/* =========================================
   ROOT VARIABLES
========================================= */

:root {

    --bg: #f5f6f8;
    --surface: #ffffff;
    --surface-soft: #f8f9fb;

    --text: #111318;
    --muted: #70747d;

    --border: #e3e5e9;

    --accent: #111318;

    --sidebar: #ffffff;

    --radius: 18px;

    --sidebar-width: 280px;

    --shadow:
        0 10px 35px rgba(0, 0, 0, 0.06);
}


body.dark {

    --bg: #0d0f12;
    --surface: #15181d;
    --surface-soft: #1b1f25;

    --text: #f5f6f8;
    --muted: #9ca1aa;

    --border: #2a2e35;

    --accent: #ffffff;

    --sidebar: #111419;

    --shadow:
        0 10px 35px rgba(0, 0, 0, 0.25);
}



/* =========================================
   GLOBAL
========================================= */

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {

    margin: 0;

    background: var(--bg);

    color: var(--text);

    font-family:
        Inter,
        -apple-system,
        BlinkMacSystemFont,
        "Segoe UI",
        Arial,
        sans-serif;

    transition:
        background 0.25s ease,
        color 0.25s ease;
}

a {
    text-decoration: none;
    color: inherit;
}



/* =========================================
   SIDEBAR
========================================= */

.sidebar {

    position: fixed;

    left: 0;
    top: 0;

    width: var(--sidebar-width);

    height: 100vh;

    background: var(--sidebar);

    border-right: 1px solid var(--border);

    padding: 30px 20px;

    overflow-y: auto;

    z-index: 1000;
}


.brand {

    padding: 0 10px 30px;

    border-bottom:
        1px solid var(--border);
}


.brand-main {

    font-size: 20px;

    font-weight: 800;

    letter-spacing: 1px;
}


.brand-sub {

    margin-top: 5px;

    color: var(--muted);

    font-size: 12px;

    text-transform: uppercase;

    letter-spacing: 1px;
}


.sidebar-section {

    padding-top: 25px;
}


.sidebar-title {

    font-size: 10px;

    font-weight: 800;

    letter-spacing: 1.5px;

    color: var(--muted);

    padding: 0 10px 10px;
}


.nav-link {

    display: block;

    padding: 12px 10px;

    margin: 3px 0;

    border-radius: 9px;

    font-size: 14px;

    color: var(--muted);

    transition: 0.2s ease;
}


.nav-link:hover {

    background: var(--surface-soft);

    color: var(--text);
}


.nav-link.active {

    background: var(--text);

    color: var(--bg);

    font-weight: 700;
}



/* =========================================
   ROADMAP
========================================= */

.roadmap-item {

    display: flex;

    align-items: center;

    gap: 10px;

    padding: 9px 10px;

    color: var(--muted);

    font-size: 13px;

    border-radius: 8px;

    margin-bottom: 2px;
}


.roadmap-item span {

    width: 25px;

    font-size: 10px;

    font-weight: 700;

    color: var(--muted);
}


.roadmap-item.active {

    color: var(--text);

    font-weight: 700;

    background: var(--surface-soft);
}



/* =========================================
   SIDEBAR PROGRESS
========================================= */

.sidebar-progress {

    margin-top: 30px;

    padding: 15px;

    background: var(--surface-soft);

    border: 1px solid var(--border);

    border-radius: 12px;
}


.progress-top {

    display: flex;

    justify-content: space-between;

    font-size: 9px;

    font-weight: 800;

    color: var(--muted);

    margin-bottom: 9px;
}


.progress {

    height: 5px;

    background: var(--border);
}


.progress-bar {

    background: var(--text);
}



/* =========================================
   MAIN CONTENT
========================================= */

.main-content {

    margin-left: var(--sidebar-width);

    min-height: 100vh;

    padding: 30px 45px;
}



/* =========================================
   TOPBAR
========================================= */

.topbar {

    display: flex;

    justify-content: space-between;

    align-items: center;

    gap: 30px;

    margin-bottom: 35px;
}


.topbar-label {

    color: var(--muted);

    font-size: 10px;

    font-weight: 800;

    letter-spacing: 1.5px;

    margin-bottom: 7px;
}


.topbar h1 {

    font-size: 26px;

    margin: 0;

    font-weight: 750;
}


.topbar-actions {

    display: flex;

    gap: 10px;
}


.search-box {

    width: 230px;

    border: 1px solid var(--border);

    background: var(--surface);

    color: var(--text);

    border-radius: 10px;

    padding: 11px 14px;

    outline: none;
}


.search-box:focus {

    border-color: var(--text);
}


.theme-button,
#themeBtnMobile,
#menuBtn {

    border: 1px solid var(--border);

    background: var(--surface);

    color: var(--text);

    border-radius: 10px;

    padding: 10px 14px;

    font-size: 11px;

    font-weight: 700;

    cursor: pointer;

    transition: 0.2s ease;
}


.theme-button:hover,
#themeBtnMobile:hover,
#menuBtn:hover {

    background: var(--text);

    color: var(--bg);
}



/* =========================================
   HERO
========================================= */

.hero-section {

    display: grid;

    grid-template-columns: 1fr 1fr;

    gap: 25px;

    background: var(--surface);

    border: 1px solid var(--border);

    border-radius: var(--radius);

    padding: 45px;

    box-shadow: var(--shadow);

    margin-bottom: 70px;
}


.hero-content {

    display: flex;

    flex-direction: column;

    justify-content: center;

    align-items: flex-start;
}


.hero-tag,
.lesson-tag {

    display: inline-block;

    font-size: 10px;

    font-weight: 800;

    letter-spacing: 1.5px;

    color: var(--muted);

    margin-bottom: 12px;
}


.hero-content h2 {

    font-size: 42px;

    line-height: 1.08;

    margin-bottom: 18px;

    font-weight: 800;
}


.hero-content p {

    max-width: 550px;

    color: var(--muted);

    line-height: 1.7;

    margin-bottom: 25px;
}


.primary-button {

    display: inline-flex;

    align-items: center;

    justify-content: center;

    border: none;

    background: var(--text);

    color: var(--bg);

    border-radius: 10px;

    padding: 12px 20px;

    font-size: 11px;

    font-weight: 800;

    letter-spacing: 0.7px;

    cursor: pointer;

    transition: 0.25s ease;
}


.primary-button:hover {

    transform: translateY(-2px);

    box-shadow:
        0 10px 25px rgba(0,0,0,0.12);
}



/* =========================================
   CODE WINDOW
========================================= */

.code-window {

    background: #0d0f12;

    border-radius: 14px;

    overflow: hidden;

    border: 1px solid #292d33;
}


.code-top {

    height: 38px;

    display: flex;

    align-items: center;

    gap: 6px;

    padding: 0 15px;

    border-bottom: 1px solid #292d33;
}


.code-top span {

    width: 7px;

    height: 7px;

    border-radius: 50%;

    background: #5d626a;
}


.code-window pre {

    padding: 25px;

    margin: 0;

    color: #e8eaed;

    font-size: 14px;

    line-height: 1.8;

    overflow-x: auto;
}



/* =========================================
   SECTIONS
========================================= */

.section-block {

    margin-bottom: 75px;
}


.section-heading {

    display: flex;

    justify-content: space-between;

    margin-bottom: 25px;
}


.section-label {

    color: var(--muted);

    font-size: 9px;

    font-weight: 800;

    letter-spacing: 1.5px;

    margin-bottom: 7px;
}


.section-heading h2 {

    font-size: 28px;

    margin: 0;

    font-weight: 800;
}


.section-heading p {

    color: var(--muted);

    margin-top: 8px;
}



/* =========================================
   INTRO CARD
========================================= */

.intro-card {

    display: flex;

    gap: 25px;

    padding: 30px;

    background: var(--surface);

    border: 1px solid var(--border);

    border-radius: var(--radius);
}


.intro-number {

    font-size: 42px;

    font-weight: 900;

    color: var(--border);
}


.intro-card h3 {

    font-size: 20px;

    margin-bottom: 10px;
}


.intro-card p {

    color: var(--muted);

    line-height: 1.7;

    margin-bottom: 20px;
}


.intro-points {

    display: flex;

    flex-wrap: wrap;

    gap: 8px;
}


.intro-points span {

    border: 1px solid var(--border);

    padding: 7px 10px;

    border-radius: 7px;

    font-size: 11px;

    color: var(--muted);
}



/* =========================================
   DAY GRID
========================================= */

.day-grid {

    display: grid;

    grid-template-columns:
        repeat(4, minmax(0, 1fr));

    gap: 15px;
}


.day-card {

    background: var(--surface);

    border: 1px solid var(--border);

    border-radius: var(--radius);

    padding: 22px;

    transition: 0.25s ease;
}


.day-card:hover {

    transform: translateY(-4px);

    box-shadow: var(--shadow);
}


.day-number {

    color: var(--muted);

    font-size: 10px;

    font-weight: 800;

    letter-spacing: 1px;

    margin-bottom: 15px;
}


.day-card h3 {

    font-size: 17px;

    margin-bottom: 10px;
}


.day-card p {

    font-size: 13px;

    line-height: 1.6;

    color: var(--muted);

    min-height: 60px;
}


.day-meta {

    display: flex;

    gap: 8px;

    margin: 15px 0;
}


.day-meta span {

    font-size: 9px;

    font-weight: 700;

    border: 1px solid var(--border);

    padding: 6px 8px;

    border-radius: 6px;

    color: var(--muted);
}


.day-footer {

    border-top: 1px solid var(--border);

    padding-top: 15px;

    display: flex;

    justify-content: space-between;

    align-items: center;
}


.day-footer a {

    font-size: 10px;

    font-weight: 800;
}


.completed {

    color: #4d8b61;

    font-size: 9px;

    font-weight: 800;
}


.locked-card {

    opacity: 0.55;
}



/* =========================================
   FULL LESSON
========================================= */

.day-lesson {

    max-width: 1050px;

    margin: 0 auto 90px;
}


.lesson-header {

    display: flex;

    justify-content: space-between;

    align-items: flex-start;

    gap: 20px;

    margin-bottom: 30px;
}


.lesson-header h2 {

    font-size: 34px;

    margin: 0 0 8px;

    font-weight: 800;
}


.lesson-header p {

    margin: 0;

    color: var(--muted);
}


.language-btn {

    border: 1px solid var(--border);

    background: var(--surface);

    color: var(--text);

    padding: 11px 18px;

    border-radius: 10px;

    font-size: 11px;

    font-weight: 800;

    cursor: pointer;

    white-space: nowrap;

    transition: 0.25s ease;
}


.language-btn:hover {

    background: var(--text);

    color: var(--bg);

    transform: translateY(-2px);
}



/* =========================================
   LESSON CARD
========================================= */

.lesson-card {

    background: var(--surface);

    border: 1px solid var(--border);

    border-radius: var(--radius);

    padding: 32px;

    margin-bottom: 18px;

    box-shadow:
        0 4px 20px rgba(0,0,0,0.025);
}


.topic-number {

    color: var(--muted);

    font-size: 10px;

    font-weight: 900;

    letter-spacing: 1.5px;

    margin-bottom: 10px;
}


.lesson-card h3 {

    font-size: 23px;

    margin-bottom: 18px;

    font-weight: 800;
}


.lesson-card p {

    color: var(--muted);

    line-height: 1.8;

    font-size: 15px;
}


.lesson-list {

    margin: 0;

    padding-left: 20px;
}


.lesson-list li {

    color: var(--muted);

    line-height: 1.8;

    margin-bottom: 12px;
}



/* =========================================
   COMPARISON TABLE
========================================= */

.comparison-table {

    border: 1px solid var(--border);

    border-radius: 12px;

    overflow: hidden;

    margin-top: 25px;
}


.comparison-header,
.comparison-row {

    display: grid;

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


.comparison-header {

    background: var(--text);

    color: var(--bg);

    font-weight: 800;
}


.comparison-header div,
.comparison-row div {

    padding: 15px;

    border-right: 1px solid var(--border);

    font-size: 13px;
}


.comparison-header div:last-child,
.comparison-row div:last-child {

    border-right: none;
}


.comparison-row {

    border-top: 1px solid var(--border);
}


.comparison-row div {

    color: var(--muted);

    line-height: 1.6;
}



/* =========================================
   IMPORTANT NOTE
========================================= */

.important-note {

    border: 1px solid var(--border);

    background: var(--surface-soft);

    padding: 25px;

    border-radius: 14px;

    margin: 20px 0;
}


.note-label {

    display: block;

    font-size: 9px;

    font-weight: 900;

    letter-spacing: 1.5px;

    margin-bottom: 10px;
}


.important-note p {

    margin: 0;

    color: var(--muted);

    line-height: 1.7;
}



/* =========================================
   LESSON SUMMARY
========================================= */

.lesson-summary {

    display: flex;

    justify-content: space-between;

    align-items: center;

    background: var(--text);

    color: var(--bg);

    border-radius: var(--radius);

    padding: 30px;

    margin-top: 30px;
}


.summary-label {

    font-size: 9px;

    font-weight: 900;

    letter-spacing: 1.5px;
}


.lesson-summary h3 {

    margin: 7px 0 0;

    font-size: 22px;
}


.summary-stats {

    display: flex;

    gap: 35px;
}


.summary-stats div {

    text-align: center;
}


.summary-stats strong {

    display: block;

    font-size: 17px;
}


.summary-stats span {

    display: block;

    font-size: 9px;

    opacity: 0.6;

    margin-top: 4px;
}



/* =========================================
   MCQ TEST
========================================= */

.test-card {

    display: flex;

    align-items: center;

    justify-content: space-between;

    gap: 25px;

    background: var(--surface);

    border: 1px solid var(--border);

    border-radius: var(--radius);

    padding: 28px;
}


.test-number {

    color: var(--muted);

    font-size: 9px;

    font-weight: 900;

    letter-spacing: 1.5px;

    margin-bottom: 8px;
}


.test-info h3 {

    font-size: 20px;

    margin-bottom: 5px;
}


.test-info p {

    color: var(--muted);

    margin: 0;

    font-size: 13px;
}


.test-stats {

    display: flex;

    gap: 25px;
}


.test-stats div {

    text-align: center;
}


.test-stats strong {

    display: block;

    font-size: 18px;
}


.test-stats span {

    display: block;

    font-size: 9px;

    color: var(--muted);

    margin-top: 3px;
}



/* =========================================
   TEST CONTAINER
========================================= */

.test-container {

    margin-top: 20px;

    background: var(--surface);

    border: 1px solid var(--border);

    border-radius: var(--radius);

    padding: 30px;
}


.test-top {

    display: flex;

    justify-content: space-between;

    color: var(--muted);

    font-size: 11px;

    font-weight: 800;

    margin-bottom: 25px;
}


#timer {

    color: var(--text);
}


.question-box h3 {

    font-size: 21px;

    line-height: 1.5;

    margin-bottom: 25px;
}


.option {

    display: block;

    width: 100%;

    text-align: left;

    padding: 15px;

    margin-bottom: 10px;

    border: 1px solid var(--border);

    background: var(--surface);

    color: var(--text);

    border-radius: 10px;

    cursor: pointer;

    transition: 0.2s ease;
}


.option:hover {

    border-color: var(--text);

    background: var(--surface-soft);
}


.option.selected {

    background: var(--text);

    color: var(--bg);

    border-color: var(--text);
}


.test-controls {

    margin-top: 25px;

    text-align: right;
}



/* =========================================
   RESULT
========================================= */

.test-result {

    text-align: center;

    padding: 50px;

    margin-top: 20px;

    background: var(--surface);

    border: 1px solid var(--border);

    border-radius: var(--radius);
}


.result-label {

    font-size: 9px;

    font-weight: 900;

    letter-spacing: 1.5px;

    color: var(--muted);

    margin-bottom: 10px;
}


.test-result h2 {

    font-size: 32px;

    margin-bottom: 10px;
}


.test-result p {

    color: var(--muted);

    margin-bottom: 25px;
}



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

.practice-card {

    padding: 40px;

    background: var(--surface);

    border: 1px solid var(--border);

    border-radius: var(--radius);

    text-align: center;
}


.practice-card h3 {

    font-size: 20px;
}


.practice-card p {

    color: var(--muted);

    margin: 0;
}



/* =========================================
   FOOTER
========================================= */

.footer {

    border-top: 1px solid var(--border);

    padding: 30px 0;

    display: flex;

    justify-content: space-between;

    color: var(--muted);

    font-size: 11px;

    margin-top: 50px;
}


.footer div {

    font-weight: 800;

    color: var(--text);
}



/* =========================================
   MOBILE HEADER
========================================= */

.mobile-header {

    display: none;
}



/* =========================================
   SEARCH HIDDEN
========================================= */

.search-hidden {

    display: none !important;
}



/* =========================================
   RESPONSIVE
========================================= */

@media (max-width: 1100px) {

    .main-content {

        padding: 25px;
    }

    .day-grid {

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

    .hero-section {

        grid-template-columns: 1fr;
    }

}


@media (max-width: 800px) {

    .sidebar {

        transform: translateX(-100%);

        transition: 0.3s ease;
    }


    .sidebar.open {

        transform: translateX(0);
    }


    .main-content {

        margin-left: 0;

        padding: 20px;
    }


    .mobile-header {

        display: flex;

        justify-content: space-between;

        align-items: center;

        padding: 15px 20px;

        background: var(--surface);

        border-bottom: 1px solid var(--border);

        position: sticky;

        top: 0;

        z-index: 900;
    }


    .mobile-brand {

        font-weight: 900;

        letter-spacing: 1px;
    }


    .mobile-actions {

        display: flex;

        gap: 6px;
    }


    .topbar {

        flex-direction: column;

        align-items: flex-start;
    }


    .topbar-actions {

        width: 100%;
    }


    .search-box {

        flex: 1;

        width: auto;
    }


    .hero-section {

        padding: 30px;
    }


    .hero-content h2 {

        font-size: 34px;
    }


    .test-card {

        flex-direction: column;

        align-items: flex-start;
    }

}


@media (max-width: 600px) {

    .day-grid {

        grid-template-columns: 1fr;
    }


    .hero-section {

        padding: 25px;
    }


    .hero-content h2 {

        font-size: 30px;
    }


    .lesson-header {

        flex-direction: column;
    }


    .language-btn {

        width: 100%;
    }


    .lesson-card {

        padding: 22px;
    }


    .comparison-header div,
    .comparison-row div {

        padding: 11px;

        font-size: 11px;
    }


    .lesson-summary {

        flex-direction: column;

        align-items: flex-start;

        gap: 25px;
    }


    .summary-stats {

        width: 100%;

        justify-content: space-between;

        gap: 10px;
    }


    .footer {

        flex-direction: column;

        gap: 8px;
    }

}


@media (max-width: 450px) {

    .main-content {

        padding: 15px;
    }


    .topbar-actions {

        flex-direction: column;
    }


    .search-box {

        width: 100%;
    }


    .theme-button {

        width: 100%;
    }


    .hero-content h2 {

        font-size: 27px;
    }


    .code-window pre {

        font-size: 11px;

        padding: 18px;
    }

}

/* =========================================
   DAY 02 DATA TYPES
========================================= */

.lesson-code {
    margin-top: 20px;
}


.output-box {

    margin-top: 18px;

    padding: 14px 16px;

    border: 1px solid var(--border);

    border-radius: 10px;

    background: var(--surface-soft);

    color: var(--muted);

    line-height: 1.6;
}


.output-box strong {

    color: var(--text);

    margin-right: 8px;
}


.output-box code {

    color: var(--text);

    font-weight: 700;

    font-size: 13px;
}


@media (max-width: 600px) {

    .output-box {

        font-size: 13px;

    }

}




/* =========================================
   PREMIUM SOCIAL LINKS - BRAND COLORS
========================================= */

.social-links {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-left: auto;
    margin-right: 18px;
}

.social-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;

    padding: 9px 13px;

    border: 1px solid var(--border);
    border-radius: 9px;

    background: var(--surface);
    color: var(--text);

    text-decoration: none;

    font-size: 10px;
    font-weight: 800;
    letter-spacing: 0.5px;
    text-transform: uppercase;

    transition: all 0.25s ease;
}

.social-link svg {
    width: 17px;
    height: 17px;

    fill: none;
    stroke: currentColor;
    stroke-width: 1.8;
    stroke-linecap: round;
    stroke-linejoin: round;

    transition: transform 0.25s ease;
}


/* =========================================
   INSTAGRAM
========================================= */

.social-link:nth-child(1) {
    color: #E1306C;
}

.social-link:nth-child(1):hover {
    background: #E1306C;
    color: #ffffff;
    border-color: #E1306C;
}


/* =========================================
   YOUTUBE
========================================= */

.social-link:nth-child(2) {
    color: #FF0000;
}

.social-link:nth-child(2):hover {
    background: #FF0000;
    color: #ffffff;
    border-color: #FF0000;
}


/* =========================================
   LINKEDIN
========================================= */

.social-link:nth-child(3) {
    color: #0A66C2;
}

.social-link:nth-child(3):hover {
    background: #0A66C2;
    color: #ffffff;
    border-color: #0A66C2;
}


/* =========================================
   HOVER EFFECT
========================================= */

.social-link:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.12);
}

.social-link:hover svg {
    transform: scale(1.12);
}


/* YouTube play triangle */
.social-link:nth-child(2) svg polygon {
    fill: currentColor;
    stroke: none;
}


/* =========================================
   MOBILE
========================================= */

@media (max-width: 1000px) {

    .social-link span {
        display: none;
    }

    .social-link {
        width: 38px;
        height: 38px;
        padding: 0;
        justify-content: center;
    }

    .social-link svg {
        width: 18px;
        height: 18px;
    }
}

@media (max-width: 600px) {

    .social-links {
        display: none;
    }

}