/* ── Fonts ─────────────────────────────────────────────── */
@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;700&display=swap');
@import url('https://fonts.googleapis.com/css2?family=CMU+Serif:wght@400;700&display=swap');

/* ── Variables ──────────────────────────────────────────── */
:root {
    --bg-light:       #f5f5f5;
    --text-dark:      #2a2a2a;
    --color-blue:     #0088aa;
    --color-yellow:   #cc8800;
    --color-dark-blue:#1A2A4F;
    --color-red:      #d42f1f;
    --color-green:    #2e9e5b;
    --color-purple:   #8855aa;
}

/* ── Base ───────────────────────────────────────────────── */
.reveal {
    font-family: 'CMU Serif', 'Times New Roman', serif;
    font-size: 32px;
    color: var(--text-dark);
    background-color: var(--bg-light);
}

.reveal .slides {
    background: transparent;
    padding: 0 !important;
}

/* ── Slide background (dice watermark) ──────────────────── */
.reveal .slide-background {
    background-color: var(--bg-light);
}

.reveal .slide-background-content {
    background-size: cover;
    background-position: center;
    opacity: 0.18;
}

/* ── Slide layout ───────────────────────────────────────── */
.reveal .slides > section,
.reveal .slides > section > section {
    padding: 1.8em 2.8em !important;
    min-height: 100%;
    width: 100%;
    box-sizing: border-box;
    display: block;
    text-align: left;
}

/* ── Scrollbar ──────────────────────────────────────────── */
.reveal .slides section::-webkit-scrollbar {
    width: 6px;
}

.reveal .slides section::-webkit-scrollbar-track {
    background: transparent;
}

.reveal .slides section::-webkit-scrollbar-thumb {
    background-color: rgba(0, 136, 170, 0.3);
    border-radius: 10px;
}

.reveal .slides section::-webkit-scrollbar-thumb:hover {
    background-color: var(--color-blue);
}

/* ── Typography ─────────────────────────────────────────── */
.reveal h1,
.reveal h2,
.reveal h3,
.reveal h4 {
    font-family: 'JetBrains Mono', monospace;
    font-weight: 700;
    color: var(--color-blue);
    text-transform: none;
    text-shadow: none;
}

.reveal h1 { font-size: 2.5em; }

.reveal h2 {
    font-size: 2em;
    border-bottom: 3px solid var(--color-blue);
    padding-bottom: 0.3em;
    margin-top: 0;
}

.reveal h3 {
    font-size: 1.3em;
    color: var(--color-dark-blue);
}

.reveal strong { color: var(--color-yellow); font-weight: 700; }
.reveal em     { color: var(--color-dark-blue); }

.reveal a            { color: var(--color-blue); text-decoration: none; }
.reveal a:hover      { color: var(--color-purple); text-decoration: underline; }

/* ── Lists ──────────────────────────────────────────────── */
.reveal ul,
.reveal ol  { margin-left: 1em; }
.reveal li  { margin-bottom: 0.5em; }

/* ── Code ───────────────────────────────────────────────── */
.reveal code {
    font-family: 'JetBrains Mono', monospace;
    background-color: rgba(0, 136, 170, 0.08);
    padding: 0.2em 0.4em;
    border-radius: 4px;
    color: var(--color-blue);
}

.reveal pre {
    background-color: rgba(245, 245, 245, 0.95);
    border: 2px solid var(--color-blue);
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

.reveal pre code {
    background-color: transparent;
    padding: 1em;
    max-height: 600px;
    color: var(--text-dark);
}

/* ── Tables ─────────────────────────────────────────────── */
.reveal table {
    border-collapse: collapse;
    margin: 1em auto;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.88em;
    background-color: rgba(255, 255, 255, 0.75);
    width: 100%;
}

.reveal table th {
    background-color: var(--color-blue);
    color: white;
    font-weight: 700;
    padding: 0.5em 1em;
    border: 2px solid var(--color-blue);
}

.reveal table td {
    padding: 0.5em 1em;
    border: 1px solid rgba(0, 136, 170, 0.3);
    color: var(--text-dark);
}

.reveal table tr:nth-child(even) td {
    background-color: rgba(0, 136, 170, 0.05);
}

/* ── Math ───────────────────────────────────────────────── */
.reveal .MathJax,
.reveal .katex {
    color: var(--color-dark-blue);
    text-shadow: none;
}

/* ── Columns ────────────────────────────────────────────── */
.reveal .columns {
    display: flex;
    gap: 2em;
    align-items: flex-start;
    width: 100%;
}

.reveal .column {
    flex: 1;
    padding: 1.2em 1.5em;
    background-color: rgba(255, 255, 255, 0.55);
    border-radius: 10px;
    border: 1px solid rgba(0, 136, 170, 0.15);
}

/* ── Blockquotes ────────────────────────────────────────── */
.reveal blockquote {
    background-color: rgba(0, 136, 170, 0.07);
    border-left: 5px solid var(--color-blue);
    padding: 1em;
    font-style: italic;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
    color: var(--text-dark);
}

/* ── Slide number ───────────────────────────────────────── */
.reveal .slide-number {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.75em;
    color: var(--color-blue);
    background-color: rgba(255, 255, 255, 0.85);
    padding: 0.4em 0.6em;
    border-radius: 5px;
    border: 1px solid rgba(0, 136, 170, 0.25);
}

/* ── Progress bar ───────────────────────────────────────── */
.reveal .progress { background: rgba(0, 136, 170, 0.15); }
.reveal .progress span { background: var(--color-blue); box-shadow: none; }

/* ── Title slide ────────────────────────────────────────── */
.reveal .slides > section.title-slide,
.reveal section.title-slide {
    text-align: center !important;
    display: flex !important;
    flex-direction: column !important;
    justify-content: center !important;
    align-items: center !important;
    height: 100vh !important;
    width: 100vw !important;
    padding: 0 !important;
    background-color: var(--bg-light) !important;
}

.reveal .title-slide h1 {
    color: var(--color-dark-blue);
    font-size: 3.2em;
    text-shadow: none;
    margin: 0 0 0.4em 0;
    line-height: 1.2;
}

.reveal .title-slide .author,
.reveal .title-slide .date {
    font-size: 1.4em;
    margin: 0.4em 0;
    color: var(--text-dark);
    opacity: 0.8;
}

/* ── Callouts ───────────────────────────────────────────── */
.reveal .callout {
    border-radius: 8px;
    font-size: 0.88em;
    background-color: rgba(255, 255, 255, 0.75);
    border-left-width: 5px;
    box-shadow: 0 1px 6px rgba(0, 0, 0, 0.06);
    margin: 0.6em 0;
}

.reveal .callout-note {
    border-left-color: var(--color-blue);
    background-color: rgba(0, 136, 170, 0.07);
}

.reveal .callout-tip {
    border-left-color: var(--color-green);
    background-color: rgba(46, 158, 91, 0.07);
}

.reveal .callout-important {
    border-left-color: var(--color-red);
    background-color: rgba(212, 47, 31, 0.07);
}

.reveal .callout-title {
    font-family: 'JetBrains Mono', monospace;
    font-weight: 700;
    color: var(--text-dark);
}

/* ── Navigation controls (tablet) ──────────────────────── */
.reveal .controls {
    bottom: 1.5em !important;
    right: 1.5em !important;
}

.reveal .controls button {
    color: var(--color-blue) !important;
    opacity: 0.7;
    width: 48px !important;
    height: 48px !important;
    transition: opacity 0.2s ease;
}

.reveal .controls button:hover,
.reveal .controls button:focus {
    opacity: 1;
    color: var(--color-dark-blue) !important;
}

/* ── Chalkboard buttons (tablet) ────────────────────────── */
.reveal .chalkboard-button,
.plugin-chalkboard .chalkboard-button {
    opacity: 1 !important;
    width: 44px !important;
    height: 44px !important;
    border-radius: 8px !important;
    background-color: rgba(255, 255, 255, 0.85) !important;
    border: 1px solid rgba(0, 136, 170, 0.3) !important;
    margin: 4px !important;
}

/* ── Cursor (always visible on tablet) ──────────────────── */
.reveal,
.reveal * { cursor: default !important; }

.reveal a,
.reveal button,
.reveal [role="button"],
.option-button { cursor: pointer !important; }

/* ── Quiz option buttons ────────────────────────────────── */
.option-button {
    background-color: #d6f0f7 !important;
    color: #1B211A !important;
    border: 1px solid var(--color-blue) !important;
    padding: 0.6em 1.2em !important;
    font-size: 0.9em !important;
    border-radius: 6px !important;
    min-height: 48px !important;
}

/* ── Definition box ─────────────────────────────────────── */
.definition-box {
    background-color: rgba(0, 136, 170, 0.07);
    border-left: 5px solid var(--color-blue);
    border-radius: 0 8px 8px 0;
    padding: 1em 1.5em;
    margin: 0.8em 0;
    font-size: 1.05em;
    color: var(--text-dark);
}

/* ── Formula highlight ──────────────────────────────────── */
.formula-highlight {
    background-color: rgba(0, 136, 170, 0.06);
    border: 2px solid var(--color-blue);
    border-radius: 10px;
    padding: 0.8em 2em;
    text-align: center;
    margin: 0.8em auto;
    max-width: 80%;
    box-shadow: 0 2px 12px rgba(0, 136, 170, 0.12);
}

/* ── Discriminant boxes ─────────────────────────────────── */
.disc-box {
    border-radius: 8px;
    padding: 1.2em 1em;
    text-align: center;
    margin: 0.3em;
    background-color: rgba(255, 255, 255, 0.65);
}

.disc-box.two-solutions {
    border: 2px solid var(--color-green);
    background-color: rgba(46, 158, 91, 0.07);
}

.disc-box.one-solution {
    border: 2px solid var(--color-blue);
    background-color: rgba(0, 136, 170, 0.07);
}

.disc-box.no-solutions {
    border: 2px solid var(--color-red);
    background-color: rgba(212, 47, 31, 0.07);
}

.disc-box h3              { font-size: 1.5em; margin-bottom: 0.3em; }
.two-solutions h3         { color: var(--color-green) !important; }
.one-solution h3          { color: var(--color-blue) !important; }
.no-solutions h3          { color: var(--color-red) !important; }

/* ── Coefficient cards (Anatomy slide) ──────────────────── */
.coeff-card {
    border-radius: 10px;
    padding: 1.2em 1em;
    text-align: center;
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.05em;
    margin: 0.3em;
    border-top: 4px solid transparent;
    background-color: rgba(255, 255, 255, 0.7);
}

.coeff-a {
    border-top-color: var(--color-red);
    background-color: rgba(212, 47, 31, 0.06);
}

.coeff-b {
    border-top-color: var(--color-blue);
    background-color: rgba(0, 136, 170, 0.06);
}

.coeff-c {
    border-top-color: var(--color-green);
    background-color: rgba(46, 158, 91, 0.06);
}

/* ── Oral recitation ────────────────────────────────────── */
.recitation-eq {
    text-align: center;
    font-size: 2em;
    padding: 0.8em 1em;
    margin: 1.5em auto 0.5em auto;
    max-width: 55%;
    border-radius: 12px;
    background-color: rgba(255, 255, 255, 0.72);
    border: 1.5px solid rgba(0, 136, 170, 0.2);
    box-shadow: 0 3px 14px rgba(0, 0, 0, 0.07);
}

.recitation-verdict {
    text-align: center;
    font-size: 1em;
    padding: 0.5em 2em;
    margin: 0 auto;
    max-width: 55%;
    border-radius: 0 0 10px 10px;
    font-family: 'JetBrains Mono', monospace;
}

.verdict-yes {
    background-color: rgba(46, 158, 91, 0.1);
    border-top: 3px solid var(--color-green);
    color: var(--color-green);
}

.verdict-no {
    background-color: rgba(212, 47, 31, 0.07);
    border-top: 3px solid var(--color-red);
    color: var(--color-red);
}

/* ── Method table ───────────────────────────────────────── */
.method-table table { width: 100%; }

/* ── Fragment highlight ─────────────────────────────────── */
.reveal .fragment.highlight-current-blue.current-fragment {
    color: var(--color-blue);
    font-weight: bold;
}

/* ── Highlight utility ──────────────────────────────────── */
.reveal .highlight {
    color: var(--color-yellow);
    background-color: rgba(204, 136, 0, 0.12);
    padding: 0.1em 0.3em;
    border-radius: 3px;
}