/* =========================================
   RESET
========================================= */

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

html {
    scroll-behavior: smooth;
}

body {
    font-family:
        Tahoma,
        Arial,
        sans-serif;

    background: #ffffff;
    color: #172033;

    line-height: 1.7;

    overflow-x: hidden;
}

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

button,
input,
textarea,
select {
    font-family: inherit;
}

button {
    cursor: pointer;
}


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

:root {

    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #eff6ff;
    --primary-soft: #dbeafe;

    --dark: #172033;
    --gray: #667085;

    --light: #f7f9fc;

    --border: #e5eaf2;

    --white: #ffffff;

    --danger: #dc2626;

    --shadow:
        0 12px 35px rgba(37, 99, 235, 0.09);

    --shadow-hover:
        0 20px 45px rgba(37, 99, 235, 0.16);

    --radius: 18px;
}


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

.container {
    width: min(
        1150px,
        calc(100% - 40px)
    );

    margin: auto;
}

.hidden {
    display: none !important;
}


/* =========================================
   BUTTONS
========================================= */

.btn {
    display: inline-flex;

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

    border: 0;

    border-radius: 11px;

    padding: 11px 20px;

    font-size: 15px;

    font-weight: 700;

    transition:
        transform 0.25s ease,
        background 0.25s ease,
        box-shadow 0.25s ease,
        color 0.25s ease;

    position: relative;

    overflow: hidden;
}

.btn::after {
    content: "";

    position: absolute;

    width: 0;
    height: 0;

    border-radius: 50%;

    background: rgba(255,255,255,0.2);

    transform: translate(-50%, -50%);

    transition:
        width 0.4s ease,
        height 0.4s ease;
}

.btn:hover::after {
    width: 300px;
    height: 300px;
}

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

.btn-primary {
    background: var(--primary);
    color: white;

    box-shadow:
        0 7px 18px rgba(37, 99, 235, 0.2);
}

.btn-primary:hover {
    background: var(--primary-dark);

    box-shadow:
        0 12px 25px rgba(37, 99, 235, 0.28);
}

.btn-outline {
    border: 1px solid var(--primary);

    color: var(--primary);

    background: transparent;
}

.btn-outline:hover {
    background: var(--primary-light);
}

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

.btn-large {
    padding: 14px 27px;
    font-size: 16px;
}


/* =========================================
   LOGO
========================================= */

.logo {
    display: flex;

    align-items: center;

    gap: 10px;

    font-size: 21px;

    font-weight: 800;
}

.logo-icon {
    width: 42px;
    height: 42px;

    display: flex;

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

    background:
        linear-gradient(
            135deg,
            var(--primary),
            #60a5fa
        );

    color: white;

    border-radius: 13px;

    font-weight: 800;

    box-shadow:
        0 8px 20px rgba(37,99,235,0.22);
}


/* =========================================
   NAVBAR
========================================= */

.navbar {
    position: sticky;

    top: 0;

    z-index: 100;

    background:
        rgba(255,255,255,0.94);

    backdrop-filter:
        blur(12px);

    border-bottom:
        1px solid rgba(229,234,242,0.9);
}

.nav-content {
    min-height: 74px;

    display: flex;

    align-items: center;

    justify-content: space-between;

    gap: 25px;
}

.nav-links {
    display: flex;

    align-items: center;

    gap: 28px;
}

.nav-links a {
    color: var(--gray);

    font-size: 14px;

    position: relative;

    transition: color 0.25s ease;
}

.nav-links a::after {
    content: "";

    position: absolute;

    bottom: -8px;

    right: 0;

    width: 0;

    height: 2px;

    background: var(--primary);

    transition: width 0.25s ease;
}

.nav-links a:hover {
    color: var(--primary);
}

.nav-links a:hover::after {
    width: 100%;
}

.nav-buttons {
    display: flex;
    gap: 10px;
}


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

.hero {
    padding: 90px 0;

    background:
        radial-gradient(
            circle at 10% 20%,
            #dbeafe 0,
            transparent 28%
        ),

        linear-gradient(
            135deg,
            #f5f9ff,
            #ffffff
        );

    position: relative;

    overflow: hidden;
}

.hero::before {
    content: "";

    position: absolute;

    width: 300px;
    height: 300px;

    border-radius: 50%;

    background:
        rgba(37,99,235,0.07);

    top: -120px;
    left: -100px;

    animation:
        pulseCircle 5s ease-in-out infinite;
}

.hero-content {
    min-height: 500px;

    display: grid;

    grid-template-columns:
        1.25fr 0.75fr;

    align-items: center;

    gap: 70px;

    position: relative;

    z-index: 2;
}

.hero-badge {
    display: inline-block;

    background:
        var(--primary-light);

    color:
        var(--primary);

    padding:
        7px 14px;

    border-radius:
        30px;

    font-size:
        13px;

    font-weight:
        700;

    margin-bottom:
        20px;

    animation:
        fadeUp 0.7s ease both;
}

.hero h1 {
    font-size:
        clamp(38px, 5vw, 62px);

    line-height:
        1.15;

    margin-bottom:
        22px;

    animation:
        fadeUp 0.8s 0.1s ease both;
}

.hero h1 span {
    color:
        var(--primary);
}

.hero-text p {
    color:
        var(--gray);

    max-width:
        620px;

    font-size:
        17px;

    margin-bottom:
        30px;

    animation:
        fadeUp 0.8s 0.2s ease both;
}

.hero-actions {
    display: flex;

    gap: 12px;

    flex-wrap: wrap;

    animation:
        fadeUp 0.8s 0.3s ease both;
}

.hero-card {
    background:
        rgba(255,255,255,0.95);

    padding:
        40px;

    border-radius:
        27px;

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

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

    text-align:
        center;

    position:
        relative;
}

.hero-card::before {
    content: "";

    position: absolute;

    inset: -2px;

    border-radius: 29px;

    background:
        linear-gradient(
            135deg,
            rgba(37,99,235,0.25),
            transparent
        );

    z-index: -1;
}

.hero-card-icon {
    font-size: 60px;

    margin-bottom: 15px;
}

.hero-card h3 {
    font-size: 24px;

    margin-bottom: 8px;
}

.hero-card p {
    color: var(--gray);
}

.hero-stat {
    margin-top: 30px;

    padding-top: 20px;

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

    display: flex;

    justify-content: center;

    gap: 10px;

    align-items: center;
}

.hero-stat strong {
    color:
        var(--primary);

    font-size:
        25px;
}

.hero-stat span {
    color:
        var(--gray);
}


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

.section {
    padding: 90px 0;
}

.section-light {
    background:
        var(--light);
}

.section-header {
    text-align:
        center;

    max-width:
        700px;

    margin:
        0 auto 45px;
}

.section-header > span {
    color:
        var(--primary);

    font-weight:
        700;

    font-size:
        14px;
}

.section-header h2 {
    font-size:
        34px;

    margin:
        8px 0;
}

.section-header p {
    color:
        var(--gray);
}


/* =========================================
   FEATURES
========================================= */

.features-grid {
    display:
        grid;

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

    gap:
        18px;
}

.feature-card {
    padding:
        28px;

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

    border-radius:
        var(--radius);

    background:
        white;

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

.feature-card:hover {
    transform:
        translateY(-9px);

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

    border-color:
        #bfdbfe;
}

.feature-icon {
    font-size:
        34px;

    margin-bottom:
        15px;

    transition:
        transform 0.3s ease;
}

.feature-card:hover
.feature-icon {
    transform:
        scale(1.12)
        rotate(-4deg);
}

.feature-card h3 {
    margin-bottom:
        8px;
}

.feature-card p {
    color:
        var(--gray);

    font-size:
        14px;
}


/* =========================================
   COURSES / TEACHERS
========================================= */

.courses-grid,
.teachers-grid {
    display:
        grid;

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

    gap:
        20px;
}

.course-card,
.teacher-card {
    background:
        white;

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

    border-radius:
        var(--radius);

    overflow:
        hidden;

    box-shadow:
        0 5px 20px rgba(0,0,0,0.035);

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

.course-card:hover,
.teacher-card:hover {
    transform:
        translateY(-8px);

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

    border-color:
        #bfdbfe;
}

.course-card-image {
    width:
        100%;

    height:
        200px;

    object-fit:
        cover;

    background:
        var(--primary-light);
}

.course-card-content,
.teacher-card-content {
    padding:
        22px;
}

.course-card h3,
.teacher-card h3 {
    margin-bottom:
        7px;
}

.course-card p,
.teacher-card p {
    color:
        var(--gray);

    font-size:
        14px;
}

.teacher-card {
    text-align:
        center;
}

.teacher-card-image {
    width:
        130px;

    height:
        130px;

    border-radius:
        50%;

    margin:
        25px auto 0;

    display:
        block;

    object-fit:
        cover;

    border:
        4px solid var(--primary-light);

    transition:
        transform 0.3s ease;
}

.teacher-card:hover
.teacher-card-image {
    transform:
        scale(1.07);
}


/* =========================================
   EMPTY STATE
========================================= */

.empty-state {
    grid-column:
        1 / -1;

    text-align:
        center;

    padding:
        55px 25px;

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

    border-radius:
        var(--radius);

    background:
        white;
}

.empty-icon {
    font-size:
        42px;

    margin-bottom:
        10px;
}

.empty-state h3 {
    margin-bottom:
        6px;
}

.empty-state p {
    color:
        var(--gray);
}


/* =========================================
   CTA
========================================= */

.cta-section {
    padding:
        85px 0;

    background:
        linear-gradient(
            135deg,
            #2563eb,
            #1d4ed8
        );

    color:
        white;

    text-align:
        center;

    position:
        relative;

    overflow:
        hidden;
}

.cta-section::before,
.cta-section::after {
    content:
        "";

    position:
        absolute;

    border-radius:
        50%;

    background:
        rgba(255,255,255,0.08);
}

.cta-section::before {
    width:
        300px;

    height:
        300px;

    top:
        -150px;

    right:
        -100px;
}

.cta-section::after {
    width:
        220px;

    height:
        220px;

    bottom:
        -120px;

    left:
        -70px;
}

.cta-content {
    position:
        relative;

    z-index:
        2;
}

.cta-content h2 {
    font-size:
        38px;

    margin-bottom:
        10px;
}

.cta-content p {
    opacity:
        0.9;

    margin-bottom:
        25px;
}


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

.footer {
    background:
        #0f172a;

    color:
        white;
}

.footer-content {
    padding:
        50px 0;

    display:
        flex;

    justify-content:
        space-between;

    gap:
        40px;
}

.footer-logo {
    margin-bottom:
        15px;
}

.footer-content p {
    color:
        #94a3b8;
}

.footer-links {
    display:
        flex;

    gap:
        20px;

    align-items:
        center;

    color:
        #94a3b8;
}

.footer-links a {
    transition:
        color 0.25s ease;
}

.footer-links a:hover {
    color:
        white;
}

.footer-bottom {
    text-align:
        center;

    padding:
        18px;

    border-top:
        1px solid #1e293b;

    color:
        #64748b;

    font-size:
        13px;
}


/* =========================================
   ADMIN
========================================= */

.admin-page {
    background:
        #f5f7fb;
}

.sidebar {
    position:
        fixed;

    right:
        0;

    top:
        0;

    bottom:
        0;

    width:
        250px;

    background:
        #ffffff;

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

    padding:
        25px 15px;

    display:
        flex;

    flex-direction:
        column;

    z-index:
        50;

    box-shadow:
        -5px 0 25px rgba(15,23,42,0.03);
}

.sidebar-logo {
    display:
        flex;

    align-items:
        center;

    gap:
        10px;

    font-size:
        21px;

    font-weight:
        800;

    padding:
        0 10px 30px;
}

.sidebar-nav {
    display:
        flex;

    flex-direction:
        column;

    gap:
        5px;
}

.sidebar-nav a,
.sidebar-bottom a,
.sidebar-bottom button {
    display:
        flex;

    align-items:
        center;

    gap:
        12px;

    padding:
        12px;

    border-radius:
        11px;

    color:
        var(--gray);

    background:
        transparent;

    border:
        0;

    font-size:
        14px;

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

.sidebar-nav a:hover,
.sidebar-nav a.active {
    background:
        var(--primary-light);

    color:
        var(--primary);

    transform:
        translateX(-3px);
}

.sidebar-bottom {
    margin-top:
        auto;

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

    padding-top:
        15px;
}

.sidebar-bottom button {
    width:
        100%;

    cursor:
        pointer;

    color:
        var(--danger);
}

.admin-main {
    margin-right:
        250px;

    min-height:
        100vh;

    padding:
        30px;
}

.admin-header {
    display:
        flex;

    justify-content:
        space-between;

    align-items:
        center;

    margin-bottom:
        30px;
}

.admin-header h1 {
    font-size:
        28px;
}

.admin-header p {
    color:
        var(--gray);
}

.admin-user {
    display:
        flex;

    align-items:
        center;

    gap:
        10px;
}

.admin-user small {
    display:
        block;

    color:
        var(--gray);

    font-size:
        12px;
}

.admin-avatar {
    width:
        42px;

    height:
        42px;

    border-radius:
        50%;

    background:
        linear-gradient(
            135deg,
            var(--primary),
            #60a5fa
        );

    color:
        white;

    display:
        flex;

    align-items:
        center;

    justify-content:
        center;

    font-weight:
        800;
}

.stats-grid {
    display:
        grid;

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

    gap:
        18px;

    margin-bottom:
        25px;
}

.stat-card {
    background:
        white;

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

    border-radius:
        var(--radius);

    padding:
        22px;

    display:
        flex;

    align-items:
        center;

    gap:
        15px;

    transition:
        transform 0.3s ease,
        box-shadow 0.3s ease;
}

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

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

.stat-icon {
    width:
        48px;

    height:
        48px;

    border-radius:
        13px;

    background:
        var(--primary-light);

    display:
        flex;

    align-items:
        center;

    justify-content:
        center;

    font-size:
        22px;
}

.stat-card span {
    display:
        block;

    color:
        var(--gray);

    font-size:
        13px;
}

.stat-card strong {
    display:
        block;

    font-size:
        25px;

    color:
        var(--dark);
}

.admin-welcome {
    background:
        white;

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

    border-radius:
        var(--radius);

    padding:
        35px;
}

.admin-welcome p {
    color:
        var(--gray);

    margin-top:
        8px;
}

.admin-section {
    display:
        none;

    animation:
        sectionIn 0.35s ease;
}

.admin-section.active {
    display:
        block;
}

.section-top {
    display:
        flex;

    align-items:
        center;

    justify-content:
        space-between;

    margin-bottom:
        25px;
}

.section-top h2 {
    font-size:
        25px;
}

.section-top p {
    color:
        var(--gray);
}

.admin-form {
    background:
        white;

    padding:
        25px;

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

    border-radius:
        var(--radius);

    margin-bottom:
        25px;

    box-shadow:
        0 5px 18px rgba(15,23,42,0.025);
}

.admin-form h3 {
    margin-bottom:
        20px;
}

.form-grid {
    display:
        grid;

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

    gap:
        18px;
}

.form-group {
    margin-bottom:
        18px;
}

.form-group label {
    display:
        block;

    margin-bottom:
        7px;

    font-size:
        14px;

    font-weight:
        700;
}

.form-group input,
.form-group textarea,
.form-group select {
    width:
        100%;

    padding:
        13px 14px;

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

    border-radius:
        11px;

    outline:
        none;

    background:
        white;

    color:
        var(--dark);

    font-size:
        14px;

    transition:
        border 0.25s ease,
        box-shadow 0.25s ease;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    border-color:
        var(--primary);

    box-shadow:
        0 0 0 4px
        rgba(37,99,235,0.1);
}

.admin-list {
    display:
        grid;

    gap:
        12px;
}

.admin-item {
    background:
        white;

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

    border-radius:
        13px;

    padding:
        18px;

    display:
        flex;

    align-items:
        center;

    justify-content:
        space-between;

    gap:
        20px;

    transition:
        transform 0.25s ease,
        box-shadow 0.25s ease;
}

.admin-item:hover {
    transform:
        translateY(-3px);

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

.admin-item-info h3 {
    margin-bottom:
        4px;
}

.admin-item-info p {
    color:
        var(--gray);

    font-size:
        13px;
}

.admin-item-actions {
    display:
        flex;

    gap:
        8px;

    flex-wrap:
        wrap;
}

.delete-btn {
    border:
        0;

    background:
        #fff1f2;

    color:
        var(--danger);

    padding:
        8px 12px;

    border-radius:
        8px;

    transition:
        0.2s ease;
}

.delete-btn:hover {
    background:
        #ffe4e6;

    transform:
        translateY(-2px);
}

.edit-btn {
    border:
        0;

    background:
        var(--primary-light);

    color:
        var(--primary);

    padding:
        8px 12px;

    border-radius:
        8px;

    transition:
        0.2s ease;
}

.edit-btn:hover {
    background:
        var(--primary-soft);

    transform:
        translateY(-2px);
}


/* =========================================
   REVEAL ANIMATION
========================================= */

.reveal {
    opacity:
        0;

    transform:
        translateY(25px);

    animation:
        fadeUp 0.8s ease forwards;
}


/* =========================================
   FLOATING
========================================= */

.floating {
    animation:
        floating 4s ease-in-out infinite;
}


/* =========================================
   ANIMATIONS
========================================= */

@keyframes fadeUp {

    from {
        opacity: 0;
        transform: translateY(25px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }

}

@keyframes floating {

    0%,
    100% {
        transform:
            translateY(0);
    }

    50% {
        transform:
            translateY(-12px);
    }

}

@keyframes pulseCircle {

    0%,
    100% {
        transform:
            scale(1);
    }

    50% {
        transform:
            scale(1.15);
    }

}

@keyframes sectionIn {

    from {
        opacity: 0;
        transform:
            translateY(10px);
    }

    to {
        opacity: 1;
        transform:
            translateY(0);
    }

}


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

@media (max-width: 900px) {

    .nav-links {
        display:
            none;
    }

    .hero-content {
        grid-template-columns:
            1fr;

        gap:
            40px;
    }

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

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

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

    .sidebar {
        width:
            210px;
    }

    .admin-main {
        margin-right:
            210px;
    }

}

@media (max-width: 650px) {

    .container {
        width:
            min(
                100% - 25px,
                1150px
            );
    }

    .nav-buttons .btn-outline {
        display:
            none;
    }

    .hero {
        padding:
            60px 0;
    }

    .hero h1 {
        font-size:
            40px;
    }

    .section {
        padding:
            60px 0;
    }

    .features-grid,
    .courses-grid,
    .teachers-grid,
    .stats-grid,
    .form-grid {
        grid-template-columns:
            1fr;
    }

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

    .footer-links {
        flex-wrap:
            wrap;
    }

    .sidebar {
        position:
            static;

        width:
            100%;

        min-height:
            auto;
    }

    .sidebar-nav {
        flex-direction:
            row;

        overflow-x:
            auto;
    }

    .sidebar-nav a {
        white-space:
            nowrap;
    }

    .sidebar-bottom {
        margin-top:
            10px;
    }

    .admin-main {
        margin-right:
            0;

        padding:
            20px 12px;
    }

    .admin-header {
        align-items:
            flex-start;
    }

    .section-top {
        align-items:
            flex-start;

        gap:
            15px;

        flex-direction:
            column;
    }

}