/* ======================== Global Styles ======================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --accent-color: #f093fb;
    --light-bg: #f5f7ff;
    --dark-text: #2d3748;
    --light-text: #718096;
    --border-color: #e2e8f0;
    --success-color: #48bb78;
    --warning-color: #ed8936;
    --danger-color: #f56565;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: var(--dark-text);
    background: linear-gradient(135deg, #f5f7ff 0%, #fff 100%);
    overflow-x: hidden;
}

/* ======================== Navigation ======================== */
.navbar {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 2px solid var(--border-color);
    padding: 1rem 0;
    animation: slideDown 0.6s ease-out;
}

@keyframes slideDown {
    from {
        transform: translateY(-100%);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 2rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    white-space: nowrap;
}

.logo-icon {
    font-size: 2rem;
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

.nav-menu {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 5px;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--primary-color);
    border-radius: 2px;
    transition: var(--transition);
}

.hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(8px, 8px);
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(8px, -8px);
}

.nav-link {
    position: relative;
    text-decoration: none;
    color: var(--dark-text);
    font-weight: 500;
    transition: var(--transition);
}

.nav-link::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -5px;
    left: 0;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    transition: width 0.3s ease;
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.nav-link.active {
    color: var(--primary-color);
}

/* ======================== Hero Section ======================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
}

.hero-background {
    position: absolute;
    width: 100%;
    height: 100%;
    overflow: hidden;
}

.floating-molecule {
    position: absolute;
    width: 100px;
    height: 100px;
    border: 3px solid rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    animation: float 6s infinite ease-in-out;
}

.floating-molecule:nth-child(1) {
    top: 20%;
    left: 10%;
    animation-delay: 0s;
}

.floating-molecule:nth-child(2) {
    top: 50%;
    right: 15%;
    width: 150px;
    height: 150px;
    animation-delay: 2s;
}

.floating-molecule:nth-child(3) {
    bottom: 20%;
    left: 30%;
    width: 80px;
    height: 80px;
    animation-delay: 4s;
}

@keyframes float {
    0%, 100% { transform: translateY(0px) translateX(0px); }
    50% { transform: translateY(-50px) translateX(30px); }
}

.hero-content {
    position: relative;
    z-index: 10;
    text-align: center;
    animation: fadeInUp 0.8s ease-out;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-title {
    font-size: 4rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
    animation: fadeInUp 0.8s ease-out 0.2s both;
}

.hero-subtitle {
    font-size: 2rem;
    font-weight: 300;
    margin-bottom: 1rem;
    animation: fadeInUp 0.8s ease-out 0.4s both;
}

.hero-description {
    font-size: 1.2rem;
    max-width: 600px;
    margin: 2rem auto;
    line-height: 1.6;
    animation: fadeInUp 0.8s ease-out 0.6s both;
}

.cta-button {
    display: inline-block;
    padding: 1rem 2.5rem;
    background: rgba(255, 255, 255, 0.2);
    border: 2px solid white;
    color: white;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 50px;
    cursor: pointer;
    transition: var(--transition);
    backdrop-filter: blur(10px);
    animation: fadeInUp 0.8s ease-out 0.8s both;
}

.cta-button:hover {
    background: white;
    color: var(--primary-color);
    transform: translateY(-3px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.2);
}

/* ======================== Container & Common Styles ======================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.section-title {
    font-size: 3rem;
    font-weight: 800;
    text-align: center;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-subtitle {
    text-align: center;
    font-size: 1.1rem;
    color: var(--light-text);
    margin-bottom: 3rem;
}

/* ======================== Reactions Section ======================== */
.reactions-section {
    padding: 6rem 0;
    background: var(--light-bg);
}

.search-filter {
    display: flex;
    gap: 1rem;
    margin-bottom: 3rem;
    justify-content: center;
    flex-wrap: wrap;
}

.search-box,
.filter-select {
    padding: 0.8rem 1.5rem;
    border: 2px solid var(--border-color);
    border-radius: 50px;
    font-size: 1rem;
    transition: var(--transition);
    background: white;
}

.search-box {
    min-width: 300px;
}

.search-box:focus,
.filter-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.reactions-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
}

.reaction-card {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    cursor: pointer;
    transition: var(--transition);
    border: 2px solid transparent;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
    position: relative;
    overflow: hidden;
}

.reaction-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    transition: left 0.5s ease;
}

.reaction-card:hover::before {
    left: 100%;
}

.reaction-card:hover {
    transform: translateY(-10px);
    border-color: var(--primary-color);
    box-shadow: 0 15px 40px rgba(102, 126, 234, 0.2);
}

.reaction-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: 1rem;
}

.reaction-title {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--dark-text);
}

.reaction-category {
    display: inline-block;
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
}

.category-cations {
    background: rgba(102, 126, 234, 0.2);
    color: var(--primary-color);
}

.category-anions {
    background: rgba(240, 147, 251, 0.2);
    color: var(--accent-color);
}

.category-gases {
    background: rgba(72, 187, 120, 0.2);
    color: var(--success-color);
}

.reaction-formula {
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    color: var(--light-text);
    margin: 0.5rem 0;
    background: var(--light-bg);
    padding: 0.5rem;
    border-radius: 5px;
    overflow-x: auto;
}

.reaction-observation {
    font-size: 0.95rem;
    color: var(--light-text);
    line-height: 1.6;
}

.click-hint {
    display: inline-block;
    margin-top: 1rem;
    color: var(--primary-color);
    font-weight: 600;
    font-size: 0.85rem;
}

/* ======================== Modal ======================== */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(5px);
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.modal-content {
    background-color: white;
    margin: 5% auto;
    padding: 2rem;
    border-radius: 15px;
    max-width: 600px;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: 0 25px 50px rgba(0, 0, 0, 0.3);
    animation: slideUp 0.3s ease;
}

@keyframes slideUp {
    from {
        transform: translateY(50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.close {
    color: var(--light-text);
    float: right;
    font-size: 2rem;
    font-weight: bold;
    cursor: pointer;
    transition: var(--transition);
}

.close:hover {
    color: var(--primary-color);
}

.modal-content h2 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.modal-content p {
    line-height: 1.8;
    color: var(--dark-text);
    margin-bottom: 1rem;
}

/* ======================== Elements Section ======================== */
.elements-section {
    padding: 6rem 0;
    background: white;
}

.periodic-table {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(60px, 1fr));
    gap: 0.5rem;
    margin-top: 2rem;
}

.element-box {
    aspect-ratio: 1;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition);
    color: white;
    font-weight: 700;
    position: relative;
    overflow: hidden;
}

.element-box:hover {
    transform: scale(1.1) translateY(-5px);
    box-shadow: 0 15px 30px rgba(102, 126, 234, 0.4);
}

.element-box::after {
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.3) 0%, transparent 70%);
    opacity: 0;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% {
        transform: scale(1);
        opacity: 1;
    }
    100% {
        transform: scale(1.5);
        opacity: 0;
    }
}

/* ======================== Tests Section ======================== */
.tests-section {
    padding: 6rem 0;
    background: var(--light-bg);
}

.tests-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.test-card {
    background: white;
    border-radius: 15px;
    padding: 2.5rem;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
    border-top: 4px solid var(--primary-color);
}

.test-card:hover {
    transform: translateY(-15px);
    box-shadow: 0 20px 40px rgba(102, 126, 234, 0.2);
}

.test-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    animation: bounce 2s infinite;
}

.test-card h3 {
    color: var(--dark-text);
    margin-bottom: 0.5rem;
}

.test-card p {
    color: var(--light-text);
    margin-bottom: 1rem;
}

.test-difficulty {
    display: inline-block;
    padding: 0.5rem 1rem;
    background: linear-gradient(135deg, var(--accent-color), var(--secondary-color));
    color: white;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
}

/* ======================== Quiz Modal ======================== */
.quiz-content {
    background-color: white;
    margin: 5% auto;
    padding: 2.5rem;
    border-radius: 15px;
    max-width: 700px;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: 0 25px 50px rgba(0, 0, 0, 0.3);
    animation: slideUp 0.3s ease;
}

.quiz-header h2 {
    color: var(--primary-color);
    margin-bottom: 1.5rem;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--border-color);
    border-radius: 10px;
    overflow: hidden;
    margin-bottom: 1rem;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    width: 0%;
    transition: width 0.3s ease;
}

#questionCounter {
    color: var(--light-text);
    font-size: 0.9rem;
    margin-bottom: 1.5rem;
}

.quiz-question {
    margin-bottom: 2rem;
}

.quiz-question p {
    color: var(--dark-text);
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
    font-weight: 500;
}

.quiz-options {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.option-button {
    padding: 1rem;
    border: 2px solid var(--border-color);
    background: white;
    border-radius: 10px;
    cursor: pointer;
    transition: var(--transition);
    text-align: left;
    font-size: 1rem;
}

.option-button:hover {
    border-color: var(--primary-color);
    background: rgba(102, 126, 234, 0.05);
}

.option-button.correct {
    background: rgba(72, 187, 120, 0.2);
    border-color: var(--success-color);
    color: var(--success-color);
}

.option-button.incorrect {
    background: rgba(245, 101, 101, 0.2);
    border-color: var(--danger-color);
    color: var(--danger-color);
}

.submit-quiz-button {
    width: 100%;
    padding: 1rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    margin-top: 1rem;
}

.submit-quiz-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(102, 126, 234, 0.3);
}

.quiz-results {
    text-align: center;
}

.quiz-results h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.score-display {
    font-size: 3rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin: 1rem 0;
}

/* ======================== Statistics Section ======================== */
.stats-section {
    padding: 4rem 0;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
}

.stat-card {
    text-align: center;
    padding: 2rem;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 15px;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    transition: var(--transition);
}

.stat-card:hover {
    transform: translateY(-10px);
    background: rgba(255, 255, 255, 0.15);
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 1rem;
    opacity: 0.9;
}

/* ======================== About Section ======================== */
.about-section {
    padding: 6rem 0;
    background: white;
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
}

.about-text {
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--dark-text);
}

.about-text p {
    margin-bottom: 1rem;
}

.features-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-top: 2rem;
}

.feature {
    padding: 1rem;
    background: var(--light-bg);
    border-left: 4px solid var(--primary-color);
    border-radius: 5px;
    transition: var(--transition);
}

.feature:hover {
    transform: translateX(10px);
    background: rgba(102, 126, 234, 0.1);
}

.about-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.animated-flask {
    width: 200px;
    height: 250px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 0 0 30px 30px;
    border: 3px solid var(--primary-color);
    position: relative;
    animation: flask-float 3s ease-in-out infinite;
}

@keyframes flask-float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-20px); }
}

.animated-flask::before {
    content: '';
    position: absolute;
    width: 100%;
    height: 40%;
    background: rgba(240, 147, 251, 0.5);
    bottom: 0;
    border-radius: 0 0 30px 30px;
    animation: liquid-flow 2s ease-in-out infinite;
}

@keyframes liquid-flow {
    0%, 100% { height: 40%; opacity: 0.5; }
    50% { height: 60%; opacity: 0.8; }
}

/* ======================== Footer ======================== */
.footer {
    background: linear-gradient(135deg, var(--dark-text), #1a202c);
    color: white;
    padding: 3rem 0;
    text-align: center;
}

.footer a {
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition);
}

.footer a:hover {
    text-decoration: underline;
}

/* ======================== Responsive Design ======================== */
@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 27px rgba(0, 0, 0, 0.05);
        padding: 2rem 0;
        gap: 1rem;
        z-index: 999;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-link {
        font-size: 1rem;
        padding: 0.5rem 0;
        display: block;
    }

    .nav-menu .nav-link::after {
        width: 0;
    }

    .nav-menu .nav-link.active::after {
        width: 0;
    }

    .nav-menu .nav-link.active {
        color: var(--primary-color);
        background: rgba(102, 126, 234, 0.1);
        border-radius: 5px;
    }

    .hero {
        min-height: 80vh;
        padding: 2rem 0;
    }

    .hero-title {
        font-size: 2.2rem;
    }

    .hero-subtitle {
        font-size: 1.3rem;
    }

    .hero-description {
        font-size: 0.95rem;
    }

    .cta-button {
        padding: 0.8rem 2rem;
        font-size: 1rem;
    }

    .section-title {
        font-size: 1.8rem;
    }

    .reactions-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .reaction-card {
        padding: 1.5rem;
    }

    .search-filter {
        flex-direction: column;
    }

    .search-box {
        width: 100%;
        min-width: unset;
    }

    .filter-select {
        width: 100%;
    }

    .about-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 1rem;
    }

    .stat-card {
        padding: 1.5rem;
    }

    .stat-number {
        font-size: 1.8rem;
    }

    .tests-grid {
        grid-template-columns: 1fr;
    }

    .test-card {
        padding: 2rem 1.5rem;
    }

    .test-icon {
        font-size: 2.5rem;
    }

    .test-difficulty {
        font-size: 0.8rem;
    }

    .periodic-table {
        grid-template-columns: repeat(auto-fit, minmax(50px, 1fr));
        gap: 0.3rem;
    }

    .element-box {
        font-size: 0.8rem;
    }

    .modal-content,
    .quiz-content {
        width: 95%;
        margin: 10% auto;
        padding: 1.5rem;
    }

    .animated-flask {
        width: 150px;
        height: 200px;
    }

    .floating-molecule {
        display: none;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }

    .nav-container {
        padding: 0 1rem;
    }

    .logo {
        font-size: 1.2rem;
    }

    .logo-icon {
        font-size: 1.5rem;
    }

    .hero {
        min-height: 60vh;
        padding: 1rem 0;
    }

    .hero-content {
        padding: 1rem;
    }

    .hero-title {
        font-size: 1.6rem;
        margin-bottom: 0.3rem;
    }

    .hero-subtitle {
        font-size: 1rem;
        margin-bottom: 0.5rem;
    }

    .hero-description {
        font-size: 0.85rem;
        margin: 1rem auto;
        max-width: 90%;
    }

    .cta-button {
        padding: 0.7rem 1.5rem;
        font-size: 0.9rem;
    }

    .section-title {
        font-size: 1.5rem;
        margin-bottom: 0.5rem;
    }

    .section-subtitle {
        font-size: 0.9rem;
        margin-bottom: 1.5rem;
    }

    .reactions-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .reaction-card {
        padding: 1rem;
        border-radius: 10px;
    }

    .reaction-title {
        font-size: 1.1rem;
    }

    .reaction-formula {
        font-size: 0.8rem;
        padding: 0.3rem;
    }

    .reaction-observation {
        font-size: 0.85rem;
    }

    .search-filter {
        flex-direction: column;
        gap: 0.8rem;
        margin-bottom: 1.5rem;
    }

    .search-box,
    .filter-select {
        width: 100%;
        padding: 0.6rem 1rem;
        font-size: 0.9rem;
        border-radius: 8px;
    }

    .stats-section {
        padding: 3rem 0;
    }

    .stats-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .stat-card {
        padding: 1.2rem;
    }

    .stat-number {
        font-size: 1.5rem;
    }

    .stat-label {
        font-size: 0.9rem;
    }

    .tests-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .test-card {
        padding: 1.5rem 1rem;
        border-top-width: 3px;
    }

    .test-icon {
        font-size: 2rem;
        margin-bottom: 0.5rem;
    }

    .test-card h3 {
        font-size: 1.1rem;
        margin-bottom: 0.3rem;
    }

    .test-card p {
        font-size: 0.85rem;
        margin-bottom: 0.5rem;
    }

    .test-difficulty {
        padding: 0.4rem 0.8rem;
        font-size: 0.75rem;
    }

    .periodic-table {
        grid-template-columns: repeat(auto-fit, minmax(45px, 1fr));
        gap: 0.25rem;
    }

    .element-box {
        font-size: 0.7rem;
        border-radius: 6px;
    }

    .modal-content,
    .quiz-content {
        width: 90%;
        margin: 5% auto;
        padding: 1.2rem;
        border-radius: 12px;
        max-height: 90vh;
    }

    .modal-content h2,
    .quiz-content h2 {
        font-size: 1.3rem;
        margin-bottom: 0.8rem;
    }

    .modal-content p,
    .quiz-content p {
        font-size: 0.9rem;
        line-height: 1.5;
    }

    .close {
        font-size: 1.5rem;
    }

    .quiz-question p {
        font-size: 1rem;
    }

    .option-button {
        padding: 0.8rem;
        font-size: 0.9rem;
        border-radius: 8px;
    }

    .submit-quiz-button {
        padding: 0.8rem;
        font-size: 0.95rem;
        margin-top: 0.8rem;
    }

    .score-display {
        font-size: 2rem;
    }

    .about-content {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .about-text {
        font-size: 0.95rem;
        line-height: 1.6;
    }

    .about-text p {
        margin-bottom: 0.8rem;
    }

    .features-list {
        gap: 0.7rem;
        margin-top: 1rem;
    }

    .feature {
        padding: 0.7rem;
        font-size: 0.9rem;
    }

    .animated-flask {
        width: 120px;
        height: 160px;
        border-radius: 0 0 20px 20px;
    }

    .footer {
        padding: 2rem 1rem;
    }

    .footer p {
        font-size: 0.9rem;
        margin-bottom: 0.5rem;
    }

    .progress-bar {
        height: 6px;
        margin-bottom: 0.8rem;
    }

    #questionCounter {
        font-size: 0.85rem;
        margin-bottom: 1rem;
    }

    .quiz-options {
        gap: 0.8rem;
    }

    .quiz-results h3 {
        font-size: 1.2rem;
    }

    .quiz-results p {
        font-size: 0.9rem;
    }
}

/* ======================== Scrollbar ======================== */
::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: var(--light-bg);
}

::-webkit-scrollbar-thumb {
    background: linear-gradient(180deg, var(--primary-color), var(--secondary-color));
    border-radius: 10px;
}

::-webkit-scrollbar-thumb:hover {
    background: linear-gradient(180deg, var(--secondary-color), var(--primary-color));
}