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

html {
    scroll-behavior: smooth;
}

body {
    font-family: Arial, Helvetica, sans-serif;
    background: #070b16;
    color: white;
    line-height: 1.6;
}


/* Navbar */

.navbar {
    width: 100%;
    padding: 20px 7%;
    display: flex;
    align-items: center;
    justify-content: space-between;

    position: sticky;
    top: 0;
    z-index: 1000;

    background: rgba(7, 11, 22, 0.9);
    backdrop-filter: blur(12px);

    border-bottom: 1px solid #1a2235;
}

.logo {
    font-size: 25px;
    font-weight: bold;
}

.logo span {
    font-size: 28px;
}

.navbar nav {
    display: flex;
    gap: 35px;
}

.navbar nav a {
    color: #b8c0d4;
    text-decoration: none;
    transition: 0.3s;
}

.navbar nav a:hover {
    color: #00aaff;
}

.nav-btn {
    text-decoration: none;
    color: white;

    padding: 10px 20px;

    border: 1px solid #00aaff;
    border-radius: 8px;

    transition: 0.3s;
}

.nav-btn:hover {
    background: #00aaff;
}


/* Hero */

.hero {
    min-height: 90vh;

    display: flex;
    align-items: center;
    justify-content: space-between;

    gap: 70px;

    padding: 80px 7%;

    background:
        radial-gradient(circle at 80% 30%, #003c6340, transparent 35%),
        #070b16;
}

.hero-content {
    max-width: 650px;
}

.tagline,
.section-tag {
    color: #00aaff;
    font-size: 13px;
    font-weight: bold;
    letter-spacing: 3px;
}

.hero h1 {
    font-size: clamp(45px, 6vw, 80px);
    line-height: 1.05;

    margin: 20px 0;
}

.hero h1 span,
.intro h2 span,
.practice h2 span {
    color: #00aaff;
}

.hero-text {
    color: #aeb7ca;
    font-size: 18px;
    max-width: 570px;
}

.hero-buttons {
    display: flex;
    gap: 15px;
    margin-top: 35px;
}

.primary-btn,
.secondary-btn {
    display: inline-block;

    padding: 14px 25px;

    border-radius: 8px;

    text-decoration: none;

    font-weight: bold;

    transition: 0.3s;
}

.primary-btn {
    background: #00aaff;
    color: white;
}

.primary-btn:hover {
    transform: translateY(-3px);
}

.secondary-btn {
    color: white;
    border: 1px solid #26334d;
}

.secondary-btn:hover {
    border-color: #00aaff;
}


/* Code Card */

.code-card {
    width: 420px;

    background: #0d1424;

    border: 1px solid #1c2a42;

    border-radius: 15px;

    box-shadow: 0 20px 70px #00000080;
}

.code-top {
    padding: 15px;

    border-bottom: 1px solid #1c2a42;
}

.code-top span {
    display: inline-block;

    width: 10px;
    height: 10px;

    margin-right: 6px;

    border-radius: 50%;

    background: #506078;
}

.code {
    padding: 30px;

    font-family: monospace;
    font-size: 16px;
}

.code p {
    margin: 10px 0;
}

.purple {
    color: #c792ea;
}

.green {
    color: #7ee787;
}

.output {
    color: #00aaff;
}


/* Introduction */

.intro {
    padding: 100px 7%;

    display: grid;
    grid-template-columns: 1fr 1fr;

    gap: 70px;

    background: #0a101e;
}

.intro h2 {
    font-size: 45px;
    margin-top: 15px;
}

.intro > p {
    color: #aeb7ca;
    font-size: 18px;
}


/* Sections */

.lessons,
.projects {
    padding: 100px 7%;
}

.section-heading {
    text-align: center;
    margin-bottom: 50px;
}

.section-heading h2 {
    font-size: 45px;
    margin: 10px 0;
}

.section-heading p:last-child {
    color: #8994aa;
}


/* Lesson Cards */

.lesson-grid {
    display: grid;

    grid-template-columns: repeat(4, 1fr);

    gap: 20px;
}

.lesson-card {
    padding: 30px;

    background: #0d1424;

    border: 1px solid #1c2a42;

    border-radius: 15px;

    transition: 0.3s;
}

.lesson-card:hover {
    transform: translateY(-7px);
    border-color: #00aaff;
}

.lesson-icon {
    font-size: 35px;
}

.lesson-card h3 {
    margin: 20px 0 10px;
}

.lesson-card p {
    color: #8994aa;
    font-size: 14px;
    margin-bottom: 20px;
}

.lesson-card a {
    color: #00aaff;
    text-decoration: none;
    font-weight: bold;
}


/* Practice */

.practice {
    padding: 100px 7%;

    display: grid;

    grid-template-columns: 1fr 1fr;

    gap: 70px;

    background: #0a101e;
}

.practice h2 {
    font-size: 50px;
    margin: 15px 0;
}

.practice-content > p:not(.section-tag) {
    color: #8994aa;
    max-width: 550px;
    margin-bottom: 30px;
}

.practice-box {
    padding: 35px;

    border: 1px solid #1c2a42;

    border-radius: 15px;

    background: #0d1424;
}

.practice-box div {
    padding: 15px 0;

    border-bottom: 1px solid #1c2a42;

    color: #b8c0d4;
}

.practice-box div:last-child {
    border-bottom: none;
}


/* Projects */

.project-grid {
    display: grid;

    grid-template-columns: repeat(3, 1fr);

    gap: 25px;
}

.project-card {
    padding: 35px;

    background: #0d1424;

    border: 1px solid #1c2a42;

    border-radius: 15px;
}

.project-card span {
    color: #00aaff;
    font-weight: bold;
}

.project-card h3 {
    margin: 20px 0 8px;
}

.project-card p {
    color: #8994aa;
}


/* Footer */

footer {
    padding: 50px 7%;

    text-align: center;

    background: #050811;

    border-top: 1px solid #1a2235;
}

.footer-logo {
    font-size: 25px;
    font-weight: bold;
}

footer p {
    color: #8994aa;
    margin-top: 10px;
}

.copyright {
    font-size: 13px;
}


/* Responsive */

@media (max-width: 1000px) {

    .navbar nav {
        gap: 15px;
    }

    .hero {
        flex-direction: column;
        text-align: center;
    }

    .hero-text {
        margin: auto;
    }

    .hero-buttons {
        justify-content: center;
    }

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

    .code-card {
        width: 100%;
        max-width: 500px;
    }
}


@media (max-width: 700px) {

    .navbar {
        flex-wrap: wrap;
        gap: 15px;
    }

    .navbar nav {
        order: 3;
        width: 100%;
        justify-content: center;
    }

    .nav-btn {
        display: none;
    }

    .intro,
    .practice {
        grid-template-columns: 1fr;
    }

    .lesson-grid,
    .project-grid {
        grid-template-columns: 1fr;
    }

    .hero {
        padding-top: 60px;
    }

    .hero h1 {
        font-size: 48px;
    }

    .hero-buttons {
        flex-direction: column;
    }

    .intro h2,
    .section-heading h2,
    .practice h2 {
        font-size: 36px;
    }
}

/* Active Navigation */

.navbar nav a.active {
    color: #00aaff;
}


/* Lessons Hero */

.lessons-hero {
    padding: 100px 7%;
    text-align: center;

    background:
        radial-gradient(
            circle at center,
            #003c6340,
            transparent 45%
        ),
        #070b16;
}

.lessons-hero h1 {
    font-size: clamp(45px, 6vw, 70px);
    line-height: 1.1;
    margin: 20px 0;
}

.lessons-hero h1 span {
    color: #00aaff;
}

.lessons-hero > p:last-child {
    max-width: 650px;
    margin: auto;

    color: #8994aa;
    font-size: 18px;
}


/* Course Section */

.course-section {
    padding: 80px 7%;
    background: #0a101e;
}

.course-header {
    display: flex;
    justify-content: space-between;
    align-items: center;

    gap: 40px;

    margin-bottom: 40px;
}

.course-header h2 {
    font-size: 32px;
    margin: 10px 0;
}

.course-header p:not(.section-tag) {
    color: #8994aa;
}


/* Progress */

.progress-box {
    width: 250px;
}

.progress-box span {
    color: #8994aa;
    font-size: 14px;
}

.progress-bar {
    width: 100%;
    height: 7px;

    margin-top: 10px;

    background: #182238;

    border-radius: 10px;

    overflow: hidden;
}

.progress-bar div {
    width: 0%;
    height: 100%;

    background: #00aaff;
}


/* Lesson List */

.lesson-list {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.lesson-item {
    display: flex;
    align-items: center;

    gap: 25px;

    padding: 25px;

    background: #0d1424;

    border: 1px solid #1c2a42;

    border-radius: 14px;

    transition: 0.3s;
}

.lesson-item:hover {
    transform: translateX(5px);
    border-color: #00aaff;
}


/* Number */

.lesson-number {
    min-width: 55px;
    height: 55px;

    display: flex;
    align-items: center;
    justify-content: center;

    border-radius: 12px;

    background: #101d32;

    color: #00aaff;

    font-weight: bold;
}


/* Lesson Info */

.lesson-info {
    flex: 1;
}

.lesson-label {
    color: #00aaff;

    font-size: 11px;

    font-weight: bold;

    letter-spacing: 1.5px;
}

.lesson-info h3 {
    margin: 5px 0;

    font-size: 20px;
}

.lesson-info p {
    color: #8994aa;

    font-size: 14px;

    margin-bottom: 8px;
}

.lesson-meta {
    color: #69758c;

    font-size: 12px;
}


/* Start Button */

.lesson-start {
    padding: 10px 18px;

    border: 1px solid #26334d;

    border-radius: 8px;

    color: white;

    text-decoration: none;

    transition: 0.3s;

    white-space: nowrap;
}

.lesson-start:hover {
    background: #00aaff;

    border-color: #00aaff;
}


/* Mobile */

@media (max-width: 700px) {

    .course-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .progress-box {
        width: 100%;
    }

    .lesson-item {
        align-items: flex-start;
    }

    .lesson-number {
        min-width: 45px;
        height: 45px;
    }

    .lesson-start {
        align-self: center;
    }
}

/* ============================= */
/* LESSON PAGE */
/* ============================= */

.lesson-page-header {
    padding: 70px 7%;

    background:
        radial-gradient(
            circle at 70% 30%,
            #003c6340,
            transparent 40%
        ),
        #070b16;
}

.lesson-breadcrumb {
    color: #69758c;
    font-size: 13px;
    margin-bottom: 25px;
}

.lesson-page-header h1 {
    font-size: clamp(40px, 5vw, 65px);
    margin: 15px 0;
}

.lesson-page-header > p {
    color: #8994aa;
    font-size: 18px;
    max-width: 650px;
}

.lesson-page-meta {
    margin-top: 20px;
    color: #69758c;
    font-size: 14px;
}


/* Main Layout */

.lesson-container {
    display: grid;

    grid-template-columns: 250px 1fr;

    gap: 60px;

    max-width: 1250px;

    margin: auto;

    padding: 70px 30px;
}


/* Sidebar */

.lesson-sidebar {
    position: sticky;
    top: 100px;

    align-self: start;

    padding: 20px;

    background: #0d1424;

    border: 1px solid #1c2a42;

    border-radius: 12px;
}

.lesson-sidebar h3 {
    margin-bottom: 15px;
}

.lesson-sidebar a {
    display: block;

    padding: 10px;

    color: #8994aa;

    text-decoration: none;

    border-radius: 7px;

    font-size: 14px;
}

.lesson-sidebar a:hover,
.lesson-sidebar .side-active {
    color: #00aaff;
    background: #101d32;
}


/* Lesson Content */

.lesson-content {
    max-width: 800px;
}

.lesson-content section {
    margin-bottom: 65px;
    scroll-margin-top: 100px;
}

.lesson-content h2 {
    font-size: 32px;
    margin-bottom: 20px;
}

.lesson-content h3 {
    margin: 20px 0 10px;
}

.lesson-content p {
    color: #aeb7ca;
    margin-bottom: 15px;
}

.lesson-content code {
    padding: 3px 7px;

    background: #111b2e;

    color: #7ee787;

    border-radius: 5px;

    font-family: monospace;
}


/* Info Box */

.info-box {
    padding: 20px;

    margin-top: 25px;

    background: #0d1b2d;

    border-left: 4px solid #00aaff;

    border-radius: 8px;

    color: #b8c0d4;
}

.info-box strong {
    color: #00aaff;
}


/* Feature List */

.feature-list {
    display: grid;

    gap: 15px;

    margin-top: 25px;
}

.feature-list div {
    padding: 20px;

    background: #0d1424;

    border: 1px solid #1c2a42;

    border-radius: 10px;
}

.feature-list strong {
    color: white;
}

.feature-list p {
    margin: 5px 0 0;
}


/* Uses */

.use-grid {
    display: grid;

    grid-template-columns: repeat(2, 1fr);

    gap: 15px;

    margin-top: 25px;
}

.use-card {
    padding: 25px;

    background: #0d1424;

    border: 1px solid #1c2a42;

    border-radius: 10px;
}

.use-card span {
    font-size: 28px;
}

.use-card h3 {
    margin: 10px 0;
}

.use-card p {
    font-size: 14px;
}


/* Code */

.code-example {
    margin: 25px 0;

    overflow: hidden;

    background: #090e19;

    border: 1px solid #1c2a42;

    border-radius: 10px;
}

.code-title {
    padding: 12px 18px;

    background: #111827;

    color: #00aaff;

    font-size: 13px;

    font-weight: bold;
}

.code-example pre {
    padding: 25px;

    overflow-x: auto;

    color: #7ee787;

    font-size: 15px;
}


/* Output */

.output-box {
    padding: 18px;

    margin: 15px 0 20px;

    background: #080d16;

    border: 1px solid #1c2a42;

    border-radius: 8px;

    color: #7ee787;

    font-family: monospace;
}


/* Quiz */

.quiz-question {
    padding: 25px;

    margin-top: 25px;

    background: #0d1424;

    border: 1px solid #1c2a42;

    border-radius: 12px;
}

.quiz-question label {
    display: block;

    padding: 12px;

    margin: 8px 0;

    color: #b8c0d4;

    background: #101827;

    border-radius: 7px;

    cursor: pointer;
}

.quiz-question button {
    margin-top: 15px;

    padding: 11px 20px;

    border: none;

    border-radius: 7px;

    background: #00aaff;

    color: white;

    font-weight: bold;

    cursor: pointer;
}

#quiz-result {
    margin-top: 15px;

    font-weight: bold;
}


/* Lesson Navigation */

.lesson-navigation {
    display: flex;

    justify-content: space-between;

    gap: 15px;

    padding-top: 30px;

    border-top: 1px solid #1c2a42;
}

.lesson-nav-btn {
    padding: 13px 20px;

    color: white;

    text-decoration: none;

    border: 1px solid #26334d;

    border-radius: 8px;
}


/* Mobile */

@media (max-width: 800px) {

    .lesson-container {
        grid-template-columns: 1fr;
    }

    .lesson-sidebar {
        position: static;
    }

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

    .lesson-navigation {
        flex-direction: column;
    }
}

/* =========================
   PRACTICE PAGE
========================= */

.practice-container {
    max-width: 850px;
    margin: 60px auto;
    padding: 0 20px;
}

.practice-card {
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 20px;
    padding: 40px;
}

.question-number {
    color: #8b5cf6;
    font-weight: 700;
    margin-bottom: 20px;
}

.practice-card h2 {
    font-size: 26px;
    margin-bottom: 30px;
}

.practice-options {
    display: grid;
    gap: 15px;
    margin-bottom: 30px;
}

.practice-option {
    width: 100%;
    padding: 16px 20px;
    text-align: left;
    background: rgba(255, 255, 255, 0.05);
    color: #fff;
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    cursor: pointer;
    font-size: 16px;
    transition: 0.2s;
}

.practice-option:hover {
    transform: translateY(-2px);
    border-color: #8b5cf6;
}

.practice-option.selected {
    border-color: #8b5cf6;
}

.practice-option.correct {
    border-color: #22c55e;
}

.practice-option.wrong {
    border-color: #ef4444;
}

#practice-result {
    margin-top: 20px;
    font-weight: 600;
}

.practice-score {
    margin-top: 30px;
    padding: 40px;
    text-align: center;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 20px;
}

.score-number {
    font-size: 60px;
    font-weight: 800;
    margin: 20px 0 30px;
}

.practice-score .lesson-nav-btn {
    display: inline-block;
    margin-left: 10px;
}

@media (max-width: 600px) {

    .practice-card {
        padding: 25px;
    }

    .practice-card h2 {
        font-size: 21px;
    }

    .practice-score .lesson-nav-btn {
        margin-left: 0;
        margin-top: 15px;
    }

}

/* ============================= */
/* PROJECTS PAGE */
/* ============================= */

.projects-container {

    max-width: 1100px;

    margin: 60px auto;

    padding: 0 20px;

    display: grid;

    grid-template-columns:
        repeat(2, 1fr);

    gap: 25px;
}


.project-card {

    position: relative;

    padding: 35px;

    background:
        rgba(255, 255, 255, 0.04);

    border:
        1px solid
        rgba(255, 255, 255, 0.08);

    border-radius: 20px;

    transition:
        transform 0.3s,
        border-color 0.3s,
        box-shadow 0.3s;
}


.project-card:hover {

    transform: translateY(-6px);

    border-color:
        rgba(139, 92, 246, 0.6);

    box-shadow:
        0 15px 40px
        rgba(0, 0, 0, 0.25);
}


.project-number {

    position: absolute;

    top: 20px;

    right: 25px;

    font-size: 14px;

    font-weight: 700;

    color: #8b5cf6;
}


.project-icon {

    width: 65px;

    height: 65px;

    display: flex;

    align-items: center;

    justify-content: center;

    font-size: 32px;

    background:
        rgba(139, 92, 246, 0.12);

    border-radius: 16px;

    margin-bottom: 25px;
}


.project-card h2 {

    font-size: 25px;

    margin-bottom: 12px;
}


.project-card p {

    color: #b8b8c7;

    line-height: 1.7;

    margin-bottom: 22px;
}


.project-tags {

    display: flex;

    flex-wrap: wrap;

    gap: 8px;

    margin-bottom: 25px;
}


.project-tags span {

    padding: 6px 12px;

    font-size: 13px;

    border-radius: 20px;

    background:
        rgba(255, 255, 255, 0.06);

    color: #cfcfe0;

    border:
        1px solid
        rgba(255, 255, 255, 0.08);
}


.project-card .primary-btn {

    display: inline-block;

    text-decoration: none;
}


/* Mobile */

@media (max-width: 700px) {

    .projects-container {

        grid-template-columns: 1fr;

        margin-top: 40px;
    }

    .project-card {

        padding: 28px;
    }

    .project-card h2 {

        font-size: 22px;
    }

}

/* ============================= */
/* PROJECT DETAIL PAGE */
/* ============================= */

.project-page-container {

    max-width: 950px;

    margin: 60px auto;

    padding: 0 20px;
}


.project-section {

    margin-bottom: 45px;

    padding: 30px;

    background:
        rgba(255, 255, 255, 0.04);

    border:
        1px solid
        rgba(255, 255, 255, 0.08);

    border-radius: 18px;
}


.project-section h2 {

    font-size: 25px;

    margin-bottom: 18px;
}


.project-section p {

    color: #b8b8c7;

    line-height: 1.7;

    margin-bottom: 20px;
}


.project-section ul {

    padding-left: 22px;

    color: #c8c8d5;

    line-height: 2;
}


.operation-grid {

    display: grid;

    grid-template-columns:
        repeat(4, 1fr);

    gap: 15px;

    margin-top: 25px;
}


.operation-card {

    padding: 25px 15px;

    text-align: center;

    background:
        rgba(255, 255, 255, 0.05);

    border:
        1px solid
        rgba(255, 255, 255, 0.08);

    border-radius: 14px;
}


.operation-card strong {

    display: block;

    font-size: 32px;

    color: #8b5cf6;

    margin-bottom: 8px;
}


.operation-card span {

    color: #b8b8c7;

    font-size: 14px;
}


.project-checklist li {

    margin-bottom: 8px;
}


.project-navigation {

    display: flex;

    justify-content: space-between;

    align-items: center;

    margin: 50px 0;
}


@media (max-width: 650px) {

    .project-section {

        padding: 22px;
    }

    .operation-grid {

        grid-template-columns:
            repeat(2, 1fr);
    }

    .project-navigation {

        flex-direction: column;

        gap: 15px;
    }

}

/* ============================= */
/* NUMBER GUESSING PROJECT */
/* ============================= */

.game-flow {

    display: grid;

    grid-template-columns:
        repeat(4, 1fr);

    gap: 15px;

    margin-top: 25px;
}


.game-step {

    padding: 20px 15px;

    text-align: center;

    background:
        rgba(255, 255, 255, 0.05);

    border:
        1px solid
        rgba(255, 255, 255, 0.08);

    border-radius: 14px;
}


.game-step strong {

    display: flex;

    align-items: center;

    justify-content: center;

    width: 40px;

    height: 40px;

    margin: 0 auto 12px;

    border-radius: 50%;

    background:
        rgba(139, 92, 246, 0.15);

    color: #8b5cf6;

    font-size: 18px;
}


.game-step span {

    display: block;

    color: #b8b8c7;

    font-size: 14px;

    line-height: 1.5;
}


@media (max-width: 700px) {

    .game-flow {

        grid-template-columns:
            repeat(2, 1fr);
    }

}


@media (max-width: 450px) {

    .game-flow {

        grid-template-columns: 1fr;
    }

}

/* ============================= */
/* LIVE CALCULATOR */
/* ============================= */

.live-calculator {

    max-width: 600px;

    margin: 25px auto 0;

    padding: 30px;

    display: flex;

    flex-direction: column;

    gap: 15px;

    background:
        rgba(255, 255, 255, 0.04);

    border:
        1px solid
        rgba(255, 255, 255, 0.08);

    border-radius: 18px;
}


.live-calculator input,
.live-calculator select {

    width: 100%;

    box-sizing: border-box;

    padding: 15px;

    border-radius: 10px;

    border:
        1px solid
        rgba(255, 255, 255, 0.12);

    background:
        rgba(255, 255, 255, 0.06);

    color: #fff;

    font-size: 16px;

    outline: none;
}


.live-calculator select option {

    background: #111827;

    color: #fff;
}


.live-calculator input:focus,
.live-calculator select:focus {

    border-color: #8b5cf6;
}


.live-calculator .primary-btn {

    border: none;

    cursor: pointer;

    width: 100%;
}


.calculator-result {

    padding: 18px;

    text-align: center;

    border-radius: 10px;

    background:
        rgba(139, 92, 246, 0.10);

    border:
        1px solid
        rgba(139, 92, 246, 0.25);

    color: #fff;

    font-size: 20px;

    font-weight: 700;
}

/* ============================= */
/* LIVE NUMBER GUESSING GAME */
/* ============================= */

.guess-game {

    max-width: 600px;

    margin: 25px auto 0;

    padding: 30px;

    display: flex;

    flex-direction: column;

    gap: 16px;

    text-align: center;

    background:
        rgba(255, 255, 255, 0.04);

    border:
        1px solid
        rgba(255, 255, 255, 0.08);

    border-radius: 18px;
}


.guess-status {

    padding: 18px;

    border-radius: 10px;

    background:
        rgba(139, 92, 246, 0.10);

    color: #fff;

    font-weight: 600;

    line-height: 1.5;
}


.guess-game input {

    width: 100%;

    box-sizing: border-box;

    padding: 15px;

    border-radius: 10px;

    border:
        1px solid
        rgba(255, 255, 255, 0.12);

    background:
        rgba(255, 255, 255, 0.06);

    color: #fff;

    font-size: 17px;

    text-align: center;

    outline: none;
}


.guess-game input:focus {

    border-color: #8b5cf6;
}


.guess-game .primary-btn {

    width: 100%;

    border: none;

    cursor: pointer;
}


.guess-attempts {

    color: #b8b8c7;

    font-size: 16px;
}


.guess-attempts span {

    color: #8b5cf6;

    font-weight: 700;
}


.guess-game .lesson-nav-btn {

    cursor: pointer;

    border: none;
}

/* =============================
   INTERACTIVE TO-DO LIST
============================= */

.todo-app {
    max-width: 700px;
    margin: 25px auto 0;
    padding: 30px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 18px;
}

.todo-input-row {
    display: flex;
    gap: 12px;
}

.todo-input-row input {
    flex: 1;
    min-width: 0;
    padding: 15px;
    border-radius: 10px;
    border: 1px solid rgba(255, 255, 255, 0.12);
    background: rgba(255, 255, 255, 0.06);
    color: #fff;
    font-size: 16px;
    outline: none;
}

.todo-input-row input:focus {
    border-color: #8b5cf6;
}

.todo-input-row .primary-btn {
    border: none;
    cursor: pointer;
    white-space: nowrap;
}

.todo-actions {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin: 25px 0 15px;
    color: #b8b8c7;
}

.todo-actions .lesson-nav-btn {
    cursor: pointer;
    border: none;
}

.todo-list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.todo-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 15px;
    padding: 15px 18px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 12px;
}

.todo-item.completed {
    opacity: 0.6;
}

.todo-item.completed .todo-text {
    text-decoration: line-through;
}

.todo-text {
    flex: 1;
    color: #fff;
    line-height: 1.5;
    word-break: break-word;
}

.todo-buttons {
    display: flex;
    gap: 8px;
}

.todo-complete,
.todo-delete {
    padding: 8px 12px;
    border-radius: 8px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    cursor: pointer;
    color: #fff;
    background: rgba(255, 255, 255, 0.06);
}

.todo-complete:hover {
    border-color: #22c55e;
}

.todo-delete:hover {
    border-color: #ef4444;
}

.todo-empty {
    padding: 25px;
    text-align: center;
    color: #8f8fa0;
}

@media (max-width: 600px) {

    .todo-app {
        padding: 20px;
    }

    .todo-input-row {
        flex-direction: column;
    }

    .todo-input-row .primary-btn {
        width: 100%;
    }

    .todo-item {
        align-items: flex-start;
        flex-direction: column;
    }

    .todo-buttons {
        width: 100%;
    }

    .todo-complete,
    .todo-delete {
        flex: 1;
    }
}

/* =============================
   INTERACTIVE QUIZ APP
============================= */

.quiz-app {
    max-width: 750px;
    margin: 25px auto 0;
    padding: 30px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 18px;
}

.quiz-top {
    display: flex;
    justify-content: space-between;
    gap: 15px;
    margin-bottom: 25px;
    color: #b8b8c7;
    font-weight: 600;
}

.quiz-question-box {
    padding: 25px;
    background: rgba(255, 255, 255, 0.04);
    border-radius: 15px;
}

.quiz-question-box h3 {
    font-size: 23px;
    line-height: 1.5;
    margin-bottom: 25px;
}

.quiz-options {
    display: grid;
    gap: 12px;
}

.quiz-option {
    width: 100%;
    padding: 15px 18px;
    text-align: left;
    border-radius: 10px;
    border: 1px solid rgba(255, 255, 255, 0.10);
    background: rgba(255, 255, 255, 0.05);
    color: #fff;
    cursor: pointer;
    font-size: 16px;
    transition: 0.2s;
}

.quiz-option:hover {
    border-color: #8b5cf6;
    transform: translateY(-2px);
}

.quiz-option.correct {
    border-color: #22c55e;
    background: rgba(34, 197, 94, 0.12);
}

.quiz-option.wrong {
    border-color: #ef4444;
    background: rgba(239, 68, 68, 0.12);
}

.quiz-option:disabled {
    cursor: not-allowed;
}

.quiz-feedback {
    min-height: 25px;
    margin-top: 20px;
    font-weight: 600;
}

#quiz-next-btn {
    width: 100%;
    margin-top: 20px;
    border: none;
    cursor: pointer;
}

.quiz-result-card {
    text-align: center;
}

.quiz-final-score {
    margin: 25px 0;
    font-size: 55px;
    font-weight: 800;
    color: #8b5cf6;
}

.quiz-result-card .primary-btn {
    border: none;
    cursor: pointer;
}

@media (max-width: 600px) {

    .quiz-app {
        padding: 20px;
    }

    .quiz-question-box {
        padding: 20px;
    }

    .quiz-question-box h3 {
        font-size: 19px;
    }

    .quiz-top {
        flex-direction: column;
    }
}

/* =============================
   PYSTEP DASHBOARD
============================= */

.dashboard-section {
    max-width: 1100px;
    margin: 80px auto;
    padding: 0 20px;
}

.section-heading {
    text-align: center;
    margin-bottom: 40px;
}

.section-label {
    display: inline-block;
    margin-bottom: 10px;
    color: #8b5cf6;
    font-size: 13px;
    font-weight: 800;
    letter-spacing: 2px;
}

.section-heading h2 {
    font-size: 36px;
    margin-bottom: 12px;
}

.section-heading p {
    color: #a9a9ba;
    line-height: 1.6;
}

.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 22px;
}

.dashboard-card {
    padding: 30px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 20px;
    transition: 0.3s;
}

.dashboard-card:hover {
    transform: translateY(-5px);
    border-color: rgba(139, 92, 246, 0.5);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.2);
}

.dashboard-icon {
    width: 55px;
    height: 55px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 22px;
    border-radius: 15px;
    background: rgba(139, 92, 246, 0.12);
    font-size: 27px;
}

.dashboard-card h3 {
    font-size: 22px;
    margin-bottom: 12px;
}

.dashboard-card p {
    color: #b8b8c7;
    line-height: 1.7;
    margin-bottom: 25px;
}

.progress-info {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin: 20px 0 10px;
}

.progress-info strong {
    font-size: 25px;
    color: #8b5cf6;
}

.progress-info span {
    color: #a9a9ba;
    font-size: 14px;
}

.progress-bar {
    width: 100%;
    height: 10px;
    overflow: hidden;
    margin-bottom: 25px;
    border-radius: 20px;
    background: rgba(255, 255, 255, 0.08);
}

.progress-fill {
    width: 0%;
    height: 100%;
    border-radius: 20px;
    background: #8b5cf6;
    transition: width 0.5s ease;
}

.dashboard-btn {
    display: inline-block;
    padding: 11px 18px;
    border-radius: 10px;
    background: rgba(139, 92, 246, 0.12);
    color: #fff;
    text-decoration: none;
    border: 1px solid rgba(139, 92, 246, 0.25);
    transition: 0.2s;
}

.dashboard-btn:hover {
    background: rgba(139, 92, 246, 0.22);
}

@media (max-width: 800px) {

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

    .section-heading h2 {
        font-size: 30px;
    }
}

/* =============================
   LESSON COMPLETION
============================= */

.lesson-complete-box {
    margin: 35px 0;
    padding: 25px;
    text-align: center;
    background: rgba(139, 92, 246, 0.08);
    border: 1px solid rgba(139, 92, 246, 0.25);
    border-radius: 16px;
}

.lesson-complete-box p {
    margin-bottom: 15px;
    color: #b8b8c7;
}

.complete-lesson-btn {
    padding: 13px 22px;
    border: none;
    border-radius: 10px;
    background: #8b5cf6;
    color: #fff;
    font-size: 15px;
    font-weight: 700;
    cursor: pointer;
    transition: 0.2s;
}

.complete-lesson-btn:hover {
    transform: translateY(-2px);
}

.complete-lesson-btn.completed {
    background: #22c55e;
    cursor: default;
}

/* =============================
   DASHBOARD PAGE
============================= */

.dashboard-page-header {
    max-width: 1100px;
    margin: 70px auto 40px;
    padding: 0 20px;
}

.dashboard-page-header > span {
    color: #8b5cf6;
    font-size: 13px;
    font-weight: 800;
    letter-spacing: 2px;
}

.dashboard-page-header h1 {
    margin: 10px 0;
    font-size: 42px;
}

.dashboard-page-header p {
    color: #a9a9ba;
    line-height: 1.7;
}


.main-dashboard {
    max-width: 1100px;
    margin: 0 auto 80px;
    padding: 0 20px;
}


/* OVERVIEW */

.dashboard-overview {
    display: grid;
    grid-template-columns:
        repeat(4, 1fr);
    gap: 18px;
    margin-bottom: 25px;
}

.overview-card {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 22px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 16px;
}

.overview-icon {
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    border-radius: 13px;
    background: rgba(139, 92, 246, 0.12);
    font-size: 23px;
}

.overview-card span {
    display: block;
    margin-bottom: 5px;
    color: #a9a9ba;
    font-size: 13px;
}

.overview-card strong {
    font-size: 21px;
}


/* PANELS */

.dashboard-panel {
    margin-bottom: 25px;
    padding: 30px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 18px;
}

.panel-heading {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 20px;
    margin-bottom: 25px;
}

.panel-label {
    color: #8b5cf6;
    font-size: 12px;
    font-weight: 800;
    letter-spacing: 1.5px;
}

.panel-heading h2 {
    margin-top: 6px;
    font-size: 25px;
}

#dashboard-progress-text {
    color: #b8b8c7;
}


/* PROGRESS */

.dashboard-progress-bar {
    width: 100%;
    height: 14px;
    overflow: hidden;
    border-radius: 20px;
    background: rgba(255, 255, 255, 0.08);
}

.dashboard-progress-fill {
    width: 0%;
    height: 100%;
    border-radius: 20px;
    background: #8b5cf6;
    transition: width 0.5s ease;
}


/* LESSON STATUS */

.lesson-status-list {
    display: grid;
    grid-template-columns:
        repeat(2, 1fr);
    gap: 12px;
}

.lesson-status-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 15px;
    padding: 16px 18px;
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.07);
}

.lesson-status-item strong {
    font-size: 15px;
}

.lesson-status-item span {
    color: #a9a9ba;
    font-size: 13px;
}

.lesson-status-item.completed {
    border-color: rgba(34, 197, 94, 0.35);
}

.lesson-status-item.completed span {
    color: #22c55e;
}


/* QUICK ACTIONS */

.dashboard-actions {
    display: grid;
    grid-template-columns:
        repeat(3, 1fr);
    gap: 15px;
}

.dashboard-action {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 20px;
    color: #fff;
    text-decoration: none;
    border-radius: 14px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.08);
    transition: 0.2s;
}

.dashboard-action:hover {
    transform: translateY(-3px);
    border-color: rgba(139, 92, 246, 0.5);
}

.dashboard-action > span {
    font-size: 27px;
}

.dashboard-action strong {
    display: block;
    margin-bottom: 5px;
}

.dashboard-action p {
    margin: 0;
    color: #a9a9ba;
    font-size: 13px;
}


/* MOBILE */

@media (max-width: 850px) {

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

    .dashboard-actions {
        grid-template-columns: 1fr;
    }

}


@media (max-width: 600px) {

    .dashboard-page-header h1 {
        font-size: 32px;
    }

    .dashboard-overview {
        grid-template-columns: 1fr;
    }

    .dashboard-panel {
        padding: 22px;
    }

    .lesson-status-list {
        grid-template-columns: 1fr;
    }

    .panel-heading {
        align-items: flex-start;
        flex-direction: column;
    }

}

/* Dashboard Header */

.dashboard-page-header {
    position: relative;
    padding: 90px 20px 70px;
    text-align: center;
    overflow: hidden;
    background:
        radial-gradient(
            circle at 50% 0%,
            rgba(139, 92, 246, 0.18),
            transparent 55%
        );
}

.dashboard-header-content {
    position: relative;
    z-index: 1;
    max-width: 800px;
    margin: auto;
}

.dashboard-label {
    display: inline-block;
    margin-bottom: 15px;
    color: #8b5cf6;
    font-size: 13px;
    font-weight: 800;
    letter-spacing: 2px;
}

.dashboard-page-header h1 {
    margin: 0 0 15px;
    font-size: 48px;
    font-weight: 800;
}

.dashboard-page-header p {
    max-width: 650px;
    margin: auto;
    color: #a9a9ba;
    font-size: 17px;
    line-height: 1.7;
}


/* Footer */

.footer {
    margin-top: 80px;
    padding: 50px 20px 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    background: rgba(0, 0, 0, 0.20);
}

.footer-content {
    max-width: 1100px;
    margin: auto;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 40px;
}

.footer-brand h2 {
    margin: 0 0 8px;
    font-size: 26px;
    color: #fff;
}

.footer-brand p {
    margin: 0;
    color: #8f8fa0;
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
}

.footer-links a {
    color: #a9a9ba;
    text-decoration: none;
    transition: 0.2s;
}

.footer-links a:hover {
    color: #8b5cf6;
}

.footer-bottom {
    max-width: 1100px;
    margin: 40px auto 0;
    padding-top: 20px;
    text-align: center;
    border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.footer-bottom p {
    margin: 0;
    color: #77778a;
    font-size: 13px;
}


/* Mobile */

@media (max-width: 600px) {

    .dashboard-page-header {
        padding: 65px 20px 50px;
    }

    .dashboard-page-header h1 {
        font-size: 36px;
    }

    .dashboard-page-header p {
        font-size: 15px;
    }

    .footer-content {
        flex-direction: column;
    }

    .footer-links {
        flex-direction: column;
        gap: 12px;
    }
}