/* Materials Reader — Premium Styling */
* { margin:0; padding:0; box-sizing:border-box; }

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    color: #1E1E20;
    background: #FBFAF8;
    line-height: 1.8;
    -webkit-font-smoothing: antialiased;
}

/* Top Bar */
.topbar {
    background: #161618;
    padding: 14px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: sticky;
    top: 0;
    z-index: 100;
}
.topbar a {
    color: rgba(255,255,255,0.7);
    text-decoration: none;
    font-size: 0.85rem;
    font-weight: 500;
    transition: color 0.2s;
}
.topbar a:hover { color: #fff; }
.topbar-title {
    color: #fff;
    font-family: Georgia, 'Times New Roman', 'Songti SC', serif;
    font-size: 1rem;
    font-weight: 700;
}

/* Container */
.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 60px 24px 80px;
}

/* Headings */
h1 {
    font-family: Georgia, 'Times New Roman', 'Songti SC', serif;
    font-size: 2.5rem;
    font-weight: 700;
    color: #161618;
    margin-bottom: 0.5rem;
    line-height: 1.2;
}
h2 {
    font-family: Georgia, 'Times New Roman', 'Songti SC', serif;
    font-size: 1.6rem;
    font-weight: 700;
    color: #161618;
    margin: 3rem 0 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid #E8E5DF;
}
h3 {
    font-family: 'Inter', sans-serif;
    font-size: 1.1rem;
    font-weight: 700;
    color: #161618;
    margin: 2rem 0 0.75rem;
}
h4 {
    font-size: 0.95rem;
    font-weight: 700;
    margin: 1.5rem 0 0.5rem;
}

/* Meta */
.meta {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
    margin: 1rem 0 2rem;
}
.meta-item {
    font-size: 0.85rem;
    color: #8C1C2E;
    font-weight: 600;
    background: #FDF2F4;
    padding: 4px 14px;
    border-radius: 100px;
}

/* Tables */
table {
    width: 100%;
    border-collapse: collapse;
    margin: 1.5rem 0;
    font-size: 0.9rem;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0,0,0,0.04);
}
th {
    background: #161618;
    color: #fff;
    padding: 12px 16px;
    text-align: left;
    font-weight: 600;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}
td {
    padding: 10px 16px;
    border-bottom: 1px solid #E8E5DF;
    background: #fff;
}
tr:last-child td { border-bottom: none; }

/* Code / Inline */
code {
    background: #F7F4EF;
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 0.9em;
    color: #8C1C2E;
    font-weight: 600;
}
strong { color: #161618; }

/* Blockquote / Tips */
blockquote {
    background: #FDF2F4;
    border-left: 4px solid #8C1C2E;
    padding: 1rem 1.5rem;
    margin: 1.5rem 0;
    border-radius: 0 8px 8px 0;
    font-size: 0.9rem;
    color: #5C5C60;
}

/* Lists */
ul, ol { margin: 1rem 0 1rem 1.5rem; }
li { margin-bottom: 0.4rem; }

/* Section Card */
.card {
    background: #fff;
    border: 1px solid #E8E5DF;
    border-radius: 12px;
    padding: 1.5rem;
    margin: 1.5rem 0;
    box-shadow: 0 2px 8px rgba(0,0,0,0.04);
}

/* Progress Steps */
.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 1rem;
    margin: 1.5rem 0;
}
.step {
    background: #fff;
    border: 1px solid #E8E5DF;
    border-radius: 12px;
    padding: 1.25rem;
    text-align: center;
    box-shadow: 0 2px 8px rgba(0,0,0,0.04);
}
.step-num {
    font-family: Georgia, 'Times New Roman', 'Songti SC', serif;
    font-size: 2rem;
    font-weight: 700;
    color: #8C1C2E;
    opacity: 0.3;
}
.step h4 { margin: 0.5rem 0 0.25rem; font-size: 0.9rem; }
.step p { font-size: 0.8rem; color: #5C5C60; }

/* Horizontal Rule */
hr {
    border: none;
    border-top: 1px solid #E8E5DF;
    margin: 2rem 0;
}

/* Checkboxes */
input[type="checkbox"] {
    margin-right: 8px;
    accent-color: #8C1C2E;
}

/* Print */
@media print {
    .topbar { display: none; }
    body { font-size: 11pt; }
    .container { max-width: 100%; padding: 0; }
}