* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Arial, sans-serif;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: rgb(0, 0, 0);
    padding: 1px 15px;
    top: 0;
    z-index: 1000;
}

header img {
    width: 160px;
}

.nav-anim {
    position: relative;
    display: flex;
    align-items: center;
    height: 50px;
}

.nav-anim a {
    position: relative;
    display: inline-block;
    color: white;
    text-decoration: none;
    font-size: 18px;
    font-weight: 500;
    padding: 0 22px;
    z-index: 1;
}

.hamburger {
    display: none;
}

.nav-anim a.active:nth-child(2)~span {
    left: 90px;
    width: 95px;
}

.nav-anim a.activeP:nth-child(3)~span {
    left: 185px;
    width: 110px;
}

.nav-anim a.activeC:nth-child(4)~span {
    left: 300px;
    width: 120px;
}

.nav-anim a.activeAb:nth-child(5)~span {
    left: 435px;
    width: 105px;
}

.nav-anim a.activeLogin:nth-child(6)~span {
    left: 550px;
    width: 80px;
}

.nav-anim span {
    position: absolute;
    top: 0;
    left: 0;
    width: 90px;
    height: 100%;
    background: linear-gradient(45deg, #ff9800, #ff5722);
    border-radius: 6px;
    transition: 0.5s;
    z-index: 0;
}

.nav-anim a:nth-child(1):hover~span {
    left: 0;
    width: 90px;
}

.nav-anim a:nth-child(2):hover~span {
    left: 90px;
    width: 95px;
}

.nav-anim a:nth-child(3):hover~span {
    left: 185px;
    width: 110px;
}

.nav-anim a:nth-child(4):hover~span {
    left: 300px;
    width: 120px;
}

.nav-anim a:nth-child(5):hover~span {
    left: 435px;
    width: 105px;
}

.nav-anim a:nth-child(6):hover~span {
    left: 550px;
    width: 80px;
}


.home {
    position: relative;
    height: 100vh;
    width: 100%;
    overflow: hidden;
}

.bg-video {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 100%;
    height: 100%;
    transform: translate(-50%, -50%);
    object-fit: cover;
    z-index: -2;
}

.overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    z-index: -1;
}

.home-content {
    position: relative;
    top: 50%;
    transform: translateY(-50%);
    text-align: center;
    color: white;
    padding: 20px;
}

.home-content h2 {
    font-size: 45px;
    margin-bottom: 15px;
}

.home-content p {
    font-size: 22px;
    margin-top: 10px;
}

.btn0 {
    margin-top: 25px;
    padding: 12px 18px;
    font-size: 18px;
    border: none;
    border-radius: 6px;
    background-color: #ff9800;
    color: white;
    cursor: pointer;
    text-decoration: none;
}

.btn0:hover {
    background-color: #ffd54f;
    color: rgba(255, 255, 255, 0.604);
}

footer {
    background-color: black;
    padding: 15px;
    bottom: 0;
    z-index: 1000;
}

footer p {
    color: white;
    text-align: center;
    font-size: 16px;
}

@media (max-width: 768px) {

    .home-content h2 {
        font-size: 32px;
    }

    .home-content p {
        font-size: 18px;
    }

}

.about {
    background: black;
    padding: 40px;
    border-radius: 15px;
    color: white;
    font-size: 25px;
    text-align: center;
    margin: 10px;
    height: 600px;
    box-shadow: 0 10px 30px rgba(0, 123, 255, 0.4);
    align-content: center;
}

body {
    background-color: black;
    color: white;
}

.swiper-section {
    padding: 80px 20px;
    text-align: center;
}

.swiper-section h2 {
    color: #ff9800;
    font-size: 38px;
    margin-bottom: 40px;
}

.swiper {
    width: 85%;
    max-width: 900px;
    margin: auto;
}

.swiper-slide {
    background-color: #0d1b2a;
    padding: 50px 30px;
    border-radius: 15px;
    box-shadow: 0 0 25px rgba(0, 123, 255, 0.7);
    transition: transform 0.3s;
}

.swiper-slide:hover {
    transform: scale(1.05);
}

.swiper-slide h3 {
    color: #00aaff;
    font-size: 28px;
    margin-bottom: 15px;
}

.swiper-slide p {
    font-size: 18px;
    line-height: 1.6;
}

@media (max-width: 768px) {
    .swiper {
        width: 95%;
    }

    .swiper-section h2 {
        font-size: 28px;
    }

    .swiper-slide h3 {
        font-size: 22px;
    }

    .swiper-slide p {
        font-size: 16px;
    }
}

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

/*topics */
body {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    margin: 0;
    background-color: rgba(0, 0, 0, 0.988);
}

.topic {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
    overflow: hidden;
}

header {
    width: 100%;
    flex-shrink: 0;
}

footer {
    width: 100%;
    flex-shrink: 0;
}

.slider-container {
    margin: auto;
}

.slider-container {
    perspective: 1000px;
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 100%;
}

.slider-track {
    display: flex;
    align-items: center;
    justify-content: flex-start;
    transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    will-change: transform;
}

.card {
    width: 250px;
    height: 280px;
    background-color: #0d1b2a;
    color: white;
    text-align: center;
    border-radius: 20px;
    margin: 0 -90px;
    transition: all 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    transform: scale(0.8) rotateY(30deg);
    filter: brightness(1.5) blur(2px);
    opacity: 0.5;
}

.card.right-side {
    transform: scale(0.6) rotateY(-25deg);
}

.card.active {
    color: #fff;
    transform: scale(1.3) rotateY(0deg) translateZ(50px);
    opacity: 1;
    filter: brightness(1) blur(0);
    z-index: 100;
}

.controls {
    margin-top: 40px;
}

.controls button {
    padding: 12px 30px;
    border: none;
    cursor: pointer;
    font-weight: bold;
    text-transform: uppercase;
    letter-spacing: 1px;
    transition: 0.3s;
}

.btn1 {
    margin-top: 25px;
    padding: 6px 14px;
    font-size: 14px;
    border: none;
    border-radius: 6px;
    background-color: #ff9800;
    color: white;
    cursor: pointer;
    text-decoration: none;
}

.btn1:hover {
    background-color: #ffd54f;
    color: rgba(255, 255, 255, 0.604);
}

.nav-link.active-link {
    border-bottom: 2px solid #ff9800;
    padding-bottom: 5px;
    transition: 0.3s;
}

.topic-card {
    background: #0d1b2a;
    padding: 20px;
    border-radius: 18px;
    box-shadow: 0 0 50px rgba(26, 62, 141, 0.45);
    transition: transform 0.3s, box-shadow 0.3s;
    width: 250px;
    height: 280px;
}

.topic-card:hover {
    transform: translateY(-12px);
    box-shadow: 0 0 70px rgba(26, 62, 141, 0.9);
}

.topic-card h3 {
    color: #ff9800;
    font-size: 20px;
}

.topic-card p {
    font-size: 15px;
}

.topic-card ul {
    list-style: none;
}

.topic-card li {
    color: #cfd8ff;
    font-size: 15px;
}

@media (max-width: 768px) {

    .hamburger {
        display: block;
        cursor: pointer;
        width: 30px;
        height: 3px;
        background-color: white;
        position: relative;
        margin-right: 20px;
        transition: background-color 0.3s;
        flex-shrink: 0;
    }

    .hamburger::before,
    .hamburger::after {
        content: '';
        position: absolute;
        width: 30px;
        height: 3px;
        background-color: white;
        transition: transform 0.3s ease, top 0.3s ease;
    }

    .hamburger::before {
        top: -10px;
    }

    .hamburger::after {
        top: 10px;
    }

    /* Hamburger → X when active */
    .hamburger.open {
        background-color: transparent;
    }

    .hamburger.open::before {
        top: 0;
        transform: rotate(45deg);
    }

    .hamburger.open::after {
        top: 0;
        transform: rotate(-45deg);
    }

    .nav-anim {
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: flex-start;
        background-color: rgba(0, 0, 0, 0.97);
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        transition: left 0.35s ease;
        padding-top: 30px;
        z-index: 999;
        overflow-y: auto;
    }

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

    .nav-anim a {
        display: block;
        width: 100%;
        text-align: center;
        padding: 18px 20px;
        color: white;
        text-decoration: none;
        font-size: 20px;
        position: relative;
        z-index: 1;
        transition: color 0.2s;
    }

    .nav-anim a:hover {
        color: #ff9800;
    }

    /* Hide the sliding span on mobile — use a simple bottom border highlight instead */
    .nav-anim span {
        display: none;
    }

    /* Override all desktop span hover rules on mobile */
    .nav-anim a:nth-child(1):hover~span,
    .nav-anim a:nth-child(2):hover~span,
    .nav-anim a:nth-child(3):hover~span,
    .nav-anim a:nth-child(4):hover~span,
    .nav-anim a:nth-child(5):hover~span,
    .nav-anim a:nth-child(6):hover~span,
    .nav-anim a:nth-child(7):hover~span {
        display: none;
    }

    /* Dividers between links */
    .nav-anim a+a {
        border-top: 1px solid rgba(255, 255, 255, 0.08);
    }

    /* Topic Card Mobile Overrides */
    .card {
        width: 220px;
        height: 260px;
        margin: 0 -60px;
        transform: scale(0.75) rotateY(25deg);
        transition: all 0.6s cubic-bezier(0.4,0,0.2,1);
    }

    .card.active {
        transform: scale(1.15) rotateY(0deg) translateZ(40px);
        opacity: 1;
        filter: brightness(1) blur(0);
    }

    .card.right-side {
        transform: scale(0.7) rotateY(-20deg);
    }

    .slider-track {
        display: flex;
        align-items: center;
        justify-content: flex-start;
        transition: transform 0.6s cubic-bezier(0.4,0,0.2,1);
        will-change: transform;
    }

}

.features {
    display: flex;
    justify-content: center;
    gap: 30px;
    padding: 80px 20px;
    flex-wrap: wrap;
    background-color: #000;
}

.feature-card {
    background: #111;
    border: 1px solid #333;
    border-radius: 10px;
    padding: 30px;
    width: 300px;
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 10px 20px rgba(255, 152, 0, 0.2);
}

.feature-card img {
    width: 60px;
    margin-bottom: 20px;
    filter: invert(1);
}

.feature-card h3 {
    color: #ff9800;
    margin-bottom: 15px;
    font-size: 24px;
}

.feature-card p {
    color: #ccc;
    font-size: 16px;
    line-height: 1.6;
    margin-bottom: 20px;
}

.btn-small {
    display: inline-block;
    padding: 8px 20px;
    background: transparent;
    border: 2px solid #ff9800;
    color: #ff9800;
    text-decoration: none;
    border-radius: 5px;
    font-weight: bold;
    transition: 0.3s;
}

.btn-small:hover {
    background: #ff9800;
    color: #fff;
}

.quote-section {
    padding: 80px 20px;
    background-color: #0d1b2a;
    text-align: center;
    display: flex;
    justify-content: center;
    align-items: center;
}

blockquote {
    font-size: 28px;
    font-style: italic;
    color: #ddd;
    max-width: 900px;
    position: relative;
    padding: 20px;
}

blockquote::before {
    content: "\201C";
    font-size: 80px;
    color: #ff9800;
    position: absolute;
    top: -30px;
    left: -20px;
    opacity: 0.3;
}

blockquote cite {
    display: block;
    margin-top: 20px;
    font-size: 18px;
    color: #ff9800;
    font-style: normal;
    font-weight: bold;
}

.cta-section {
    padding: 100px 20px;
    background: linear-gradient(45deg, #ff9800, #ff5722);
    ;
    text-align: center;
    color: #fff;
}

.cta-section h2 {
    font-size: 42px;
    margin-bottom: 15px;
    color: black;
}

.cta-section p {
    font-size: 22px;
    margin-bottom: 30px;
    color: rgba(0, 0, 0, 0.8);
}

.btn-large {
    padding: 15px 40px;
    background: black;
    color: #ff9800;
    text-decoration: none;
    font-size: 20px;
    font-weight: bold;
    border-radius: 50px;
    transition: 0.3s;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.btn-large:hover {
    transform: scale(1.05);
    background: #222;
    color: white;
}

@media (max-width: 768px) {
    .features {
        flex-direction: column;
        align-items: center;
    }

    .about-content h2 {
        font-size: 32px;
    }

    .about-content p {
        font-size: 18px;
    }

    blockquote {
        font-size: 22px;
    }

    .cta-section h2 {
        font-size: 32px;
    }

}




/*login.html*/

 
main {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 60px 20px;
    position: relative;
    overflow: hidden;
}
/* animated grid background */
main::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(0, 170, 255, 0.04) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0, 170, 255, 0.04) 1px, transparent 1px);
    background-size: 50px 50px;
    animation: gridMove 20s linear infinite;
}
@keyframes gridMove {
    from {
        background-position: 0 0;
    }
    to {
        background-position: 50px 50px;
    }
}
/* glowing orbs */
main::after {
    content: '';
    position: absolute;
    width: 500px;
    height: 500px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(255, 152, 0, 0.08) 0%, transparent 70%);
    top: -100px;
    right: -100px;
    pointer-events: none;
}
/* ── CARD ── */
.auth-card {
    position: relative;
    z-index: 2;
    background: #0d1b2a;
    border: 1px solid rgba(0, 170, 255, 0.15);
    border-radius: 24px;
    padding: 50px 45px;
    width: 100%;
    max-width: 460px;
    box-shadow: 0 0 80px rgba(26, 62, 141, 0.35), 0 0 0 1px rgba(255, 152, 0, 0.05);
    animation: fadeUp 0.6s ease both;
}
@keyframes fadeUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}
.auth-card .brand {
    text-align: center;
    margin-bottom: 32px;
}
.auth-card .brand h1 {
    font-family: 'Orbitron', sans-serif;
    font-size: 28px;
    background: linear-gradient(90deg, #ff9800, #ff5722);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: 2px;
}
.auth-card .brand p {
    color: #6b8099;
    font-size: 14px;
    margin-top: 6px;
}
.form-group {
    margin-bottom: 22px;
}
.form-group label {
    display: block;
    font-size: 13px;
    font-weight: 600;
    color: #00aaff;
    letter-spacing: 1px;
    text-transform: uppercase;
    margin-bottom: 8px;
}
.input-wrap {
    position: relative;
}
.input-wrap .icon {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    color: #6b8099;
    font-size: 16px;
    pointer-events: none;
}
.input-wrap input {
    width: 100%;
    background: #060f1a;
    border: 1px solid rgba(0, 170, 255, 0.2);
    border-radius: 10px;
    padding: 13px 16px 13px 44px;
    color: white;
    font-family: 'Exo 2', sans-serif;
    font-size: 15px;
    transition: border-color 0.3s, box-shadow 0.3s;
    outline: none;
}
.input-wrap input::placeholder {
    color: #3a5068;
}
.input-wrap input:focus {
    border-color: #ff9800;
    box-shadow: 0 0 0 3px rgba(255, 152, 0, 0.12);
}
.toggle-pw {
    position: absolute;
    right: 14px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: #6b8099;
    cursor: pointer;
    font-size: 15px;
    transition: color 0.2s;
}
.toggle-pw:hover {
    color: #ff9800;
}
.forgot {
    text-align: right;
    margin-top: -12px;
    margin-bottom: 22px;
}
.forgot a {
    color: #6b8099;
    font-size: 13px;
    text-decoration: none;
    transition: color 0.2s;
}
.forgot a:hover {
    color: #ff9800;
}
.btn-auth {
    width: 100%;
    padding: 14px;
    background: linear-gradient(45deg, #ff9800, #ff5722);
    border: none;
    border-radius: 10px;
    color: white;
    font-family: 'Orbitron', sans-serif;
    font-size: 14px;
    letter-spacing: 2px;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.3s;
}
.btn-auth:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 20px rgba(255, 87, 34, 0.3);
    box-shadow: 0 8px 30px rgba(255, 87, 34, 0.5);
}
.btn-auth:active {
    transform: translateY(0);
}
.divider {
    display: flex;
    align-items: center;
    gap: 12px;
    margin: 28px 0;
    color: #3a5068;
    font-size: 13px;
}
.divider::before,
.divider::after {
    content: '';
    flex: 1;
    height: 1px;
    background: rgba(0, 170, 255, 0.1);
}
.auth-link {
    text-align: center;
    font-size: 14px;
    color: #6b8099;
}
.auth-link a {
    color: #ff9800;
    text-decoration: none;
    font-weight: 600;
    transition: color 0.2s;
}
.auth-link a:hover {
    color: #ffd54f;
}
/* ── MOBILE ── */
@media (max-width: 768px) {
    .auth-card {
        padding: 36px 24px;
    }
}




/*practice.html*/

    .topic-tabs {
        display: flex;
        flex-wrap: wrap;
        justify-content: center;
        gap: 12px;
        margin-bottom: 40px;
    }

    .tab-btn {
        padding: 10px 24px;
        border: 2px solid #ff9800;
        background: transparent;
        color: #ff9800;
        border-radius: 30px;
        font-size: 16px;
        font-weight: bold;
        cursor: pointer;
        transition: 0.3s;
    }
    .tab-btn:hover,
    .tab-btn.active {
        background: #ff9800;
        color: #fff;
    }
    .quiz-panel {
        display: none;
    }
    .quiz-panel.active {
        display: block;
    }
    .topic-title {
        font-size: 28px;
        color: #00aaff;
        margin-bottom: 8px;
    }
    .topic-desc {
        color: #aaa;
        font-size: 16px;
        margin-bottom: 30px;
    }
    .question-card {
        background: #111;
        border: 1px solid #333;
        padding: 24px;
        margin: 20px auto;
        max-width: 680px;
        border-radius: 12px;
        text-align: left;
        transition: border-color 0.3s;
    }
    .question-card.correct {
        border-color: #4caf50;
    }
    .question-card.wrong {
        border-color: #ff9800;
    }
    .question-card h3 {
        color: #fff;
        font-size: 18px;
        margin-bottom: 16px;
        line-height: 1.5;
    }
    .question-card label {
        display: flex;
        align-items: center;
        gap: 10px;
        color: #ccc;
        font-size: 17px;
        margin-bottom: 10px;
        cursor: pointer;
        padding: 8px 12px;
        border-radius: 8px;
        transition: background 0.2s;
    }
    .question-card label:hover {
        background: #1a2a3a;
    }
    .question-card input[type="radio"] {
        accent-color: #ff9800;
        width: 17px;
        height: 17px;
        flex-shrink: 0;
    }
    .status-badge {
        display: none;
        font-size: 13px;
        font-weight: bold;
        padding: 3px 10px;
        border-radius: 20px;
        margin-left: 6px;
        vertical-align: middle;
    }
    .badge-correct {
        background: #4caf50;
        color: #fff;
    }
    .badge-wrong {
        background: #ff9800;
        color: #fff;
    }
    .explanation {
        display: none;
        margin-top: 18px;
        background: #0d1b2a;
        border-left: 4px solid #00aaff;
        border-radius: 0 10px 10px 0;
        padding: 16px 18px;
        color: #cde;
        font-size: 15px;
        line-height: 1.7;
    }
    .explanation.visible {
        display: block;
    }
    .explanation strong {
        color: #ff9800;
    }
    .explanation .step {
        display: flex;
        gap: 10px;
        margin: 6px 0;
    }
    .step-num {
        background: #00aaff;
        color: #000;
        font-weight: bold;
        border-radius: 50%;
        width: 24px;
        height: 24px;
        display: flex;
        align-items: center;
        justify-content: center;
        flex-shrink: 0;
        font-size: 13px;
        margin-top: 2px;
    }
    .correct-label {
        color: #4caf50 !important;
        font-weight: bold;
    }
    .wrong-label {
        color: #ff9800 !important;
    }
    .btn-submit {
        padding: 13px 36px;
        font-size: 18px;
        background: linear-gradient(45deg, #ff9800, #ff5722);
        color: white;
        border: none;
        border-radius: 8px;
        cursor: pointer;
        margin-top: 24px;
        transition: 0.3s;
        font-weight: bold;
    }
    .btn-submit:hover {
        transform: scale(1.05);
        opacity: 0.9;
    }
    .btn-submit:disabled {
        opacity: 0.5;
        cursor: not-allowed;
        transform: none;
    }
    .score-box {
        display: none;
        margin: 30px auto;
        max-width: 480px;
        background: #0d1b2a;
        border-radius: 16px;
        padding: 30px;
        text-align: center;
        box-shadow: 0 0 40px rgba(0, 170, 255, 0.3);
    }
    .score-box .score-num {
        font-size: 64px;
        font-weight: bold;
    }
    .score-box .score-label {
        font-size: 20px;
        color: #aaa;
        margin-bottom: 12px;
    }
    .score-box .score-msg {
        font-size: 18px;
        color: #ccc;
    }
    .score-perfect {
        color: #4caf50;
    }
    .score-good {
        color: #ff9800;
    }
    .score-retry {
        color: #ff9800;
    }
    .btn-retry {
        margin-top: 20px;
        padding: 10px 28px;
        border: 2px solid #ff9800;
        background: transparent;
        color: #ff9800;
        border-radius: 30px;
        font-size: 16px;
        font-weight: bold;
        cursor: pointer;
        transition: 0.3s;
    }
    .btn-retry:hover {
        background: #ff9800;
        color: #fff;
    }
    .progress-wrap {
        max-width: 680px;
        margin: 0 auto 10px;
        background: #222;
        border-radius: 20px;
        height: 8px;
        overflow: hidden;
    }
    .progress-bar {
        height: 100%;
        background: linear-gradient(45deg, #ff9800, #ff5722);
        border-radius: 20px;
        transition: width 0.5s;
        width: 0%;
    }
    .progress-label {
        max-width: 680px;
        margin: 0 auto 20px;
        color: #777;
        font-size: 14px;
        text-align: right;
    }
    .practice-section {
        padding: 80px 20px 60px;
        text-align: center;
        background-color: #000814;
        min-height: 80vh;
    }
    .practice-section>h2 {
        font-size: 40px;
        color: #ff9800;
        margin-bottom: 10px;
    }
    .practice-section>.subtitle {
        color: #aaa;
        font-size: 18px;
        margin-bottom: 40px;
    }