
.final-text { flex: 1; height: 50px; background: #020617; border: 1px solid var(--border-color); color: #e2e8f0; border-radius: 6px; padding: 8px; resize: none; font-family: monospace; }

/* =========================================
   4. 通用与模态框样式
   ========================================= */
.toast {
    position: fixed; top: 100px; left: 50%; transform: translateX(-50%);
    background: #10b981; color: white; padding: 8px 16px; border-radius: 20px;
    opacity: 0; pointer-events: none; transition: top 0.3s, opacity 0.3s; z-index: 999;
}
.toast.show { opacity: 1; top: 80px; }

/* 设置弹窗 */
.modal-overlay { display: none; position: fixed; top:0; left:0; width:100%; height:100%; background:rgba(0,0,0,0.8); z-index:1000; justify-content:center; align-items:center; }
.modal { background: var(--card-bg); padding: 25px; border-radius: 12px; width: 90%; max-width: 400px; border: 1px solid var(--border-color); box-shadow: 0 5px 30px rgba(0,0,0,0.5); }
.modal input { width: 100%; padding: 10px; margin: 5px 0 15px; background: #0f172a; border: 1px solid #334155; color: white; border-radius: 4px; box-sizing: border-box; }


/* === 集合弹窗样式 === */
.collection-modal-content {
    width: 95%;
    max-width: 600px; 
    max-height: 80vh; 
    overflow-y: auto; 
    display: flex;
    flex-direction: column;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 10px;
}

.modal-header h2 {
    margin: 0;
    font-size: 1.3rem;
    color: var(--accent-color);
}

.close-btn {
    background: none;
    border: none;
    color: var(--text-sub);
    font-size: 2rem;
    cursor: pointer;
    line-height: 1;
}
.close-btn:hover { color: white; }

/* 二级列表网格 */
.collection-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); 
    gap: 10px;
}

.collection-item {
    background: #0f172a;
    border: 1px solid var(--border-color);
    color: #e2e8f0;
    padding: 12px 8px;
    border-radius: 8px;
    cursor: pointer;
    text-align: center;
    font-size: 0.9rem;
    transition: 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 40px;
}

.collection-item:hover {
    background: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 10px rgba(0,0,0,0.2);
}

/* =========================================
   5. 锁定屏幕样式 (Lock Screen)
   ========================================= */
.lock-screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: var(--bg-color); 
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000; 
}

.login-box {
    background-color: var(--card-bg);
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.5);
    width: 90%;
    max-width: 400px;
    text-align: center;
}

.login-box h1 {
    color: var(--accent-color);
    margin-bottom: 20px;
    font-size: 1.5rem;
}

.login-box p {
    color: var(--text-sub);
    margin-bottom: 15px;
}

.login-box input[type="email"],
.login-box input[type="password"] {
    width: 100%;
    padding: 12px;
    margin-bottom: 15px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background-color: var(--bg-color);
    color: var(--text-main);
    box-sizing: border-box;
    transition: border-color 0.3s;
}

.login-box input:focus {
    border-color: var(--accent-color);
    outline: none;
}

.login-box button {
    width: 100%;
    padding: 12px;
    background-color: var(--accent-color);
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1rem;
    transition: background-color 0.3s;
}

.login-box button:hover {
    background-color: var(--btn-hover);
}

.error-message {
    color: #ef4444; 
    margin-top: 15px;
    font-size: 0.9rem;
}


/* =========================================
   6. 响应式调整 (Responsive Overrides)
   ========================================= */

@media screen and (min-width: 768px) {
    /* 预设网格：至少 4 列 */
    .preset-grid {
        grid-template-columns: repeat(4, 1fr);
    }

    /* 生成器网格：至少 3 列 */
    .gen-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media screen and (min-width: 1024px) {
    /* 进一步优化大屏幕布局 */
    .preset-grid {
        grid-template-columns: repeat(5, 1fr);
    }
    .gen-grid {
        grid-template-columns: repeat(4, 1fr);
    }
    .fixed-bar {
        padding: 15px 40px; 
    }
}