/* ===== NINETEEN SIMPLE CHEMISTRY - COMPLETE STYLES ===== */

/* ===== VARIABLES ===== */
:root {
    --nineteen-primary-bg: #f5f4ed;
    --nineteen-secondary-bg: #ffc62f;
    --nineteen-font-color: #1e1e1e;
    --nineteen-gradient-1: linear-gradient(135deg, #ffebc4 0%, #ffebc4ad 100%);
    --nineteen-gradient-2: linear-gradient(45deg, #dfab46 40%, #dfb86d 40%, #dfab46 61%);
}

/* ===== MODAL OVERLAY ===== */
.nineteen-chemistry-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    display: none;
    justify-content: center;
    align-items: center;
    z-index: 10000;
    overflow-y: auto;
    padding: 20px;
}

.nineteen-chemistry-modal.active {
    display: flex;
}

/* ===== MODAL CONTENT ===== */
.nineteen-modal-content {
    background: var(--nineteen-gradient-1);
    border-radius: 30px;
    padding: 30px;
    max-width: 1200px;
    width: 100%;
    max-height: 95vh;
    overflow-y: auto;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
    animation: nineteenSlideUp 0.5s ease-out;
    position: relative;
    border: 6px solid var(--nineteen-secondary-bg);
}

@keyframes nineteenSlideUp {
    from {
        transform: translateY(50px);
        opacity: 0;
    }

    to {
        transform: translateY(0);
        opacity: 1;
    }
}

/* ===== CLOSE BUTTON ===== */
.nineteen-modal-close {
    position: absolute;
    top: 15px;
    right: 15px;
    background: var(--nineteen-font-color);
    color: white;
    border: none;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    font-size: 2rem;
    cursor: pointer;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10;
    font-weight: bold;
}

.nineteen-modal-close:hover {
    transform: scale(1.1) rotate(90deg);
    background: #ff4444;
}

/* ===== MODAL HEADER ===== */
.nineteen-modal-header {
    text-align: center;
    margin-bottom: 25px;
    padding-bottom: 20px;
    border-bottom: 3px solid var(--nineteen-secondary-bg);
}

.nineteen-modal-title {
    font-size: clamp(2rem, 5vw, 3.5rem);
    color: var(--nineteen-font-color);
    margin-bottom: 15px;
    font-weight: 900;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
}

.nineteen-score-display {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    background: var(--nineteen-secondary-bg);
    padding: 12px 25px;
    border-radius: 25px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.nineteen-score-label {
    font-size: clamp(1rem, 2vw, 1.3rem);
    font-weight: bold;
    color: var(--nineteen-font-color);
}

.nineteen-score-value {
    font-size: clamp(1.2rem, 3vw, 1.8rem);
    font-weight: 900;
    color: var(--nineteen-font-color);
}

/* ===== TAB NAVIGATION ===== */
.nineteen-tab-nav {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.nineteen-tab-btn {
    background: white;
    border: 3px solid #ddd;
    padding: 15px 25px;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    min-width: 120px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.nineteen-tab-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
}

.nineteen-tab-btn.active {
    background: var(--nineteen-secondary-bg);
    border-color: var(--nineteen-font-color);
    transform: translateY(-3px);
}

.nineteen-tab-text {
    font-size: clamp(0.9rem, 1.5vw, 1.1rem);
    font-weight: bold;
    color: var(--nineteen-font-color);
}

/* ===== TAB PANES ===== */
.nineteen-modal-body {
    background: var(--nineteen-primary-bg);
    border-radius: 20px;
    padding: 25px;
    min-height: 400px;
}

.nineteen-tab-pane {
    display: none;
    animation: nineteenFadeIn 0.4s ease-out;
}

.nineteen-tab-pane.active {
    display: block;
}

@keyframes nineteenFadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===== THEORY TAB ===== */
.nineteen-pagination-flexbox {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-bottom: 20px;
}

.nineteen-pagination-flexbox>button {
    background: var(--nineteen-font-color);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 50%;
    cursor: pointer;
    font-weight: bold;
    transition: all 0.3s ease;
    min-width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    aspect-ratio: 1 / 1;
}

.nineteen-pagination-flexbox>button:hover {
    transform: scale(1.1);
}

.nineteen-pagination-flexbox>button.active {
    background: var(--nineteen-primary-bg);
    color: var(--nineteen-font-color);
    box-shadow: 0px 0px 5px rgba(0, 0, 0, 0.35);
}

div[data-nineteen-slide] {
    clip-path: circle(0% at top center);
    transition: clip-path 0.75s ease-in;
}

div[data-nineteen-slide].unclip {
    clip-path: circle(200% at top center);
}

/* ===== CHEMICAL REACTION GAME (SLIDE 2) ===== */
.nineteen-card {
    background: white;
    border-radius: 15px;
    padding: 20px;
    margin-bottom: 20px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.nineteen-card-title {
    color: var(--nineteen-font-color);
    font-size: 1.3rem;
    margin-bottom: 15px;
    font-weight: bold;
}

.nineteen-recipe-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 10px;
}

.nineteen-recipe-item {
    background: #f3e8ff;
    padding: 12px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.9rem;
}

.nineteen-imagereaction {
    width: 30px;
    height: 30px;
    object-fit: contain;
}

.nineteen-elements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 15px;
}

.nineteen-element {
    padding: 20px;
    border-radius: 12px;
    cursor: move;
    text-align: center;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
    transition: all 0.3s;
    user-select: none;
    touch-action: none;
}

.nineteen-element:hover {
    transform: scale(1.1);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
}

.nineteen-element:active {
    transform: scale(0.95);
}

.nineteen-element-symbol {
    font-size: 2rem;
    font-weight: bold;
    color: white;
    margin-bottom: 5px;
}

.nineteen-element-name {
    font-size: 0.9rem;
    color: white;
    font-weight: 600;
}

.nineteen-mixing-bowl {
    border: 4px dashed #a78bfa;
    border-radius: 15px;
    padding: 30px;
    min-height: 150px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    background: #faf5ff;
    margin-bottom: 15px;
    transition: all 0.3s;
}

.nineteen-mixing-bowl.animating {
    background: #fef3c7;
    animation: nineteenPulse 0.5s infinite;
}

@keyframes nineteenPulse {

    0%,
    100% {
        transform: scale(1);
    }

    50% {
        transform: scale(1.02);
    }
}

.nineteen-bowl-element {
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
    position: relative;
}

.nineteen-bowl-element.animating {
    animation: nineteenBounce 0.6s infinite;
}

@keyframes nineteenBounce {

    0%,
    100% {
        transform: translateY(0);
    }

    50% {
        transform: translateY(-15px);
    }
}

.nineteen-sparkle {
    position: absolute;
    top: -10px;
    right: -10px;
    font-size: 20px;
    animation: nineteenSpin 1s linear infinite;
}

@keyframes nineteenSpin {
    from {
        transform: rotate(0deg);
    }

    to {
        transform: rotate(360deg);
    }
}

.nineteen-placeholder {
    color: #9ca3af;
    font-size: 1.1rem;
}

.nineteen-button-group {
    display: flex;
    gap: 15px;
}

.nineteen-btn {
    flex: 1;
    padding: 12px;
    border: none;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s;
}

.nineteen-btn-mix {
    background: linear-gradient(135deg, #a855f7 0%, #ec4899 100%);
    color: white;
}

.nineteen-btn-mix:hover:not(:disabled) {
    transform: scale(1.05);
}

.nineteen-btn-mix:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.nineteen-btn-reset {
    background: #6b7280;
    color: white;
    flex: 0 0 auto;
    padding: 12px 20px;
}

.nineteen-btn-reset:hover {
    background: #4b5563;
}

.nineteen-result {
    padding: 30px;
    border-radius: 15px;
    text-align: center;
    border: 4px solid #a78bfa;
    animation: nineteenBounceIn 0.5s;
}

@keyframes nineteenBounceIn {
    0% {
        transform: scale(0);
    }

    50% {
        transform: scale(1.1);
    }

    100% {
        transform: scale(1);
    }
}

.nineteen-result-emoji {
    max-width: 100px;
    height: auto;
    margin-bottom: 15px;
}

.nineteen-result-name {
    font-size: 1.8rem;
    font-weight: bold;
    color: var(--nineteen-font-color);
    margin-bottom: 10px;
}

.nineteen-result-symbol {
    font-size: 1.2rem;
    color: #4b5563;
}

/* ===== ACID/BASE GAME (SLIDE 3) ===== */
.nineteen-acidbase-game-area {
    display: flex;
    justify-content: space-around;
    margin-top: 20px;
    gap: 15px;
    flex-wrap: wrap;
}

.nineteen-acidbase-bucket {
    flex: 1;
    min-width: 180px;
    border: 4px solid #555;
    border-radius: 12px;
    padding: 15px;
    background: white;
    cursor: pointer;
    min-height: 200px;
    transition: all 0.3s ease;
}

.nineteen-acidbase-bucket:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
}

#nineteen-acidbase-acid {
    border-color: #dc3545;
    background: #fbecec;
}

#nineteen-acidbase-neutral {
    border-color: #28a745;
    background: #e6ffe6;
}

#nineteen-acidbase-base {
    border-color: #007bff;
    background: #ebf5ff;
}

#nineteenAcidBaseItems {
    margin-top: 20px;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 12px;
}

.nineteen-acidbase-item {
    background: white;
    border: 3px solid #aaa;
    padding: 12px 15px;
    border-radius: 10px;
    font-size: 1rem;
    cursor: pointer;
    user-select: none;
    width: 160px;
    transition: all 0.3s ease;
}

.nineteen-acidbase-item:hover:not(.placed) {
    transform: scale(1.05);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.nineteen-acidbase-item.selected {
    border-color: var(--nineteen-font-color);
    background: #e6f0ff;
    transform: scale(1.05);
}

.nineteen-acidbase-item.placed {
    background: #b7f8b7;
    border-color: #47a047;
    cursor: default;
}

.nineteen-acidbase-item.incorrect-flash {
    animation: nineteenFlashRed 0.5s;
}

@keyframes nineteenFlashRed {

    0%,
    100% {
        background: white;
    }

    50% {
        background: #ffcccc;
    }
}

.nineteen-alert-dialog {
    border: none;
    padding: 0;
    background: transparent;
    position: fixed;
    inset: 0;
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
}

.nineteen-alert-dialog[open] {
    display: flex;
}

.nineteen-alert-content {
    background: white;
    padding: 20px 25px;
    border-radius: 10px;
    border: 3px solid var(--nineteen-font-color);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    width: 300px;
    text-align: center;
}

#nineteenAlertMessage {
    font-size: 1.1rem;
    margin-bottom: 15px;
    color: var(--nineteen-font-color);
}

#nineteenAlertClose {
    padding: 10px 20px;
    border: none;
    background: var(--nineteen-secondary-bg);
    color: var(--nineteen-font-color);
    border-radius: 10px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: bold;
    transition: all 0.3s ease;
}

#nineteenAlertClose:hover {
    transform: scale(1.05);
}

/* ===== STATES OF MATTER ANIMATION (SLIDE 4) ===== */
.nineteen-substance-buttons {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    flex-wrap: wrap;
    justify-content: center;
}

.nineteen-substance-btn {
    padding: 12px 20px;
    border: 2px solid transparent;
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.5);
    cursor: pointer;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: bold;
}

.nineteen-substance-btn:hover {
    background: rgba(255, 255, 255, 0.8);
}

.nineteen-substance-btn.active {
    background: var(--nineteen-secondary-bg);
    border-color: var(--nineteen-font-color);
}

.nineteen-substance-btn span:first-child {
    width: 20px;
    height: 20px;
    border-radius: 50%;
}

.nineteen-state-buttons {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-bottom: 20px;
}

.nineteen-state-btn {
    padding: 12px 25px;
    border: 2px solid transparent;
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.5);
    cursor: pointer;
    transition: all 0.3s;
    font-weight: bold;
}

.nineteen-state-btn:hover {
    background: rgba(255, 255, 255, 0.8);
}

.nineteen-state-btn.active {
    background: var(--nineteen-secondary-bg);
    border-color: var(--nineteen-font-color);
}

#nineteenMoleculeCanvas {
    border-radius: 10px;
    background: #000;
    border: 3px solid #666;
    max-width: 100%;
    display: block;
    margin: 0 auto;
}

.nineteen-info-display {
    text-align: center;
    margin-top: 20px;
}

.nineteen-info-display p {
    margin: 10px 0;
    font-size: 1rem;
}

.nineteen-thermometer {
    font-weight: bold;
    font-size: 1.3rem;
    color: var(--nineteen-font-color);
}

.nineteen-unit-btn {
    padding: 10px 20px;
    border: none;
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.5);
    cursor: pointer;
    transition: all 0.3s;
    font-weight: bold;
    margin: 0 5px;
}

.nineteen-unit-btn:hover {
    background: rgba(255, 255, 255, 0.8);
}

.nineteen-unit-btn.active {
    background: var(--nineteen-secondary-bg);
    color: var(--nineteen-font-color);
}

/* ===== QUIZ TAB ===== */
.nineteen-quiz-start,
.nineteen-quiz-question-screen,
.nineteen-quiz-result {
    padding: 20px;
}

.nineteen-quiz-title {
    font-size: clamp(1.8rem, 4vw, 2.8rem);
    color: var(--nineteen-font-color);
    margin-bottom: 20px;
    font-weight: bold;
    text-align: center;
}

.nineteen-quiz-intro {
    background: white;
    border-radius: 20px;
    padding: 25px;
    margin: 20px 0;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.nineteen-quiz-desc {
    font-size: clamp(1rem, 2vw, 1.3rem);
    line-height: 1.6;
    color: #555;
    margin-bottom: 20px;
}

.nineteen-score-info {
    display: flex;
    justify-content: center;
    gap: 30px;
    flex-wrap: wrap;
    margin-top: 20px;
}

.nineteen-score-item {
    background: var(--nineteen-gradient-1);
    padding: 15px 25px;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.nineteen-score-label {
    display: block;
    font-size: clamp(0.9rem, 1.5vw, 1.1rem);
    color: #666;
    margin-bottom: 5px;
}

.nineteen-score-value {
    display: block;
    font-size: clamp(1.3rem, 3vw, 1.8rem);
    font-weight: bold;
    color: var(--nineteen-font-color);
}

.nineteen-quiz-header {
    margin-bottom: 25px;
}

.nineteen-question-number {
    font-size: clamp(1.2rem, 2.5vw, 1.6rem);
    color: var(--nineteen-font-color);
    margin-bottom: 15px;
    text-align: center;
}

.nineteen-progress-bar {
    background: #ddd;
    height: 15px;
    border-radius: 10px;
    overflow: hidden;
}

.nineteen-progress-fill {
    background: var(--nineteen-secondary-bg);
    height: 100%;
    transition: width 0.5s ease;
    border-radius: 10px;
}

.nineteen-question-card {
    background: white;
    border-radius: 20px;
    padding: 30px;
    margin: 25px 0;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.nineteen-question-text {
    font-size: clamp(1.2rem, 3vw, 1.8rem);
    font-weight: bold;
    color: var(--nineteen-font-color);
    line-height: 1.5;
    text-align: center;
}

.nineteen-options-container {
    display: flex;
    flex-direction: column;
    gap: 15px;
    margin: 25px 0;
}

.nineteen-quiz-option {
    background: white;
    border: 3px solid #ddd;
    padding: 20px;
    border-radius: 15px;
    font-size: clamp(1rem, 2vw, 1.3rem);
    font-weight: bold;
    color: var(--nineteen-font-color);
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: left;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.nineteen-quiz-option:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
    border-color: var(--nineteen-secondary-bg);
}

.nineteen-quiz-option.nineteen-selected {
    background: var(--nineteen-secondary-bg);
    border-color: var(--nineteen-font-color);
    transform: translateY(-3px);
}

.nineteen-result-title {
    font-size: clamp(2rem, 5vw, 3rem);
    color: var(--nineteen-font-color);
    margin-bottom: 25px;
    text-align: center;
    font-weight: bold;
}

.nineteen-result-score-card {
    background: white;
    border-radius: 20px;
    padding: 30px;
    margin: 25px 0;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    display: flex;
    justify-content: space-around;
    align-items: center;
    flex-wrap: wrap;
    gap: 30px;
}

.nineteen-result-main-score {
    text-align: center;
}

.nineteen-result-score-number {
    font-size: clamp(3rem, 8vw, 5rem);
    font-weight: 900;
    color: var(--nineteen-secondary-bg);
    line-height: 1;
}

.nineteen-result-score-total {
    font-size: clamp(1.5rem, 4vw, 2.5rem);
    color: #666;
}

.nineteen-result-percentage {
    width: 150px;
    height: 150px;
}

.nineteen-circular-progress {
    width: 100%;
    height: 100%;
}

.nineteen-circular-progress svg {
    width: 100%;
    height: 100%;
    transform: rotate(-90deg);
}

.nineteen-score-details {
    background: var(--nineteen-gradient-1);
    border-radius: 20px;
    padding: 25px;
    margin: 25px 0;
}

.nineteen-score-detail-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 0;
    border-bottom: 2px solid rgba(0, 0, 0, 0.1);
}

.nineteen-score-detail-item:last-child {
    border-bottom: none;
}

.nineteen-detail-label {
    font-size: clamp(1rem, 2vw, 1.3rem);
    color: #666;
}

.nineteen-detail-value {
    font-size: clamp(1.1rem, 2.5vw, 1.5rem);
    font-weight: bold;
    color: var(--nineteen-font-color);
}

.nineteen-improvement-badge {
    background: #4caf50;
    color: white;
    padding: 15px 25px;
    border-radius: 15px;
    text-align: center;
    font-size: clamp(1.1rem, 2.5vw, 1.5rem);
    font-weight: bold;
    margin-top: 15px;
    animation: nineteenPulse 2s infinite;
}

.nineteen-saved-message {
    background: #4caf50;
    color: white;
    padding: 15px 25px;
    border-radius: 15px;
    text-align: center;
    font-size: clamp(1rem, 2vw, 1.3rem);
    font-weight: bold;
    margin: 20px 0;
}

.nineteen-quiz-review {
    margin: 30px 0;
}

.nineteen-review-title {
    font-size: clamp(1.5rem, 3vw, 2rem);
    color: var(--nineteen-font-color);
    margin-bottom: 20px;
    text-align: center;
    padding-top: 20px;
    border-top: 3px solid #ddd;
}

.nineteen-review-table-wrapper {
    overflow-x: auto;
}

.nineteen-review-table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.nineteen-review-table thead {
    background: var(--nineteen-secondary-bg);
}

.nineteen-review-table th {
    padding: 15px;
    text-align: left;
    font-size: clamp(0.9rem, 1.5vw, 1.1rem);
    color: var(--nineteen-font-color);
    font-weight: bold;
}

.nineteen-review-table td {
    padding: 15px;
    border-bottom: 1px solid #ddd;
    font-size: clamp(0.9rem, 1.5vw, 1rem);
    color: #333;
}

.nineteen-review-table tr:last-child td {
    border-bottom: none;
}

.nineteen-correct-row {
    background: #e8f5e9;
}

.nineteen-wrong-row {
    background: #ffebee;
}

.nineteen-correct-answer-hint {
    display: block;
    font-size: clamp(0.8rem, 1.3vw, 0.9rem);
    color: #4caf50;
    font-weight: bold;
    margin-top: 5px;
}

.nineteen-result-badge {
    display: inline-block;
    padding: 5px 15px;
    border-radius: 10px;
    font-weight: bold;
    font-size: clamp(0.8rem, 1.3vw, 1rem);
}

.nineteen-badge-correct {
    background: #4caf50;
    color: white;
}

.nineteen-badge-wrong {
    background: #f44336;
    color: white;
}

/* ===== BUTTONS ===== */
.nineteen-btn-primary {
    background: var(--nineteen-font-color);
    color: white;
    border: none;
    padding: 15px 40px;
    font-size: clamp(1rem, 2vw, 1.3rem);
    border-radius: 25px;
    cursor: pointer;
    font-weight: bold;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
    transition: all 0.3s ease;
    display: block;
    margin: 20px auto;
}

.nineteen-btn-primary:hover:not(.nineteen-btn-disabled) {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.4);
    background: #333;
}

.nineteen-btn-primary.nineteen-btn-large {
    font-size: clamp(1.2rem, 3vw, 1.8rem);
    padding: 20px 50px;
}

.nineteen-btn-primary.nineteen-btn-disabled {
    background: #95a5a6;
    cursor: not-allowed;
    opacity: 0.6;
}

.nineteen-btn-secondary {
    background: #666;
    color: white;
    border: none;
    padding: 12px 30px;
    font-size: clamp(0.9rem, 1.8vw, 1.1rem);
    border-radius: 20px;
    cursor: pointer;
    font-weight: bold;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
    transition: all 0.3s ease;
    display: block;
    margin: 15px auto;
}

.nineteen-btn-secondary:hover {
    background: #555;
    transform: translateY(-2px);
    box-shadow: 0 7px 18px rgba(0, 0, 0, 0.3);
}

/* ===== CUSTOM SCROLLBAR ===== */
.nineteen-modal-content::-webkit-scrollbar {
    width: 12px;
}

.nineteen-modal-content::-webkit-scrollbar-track {
    background: rgba(0, 0, 0, 0.1);
    border-radius: 10px;
}

.nineteen-modal-content::-webkit-scrollbar-thumb {
    background: var(--nineteen-secondary-bg);
    border-radius: 10px;
}

.nineteen-modal-content::-webkit-scrollbar-thumb:hover {
    background: #e6b422;
}

/* ===== RESPONSIVE DESIGN ===== */
@media (max-width: 768px) {
    .nineteen-modal-content {
        padding: 20px;
        border-radius: 20px;
    }

    .nineteen-tab-nav {
        flex-direction: row;
        justify-content: space-around;
    }

    .nineteen-tab-btn {
        min-width: 90px;
        padding: 12px 15px;
    }

    .nineteen-recipe-grid {
        grid-template-columns: 1fr;
    }

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

    .nineteen-acidbase-game-area {
        flex-direction: column;
    }

    .nineteen-result-score-card {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .nineteen-modal-content {
        padding: 15px;
    }

    .nineteen-modal-header {
        margin-bottom: 20px;
    }

    .nineteen-tab-btn {
        min-width: 80px;
        padding: 10px 12px;
    }

    .nineteen-tab-text {
        font-size: 0.8rem;
    }

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

    .nineteen-review-table {
        font-size: 0.85rem;
    }

    .nineteen-review-table th,
    .nineteen-review-table td {
        padding: 10px 5px;
    }
}

/* ===== ACCESSIBILITY ===== */
@media (prefers-reduced-motion: reduce) {

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* ===== ENHANCED TEXT STYLING ===== */

/* Theory Section Text */
div[data-nineteen-slide] h3 {
    color: var(--nineteen-font-color);
    font-size: clamp(1.5rem, 3vw, 2.2rem);
    margin: 1.5rem 0 1rem 0;
    font-weight: 800;
    letter-spacing: 0.5px;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.1);
    border-bottom: 3px solid var(--nineteen-secondary-bg);
    padding-bottom: 0.5rem;
}

div[data-nineteen-slide] h4 {
    color: #4a5568;
    font-size: clamp(1.2rem, 2.5vw, 1.8rem);
    margin: 1.2rem 0 0.8rem 0;
    font-weight: 700;
    letter-spacing: 0.3px;
}

div[data-nineteen-slide] p {
    color: #2d3748;
    font-size: clamp(1rem, 2vw, 1.3rem);
    line-height: 1.8;
    margin: 1rem 0;
    font-weight: 500;
}

div[data-nineteen-slide] ul,
div[data-nineteen-slide] ol {
    margin: 1rem 0 1rem 1.5rem;
    padding-left: 1.5rem;
}

div[data-nineteen-slide] li {
    color: #374151;
    font-size: clamp(0.95rem, 1.8vw, 1.2rem);
    line-height: 1.7;
    margin: 0.8rem 0;
    font-weight: 500;
    position: relative;
    padding-left: 0.5rem;
}

div[data-nineteen-slide] ul li::marker {
    color: var(--nineteen-secondary-bg);
    font-size: 1.4em;
    font-weight: bold;
}

div[data-nineteen-slide] ol li::marker {
    color: var(--nineteen-font-color);
    font-weight: bold;
}

/* Nested Lists */
div[data-nineteen-slide] ul ul li {
    font-size: clamp(0.9rem, 1.6vw, 1.1rem);
    margin: 0.5rem 0;
}

/* pH Theory Content */
.nineteen-ph-theory-content {
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.9) 0%, rgba(255, 235, 196, 0.5) 100%);
    border-radius: 20px;
    padding: 25px;
    margin: 20px 0;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    border-left: 5px solid var(--nineteen-secondary-bg);
}

.nineteen-ph-theory-content h3 {
    color: var(--nineteen-font-color);
    font-size: clamp(1.6rem, 3.5vw, 2.4rem);
    margin-bottom: 1rem;
    font-weight: 800;
    border-bottom: none;
    text-align: center;
}

.nineteen-ph-theory-content h4 {
    color: var(--nineteen-font-color);
    font-size: clamp(1.3rem, 2.8vw, 1.9rem);
    margin: 1.5rem 0 0.8rem 0;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 10px;
}

.nineteen-ph-theory-content h4::before {
    content: '';
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--nineteen-secondary-bg);
    display: inline-block;
}

.nineteen-ph-theory-content p {
    color: #4a5568;
    font-size: clamp(1rem, 2.2vw, 1.35rem);
    line-height: 1.8;
    margin: 0.8rem 0 1.2rem 1rem;
    font-weight: 500;
}

/* Enhanced Card Titles */
.nineteen-card-title {
    color: var(--nineteen-font-color);
    font-size: clamp(1.3rem, 2.5vw, 1.8rem);
    margin-bottom: 15px;
    font-weight: 800;
    letter-spacing: 0.5px;
    text-transform: uppercase;
    border-bottom: 3px solid var(--nineteen-secondary-bg);
    padding-bottom: 10px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.nineteen-card-title::before {
    content: '◆';
    color: var(--nineteen-secondary-bg);
    font-size: 1.2em;
}

/* Recipe Item Text */
.nineteen-recipe-item {
    background: linear-gradient(135deg, #f3e8ff 0%, #e9d8fd 100%);
    padding: 15px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: clamp(0.95rem, 1.8vw, 1.1rem);
    font-weight: 600;
    color: #2d3748;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

.nineteen-recipe-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.15);
}

.nineteen-recipe-item span {
    font-weight: 700;
}

/* Element Names */
.nineteen-element-name {
    font-size: clamp(0.9rem, 1.8vw, 1.1rem);
    color: white;
    font-weight: 700;
    text-shadow: 1px 1px 3px rgba(0, 0, 0, 0.3);
    letter-spacing: 0.5px;
}

.nineteen-element-symbol {
    font-size: clamp(2rem, 4vw, 2.8rem);
    font-weight: 900;
    color: white;
    margin-bottom: 5px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
    font-family: 'Arial Black', sans-serif;
}

/* Result Text */
.nineteen-result-name {
    font-size: clamp(1.8rem, 4vw, 2.5rem);
    font-weight: 900;
    color: var(--nineteen-font-color);
    margin-bottom: 10px;
    text-shadow: 1px 1px 3px rgba(0, 0, 0, 0.1);
    letter-spacing: 1px;
}

.nineteen-result-symbol {
    font-size: clamp(1.2rem, 2.5vw, 1.6rem);
    color: #4b5563;
    font-weight: 600;
    font-family: 'Courier New', monospace;
}

/* Placeholder Text */
.nineteen-placeholder {
    color: #9ca3af;
    font-size: clamp(1.1rem, 2.2vw, 1.4rem);
    font-weight: 600;
    font-style: italic;
}

/* Acid/Base Item Text */
.nineteen-acidbase-item {
    background: linear-gradient(135deg, white 0%, #f9fafb 100%);
    border: 3px solid #cbd5e0;
    padding: 14px 18px;
    border-radius: 12px;
    font-size: clamp(1rem, 2vw, 1.2rem);
    cursor: pointer;
    user-select: none;
    width: 170px;
    transition: all 0.3s ease;
    font-weight: 700;
    color: #2d3748;
    text-align: center;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.1);
}

/* Bucket Headers */
.nineteen-acidbase-bucket h4 {
    margin: 0 0 15px 0;
    padding: 10px;
    border-radius: 10px;
    font-size: clamp(1.2rem, 2.5vw, 1.6rem);
    font-weight: 800;
    text-align: center;
    letter-spacing: 1px;
    text-transform: uppercase;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.1);
}

/* States of Matter Info Text */
.nineteen-info-display p {
    margin: 12px 0;
    font-size: clamp(1.05rem, 2.2vw, 1.35rem);
    font-weight: 600;
    color: #2d3748;
}

#nineteenResultText {
    font-size: clamp(1.2rem, 2.5vw, 1.6rem);
    font-weight: 700;
    color: var(--nineteen-font-color);
}

#nineteenTempDisplay {
    font-size: clamp(1.3rem, 2.8vw, 1.8rem);
    font-weight: 800;
    color: var(--nineteen-secondary-bg);
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.1);
}

.nineteen-thermometer {
    font-weight: 900;
    font-size: clamp(1.5rem, 3.5vw, 2.2rem);
    color: var(--nineteen-font-color);
    text-shadow: 1px 1px 3px rgba(0, 0, 0, 0.1);
    font-family: 'Courier New', monospace;
}

#nineteenMeltingPoint,
#nineteenBoilingPoint {
    font-size: clamp(1rem, 2vw, 1.3rem);
    font-weight: 700;
    color: #4a5568;
}

/* Alert Message */
#nineteenAlertMessage {
    font-size: clamp(1.1rem, 2.3vw, 1.4rem);
    margin-bottom: 15px;
    color: var(--nineteen-font-color);
    font-weight: 700;
    line-height: 1.6;
}

/* Quiz Description */
.nineteen-quiz-desc {
    font-size: clamp(1.05rem, 2.2vw, 1.4rem);
    line-height: 1.8;
    color: #4a5568;
    margin-bottom: 20px;
    font-weight: 600;
}

/* Question Text Enhancement */
.nineteen-question-text {
    font-size: clamp(1.3rem, 3.2vw, 1.9rem);
    font-weight: 800;
    color: var(--nineteen-font-color);
    line-height: 1.6;
    text-align: center;
    letter-spacing: 0.3px;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.05);
}

/* Quiz Options Enhancement */
.nineteen-quiz-option {
    background: linear-gradient(135deg, white 0%, #f9fafb 100%);
    border: 3px solid #e5e7eb;
    padding: 22px;
    border-radius: 16px;
    font-size: clamp(1.05rem, 2.2vw, 1.4rem);
    font-weight: 700;
    color: var(--nineteen-font-color);
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: left;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    line-height: 1.5;
}

/* Review Table Enhancement */
.nineteen-review-table th {
    padding: 18px;
    text-align: left;
    font-size: clamp(1rem, 1.8vw, 1.2rem);
    color: var(--nineteen-font-color);
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.nineteen-review-table td {
    padding: 18px;
    border-bottom: 1px solid #e5e7eb;
    font-size: clamp(0.95rem, 1.8vw, 1.15rem);
    color: #374151;
    font-weight: 600;
    line-height: 1.6;
}

/* Detail Labels & Values */
.nineteen-detail-label {
    font-size: clamp(1.05rem, 2.2vw, 1.4rem);
    color: #4a5568;
    font-weight: 700;
}

.nineteen-detail-value {
    font-size: clamp(1.2rem, 2.8vw, 1.6rem);
    font-weight: 900;
    color: var(--nineteen-font-color);
}

/* Score Labels */
.nineteen-score-label {
    display: block;
    font-size: clamp(1rem, 1.8vw, 1.2rem);
    color: #4a5568;
    margin-bottom: 5px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.nineteen-score-value {
    display: block;
    font-size: clamp(1.4rem, 3.2vw, 1.9rem);
    font-weight: 900;
    color: var(--nineteen-font-color);
    font-family: 'Arial Black', sans-serif;
}

/* Button Text Enhancement */
.nineteen-btn {
    font-family: 'Arial', sans-serif;
    letter-spacing: 0.5px;
    text-transform: uppercase;
    font-weight: 800;
}

.nineteen-btn-primary {
    letter-spacing: 1px;
    font-weight: 900;
}

/* Saved Message */
.nineteen-saved-message {
    background: linear-gradient(135deg, #4caf50 0%, #45a049 100%);
    color: white;
    padding: 18px 28px;
    border-radius: 16px;
    text-align: center;
    font-size: clamp(1.05rem, 2.2vw, 1.4rem);
    font-weight: 800;
    margin: 20px 0;
    box-shadow: 0 5px 15px rgba(76, 175, 80, 0.3);
    letter-spacing: 0.5px;
}

/* Improvement Badge */
.nineteen-improvement-badge {
    background: linear-gradient(135deg, #4caf50 0%, #45a049 100%);
    color: white;
    padding: 18px 28px;
    border-radius: 16px;
    text-align: center;
    font-size: clamp(1.2rem, 2.8vw, 1.6rem);
    font-weight: 900;
    margin-top: 15px;
    animation: nineteenPulse 2s infinite;
    box-shadow: 0 5px 15px rgba(76, 175, 80, 0.3);
    letter-spacing: 0.5px;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.2);
}

/* Question Number */
.nineteen-question-number {
    font-size: clamp(1.3rem, 2.8vw, 1.7rem);
    color: var(--nineteen-font-color);
    margin-bottom: 15px;
    text-align: center;
    font-weight: 800;
    letter-spacing: 0.5px;
}

/* Result Title */
.nineteen-result-title {
    font-size: clamp(2.2rem, 5.5vw, 3.2rem);
    color: var(--nineteen-font-color);
    margin-bottom: 25px;
    text-align: center;
    font-weight: 900;
    letter-spacing: 1px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
}

/* Quiz Title */
.nineteen-quiz-title {
    font-size: clamp(2rem, 4.5vw, 3rem);
    color: var(--nineteen-font-color);
    margin-bottom: 20px;
    font-weight: 900;
    text-align: center;
    letter-spacing: 1px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
}

/* Review Title */
.nineteen-review-title {
    font-size: clamp(1.6rem, 3.5vw, 2.2rem);
    color: var(--nineteen-font-color);
    margin-bottom: 20px;
    text-align: center;
    padding-top: 20px;
    border-top: 3px solid #cbd5e0;
    font-weight: 900;
    letter-spacing: 0.5px;
    text-transform: uppercase;
}

/* Correct Answer Hint */
.nineteen-correct-answer-hint {
    display: block;
    font-size: clamp(0.85rem, 1.5vw, 1rem);
    color: #059669;
    font-weight: 800;
    margin-top: 6px;
    font-style: italic;
}

/* Result Badge Text */
.nineteen-result-badge {
    display: inline-block;
    padding: 6px 16px;
    border-radius: 12px;
    font-weight: 900;
    font-size: clamp(0.85rem, 1.5vw, 1.05rem);
    letter-spacing: 0.5px;
    text-transform: uppercase;
}