/* 银发智生活 - 优化版样式 */
:root {
    --primary: #1f5bb8;
    --primary-dark: #15408a;
    --primary-light: #e8f3ff;
    --text: #222;
    --text-light: #555;
    --bg: #f5f7fa;
    --white: #fff;
    --border: #e8ecf0;
    --shadow: 0 2px 12px rgba(0,0,0,0.08);
    --shadow-hover: 0 6px 24px rgba(31,91,184,0.15);
    --radius: 12px;
    --transition: 0.25s ease;
}

* { margin:0; padding:0; box-sizing:border-box; }
html { scroll-behavior: smooth; }
body {
    background: var(--bg);
    color: var(--text);
    font-family: "Microsoft YaHei","PingFang SC","SimHei",sans-serif;
    font-size: 18px;
    line-height: 1.8;
    -webkit-text-size-adjust: 100%;
}

.container { width:94%; max-width:1200px; margin:0 auto; }

/* === 吸顶导航 === */
.nav {
    background: var(--primary);
    padding: 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}
.nav .container {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
}
.nav a {
    color: rgba(255,255,255,0.9);
    text-decoration: none;
    padding: 14px 20px;
    font-size: 19px;
    transition: background var(--transition), color var(--transition);
    white-space: nowrap;
}
.nav a:hover, .nav a:focus {
    background: var(--primary-dark);
    color: #fff;
}

/* === Hero === */
.hero {
    background: linear-gradient(135deg, #1f5bb8 0%, #2d7ae0 100%);
    color: #fff;
    padding: 55px 20px;
    text-align: center;
    margin-bottom: 30px;
    border-radius: 0 0 24px 24px;
}
.hero h1 { font-size: 40px; margin-bottom: 12px; letter-spacing: 2px; }
.hero p { font-size: 20px; opacity: 0.95; margin-bottom: 4px; }

/* === Box === */
.box {
    padding: 28px;
    margin-bottom: 25px;
    background: var(--white);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}
.box h2 {
    font-size: 26px;
    color: var(--primary);
    margin-bottom: 18px;
    border-left: 5px solid var(--primary);
    padding-left: 14px;
}

/* === Grid Cards === */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 22px;
}
.card {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 28px 24px;
    text-align: center;
    transition: transform var(--transition), box-shadow var(--transition);
    cursor: pointer;
    text-decoration: none;
    color: inherit;
    display: block;
}
.card:hover, .card:focus {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
    border-color: var(--primary);
}
.card h3 { font-size: 24px; margin-bottom: 10px; color: var(--primary); }
.card p { font-size: 17px; color: var(--text-light); margin-bottom: 16px; line-height: 1.6; }

/* === 计算器网格 === */
.calc-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
}
.calc-item {
    display: block;
    padding: 14px 10px;
    background: var(--primary-light);
    border-radius: 10px;
    text-align: center;
    color: var(--primary);
    text-decoration: none;
    font-size: 17px;
    font-weight: bold;
    transition: background var(--transition), transform var(--transition);
    min-height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
}
.calc-item:hover, .calc-item:focus {
    background: #d0e6ff;
    transform: scale(1.03);
    color: var(--primary-dark);
}

/* === Footer === */
.footer {
    background: #1a1a2e;
    color: #bbb;
    text-align: center;
    padding: 40px 0;
    margin-top: 50px;
}
.footer a {
    color: #ddd;
    margin: 0 12px;
    text-decoration: none;
    font-size: 17px;
    transition: color var(--transition);
}
.footer a:hover { color: #fff; }
.disclaimer { margin-top: 18px; font-size: 15px; color: #888; }

/* === 面包屑 === */
.breadcrumb {
    padding: 12px 0;
    font-size: 15px;
    color: var(--text-light);
}
.breadcrumb a {
    color: var(--primary);
    text-decoration: none;
}
.breadcrumb a:hover { text-decoration: underline; }
.breadcrumb span { margin: 0 6px; color: #999; }

/* === 返回顶部 === */
.back-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: 50%;
    font-size: 24px;
    cursor: pointer;
    box-shadow: 0 2px 10px rgba(0,0,0,0.2);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 999;
    transition: background var(--transition), transform var(--transition);
}
.back-top:hover { background: var(--primary-dark); transform: scale(1.1); }
.back-top.show { display: flex; }

/* === 工具页样式 === */
.tool-page { max-width: 700px; margin: 0 auto; }
.tool-page h1 {
    font-size: 26px;
    color: var(--primary);
    text-align: center;
    margin: 20px 0 16px;
}
.tool-page label {
    display: block;
    font-size: 18px;
    margin: 14px 0 6px;
    color: var(--text);
}
.tool-page input[type="number"], .tool-page select {
    width: 100%;
    padding: 14px 16px;
    font-size: 20px;
    border: 2px solid var(--border);
    border-radius: 10px;
    outline: none;
    transition: border-color var(--transition);
}
.tool-page input:focus, .tool-page select:focus {
    border-color: var(--primary);
}
.tool-page button {
    display: block;
    width: 100%;
    padding: 16px;
    margin: 24px 0;
    background: var(--primary);
    color: #fff;
    font-size: 22px;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    transition: background var(--transition), transform var(--transition);
}
.tool-page button:hover { background: var(--primary-dark); transform: scale(1.02); }
.tool-page .result {
    padding: 20px;
    border-radius: 10px;
    font-size: 20px;
    font-weight: bold;
    text-align: center;
    margin-bottom: 20px;
}
.tool-page .result.green { background: #e8f5e9; color: #2e7d32; }
.tool-page .result.yellow { background: #fff8e1; color: #f57f17; }
.tool-page .result.red { background: #ffebee; color: #c62828; }

/* Help box */
.help-box {
    background: #f0f6ff;
    border-radius: 10px;
    padding: 18px 20px;
    margin: 20px 0;
    font-size: 16px;
    line-height: 1.7;
    color: #444;
}
.help-box summary {
    font-size: 18px;
    font-weight: bold;
    color: var(--primary);
    cursor: pointer;
    padding: 4px 0;
}

/* Quiz styles */
.quiz-option {
    display: flex;
    gap: 12px;
    margin: 10px 0;
}
.quiz-option label {
    flex: 1;
    padding: 14px;
    border: 2px solid var(--border);
    border-radius: 10px;
    text-align: center;
    cursor: pointer;
    font-size: 19px;
    transition: border-color var(--transition), background var(--transition);
}
.quiz-option input:checked + label {
    border-color: var(--primary);
    background: var(--primary-light);
    color: var(--primary);
    font-weight: bold;
}

/* === 移动端适配 === */
@media (max-width: 768px) {
    .hero { padding: 35px 16px; border-radius: 0 0 16px 16px; }
    .hero h1 { font-size: 30px; }
    .hero p { font-size: 17px; }
    .nav .container { justify-content: center; }
    .nav a { padding: 12px 14px; font-size: 17px; }
    .grid { grid-template-columns: 1fr; }
    .calc-grid { grid-template-columns: 1fr; }
    .calc-item { font-size: 16px; padding: 14px 8px; }
    .box h2 { font-size: 22px; }
    .card { padding: 22px 18px; }
    .card h3 { font-size: 21px; }
    body { font-size: 17px; }
}

@media (max-width: 480px) {
    .hero h1 { font-size: 26px; }
    .hero p { font-size: 16px; }
    .nav a { padding: 11px 12px; font-size: 16px; }
    .tool-page h1 { font-size: 22px; }
    .tool-page button { font-size: 20px; padding: 14px; }
}