/* --- Global Styles & Resets --- */
:root {
    /* Light Mode Colors */
    --bg-color-light: #f4f7f9;
    --text-color-light: #333a45;
    --container-bg-light: #ffffff;
    --primary-accent-light: #007bff;
    --secondary-accent-light: #0056b3;
    --border-color-light: #e1e5e8;
    --button-bg-light: #e9ecef;
    --button-text-light: #333a45;
    --placeholder-bg-light: #f0f2f5;
    --placeholder-text-light: #6c757d;
    --svg-stroke-light: #007bff;
    --svg-fill-light: rgba(0, 123, 255, 0.08);
    --svg-text-light: #333a45;
    --slider-thumb-light: #007bff;
    --slider-track-light: #ddd;
    --section-transition-duration: 0.3s; 
    --timeline-line-color-light: #ccd1d9;
    --timeline-dot-bg-light: #fff;
    --timeline-dot-border-light: #007bff;
    --timeline-details-bg-light: #f0f4f8; 
    --glossary-dt-bg-light: #e9ecef;
    --glossary-dd-border-light: #007bff;
    --glossary-dd-bg-light: #f8f9fa;
    --focus-ring-color-light: rgba(0, 123, 255, 0.4);


    /* Dark Mode Colors */
    --bg-color-dark: #121212;
    --text-color-dark: #e0e0e0;
    --container-bg-dark: #1e1e1e;
    --primary-accent-dark: #00a1ff;
    --secondary-accent-dark: #007acc;
    --border-color-dark: #333333;
    --button-bg-dark: #333333;
    --button-text-dark: #e0e0e0;
    --placeholder-bg-dark: #2a2e33;
    --placeholder-text-dark: #888888;
    --svg-stroke-dark: #00a1ff;
    --svg-fill-dark: rgba(0, 161, 255, 0.12);
    --svg-text-dark: #e0e0e0;
    --slider-thumb-dark: #00a1ff;
    --slider-track-dark: #555;
    --timeline-line-color-dark: #444a52;
    --timeline-dot-bg-dark: #2c2c2c;
    --timeline-dot-border-dark: #00a1ff;
    --timeline-details-bg-dark: #2a2a30; 
    --glossary-dt-bg-dark: #333333;
    --glossary-dd-border-dark: #00a1ff;
    --glossary-dd-bg-dark: #272727;
    --focus-ring-color-dark: rgba(0, 161, 255, 0.5);
}

* { 
    margin: 0; 
    padding: 0; 
    box-sizing: border-box; 
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease, fill 0.3s ease, stroke 0.3s ease, box-shadow 0.2s ease, outline-color 0.2s ease, outline-width 0.1s ease; 
}
html { 
    scroll-behavior: smooth; 
}
body { 
    font-family: 'Roboto', 'Vazirmatn', sans-serif; 
    line-height: 1.7; 
    background-color: var(--bg-color-light); 
    color: var(--text-color-light); 
    display: flex; 
    justify-content: center; 
    align-items: flex-start; 
    min-height: 100vh; 
    padding: 20px; 
    overflow-x: hidden; 
}
body.dark-mode { 
    background-color: var(--bg-color-dark); 
    color: var(--text-color-dark); 
}

/* Skip Link */
.skip-link { 
    position: absolute; 
    top: -100px; 
    left: 50%; 
    transform: translateX(-50%); 
    background-color: var(--primary-accent-light); 
    color: white; 
    padding: 10px 20px; 
    border-radius: 0 0 8px 8px; 
    z-index: 9999; 
    text-decoration: none; 
    font-weight: bold; 
    transition: top 0.3s ease-in-out; 
    box-shadow: 0 2px 5px rgba(0,0,0,0.2); 
}
.skip-link:focus { 
    top: 0; 
    outline: 3px solid var(--secondary-accent-light); 
    outline-offset: 2px; 
}
body.dark-mode .skip-link { 
    background-color: var(--primary-accent-dark); 
}
body.dark-mode .skip-link:focus { 
    outline-color: var(--secondary-accent-dark); 
}

.container { 
    width: 100%; 
    max-width: 900px; 
    background-color: var(--container-bg-light); 
    padding: 25px 35px; 
    border-radius: 12px; 
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.08); 
    border: 1px solid var(--border-color-light); 
    display: flex; 
    flex-direction: column; 
}
body.dark-mode .container { 
    background-color: var(--container-bg-dark); 
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.2); 
    border: 1px solid var(--border-color-dark); 
}

header { 
    display: flex; 
    justify-content: space-between; 
    align-items: center; 
    margin-bottom: 25px; 
    padding-bottom: 15px; 
    border-bottom: 1px solid var(--border-color-light); 
    width: 100%; 
}
body.dark-mode header { 
    border-bottom: 1px solid var(--border-color-dark); 
}
header h1 { 
    font-size: 2.2rem; 
    font-weight: 700; 
    color: var(--primary-accent-light); 
    cursor: pointer; 
    user-select: none; 
    margin: 0; 
}
header h1:focus-visible { 
    outline: 3px solid var(--focus-ring-color-light); 
    outline-offset: 3px; 
    border-radius: 3px; 
}
body.dark-mode header h1 { 
    color: var(--primary-accent-dark); 
}
body.dark-mode header h1:focus-visible { 
    outline-color: var(--focus-ring-color-dark); 
}

.controls { 
    display: flex; 
    flex-direction: column; 
    align-items: flex-end; 
    gap: 5px; 
}
.lang-switcher button { 
    padding: 7px 12px; 
    margin-left: 6px; 
    background-color: var(--button-bg-light); 
    color: var(--button-text-light); 
    border: 1px solid var(--border-color-light); 
    border-radius: 6px; 
    cursor: pointer; 
    font-size: 0.85rem; 
    font-weight: 500; 
}
body.dark-mode .lang-switcher button { 
    background-color: var(--button-bg-dark); 
    color: var(--button-text-dark); 
    border: 1px solid var(--border-color-dark); 
}
.lang-switcher button:hover, .lang-switcher button:focus-visible { 
    background-color: var(--primary-accent-light); 
    color: #fff; 
    border-color: var(--primary-accent-light); 
    outline: 2px solid var(--focus-ring-color-light); 
    outline-offset: 1px; 
}
body.dark-mode .lang-switcher button:hover, body.dark-mode .lang-switcher button:focus-visible { 
    background-color: var(--primary-accent-dark); 
    color: var(--container-bg-dark); 
    border-color: var(--primary-accent-dark); 
    outline-color: var(--focus-ring-color-dark); 
}
.lang-switcher button.active-lang { 
    background-color: var(--primary-accent-light); 
    color: #fff; 
    font-weight: bold; 
    border-color: var(--primary-accent-light); 
}
body.dark-mode .lang-switcher button.active-lang { 
    background-color: var(--primary-accent-dark); 
    color: var(--container-bg-dark); 
    border-color: var(--primary-accent-dark); 
}
.dark-mode-hint { 
    font-size: 0.7rem; 
    color: #888; 
    margin-top: 3px; 
}
body.dark-mode .dark-mode-hint { 
    color: #666; 
}

main#interactive-content { 
    position: relative; 
    width: 100%; 
    /* min-height: auto; /* Let content dictate */
}

.content-section { 
    width: 100%; 
    opacity: 0; 
    transform: translateY(15px); 
    transition: opacity var(--section-transition-duration) ease-in-out, 
                transform var(--section-transition-duration) ease-in-out;
    padding-bottom: 20px; /* Consistent padding */
    border-bottom: 1px solid var(--border-color-light); 
    display: none; 
}

.content-section.active { 
    opacity: 1; 
    transform: translateY(0); 
    display: block; 
}

.content-section.exiting { 
    opacity: 0;
    transform: translateY(-15px);
    position: absolute; 
    top: 0;
    left: 0;
    width: 100%;
}

body.dark-mode .content-section { 
    border-bottom: 1px solid var(--border-color-dark); 
}
/* Remove border from the last section in the HTML that is also active */
#interactive-content > .content-section.active:last-of-type {
    border-bottom: none; 
}


.content-section h2 { 
    font-size: 1.8rem; 
    font-weight: 700; 
    color: var(--text-color-light); 
    margin-top: 0; 
    margin-bottom: 18px; 
}
.content-section h2:focus-visible { 
    outline: 3px solid var(--focus-ring-color-light); 
    outline-offset: 3px; 
    border-radius: 3px; 
}
body.dark-mode .content-section h2 { 
    color: var(--text-color-dark); 
}
body.dark-mode .content-section h2:focus-visible { 
    outline-color: var(--focus-ring-color-dark); 
}
.content-section h3 { 
    font-size: 1.3rem; 
    font-weight: 600; 
    color: var(--secondary-accent-light); 
    margin-top: 22px; 
    margin-bottom: 8px; 
}
body.dark-mode .content-section h3 { 
    color: var(--secondary-accent-dark); 
}
.content-section p { 
    margin-bottom: 16px; 
    font-size: 1rem; 
    text-align: justify; 
}
.content-section > *:last-child { /* Ensure last element in section has no bottom margin if it's a p or div */
    margin-bottom: 0; 
}


.deeper-study { 
    margin-top: 18px; 
    margin-bottom: 18px; 
    padding: 12px 15px; 
    background-color: rgba(0,123,255,0.04); 
    border-left: 3px solid var(--primary-accent-light); 
    border-radius: 0 3px 3px 0; 
}
body.dark-mode .deeper-study { 
    background-color: rgba(0,161,255,0.06); 
    border-left-color: var(--primary-accent-dark); 
}
.deeper-study strong { 
    display: block; 
    margin-bottom: 6px; 
    color: var(--secondary-accent-light); 
    font-size: 0.95rem;
}
body.dark-mode .deeper-study strong { 
    color: var(--secondary-accent-dark); 
}
.deeper-study p { 
    font-size: 0.9rem; 
    margin-bottom: 0; 
    line-height: 1.6;
}

/* SVG Placeholder and general SVG styles */
.svg-placeholder-container {
    width: 100%;
    min-height: 80px; 
    padding: 5px; 
    background-color: var(--placeholder-bg-light);
    border-radius: 8px;
    display: flex;
    justify-content: center;
    align-items: center;
    margin-top: 15px; 
    margin-bottom: 15px; 
    border: 1px dashed var(--border-color-light);
    overflow: hidden;
}
body.dark-mode .svg-placeholder-container {
    background-color: var(--placeholder-bg-dark);
    border-color: var(--border-color-dark);
}
.svg-placeholder-container.visual-placeholder:empty::before { 
    content: attr(aria-label) " (Loading...)"; 
    font-style: italic;
    color: var(--placeholder-text-light);
    text-align: center;
    font-size: 0.85em; 
}
body.dark-mode .svg-placeholder-container.visual-placeholder:empty::before {
    color: var(--placeholder-text-dark);
}
.svg-placeholder-container p.error-message {
    color: #d9534f; 
    font-style: italic;
    font-size: 0.85rem; 
    padding: 8px; 
    border: 1px dashed #d9534f;
    border-radius: 4px;
    background-color: rgba(217, 83, 79, 0.05);
}
body.dark-mode .svg-placeholder-container p.error-message {
    color: #f08080; 
    border-color: #f08080;
    background-color: rgba(240, 128, 128, 0.1);
}

.svg-placeholder-container svg { max-width: 100%; max-height: 200px; display: block; margin: auto; } 
.svg-line { stroke: var(--svg-stroke-light); stroke-width: 1.5; fill: none; }
body.dark-mode .svg-line { stroke: var(--svg-stroke-dark); }
.svg-dynamic-stroke { stroke: var(--svg-stroke-light); }
body.dark-mode .svg-dynamic-stroke { stroke: var(--svg-stroke-dark); }
.svg-path { stroke: var(--svg-stroke-light); stroke-width: 1.5; fill: var(--svg-fill-light); }
body.dark-mode .svg-path { stroke: var(--svg-stroke-dark); fill: var(--svg-fill-dark); }
.svg-point-fill { fill: var(--svg-stroke-light); }
body.dark-mode .svg-point-fill { fill: var(--svg-stroke-dark); }
.svg-text { font-family: inherit; font-size: 8px; text-anchor: middle; fill: var(--svg-text-light); }
body.dark-mode .svg-text { fill: var(--svg-text-dark); }
.svg-text.svg-title { font-size: 10px; font-weight: bold; }
.svg-dynamic-fill { fill: var(--primary-accent-light); }
body.dark-mode .svg-dynamic-fill { fill: var(--primary-accent-dark); }

/* Timeline Styles */
.timeline-container { position: relative; margin-top: 25px; padding: 15px 0; }
.timeline-container::before { 
    content: ''; 
    position: absolute; 
    left: 20px; 
    top: 0; 
    bottom: 0; 
    width: 2px; 
    background-color: var(--timeline-line-color-light); 
    border-radius: 1px; 
}
body.dark-mode .timeline-container::before { background-color: var(--timeline-line-color-dark); }
body[dir="rtl"] .timeline-container::before { 
    left: auto; 
    right: 20px; 
}

.timeline-event { 
    position: relative; 
    margin-left: 50px; 
    margin-bottom: 18px; 
    padding: 12px 15px; 
    background-color: var(--container-bg-light); 
    border-radius: 6px; 
    border: 1px solid var(--border-color-light); 
    cursor: pointer; 
    transition: transform 0.2s ease-out, box-shadow 0.2s ease-out; 
}
.timeline-event:hover, .timeline-event:focus-visible { 
    transform: translateY(-2px) scale(1.005); 
    box-shadow: 0 3px 12px rgba(0,0,0,0.06); 
    outline: 2px solid var(--focus-ring-color-light); 
    outline-offset: 2px; 
}
body.dark-mode .timeline-event { 
    background-color: var(--container-bg-dark); 
    border: 1px solid var(--border-color-dark); 
}
body.dark-mode .timeline-event:hover, body.dark-mode .timeline-event:focus-visible { 
    box-shadow: 0 3px 12px rgba(0,0,0,0.12); 
    outline-color: var(--focus-ring-color-dark); 
}
body[dir="rtl"] .timeline-event { 
    margin-left: 0; 
    margin-right: 50px; 
}

.timeline-milestone-dot { 
    position: absolute; 
    left: -29px; 
    top: 18px; 
    width: 14px; 
    height: 14px; 
    background-color: var(--timeline-dot-bg-light); 
    border: 2px solid var(--timeline-dot-border-light); 
    border-radius: 50%; 
    z-index: 1; 
}
body.dark-mode .timeline-milestone-dot { 
    background-color: var(--timeline-dot-bg-dark); 
    border: 2px solid var(--timeline-dot-border-dark); 
}
body[dir="rtl"] .timeline-milestone-dot { 
    left: auto; 
    right: -29px; 
}

.timeline-date {
    position: absolute;
    top: 16px; 
    font-size: 0.8rem; 
    font-weight: bold; 
    color: var(--secondary-accent-light); 
    background-color: var(--bg-color-light); 
    padding: 2px 6px; 
    border-radius: 4px; 
    white-space: nowrap; 
    z-index: 2; 
}
body:not([dir="rtl"]) .timeline-date { 
    left: 25px; /* Date text to the right of the line */
    text-align: left; 
}
body[dir="rtl"] .timeline-date { 
    right: 25px; /* Date text to the right of the line (visually left in RTL) */
    text-align: right; 
}
body.dark-mode .timeline-date { 
    color: var(--secondary-accent-dark); 
    background-color: var(--bg-color-dark); 
}


.timeline-content h3 { margin-top: 0; font-size: 1.15rem; margin-bottom: 6px; }
.timeline-content p { font-size: 0.9rem; margin-bottom: 6px; }
.timeline-details { 
    max-height: 0; 
    overflow: hidden; 
    margin-top: 8px; 
    padding: 0 10px; 
    background-color: var(--timeline-details-bg-light); 
    border-radius: 4px; 
    font-size: 0.85rem; 
    border-left: 2px solid var(--timeline-dot-border-light); 
    transition: max-height 0.35s cubic-bezier(0.25, 0.8, 0.25, 1), 
                padding-top 0.35s cubic-bezier(0.25, 0.8, 0.25, 1), 
                padding-bottom 0.35s cubic-bezier(0.25, 0.8, 0.25, 1), 
                opacity 0.3s ease-out 0.05s; 
    opacity: 0; 
}
.timeline-details.expanded { 
    max-height: 400px; 
    padding-top: 8px; 
    padding-bottom: 8px; 
    opacity: 1; 
}
body.dark-mode .timeline-details { background-color: var(--timeline-details-bg-dark); border-left-color: var(--timeline-dot-border-dark); }
body[dir="rtl"] .timeline-details { border-left: none; border-right: 2px solid var(--timeline-dot-border-light); }
body[dir="rtl"].dark-mode .timeline-details { border-right-color: var(--timeline-dot-border-dark); }

/* Glossary Styles */
.glossary-list { margin-top: 18px; }
.glossary-entry { margin-bottom: 18px; }
.glossary-list dt { 
    font-weight: bold; 
    font-size: 1.1rem; 
    color: var(--secondary-accent-light); 
    background-color: var(--glossary-dt-bg-light); 
    padding: 10px 15px; 
    padding-right: 40px; 
    border-radius: 6px; 
    border: 1px solid var(--border-color-light); 
    cursor: pointer; 
    position: relative; 
    transition: background-color 0.2s ease, border-radius 0.1s ease-out;
}
.glossary-list dt::after { 
    content: '▼';
    font-size: 0.8em; 
    position: absolute;
    right: 15px;
    top: 50%;
    transform: translateY(-50%) rotate(0deg);
    transition: transform 0.3s ease-out;
}
body[dir="rtl"] .glossary-list dt {
    padding-right: 15px; 
    padding-left: 40px; 
}
body[dir="rtl"] .glossary-list dt::after {
    right: auto;
    left: 15px;
}
.glossary-list dt[aria-expanded="true"]::after {
    transform: translateY(-50%) rotate(-180deg); 
}
body[dir="rtl"] .glossary-list dt[aria-expanded="true"]::after {
    transform: translateY(-50%) rotate(180deg); 
}


.glossary-list dt:hover, .glossary-list dt:focus-visible { 
    background-color: var(--primary-accent-light);
    color: #fff;
    border-color: var(--primary-accent-light);
    outline: 2px solid var(--focus-ring-color-light); 
    outline-offset: 1px; 
}
body.dark-mode .glossary-list dt { 
    color: var(--secondary-accent-dark); 
    background-color: var(--glossary-dt-bg-dark); 
    border-color: var(--border-color-dark); 
}
body.dark-mode .glossary-list dt:hover, body.dark-mode .glossary-list dt:focus-visible { 
    background-color: var(--primary-accent-dark);
    color: var(--container-bg-dark);
    border-color: var(--primary-accent-dark);
    outline-color: var(--focus-ring-color-dark); 
}
.glossary-list dt[aria-expanded="true"] { 
    border-bottom-left-radius: 0;
    border-bottom-right-radius: 0;
}

.glossary-list dd { 
    margin-left: 0; 
    padding: 0 15px; 
    margin-bottom: 0; 
    border: 1px solid var(--border-color-light); 
    border-top: none; 
    border-radius: 0 0 6px 6px; 
    font-size: 0.95rem; 
    line-height: 1.6; 
    background-color: var(--glossary-dd-bg-light);
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height 0.4s cubic-bezier(0.25, 0.8, 0.25, 1), 
                padding-top 0.4s cubic-bezier(0.25, 0.8, 0.25, 1), 
                padding-bottom 0.4s cubic-bezier(0.25, 0.8, 0.25, 1), 
                opacity 0.3s ease-out 0.05s;
}
.glossary-list dd.expanded {
    max-height: 500px; 
    padding-top: 15px;
    padding-bottom: 15px;
    opacity: 1;
    border-top: 1px dashed var(--glossary-dd-border-light); 
}
body.dark-mode .glossary-list dd { 
    border-color: var(--border-color-dark); 
    background-color: var(--glossary-dd-bg-dark);
}
body.dark-mode .glossary-list dd.expanded {
    border-top-color: var(--glossary-dd-border-dark);
}


#string-animation-placeholder .string-mode1 { animation: vibrate1 2s infinite ease-in-out; }
#string-animation-placeholder .string-mode2 { animation: vibrate2 1.5s infinite ease-in-out; stroke: var(--secondary-accent-light); }
body.dark-mode #string-animation-placeholder .string-mode2 { stroke: var(--secondary-accent-dark); }
@keyframes vibrate1 { 0%, 100% { d: path("M10 50 Q 50 30, 95 50 T 190 50"); } 50% { d: path("M10 50 Q 50 70, 95 50 T 190 50"); } }
@keyframes vibrate2 { 0%, 100% { d: path("M10 50 Q 32.5 20, 55 50 T 95 20 T 145 50 T 190 50"); } 50% { d: path("M10 50 Q 32.5 80, 55 50 T 95 80 T 145 50 T 190 50"); } }

/* Interactive Lab Styles */
#p5-canvas-container { border: 1px solid var(--border-color-light); background-color: var(--placeholder-bg-light); padding: 10px; box-shadow: inset 0 0 8px rgba(0,0,0,0.04); margin-bottom: 15px; cursor: grab; }
body.dark-mode #p5-canvas-container { border: 1px solid var(--border-color-dark); background-color: var(--placeholder-bg-dark); box-shadow: inset 0 0 8px rgba(255,255,255,0.02); }
#p5-canvas-container.grabbing { cursor: grabbing; }
#p5-canvas-container canvas { max-width: 100%; height: auto !important; display: block; margin: 0 auto; border-radius: 6px; }
#string-controls-lab { display: flex; flex-direction: column; gap: 12px; padding: 10px; border-radius: 6px; background-color: rgba(0,0,0,0.02); margin-bottom: 10px; }
body.dark-mode #string-controls-lab { background-color: rgba(255,255,255,0.02); }
.slider-control { display: flex; align-items: center; gap: 10px; }
.slider-control label { font-size: 0.9rem; min-width: 110px; }
body[dir="rtl"] .slider-control label { text-align: left; }
.slider-control input[type="range"] { flex-grow: 1; -webkit-appearance: none; appearance: none; height: 8px; background: var(--slider-track-light); border-radius: 5px; outline: none; opacity: 0.9; transition: opacity .15s ease-in-out; }
.slider-control input[type="range"]:hover, .slider-control input[type="range"]:focus-visible { opacity: 1; outline: 2px solid var(--focus-ring-color-light); outline-offset: 2px;}
body.dark-mode .slider-control input[type="range"]:hover, body.dark-mode .slider-control input[type="range"]:focus-visible { outline-color: var(--focus-ring-color-dark); }
.slider-control input[type="range"]::-webkit-slider-thumb { -webkit-appearance: none; appearance: none; width: 18px; height: 18px; background: var(--slider-thumb-light); border-radius: 50%; cursor: pointer; border: 2px solid var(--container-bg-light); box-shadow: 0 0 5px rgba(0,0,0,0.1); }
.slider-control input[type="range"]::-moz-range-thumb { width: 15px; height: 15px; background: var(--slider-thumb-light); border-radius: 50%; cursor: pointer; border: 2px solid var(--container-bg-light); box-shadow: 0 0 5px rgba(0,0,0,0.1); }
body.dark-mode .slider-control input[type="range"] { background: var(--slider-track-dark); }
body.dark-mode .slider-control input[type="range"]::-webkit-slider-thumb { background: var(--slider-thumb-dark); border: 2px solid var(--container-bg-dark); box-shadow: 0 0 5px rgba(255,255,255,0.1); }
body.dark-mode .slider-control input[type="range"]::-moz-range-thumb { background: var(--slider-thumb-dark); border: 2px solid var(--container-bg-dark); box-shadow: 0 0 5px rgba(255,255,255,0.1); }
.slider-control span { font-size: 0.9rem; min-width: 35px; text-align: right; }
.toggle-control { margin-top: 8px; text-align: center; }
.toggle-control button.lab-button { padding: 8px 15px; background-color: var(--button-bg-light); color: var(--button-text-light); border: 1px solid var(--border-color-light); border-radius: 6px; cursor: pointer; transition: background-color 0.2s ease, color 0.2s ease, box-shadow 0.2s ease; } 
body.dark-mode .toggle-control button.lab-button { background-color: var(--button-bg-dark); color: var(--button-text-dark); border: 1px solid var(--border-color-dark); }
.toggle-control button.lab-button:hover, .toggle-control button.lab-button:focus-visible { background-color: var(--primary-accent-light); color: #fff; outline: 2px solid var(--focus-ring-color-light); outline-offset: 1px; box-shadow: 0 2px 8px rgba(0,123,255,0.3); }
body.dark-mode .toggle-control button.lab-button:hover, body.dark-mode .toggle-control button.lab-button:focus-visible { background-color: var(--primary-accent-dark); color: var(--container-bg-dark); outline-color: var(--focus-ring-color-dark); box-shadow: 0 2px 8px rgba(0,161,255,0.3); }
.toggle-control button.lab-button[aria-pressed="true"] { background-color: var(--secondary-accent-light); color: #fff; font-weight: bold; }
body.dark-mode .toggle-control button.lab-button[aria-pressed="true"] { background-color: var(--secondary-accent-dark); color: var(--container-bg-dark); }

/* Further Reading Section */
#further-reading ul { list-style-type: disc; margin-left: 20px; padding-left: 20px; }
#further-reading li { margin-bottom: 10px; font-size: 1rem; }
#further-reading li i { color: #777; }
body.dark-mode #further-reading li i { color: #aaa; }

/* --- Navigation Controls --- */
.navigation-controls { 
    display: flex; 
    justify-content: space-between; 
    margin-top: 20px; 
    padding-top: 15px; 
    border-top: 1px solid var(--border-color-light); 
    width: 100%; 
}
body.dark-mode .navigation-controls {
    border-top-color: var(--border-color-dark);
}
.navigation-controls button { 
    padding: 10px 25px; 
    background-color: var(--primary-accent-light); 
    color: white; 
    border: none; 
    border-radius: 6px; 
    cursor: pointer; 
    font-size: 1rem; 
    font-weight: 500; 
    transition: background-color 0.2s ease, transform 0.1s ease, box-shadow 0.2s ease; 
}
.navigation-controls button:focus-visible { 
    outline: 3px solid var(--focus-ring-color-light); 
    outline-offset: 2px; 
    box-shadow: 0 0 0 3px var(--focus-ring-color-light); 
}
body.dark-mode .navigation-controls button { 
    background-color: var(--primary-accent-dark); 
    color: var(--container-bg-dark); 
}
body.dark-mode .navigation-controls button:focus-visible { 
    outline-color: var(--focus-ring-color-dark); 
    box-shadow: 0 0 0 3px var(--focus-ring-color-dark); 
}
.navigation-controls button:hover { 
    background-color: var(--secondary-accent-light); 
    transform: translateY(-2px); 
    box-shadow: 0 4px 10px rgba(0,123,255,0.2); 
}
body.dark-mode .navigation-controls button:hover { 
    background-color: var(--secondary-accent-dark); 
    box-shadow: 0 4px 10px rgba(0,161,255,0.2); 
}
.navigation-controls button:disabled { 
    background-color: #ccc; 
    color: #777; 
    cursor: not-allowed; 
    transform: translateY(0); 
    box-shadow: none; 
}
body.dark-mode .navigation-controls button:disabled { 
    background-color: #444; 
    color: #888; 
}

/* --- Footer --- */
footer { 
    text-align: center; 
    margin-top: 30px; 
    padding-top: 15px; 
    border-top: 1px solid var(--border-color-light); 
    font-size: 0.85rem; 
    color: #777; 
    width: 100%; 
}
body.dark-mode footer { 
    border-top: 1px solid var(--border-color-dark); 
    color: #aaa; 
}

/* --- Persian (RTL) Specific Styles --- */
body[dir="rtl"] { text-align: right; }
body[dir="rtl"] .controls { align-items: flex-start; }
body[dir="rtl"] .lang-switcher button { margin-left: 0; margin-right: 6px; }
body[dir="rtl"] .content-section p { text-align: right; }
body[dir="rtl"] #further-reading ul { margin-left: 0; margin-right: 20px; padding-left: 0; padding-right: 20px;}
body[dir="rtl"] .deeper-study { border-left: none; border-right: 3px solid var(--primary-accent-light); border-radius: 4px 0 0 4px; }
body[dir="rtl"].dark-mode .deeper-study { border-right-color: var(--primary-accent-dark); }
body[dir="rtl"] .slider-control label { min-width: auto; margin-left: 10px; margin-right: 0; }
body[dir="rtl"] .slider-control span { text-align: left;}
body[dir="rtl"] .content-section { transform: translateX(-20px) scale(0.98); } 
body[dir="rtl"] .content-section.active { transform: translateX(0) scale(1); }
body[dir="rtl"] .content-section.exiting { transform: translateX(20px) scale(0.98); } 
body[dir="rtl"] .timeline-container::before { left: auto; right: 18px; }
body[dir="rtl"] .timeline-event { margin-left: 0; margin-right: 45px; }
body[dir="rtl"] .timeline-milestone-dot { left: auto; right: -28px; } 
body[dir="rtl"] .timeline-date { 
    left: auto; 
    right: 25px; 
    text-align: right; 
}
body[dir="rtl"] .glossary-list dt { padding-right: 15px; padding-left: 40px; }
body[dir="rtl"] .glossary-list dt::after { right: auto; left: 15px; /* content: '◀'; /* Using rotation for consistency */ }
/* body[dir="rtl"] .glossary-list dt[aria-expanded="true"]::after { transform: translateY(-50%) rotate(180deg); } */
body[dir="rtl"] .glossary-list dd { border-left:none; border-right: 2px solid var(--glossary-dd-border-light); } 
body[dir="rtl"].dark-mode .glossary-list dd { border-right-color: var(--glossary-dd-border-dark); }


/* --- Responsive Design --- */
@media (max-width: 768px) {
    .container { margin: 15px; padding: 20px 25px; }
    header { flex-direction: column; align-items: stretch; }
    header h1 { text-align: center; margin-bottom: 15px; font-size: 2rem; }
    .controls { flex-direction: row; justify-content: space-between; align-items: center; width: 100%;}
    .lang-switcher { margin-bottom: 0; }
    .dark-mode-hint { margin-top: 0; text-align: right; }
    .content-section h2 { font-size: 1.6rem; }
    .content-section p { font-size: 0.95rem; }
    .navigation-controls button { padding: 10px 20px; font-size: 0.95rem; }
    .svg-container svg { max-height: 180px; }
    .slider-control { flex-direction: column; align-items: stretch; }
    .slider-control label { min-width: 100%; margin-bottom: 5px; }
    body[dir="rtl"] .slider-control label { text-align: right; }
    .slider-control span { text-align: center; margin-top: 5px; }
    .timeline-container::before { left: 10px; } 
    body[dir="rtl"] .timeline-container::before { left: auto; right: 10px; }
    .timeline-event { margin-left: 30px; }
    body[dir="rtl"] .timeline-event { margin-left: 0; margin-right: 30px; }
    .timeline-milestone-dot { left: -22px; width: 12px; height: 12px; border-width: 2px;} 
    body[dir="rtl"] .timeline-milestone-dot { left: auto; right: -22px; }
    .timeline-date { 
        left: 15px; 
        font-size: 0.75rem; 
        top: -20px; 
    }
    body[dir="rtl"] .timeline-date { 
        left: auto; 
        right: 15px; 
    }
}

@media (max-width: 480px) {
    body { padding: 10px; }
    .container { padding: 15px 20px; }
    header h1 { font-size: 1.8rem; }
    .controls { flex-direction: column; align-items: center; }
    .lang-switcher { margin-bottom: 10px; }
    .dark-mode-hint { text-align: center; }
    .lang-switcher button { padding: 7px 10px; font-size: 0.85rem; }
    .navigation-controls { flex-direction: column; }
    .navigation-controls button { width: 100%; margin-bottom: 10px; }
    .navigation-controls button:last-child { margin-bottom: 0; }
    .svg-container svg { max-height: 150px; }
    .svg-text { font-size: 6px; }
    .svg-text.svg-title { font-size: 8px; }
    #p5-canvas-container { min-height: 220px;} 
    .timeline-content h3 { font-size: 1.1rem; }
    .timeline-content p { font-size: 0.85rem; }
    .glossary-list dt { font-size: 1.05rem; }
    .glossary-list dd { font-size: 0.9rem; }
}