@import url('https://fonts.googleapis.com/css2?family=Roboto+Mono:wght@400;700&family=Noto+Sans+SC:wght@400;700&display=swap');

:root {
    --bg-color: #F9F9F7;
    --text-color: #333333;
    --heading-color: #1A1A1A;
    --primary-color: #D06519;
    --accent-color: #8A4A12;
    --code-bg-color: #F3F4F6;
    --code-text-color: #0B598E;
    --border-color: #E5E7EB;
    --warning-text-color: #B91C1C;
    --warning-bg-color: #FEF2F2;
    --success-color: #059669;
    --success-bg-color: #F0FDF4;
    --info-color: #0284C7;
    --info-bg-color: #F0F9FF;
    --surface-color: #FFFFFF;
    --surface-muted: #F6F1EA;
    --surface-subtle: #FCFBF8;
    --shadow-soft: 0 18px 40px rgba(74, 52, 37, 0.10);
    --shadow-card: 0 10px 24px rgba(74, 52, 37, 0.08);
    --font-mono: "Roboto Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    --font-sans: "Noto Sans SC", system-ui, -apple-system, "Segoe UI", "Microsoft YaHei UI", sans-serif;
}

* { box-sizing: border-box; }

body, html {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    font-family: var(--font-sans);
    background-color: #EAEAEA;
    color: var(--text-color);
    overflow: hidden;
}

#presentation {
    width: 100%;
    height: 100vh;
    background-color: var(--bg-color);
    position: relative;
    overflow: hidden;
}

.slide {
    width: 100%;
    height: 100%;
    padding: 50px 80px;
    display: none;
    flex-direction: column;
    justify-content: flex-start;
    align-items: center;
    overflow-y: auto;
    scrollbar-width: thin;
    scrollbar-color: var(--border-color) transparent;
}

.slide::-webkit-scrollbar { width: 6px; }
.slide::-webkit-scrollbar-track { background: transparent; }
.slide::-webkit-scrollbar-thumb { background: var(--border-color); border-radius: 3px; }

.slide.active {
    display: flex;
    animation: fadeIn 0.5s ease-in-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.slide-content {
    width: 100%;
    max-width: 1100px;
    text-align: left;
}

.slide.title-slide {
    text-align: center;
    justify-content: center;
    background: radial-gradient(ellipse at 50% 30%, rgba(208, 101, 25, 0.06) 0%, transparent 60%);
}

.slide.title-slide h1 {
    font-size: 3.4em;
    color: var(--heading-color);
    margin: 0 0 16px 0;
}

.slide.title-slide p {
    font-size: 1.5em;
    color: #6B7280;
    margin: 8px 0;
}

.slide.title-slide strong {
    color: var(--accent-color);
    font-size: 1.15em;
    display: block;
    margin-top: 20px;
}

.slide.title-slide .chapter-badge {
    display: inline-block;
    background: var(--surface-muted);
    color: var(--primary-color);
    padding: 6px 20px;
    border-radius: 20px;
    font-size: 0.95em;
    font-weight: 700;
    margin-bottom: 24px;
    border: 1px solid var(--border-color);
}

.slide h2 {
    font-size: 2.2em;
    color: var(--heading-color);
    border-bottom: 2px solid var(--accent-color);
    padding-bottom: 10px;
    margin-top: 0;
    width: 100%;
}

.slide h3 {
    font-size: 1.5em;
    color: var(--primary-color);
    margin-top: 28px;
    margin-bottom: 12px;
}

.slide h4 {
    font-size: 1.2em;
    color: var(--accent-color);
    margin-top: 20px;
    margin-bottom: 8px;
}

.slide p, .slide li {
    font-size: 1.15em;
    line-height: 1.75;
    max-width: 100%;
}

.slide ul, .slide ol {
    padding-left: 28px;
}

.slide li + li { margin-top: 10px; }

pre {
    background-color: var(--code-bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 18px 22px;
    width: 100%;
    overflow-x: auto;
    font-family: var(--font-mono);
    color: #333;
    font-size: 0.95em;
    line-height: 1.6;
    margin: 16px 0;
}

code {
    font-family: var(--font-mono);
    color: var(--code-text-color);
    background-color: rgba(11, 89, 142, 0.08);
    padding: 2px 7px;
    border-radius: 4px;
    font-size: 0.92em;
}

pre code {
    background-color: transparent;
    padding: 0;
}

strong { color: var(--accent-color); }

.key-point {
    background: var(--surface-muted);
    border-left: 4px solid var(--primary-color);
    padding: 16px 22px;
    margin: 20px 0;
    border-radius: 0 8px 8px 0;
    font-size: 1.1em;
}

.conclusion {
    background: var(--success-bg-color);
    border-left: 4px solid var(--success-color);
    padding: 16px 22px;
    margin: 20px 0;
    border-radius: 0 8px 8px 0;
}

.warning {
    color: var(--warning-text-color);
    background: var(--warning-bg-color);
    border-left: 4px solid var(--warning-text-color);
    padding: 16px 22px;
    margin: 20px 0;
    border-radius: 0 8px 8px 0;
}

.danger {
    background: var(--warning-bg-color);
    border-left: 4px solid #DC2626;
    padding: 16px 22px;
    margin: 20px 0;
    border-radius: 0 8px 8px 0;
}

.info-block {
    background: var(--info-bg-color);
    border-left: 4px solid var(--info-color);
    padding: 16px 22px;
    margin: 20px 0;
    border-radius: 0 8px 8px 0;
}

.comparison {
    display: flex;
    gap: 24px;
    margin: 20px 0;
}

.comparison .before,
.comparison .after {
    flex: 1;
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 22px;
    box-shadow: var(--shadow-card);
}

.comparison .before { border-top: 3px solid #DC2626; }
.comparison .after { border-top: 3px solid var(--success-color); }

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 18px;
    margin: 20px 0;
}

.card-grid.cols-2 {
    grid-template-columns: repeat(2, 1fr);
}

.card {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 22px;
    box-shadow: var(--shadow-card);
    transition: transform 0.2s, border-color 0.2s;
}

.card:hover {
    transform: translateY(-2px);
    border-color: var(--primary-color);
}

.card h4 {
    margin-top: 0;
    color: var(--primary-color);
}

.flow-steps {
    display: flex;
    gap: 12px;
    margin: 20px 0;
    align-items: stretch;
}

.flow-step {
    flex: 1;
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 18px;
    text-align: center;
    position: relative;
    box-shadow: var(--shadow-card);
}

.flow-step::after {
    content: "→";
    position: absolute;
    right: -14px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--primary-color);
    font-size: 1.5em;
    font-weight: bold;
}

.flow-step:last-child::after { content: none; }

.tree-structure {
    background: var(--code-bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 24px;
    margin: 16px 0;
    font-family: var(--font-mono);
    font-size: 0.92em;
    line-height: 1.7;
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin: 16px 0;
    font-size: 0.95em;
}

th {
    background: var(--surface-muted);
    color: var(--accent-color);
    padding: 10px 14px;
    text-align: left;
    border: 1px solid var(--border-color);
    font-weight: 700;
}

td {
    padding: 10px 14px;
    border: 1px solid var(--border-color);
    color: var(--text-color);
}

tr:nth-child(even) td { background: rgba(0, 0, 0, 0.02); }

.tag {
    display: inline-block;
    padding: 2px 10px;
    border-radius: 12px;
    font-size: 0.85em;
    font-weight: 600;
}

.tag-primary { background: rgba(208, 101, 25, 0.15); color: var(--primary-color); }
.tag-success { background: rgba(5, 150, 105, 0.12); color: var(--success-color); }
.tag-warning { background: rgba(180, 130, 20, 0.12); color: #92600A; }
.tag-danger { background: rgba(185, 28, 28, 0.1); color: var(--warning-text-color); }
.tag-info { background: rgba(2, 132, 199, 0.1); color: var(--info-color); }

.controls {
    position: fixed;
    bottom: 0;
    left: 320px;
    right: 0;
    height: 56px;
    background: var(--surface-color);
    border-top: 1px solid var(--border-color);
    border-left: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    z-index: 100;
    transition: left 0.3s ease;
}

body.toc-closed .controls {
    left: 0;
}

.controls button {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 8px 22px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 0.95em;
    font-family: var(--font-sans);
    transition: background-color 0.2s;
}

.controls button:hover {
    background-color: #E5843A;
}

.controls button:disabled {
    background-color: #D1D5DB;
    color: #6B7280;
    cursor: not-allowed;
}

.controls button:disabled:hover {
    background-color: #D1D5DB;
}

#slide-counter {
    color: #6B7280;
    font-size: 0.9em;
    min-width: 60px;
    text-align: center;
}

.progress-bar-container {
    position: fixed;
    bottom: 56px;
    left: 320px;
    right: 0;
    height: 5px;
    background: var(--border-color);
    z-index: 100;
    transition: left 0.3s ease;
}

body.toc-closed .progress-bar-container {
    left: 0;
}

#progress-bar {
    height: 100%;
    width: 0;
    background-color: var(--primary-color);
    transition: width 0.3s ease-out;
}

.slide { padding-top: 40px; padding-bottom: 70px; }

.practice-container {
    display: flex;
    gap: 24px;
    width: 100%;
    margin-top: 16px;
}

.practice-step {
    flex: 1;
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 22px;
    box-shadow: var(--shadow-card);
}

.practice-step h3 {
    margin-top: 0;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 10px;
    color: var(--primary-color);
}

@media (max-width: 768px) {
    .slide { padding: 50px 24px; }
    .slide h1 { font-size: 2.2em; }
    .slide h2 { font-size: 1.6em; }
    .comparison { flex-direction: column; }
    .flow-steps { flex-direction: column; }
    .flow-step::after { content: none; }
    .card-grid, .card-grid.cols-2 { grid-template-columns: 1fr; }
}
.ai-diagram-img {
    max-width: 800px;
    width: 100%;
    height: auto;
    display: block;
    margin: 20px auto;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}