:root {
    --primary-color: #3f51b5;
    --primary-accent: #00bcd4;
    --primary-accent-rgb: 0, 188, 212;
    --secondary-accent: #673ab7;
    --secondary-accent-rgb: 103, 58, 183;
    --text-color: #212121;
    --bg-color: #f0f2f5;
    --content-bg: #ffffff;
    --border-color: #e0e0e0;
    --card-bg-color: #ffffff;
    --bg-color-alt: #e0e0e0;
    --shadow-small: 0 2px 6px rgba(0, 0, 0, 0.08);
    --shadow-medium: 0 4px 12px rgba(0, 0, 0, 0.1);
    --transition-speed: 0.3s;
    --transition-easing: ease-in-out;
}

body.dark-mode {
    --primary-color: #64b5f6;
    --primary-accent: #80deea;
    --primary-accent-rgb: 128, 222, 234;
    --secondary-accent: #9575cd;
    --secondary-accent-rgb: 149, 117, 205;
    --text-color: #e0e0e0;
    --bg-color: #1a1a2e;
    --content-bg: #212a4f;
    --border-color: #3c4a6b;
    --card-bg-color: #212a4f;
    --bg-color-alt: #3c4a6b;
    --shadow-small: 0 2px 6px rgba(0, 0, 0, 0.3);
    --shadow-medium: 0 4px 12px rgba(0, 0, 0, 0.4);
}

@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.02); }
    100% { transform: scale(1); }
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    overflow-y: scroll;
    scrollbar-gutter: stable;
    font-family: 'Montserrat', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    transition: background-color var(--transition-speed) var(--transition-easing),
                color var(--transition-speed) var(--transition-easing);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.theme-toggle-button {
    position: fixed;
    top: 20px;
    right: 20px;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    width: 45px;
    height: 45px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5em;
    cursor: pointer;
    box-shadow: var(--shadow-medium);
    z-index: 1000;
    transition: background-color 0.3s ease;
    overflow: hidden;
}

.theme-toggle-button .icon-light,
.theme-toggle-button .icon-dark {
    position: absolute;
    transition: transform 0.4s ease-in-out;
}

body.light-mode .icon-light {
    transform: translateY(0);
}

body.light-mode .icon-dark {
    transform: translateY(100%);
}

body.dark-mode .icon-light {
    transform: translateY(-100%);
}

body.dark-mode .icon-dark {
    transform: translateY(0);
}

.hero-section {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 0 20px;
    position: relative;
    overflow: hidden;
}

.hero-title {
    font-family: 'Montserrat', sans-serif;
    font-size: 4.5em;
    font-weight: 700;
    margin-bottom: 15px;
    line-height: 1.1;
    letter-spacing: 2px;
    animation: pulse 2s infinite ease-in-out;
}

.hero-title .letter {
    display: inline-block;
    opacity: 0;
}

.hero-title .space-fix {
    width: 0.4em;
}

.hero-subtitle {
    font-family: 'Roboto', sans-serif;
    font-size: 1.8em;
    font-weight: 400;
    opacity: 0;
    margin-bottom: 40px;
    animation: pulse 2s infinite ease-in-out 0.2s;
}

body.light-mode .hero-title,
body.light-mode .hero-subtitle {
    color: var(--primary-color);
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

body.dark-mode .hero-title,
body.dark-mode .hero-subtitle {
    color: white;
    text-shadow: 3px 3px 6px rgba(0, 0, 0, 0.3);
}

.main-nav ul {
    list-style: none;
    display: flex;
    gap: 30px;
    padding: 10px 0;
}

.main-nav a {
    font-family: 'Roboto', sans-serif;
    text-decoration: none;
    font-size: 1.1em;
    font-weight: 500;
    padding: 8px 15px;
    position: relative;
    transition: color 0.3s ease, transform 0.3s ease;
    overflow: hidden;
    animation: pulse 2s infinite ease-in-out 0.4s;
}

.main-nav a::after {
    display: none;
}

body.light-mode .main-nav a {
    color: var(--primary-color);
}

body.dark-mode .main-nav a {
    color: white;
}

.main-nav a:hover {
    color: var(--primary-accent);
    transform: translateY(-2px);
}

main {
    padding: 50px 20px;
    max-width: 1200px;
    margin: 0 auto;
}

.content-section {
    background-color: var(--content-bg);
    padding: 40px;
    border-radius: 12px;
    margin-bottom: 60px;
    box-shadow: var(--shadow-medium);
    opacity: 0;
    transform: translateY(60px);
    transition: background-color var(--transition-speed) var(--transition-easing);
}

.content-section.is-visible {
    opacity: 1;
    transform: translateY(0);
}

.section-title {
    font-family: 'Montserrat', sans-serif;
    font-size: 2.5em;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 25px;
    text-align: center;
    border-bottom: 3px solid var(--border-color);
    padding-bottom: 15px;
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    width: 60px;
    height: 5px;
    background-color: var(--primary-accent);
    bottom: -4px;
    left: 50%;
    transform: translateX(-50%);
    border-radius: 2px;
}

.section-text {
    font-family: 'Roboto', sans-serif;
    font-size: 1.1em;
    line-height: 1.8;
    text-align: justify;
    max-width: 800px;
    margin: 0 auto;
}

.section-text a {
    color: var(--primary-accent);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.section-text a:hover {
    text-decoration: underline;
    color: var(--primary-color);
}

#skills .skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 15px;
    padding: 20px;
    background-color: var(--content-bg);
    border-radius: 12px;
    box-shadow: var(--shadow-medium);
}

.skill-item {
    background-color: var(--text-color);
    color: var(--bg-color);
    padding: 15px;
    border-radius: 8px;
    text-align: center;
    font-weight: 600;
    font-size: 1em;
    box-shadow: var(--shadow-small);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    will-change: transform, background-color, rotate;
    position: relative;
    overflow: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 80px;
}

body.dark-mode .skill-item {
    background-color: var(--text-color);
    color: var(--bg-color);
}

#projects .projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    padding: 20px;
    background-color: var(--content-bg);
    border-radius: 12px;
    box-shadow: var(--shadow-medium);
}

.project-card {
    background-color: var(--bg-color);
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow-small);
    position: relative;
    transition: transform 0.3s ease;
    cursor: pointer;
}

.project-card:hover {
    transform: translateY(-5px);
}

.project-img {
    width: 100%;
    height: 200px;
    object-fit: contain;
    object-position: center;
    display: block;
    transition: transform 0.4s ease-out, filter 0.4s ease-out;
    background-color: var(--bg-color);
    animation: pulse 3s infinite ease-in-out;
}

.portal-img {
    filter: drop-shadow(0 0 20px #00ff9c);
}

@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.03); }
    100% { transform: scale(1); }
}

.project-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(var(--primary-accent-rgb), 0.9);
    color: white;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 20px;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.project-card:hover .project-overlay {
    opacity: 1;
}

.project-title-overlay {
    font-family: 'Montserrat', sans-serif;
    font-size: 1.5em;
    margin-bottom: 10px;
    opacity: 0;
    transform: translateY(20px);
}

@media (max-width: 768px) {
    .project-overlay {
        display: none;
    }
}

.project-desc-overlay {
    font-family: 'Roboto', sans-serif;
    font-size: 0.95em;
    text-align: center;
    margin-bottom: 20px;
    opacity: 0;
    transform: translateY(20px);
}

.project-link {
    display: inline-block;
    background-color: var(--primary-color);
    color: white;
    padding: 10px 20px;
    border-radius: 5px;
    text-decoration: none;
    font-weight: 500;
    transition: background-color 0.3s ease;
    opacity: 0;
}

.project-link:hover {
    background-color: var(--primary-accent);
}

#certificates {
    display: none;
}

@media (min-width: 769px) {
    #certificates {
        display: block;
    }
}

#certificates .certificates-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    padding: 20px;
    background-color: var(--content-bg);
    border-radius: 12px;
    box-shadow: var(--shadow-medium);
}

.certificate-card {
    background-color: var(--bg-color);
    border-radius: 10px;
    box-shadow: var(--shadow-small);
    perspective: 1000px;
    transition: transform 0.3s ease;
    min-height: 250px;
    display: flex;
    justify-content: center;
    align-items: center;
}

@media (max-width: 768px) {
    .certificate-card {
        min-height: 220px;
    }
}

@media (max-width: 480px) {
    .certificate-card {
        min-height: 200px;
    }
}

.certificate-card:hover {
    transform: translateY(-5px);
}

.certificate-card.is-flipped .card-inner {
    transform: rotateY(180deg);
}

.card-inner {
    width: 100%;
    height: 100%;
    position: relative;
    transition: transform 0.6s;
    transform-style: preserve-3d;
    border-radius: 10px;
}

.card-front, .card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
    border-radius: 10px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 20px;
    text-align: center;
    overflow: hidden;
}

.card-front {
    background-color: var(--bg-color);
    color: var(--text-color);
    z-index: 2;
}

.certificate-img {
    width: 90%;
    height: 150px;
    object-fit: contain;
    border-radius: 5px;
    margin-bottom: 15px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

@media (max-width: 768px) {
    .certificate-img {
        height: 120px;
        margin-bottom: 12px;
    }
}

@media (max-width: 480px) {
    .certificate-img {
        height: 100px;
        margin-bottom: 10px;
    }
}

.card-back {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-accent) 100%);
    color: white;
    transform: rotateY(180deg);
}

.card-back h3 {
    font-family: 'Montserrat', sans-serif;
    font-size: 1.4em;
    margin-bottom: 10px;
    opacity: 0;
    transform: translateY(20px);
}

@media (max-width: 768px) {
    .card-back h3 {
        font-size: 1.1em;
        margin-bottom: 8px;
    }
}

@media (max-width: 480px) {
    .card-back h3 {
        font-size: 1em;
        margin-bottom: 5px;
    }
}

.card-back p {
    font-family: 'Roboto', sans-serif;
    font-size: 1em;
    margin-bottom: 20px;
    opacity: 0;
    transform: translateY(20px);
}

@media (max-width: 768px) {
    .card-back p {
        font-size: 0.85em;
        margin-bottom: 12px;
    }
}

@media (max-width: 480px) {
    .card-back p {
        font-size: 0.75em;
        margin-bottom: 8px;
    }
}

.view-cert-link {
    display: inline-block;
    background-color: white;
    color: var(--primary-accent);
    padding: 8px 18px;
    border-radius: 5px;
    text-decoration: none;
    font-weight: 500;
    transition: background-color 0.3s ease, color 0.3s ease;
    opacity: 0;
    font-size: 0.95em;
}

@media (max-width: 768px) {
    .view-cert-link {
        padding: 6px 12px;
        font-size: 0.85em;
    }
}

@media (max-width: 480px) {
    .view-cert-link {
        padding: 5px 10px;
        font-size: 0.75em;
    }
}

.view-cert-link:hover {
    background-color: #f0f0f0;
    color: var(--primary-color);
}

#contact {
    text-align: center;
}

#contact .section-text {
    font-size: 1.2em;
}

.contact-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 30px;
    margin-top: 30px;
}

.contact-subtitle {
    font-size: 1.1em;
    color: var(--text-color);
    opacity: 0.9;
    margin: 0;
    text-align: center;
}

.contact-controls {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
    width: 100%;
}

.contact-btn {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 12px;
    padding: 20px 28px;
    border-radius: 16px;
    text-decoration: none;
    font-weight: 700;
    font-size: 1.05em;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
}

.contact-btn .btn-icon {
    font-size: 2.2em;
    display: block;
    transition: transform 0.3s ease;
}

.contact-btn .btn-text {
    display: block;
    font-size: 0.95em;
    letter-spacing: 0.5px;
}

.contact-btn.email-btn {
    background: linear-gradient(135deg, var(--primary-accent) 0%, var(--primary-color) 100%);
    color: #fff;
    box-shadow: 0 8px 24px rgba(0, 188, 212, 0.25);
}

.contact-btn.email-btn:hover {
    transform: translateY(-6px) scale(1.05);
    box-shadow: 0 14px 40px rgba(0, 188, 212, 0.35);
}

.contact-btn.email-btn:active {
    transform: translateY(-2px) scale(1.02);
}

.contact-btn.email-btn:hover .btn-icon {
    transform: scale(1.15) rotate(10deg);
}

.contact-btn.whatsapp-btn {
    background: linear-gradient(135deg, #1ED760 0%, #25D366 100%);
    color: #fff;
    box-shadow: 0 8px 24px rgba(37, 211, 102, 0.25);
}

.contact-btn.whatsapp-btn:hover {
    transform: translateY(-6px) scale(1.05);
    box-shadow: 0 14px 40px rgba(37, 211, 102, 0.35);
}

.contact-btn.whatsapp-btn:active {
    transform: translateY(-2px) scale(1.02);
}

.contact-btn.whatsapp-btn:hover .btn-icon {
    transform: scale(1.15) rotate(-10deg);
}

@keyframes popIn {
    0% { transform: translateY(16px) scale(0.85); opacity: 0; }
    60% { transform: translateY(-6px) scale(1.08); opacity: 1; }
    100% { transform: translateY(0) scale(1); opacity: 1; }
}

.contact-controls .contact-btn {
    animation: popIn 500ms ease forwards;
}

.contact-controls .contact-btn:nth-child(2) {
    animation-delay: 100ms;
}

@media (max-width: 768px) {
    .contact-controls {
        flex-direction: column;
        gap: 15px;
        width: 100%;
    }

    .contact-btn {
        width: 100%;
        padding: 18px 24px;
    }

    .contact-btn .btn-icon {
        font-size: 1.8em;
    }
}

.email-aura-effect {
    text-decoration: none;
    font-size: 1.5em;
    font-weight: bold;
    display: inline-block;
    position: relative;
    padding: 5px;
    transition: color 0.3s ease;
}

body.light-mode .email-aura-effect {
    color: var(--primary-accent);
    text-shadow:
        0 0 8px rgba(var(--primary-accent-rgb), 0.7),
        0 0 15px rgba(var(--primary-accent-rgb), 0.5),
        0 0 25px rgba(var(--primary-accent-rgb), 0.3),
        0 0 40px rgba(var(--primary-accent-rgb), 0.1);
}

body.dark-mode .email-aura-effect {
    color: var(--primary-accent);
    text-shadow:
        0 0 8px rgba(var(--primary-accent-rgb), 0.7),
        0 0 15px rgba(var(--primary-accent-rgb), 0.5),
        0 0 25px rgba(var(--primary-accent-rgb), 0.3),
        0 0 40px rgba(var(--primary-accent-rgb), 0.1);
}

.email-aura-effect:hover {
    color: var(--secondary-accent);
    text-shadow:
        0 0 10px rgba(var(--secondary-accent-rgb), 0.8),
        0 0 20px rgba(var(--secondary-accent-rgb), 0.6),
        0 0 35px rgba(var(--secondary-accent-rgb), 0.4),
        0 0 50px rgba(var(--secondary-accent-rgb), 0.2);
}

#particle-game-canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: -1;
    pointer-events: none;
    background-color: var(--bg-color);
    display: block;
}

.speed-control-panel-new {
    position: fixed;
    top: 20px;
    left: 20px;
    z-index: 1001;
    background: var(--card-bg-color);
    border-radius: 12px;
    box-shadow: var(--shadow-medium);
    padding: 12px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    width: auto;
    min-width: 150px;
}

@media (max-width: 768px) {
    .speed-control-panel-new {
        top: 20px;
        left: 10px;
        padding: 10px;
        gap: 7px;
        min-width: 140px;
    }
}

@media (max-width: 480px) {
    .speed-control-panel-new {
        display: none;
        position: fixed;
        top: 60px;
        left: 5px;
        padding: 8px;
        gap: 5px;
        min-width: 100px;
    }

    .speed-control-panel-new.show-mobile {
        display: flex;
    }
}

.speed-control-label {
    font-weight: 700;
    font-size: 0.8em;
    color: var(--text-color);
}

@media (max-width: 768px) {
    .speed-control-label {
        font-size: 0.65em;
    }
}

@media (max-width: 480px) {
    .speed-control-label {
        font-size: 0.55em;
    }
}

.speed-buttons {
    display: flex;
    gap: 6px;
}

@media (max-width: 768px) {
    .speed-buttons {
        gap: 4px;
    }
}

@media (max-width: 480px) {
    .speed-buttons {
        gap: 2px;
    }
}

.speed-btn {
    background-color: var(--primary-accent);
    color: white;
    border: none;
    padding: 6px 10px;
    border-radius: 5px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.75em;
}

@media (max-width: 768px) {
    .speed-btn {
        padding: 5px 7px;
        font-size: 0.6em;
        border-radius: 3px;
    }
}

@media (max-width: 480px) {
    .speed-btn {
        padding: 3px 5px;
        font-size: 0.5em;
        border-radius: 2px;
    }
}

.speed-btn:hover {
    background-color: var(--primary-color);
    transform: scale(1.05);
}

.speed-btn:active {
    transform: scale(0.95);
}

.betting-panel {
    position: fixed;
    top: 101px;
    left: 20px;
    z-index: 1001;
    background: var(--card-bg-color);
    border-radius: 12px;
    box-shadow: var(--shadow-medium);
    padding: 10px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    width: auto;
    min-width: 140px;
}

@media (max-width: 768px) {
    .betting-panel {
        top: 93px;
        left: 10px;
        padding: 8px;
        gap: 5px;
        min-width: 120px;
    }
}

@media (max-width: 480px) {
    .betting-panel {
        display: none;
        position: fixed;
        top: 110px;
        left: 5px;
        padding: 6px;
        gap: 3px;
        min-width: 90px;
    }

    .betting-panel.show-mobile {
        display: flex;
    }
}

.betting-title {
    font-weight: 700;
    font-size: 0.75em;
    color: var(--text-color);
}

@media (max-width: 768px) {
    .betting-title {
        font-size: 0.65em;
    }
}

@media (max-width: 480px) {
    .betting-title {
        font-size: 0.5em;
    }
}

.betting-colors {
    display: flex;
    gap: 4px;
}

@media (max-width: 768px) {
    .betting-colors {
        gap: 3px;
    }
}

@media (max-width: 480px) {
    .betting-colors {
        gap: 2px;
    }
}

.color-btn {
    width: 24px;
    height: 24px;
    border: 2px solid transparent;
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-small);
}

@media (max-width: 768px) {
    .color-btn {
        width: 20px;
        height: 20px;
        border: 1px solid transparent;
    }
}

@media (max-width: 480px) {
    .color-btn {
        width: 18px;
        height: 18px;
        border: 1px solid transparent;
    }
}

.color-btn:hover {
    transform: scale(1.1);
    box-shadow: var(--shadow-medium);
}

.color-btn.selected {
    border-color: white;
    box-shadow: 0 0 15px rgba(255, 255, 255, 0.8);
}

.bet-info {
    font-size: 0.65em;
    color: var(--text-color);
    text-align: center;
    min-width: 80px;
}

@media (max-width: 768px) {
    .bet-info {
        font-size: 0.55em;
        min-width: 70px;
    }
}

@media (max-width: 480px) {
    .bet-info {
        font-size: 0.45em;
        min-width: 60px;
    }
}

.mobile-panels-toggle {
    display: none;
    position: fixed;
    top: 20px;
    left: 20px;
    z-index: 1002;
    background: var(--card-bg-color);
    color: var(--text-color);
    border: none;
    border-radius: 8px;
    padding: 8px 12px;
    font-weight: 700;
    font-size: 1.2em;
    cursor: pointer;
    box-shadow: var(--shadow-medium);
    transition: all 0.3s ease;
}

@media (max-width: 480px) {
    .mobile-panels-toggle {
        display: block;
    }

    .mobile-panels-toggle:hover {
        background-color: var(--primary-accent);
        color: white;
    }
}

.speed-control-panel-new {
    position: fixed;
    top: 20px;
    left: 20px;
    z-index: 1001;
    background: var(--card-bg-color);
    border-radius: 12px;
    box-shadow: var(--shadow-medium);
    padding: 12px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    width: auto;
    min-width: 150px;
}

@media (max-width: 480px) {
    .speed-control-panel-new {
        display: none;
    }

    .speed-control-panel-new.show-mobile {
        display: flex;
        top: 60px;
        left: 5px;
        padding: 8px;
        gap: 5px;
        min-width: 100px;
    }
}

.result-display {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: 1002;
    pointer-events: none;
}

.speed-control-panel {
    position: fixed;
    top: 20px;
    left: 20px;
    z-index: 1000;
    background: var(--card-bg-color);
    border-radius: 10px;
    box-shadow: var(--shadow-medium);
    padding: 10px 15px;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
    opacity: 0;
    visibility: hidden;
    transform: translateX(-100%);
    transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s ease;
    border: 1px solid var(--border-color);
}

.speed-control-panel.show {
    opacity: 1;
    visibility: visible;
    transform: translateX(0);
}

.speed-control-panel label {
    font-size: 0.9em;
    color: var(--text-color);
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 5px;
}

.speed-control-panel input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    width: 150px;
    height: 8px;
    background: var(--bg-color-alt);
    border-radius: 5px;
    outline: none;
    transition: background 0.3s ease;
}

.speed-control-panel input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-accent);
    cursor: grab;
    transition: background 0.3s ease, transform 0.2s ease;
    box-shadow: var(--shadow-small);
}

.speed-control-panel input[type="range"]::-webkit-slider-thumb:active {
    cursor: grabbing;
    transform: scale(1.1);
}

.speed-control-panel input[type="range"]::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-accent);
    cursor: grab;
    transition: background 0.3s ease, transform 0.2s ease;
    box-shadow: var(--shadow-small);
}

.speed-control-panel input[type="range"]::-moz-range-track {
    background: var(--bg-color-alt);
    border-radius: 5px;
}

.speed-control-panel .speed-value {
    font-weight: bold;
    color: var(--primary-accent);
    margin-left: 5px;
}

.speed-toggle-button {
    position: fixed;
    top: 20px;
    left: 20px;
    z-index: 1001;
    background: var(--primary-accent);
    color: var(--bg-color);
    border: none;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5em;
    cursor: pointer;
    box-shadow: var(--shadow-medium);
    transition: all 0.3s ease;
    opacity: 0.8;
}

.theme-toggle-button:hover {
    opacity: 1;
    transform: scale(1.05) rotate(5deg);
}

.language-toggle {
    position: fixed;
    top: 20px;
    right: 75px;
    z-index: 999;
    display: flex;
    gap: 6px;
    background: var(--card-bg-color);
    padding: 8px 10px;
    border-radius: 50px;
    box-shadow: var(--shadow-medium);
    border: 1px solid var(--border-color);
}

.lang-btn {
    background-color: transparent;
    color: var(--text-color);
    border: none;
    padding: 6px 12px;
    border-radius: 40px;
    font-weight: 700;
    font-size: 0.85em;
    cursor: pointer;
    transition: all 0.25s ease;
}

.lang-btn:hover {
    background-color: var(--primary-accent);
    color: white;
}

.lang-btn.active {
    background-color: var(--primary-accent);
    color: white;
    box-shadow: 0 2px 8px rgba(0, 188, 212, 0.3);
}

@media (max-width: 768px) {
    .language-toggle {
        top: 70px;
        right: 20px;
        padding: 6px 8px;
    }

    .lang-btn {
        padding: 5px 10px;
        font-size: 0.75em;
    }
}

@media (max-width: 992px) {
    .hero-title {
        font-size: 3.5em;
    }
    .hero-subtitle {
        font-size: 1.5em;
    }
    .main-nav ul {
        flex-wrap: wrap;
        justify-content: center;
        gap: 20px;
    }
    .section-title {
        font-size: 2em;
    }
    main {
        padding: 40px 15px;
    }
    .content-section {
        padding: 30px;
        margin-bottom: 40px;
    }
}

@media (max-width: 768px) {
    .hero-title {
        font-size: 2.8em;
    }
    .hero-subtitle {
        font-size: 1.2em;
    }
    .main-nav ul {
        flex-direction: column;
        gap: 15px;
    }
    .main-nav a {
        padding: 6px 10px;
        font-size: 1em;
    }
    .theme-toggle-button {
        width: 40px;
        height: 40px;
        font-size: 1.3em;
        top: 15px;
        right: 15px;
    }
    .section-title {
        font-size: 1.8em;
    }
    .section-text {
        font-size: 1em;
    }
    #skills .skills-grid,
    #projects .projects-grid,
    #certificates .certificates-grid {
        grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
        gap: 15px;
        padding: 15px;
    }
    .project-card, .certificate-card {
        min-height: auto;
    }
    .skill-item {
        min-height: 70px;
        padding: 10px;
        font-size: 0.9em;
    }
    .speed-control-panel {
        top: 15px;
        left: 15px;
    }
    .speed-toggle-button {
        top: 15px;
        left: 15px;
    }
    .speed-toggle-button.show {
        left: 170px;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2em;
        letter-spacing: 1px;
    }
    .hero-subtitle {
        font-size: 1em;
        margin-bottom: 25px;
    }
    .main-nav ul {
        gap: 10px;
    }
    .section-title {
        font-size: 1.5em;
    }
    .content-section {
        padding: 20px;
    }
    #skills .skills-grid,
    #projects .projects-grid,
    #certificates .certificates-grid {
        grid-template-columns: repeat(auto-fit, minmax(90px, 1fr));
        gap: 10px;
        padding: 10px;
    }
    .skill-item {
        padding: 8px;
        font-size: 0.8em;
    }
}

/* Hide certificates section and loader on small screens by default
   — Certificates will be revealed only if the user explicitly taps the nav link */
@media (max-width: 480px) {
    #certificates {
        display: none;
    }

    /* If JS reveals the certificates section, use this helper class to indicate
       it was shown via the nav (so it can be styled differently if needed) */
    #certificates.mobile-shown {
        display: block;
        animation: fadeInUp 0.4s ease-out;
    }
}