h1 {
    font-family:'Lucida Sans', 'Lucida Sans Regular', 'Lucida Grande', 'Lucida Sans Unicode', Geneva, Verdana, sans-serif;
    font-size: 25px;
    color: black;
    text-align: center;
    position: relative; 
    margin: 2;
}
h2 {
    color: #9924ff;
}
body {
    background-color: #ffffff; 
    margin: 0;
    padding: 0;
    width: 100%;
    font-family:'Lucida Sans', 'Lucida Sans Regular', 'Lucida Grande', 'Lucida Sans Unicode', Geneva, Verdana, sans-serif;
    position: relative;
    overflow-x: hidden;
    color: #111; 
}


a {
    background-color: rgba(255, 255, 255, 0);
    color: black;
    padding: 3% 5%; 
    text-align: center;
    text-decoration: none;
    display: inline-block;
    font-family: Impact, Haettenschweiler, 'Arial Narrow Bold', sans-serif;
    font-size: 175%;
    border-radius: 10px;
}
a:hover {
    background-color: rgba(0, 0, 0, 0.281);
}

div.NavBar {
    text-align: center;
    margin: 0;
    width: 100%;
    background-color: rgba(112, 13, 158, 0.798);
    position: relative;
    padding: 15px 0;
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
}


a.home img {
    width: 80px;   
    height: auto;    
    vertical-align: middle;
    display: inline-block;
    filter: invert(1);
}
a.home {
    padding: 0; 
    transition: filter 0.4s ease, color 0.4s ease;
    margin-right: 20px; 
}
.line {
    border-left: 6px solid black;
    border-top: 30px solid black;
    border-bottom: 30px solid black;
    height: 15px;
    width: 2px;
    position: relative;
    margin: -4px;
    right: 2.5px;
}

#theme-toggle {
    background: none;
    border: none;
    color: white;
    font-size: 22px;
    cursor: pointer;
    margin-left: 15px;
    transition: transform 0.2s ease, color 0.3s ease;
}

#theme-toggle:hover {
    transform: scale(1.2);
    color: #ffeb3b;
}

body, .content, .NavBar, h1, p, a {
    transition: background-color 0.4s ease, color 0.4s ease;
}


.math-tip {
    position: fixed;
    top: 30%;
    right: 25px;
    width: 230px;
    background: rgba(255, 255, 255, 0.95);
    border-radius: 12px;
    box-shadow: 0 0 15px rgba(0,0,0,0.2);
    padding: 15px 18px 20px 18px;
    font-size: 16px;
    line-height: 1.4;
    z-index: 10;
    animation: fadeIn 0.6s ease;
    transition: opacity 0.4s ease, transform 0.4s ease;
    color: #111;
}

.math-tip h3 {
    margin-top: 0;
    margin-bottom: 5px;
    color: #650094;
}


.close-tip {
    position: absolute;
    top: 8px;
    right: 10px;
    background: none;
    border: none;
    font-size: 20px;
    cursor: pointer;
    color: #004b94;
    opacity: 0.6;
    transition: opacity 0.2s ease;
}

.close-tip:hover {
    opacity: 1;
}

.math-tip.hidden {
    opacity: 0;
    transform: translateY(-10px);
    pointer-events: none;
}

div.content {
    width: 100%;
    min-height: 80vh;
    padding: 50px 10%;
    background-color: #ffffff; 
    box-shadow: 0 0 15px rgba(0, 0, 0, 0.2);
    box-sizing: border-box;
    text-align: center;
    overflow: hidden; 
    color: #111;
}

div.content h1 {
    font-size: 40px;
    margin-bottom: 10px;
}

div.content .tagline {
    font-size: 20px;
    color: #7824ff;
    font-style: italic;
    margin-bottom: 30px;
}

div.content p {
    line-height: 1.6;
    color: #111;
    max-width: 800px;
    margin: 0 auto 20px auto;
}

.feature-list {
    list-style-type: none;
    padding: 0;
    margin: 25px auto;
    max-width: 800px;
    text-align: left;
}

.feature-list details summary {
    cursor: pointer;
    background: rgba(0, 118, 215, 0.1);
    border-left: 5px solid rgba(102, 0, 145, 0.9);
    padding: 10px 15px;
    margin: 10px 0;
    border-radius: 8px;
    transition: background 0.3s ease, transform 0.2s ease;
    list-style: none;
    color: #111;
}

.feature-list details summary:hover {
    background: rgba(0, 118, 215, 0.2);
    transform: translateX(3px);
}

.feature-list summary::-webkit-details-marker {
    display: none;
}

.feature-list summary::after {
    content: "▼";
    float: right;
    font-size: 14px;
    transition: transform 0.3s ease;
}

.feature-list details[open] summary::after {
    transform: rotate(-180deg);
}

.feature-list .dropdown {
    background: rgba(255, 255, 255, 0.95);
    margin: 10px 5px 10px 15px;
    padding: 12px 15px;
    border-radius: 10px;
    box-shadow: 0 0 8px rgba(0, 0, 0, 0.1);
    color: #111;
    line-height: 1.5;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-5px); }
    to { opacity: 1; transform: translateY(0); }
}

div.content .cta-text {
    margin-top: 30px;
    font-weight: bold;
    color: #9924ff;
    font-size: 18px;
}

body.dark-mode {
    background-color: #1e1e1e;
    color: #e0e0e0;
}

body.dark-mode .content {
    background-color: #1e1e1e;
    box-shadow: 0 8px 25px rgba(255, 255, 255, 0.05);
}

body.dark-mode .NavBar {
    background-color: rgba(143, 0, 187, 0.442);
    box-shadow: 0 4px 10px rgba(255, 255, 255, 0.05);
}

body.dark-mode .NavItem {
    color: #e0e0e0;
}

body.dark-mode .NavItem:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

body.dark-mode p {
    color: #e0e0e0;
}

body.dark-mode h1{
    color: #a864f6;
}

body.dark-mode b{
    color: #a864f6;
}

body.dark-mode summary {
    color: #e0e0e0;
}

body.dark-mode .line {
    border-left: 6px solid #e0e0e0;
    border-top: 30px solid #e0e0e0;
    border-bottom: 30px solid #e0e0e0;
}

body.dark-mode .feature-list .dropdown {
    background: rgba(40, 40, 40, 0.95);
    color: #e0e0e0;
    box-shadow: 0 0 10px rgba(255, 255, 255, 0.05);
    border-left: 3px solid #9924ff;
}

body.dark-mode .math-tip {
    background: rgba(40, 40, 40, 0.95);
    color: #e0e0e0;
    box-shadow: 0 0 15px rgba(255,255,255,0.1);
}

body.dark-mode .math-tip h3 {
    color: #a864f6;
}

body.dark-mode .close-tip {
    color: #a864f6;
}

body.dark-mode .feature-list details summary:hover {
    background: rgba(193, 100, 246, 0.15);
}
body.dark-mode textarea {
    background: rgba(40, 40, 40, 0.95);
    color: #e0e0e0;
    box-shadow: 0 0 15px rgba(255,255,255,0.1);
}
body.dark-mode .output-box {
    background: rgba(40, 40, 40, 0.95);
    color: #e0e0e0;
    box-shadow: inset 0 0 10px rgba(255,255,255,0.1);
}
body {
    opacity: 0;
    transition: opacity 0.3s ease;
    transition-delay: .2s;
}

body.fade-in {
    opacity: 1;
}

body.fade-out {
    opacity: 0;
}

.simplex-text-container {
    margin: 40px auto;
    padding: 25px;
    max-width: 800px;
    background: rgba(255, 255, 255, 0.95);
    border-radius: 15px;
    box-shadow: 0 0 10px rgba(0,0,0,0.15);
    text-align: center;
    color: #111;
}

.simplex-text-container textarea {
    width: 100%;
    height: 200px;
    border-radius: 10px;
    border: 1px solid #ccc;
    padding: 12px;
    font-size: 16px;
    font-family: 'Courier New', monospace;
    resize: vertical;
    margin-top: 10px;
    position: relative;
    right: 1.75%;
}

.symbol-buttons {
    display: flex;
    justify-content: center;
    gap: 8px;
    margin-bottom: 10px;
}

.symbol-btn {
    background-color: #004b94;
    color: white;
    border: none;
    border-radius: 8px;
    padding: 6px 12px;
    font-size: 18px;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.2s ease;
}

.symbol-btn:hover {
    background-color: #006cd9;
    transform: translateY(-2px);
}

.input-actions {
    margin-top: 15px;
}

.primary-btn {
    background-color: #004b94;
    color: white;
    border: none;
    border-radius: 10px;
    padding: 10px 20px;
    margin-right: 10px;
    font-size: 16px;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.2s ease;
}

.primary-btn:hover {
    background-color: #006cd9;
    transform: translateY(-2px);
}

.output-box {
    margin-top: 30px;
    background: #f7f9fc;
    border-radius: 10px;
    padding: 15px;
    box-shadow: inset 0 0 5px rgba(0,0,0,0.1);
}

.output-box pre {
    text-align: left;
    font-size: 14px;
    font-family: 'Courier New', monospace;
    white-space: pre-wrap;
    background: rgba(245, 245, 245, 0.95);
    border-radius: 8px;
    padding: 10px;
}
.pivot-column {
    background-color: #fcca0081;
    color: #000;
    font-weight: bold;
}
.pivot-row {
    background: #fcca0081;
    color: #000;
    font-weight: bold;
}
body.dark-mode .simplex-text-container {
    background: rgba(40, 40, 40, 0.95);
    color: #e0e0e0;
}

body.dark-mode .symbol-btn {
    background-color: #64b5f6;
    color: #111;
}
body.dark-mode .symbol-btn:hover {
    background-color: #2196f3;
}

body.dark-mode .primary-btn {
    background-color: #64b5f6;
    color: #111;
}

body.dark-mode .primary-btn:hover {
    background-color: #2196f3;
}

body.dark-mode .output-box pre {
    background: rgba(60, 60, 60, 0.95);
    color: #e0e0e0;
}
body.dark-mode .home{
    filter: invert(1);
}
@media (max-width: 900px) {
    .math-tip {
        display: none; 
    }
    .side-gradient {
        display: none; 
    }
    div.content {
        padding: 30px 5%;
    }
    div.content h1 {
        font-size: 30px;
    }
    div.content .tagline {
        font-size: 18px;
    }
}
.tableau-wrapper {
    overflow-x: auto;
    margin-top: 20px;
}

.simplex-tableau {
    border-collapse: collapse;
    margin: 0 auto;
    font-family: "Courier New", monospace;
    font-size: 15px;
    min-width: 500px;
}

.simplex-tableau th,
.simplex-tableau td {
    border: 1px solid #ccc;
    padding: 8px 14px;
    text-align: center;
}

.simplex-tableau th {
    background: #004b94;
    color: white;
    font-weight: bold;
}

.simplex-tableau tr:last-child {
    border-top: 3px solid #000;
    font-weight: bold;
}

.simplex-tableau td.pivot {
    background: #ffe082;
    font-weight: bold;
}

.simplex-tableau td.negative {
    color: #d32f2f;
    font-weight: bold;
}

/* Dark Mode */
body.dark-mode .simplex-tableau th {
    background: #64b5f6;
    color: #111;
}

body.dark-mode .simplex-tableau td {
    border: 1px solid #555;
}

body.dark-mode .simplex-tableau tr:last-child {
    border-top: 3px solid #aaa;
}

body.dark-mode .simplex-tableau td.pivot {
    background: #ffca28;
}

body.dark-mode .simplex-tableau td.negative {
    color: #ff6b6b;
}
.simplex-tableau {
    border-left: 4px solid #000;
    border-right: 4px solid #000;
}
#parsed-output {
    margin-top: 30px;
    padding: 20px;
    border-radius: 12px;
    background: #f7f9fc;
    box-shadow: 0 0 12px rgba(0,0,0,0.12);
    transition: all 0.3s ease;
    font-family:'Lucida Sans','Lucida Grande','Verdana',sans-serif;
    color: #111;
}

#parsed-output h3 {
    margin-top: 0;
    margin-bottom: 12px;
    color: #004b94;
}

#parsed-result {
    display: block;
    text-align: left;
    font-size: 14px;
    white-space: pre-wrap;
    background: rgba(255,255,255,0.9);
    border-radius: 8px;
    padding: 14px;
    border: 1px solid rgba(0,0,0,0.08);
    font-family:'Lucida Sans','Lucida Grande','Verdana',sans-serif;
}

/* Dark Mode */

body.dark-mode #parsed-output {
    background: rgba(40, 40, 40, 0.95);
    color: white;
    box-shadow: 0 0 12px rgba(255,255,255,0.05);
}

body.dark-mode #parsed-result {
    background: rgba(40, 40, 40, 0.95);
    color: white;
    border: 1px solid rgba(255,255,255,0.12);
    font-family:'Lucida Sans','Lucida Grande','Verdana',sans-serif;
}
h2 {
    color: #9924ff;
}

a:hover {
    background-color: rgba(178, 77, 255, 0.3);
}

div.NavBar {
    background-color: rgba(153, 36, 255, 0.8);
}

#theme-toggle:hover {
    color: #ffe26b;
}

.feature-list details summary {
    background: rgba(153, 36, 255, 0.1);
    border-left: 5px solid #650094;
}

.feature-list details summary:hover {
    background: rgba(153, 36, 255, 0.2);
}

.feature-list .dropdown {
    border-left: 3px solid #9924ff;
}

div.content .tagline {
    color: #9924ff;
}

div.content .cta-text {
    color: #9924ff;
}

.symbol-btn {
    background-color: #9924ff;
}

.symbol-btn:hover {
    background-color: #b24dff;
}

.primary-btn {
    background-color: #9924ff;
}

.primary-btn:hover {
    background-color: #b24dff;
}

body.dark-mode .NavBar {
    background-color: rgba(153, 36, 255, 0.4);
}

body.dark-mode h1 {
    color: #a864f6;
}

body.dark-mode b {
    color: #a864f6;
}

body.dark-mode .feature-list .dropdown {
    border-left: 3px solid #9924ff;
}

body.dark-mode .math-tip h3 {
    color: #a864f6;
}

body.dark-mode .close-tip {
    color: #a864f6;
}

body.dark-mode .symbol-btn {
    background-color: #c084ff;
    color: #111;
}

body.dark-mode .symbol-btn:hover {
    background-color: #a64dff;
}

body.dark-mode .primary-btn {
    background-color: #c084ff;
    color: #111;
}

body.dark-mode .primary-btn:hover {
    background-color: #a64dff;
}

.pivot-column,
.pivot-row {
    background-color: rgba(153, 36, 255, 0.25);
    color: #000;
}

.simplex-tableau th {
    background: #9924ff;
}

body.dark-mode .simplex-tableau th {
    background: #c084ff;
}

body.dark-mode .simplex-tableau td.pivot {
    background: #ffca28;
}

#parsed-output h3 {
    color: #9924ff;
}

body.dark-mode #parsed-output {
    box-shadow: 0 0 12px rgba(255,255,255,0.05);
}

body.dark-mode #parsed-result {
    border: 1px solid rgba(255,255,255,0.12);
}
body {
    background-color: #f6f7fb;
}

div.content {
    background-color: #fafbff;
}

.simplex-text-container {
    background: rgba(250, 251, 255, 0.95);
}

.feature-list .dropdown {
    background: rgba(248, 249, 255, 0.95);
}

.output-box {
    background: #f1f4fb;
}

.output-box pre {
    background: rgba(245, 247, 252, 0.95);
}

#parsed-output {
    background: #f3f6ff;
}

#parsed-result {
    background: rgba(250, 251, 255, 0.9);
}
#lp-input {
    width: 90%;
    height: 180px;
    padding: 12px;
    font-size: 16px;
    display: block;
    margin: 15px auto;
    resize: vertical;
}


#user-answer {
    width: 60%;
    padding: 10px;
    font-size: 16px;
    display: block;
    margin: 10px auto;
}

/* Feedback text */
#quiz-feedback {
    font-size: 18px;
    text-align: center;
    margin-top: 15px;
}


.output-box {
    width: 90%;
    margin: 20px auto;
}

@media (max-width: 768px) {
    #lp-input {
        width: 95%;
        height: 160px;
    }

    #user-answer {
        width: 80%;
    }
}