@font-face {
    font-family: 'Montserrat';
    src: url('../style/Montserrat-VariableFont_wght.ttf') format('truetype');
    font-weight: 100 900;
    font-style: normal;
}

@font-face {
    font-family: 'Montserrat';
    src: url('../style/Montserrat-Italic-VariableFont_wght.ttf') format('truetype');
    font-weight: 100 900;
    font-style: italic;
}
/* ===============================
   1. RESET & CẤU HÌNH CHUNG
================================= */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: Montserrat;
    font-size: 16px;
    line-height: 1.6;
    background-color: #f9fafb;
    color: #1f2937;
}

/* ===============================
   2. TYPOGRAPHY & MÀU SẮC
================================= */

h2,
h3,
h4,
h5,
h6 {
    font-weight: 600;
    color: #111827;
}

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

.container {
    width: 100%;
    max-width: 1300px;
    margin: auto;
    padding: 0 16px;
}


/* ===============================
   3. HEADER
================================= */

.hero-text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
    z-index: 10;
    color: white;
    width: 100%;
}

.button-style {
    display: inline-block;
    padding: 8px 20px;
    border: 2px solid white;
    border-radius: 20px;
    color: white;
    background-color: transparent;
    font-size: 34px;
    font-weight: 500;
    font-family: sans-serif;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 10px;
}


.hero {
    padding: 40px 0;
}

.hero-content {
    position: relative;
    min-height: 420px;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
}

.hero-bg {
    position: absolute;
    inset: 0;
    z-index: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #1a1a1a 0%, #000 50%, #1a1a1a 100%);
}

.hero-text {
    /* position: relative; */
    z-index: 1;
    flex: 1;
    padding: 20px;
}

.hero-text h2 {
    color: #FFFFFF;
    font-size: 84px;
    font-weight: bold;
    margin-bottom: 15px;
}

.hero-text h3 {
    color: #FFFFFF;
    margin-bottom: 15px;
}

.hero-text p {
    font-size: 30px;
    line-height: 1.6;
    margin-bottom: 20px;
    color: #FFFFFF;
}

.hero-text .btn {
    background-color: #7fff00;
    color: #000;
    padding: 12px 24px;
    border: none;
    font-weight: bold;
    cursor: pointer;
    border-radius: 6px;
    text-transform: uppercase;
}

.hero-image {
    position: relative;
    z-index: 1;
    display: flex;
    gap: 32px;
    align-items: center;
    justify-content: center;
    margin-top: 24px;
    flex: 1;
    padding: 20px;
}

.hero-image img {
    max-width: 100%;
    height: auto;
}



/* ===============================
   4. NỘI DUNG CHÍNH
================================= */
main {
    padding: 40px 0;
}

.section-title {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 16px;
    text-align: center;
}

.section-subtitle {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 40px auto;
    color: #6b7280;
}

/* ===============================
   5. PHẦN BA ẢNH COURSE-PREVIEW
================================= */
.course-preview {
    width: 100%;
    max-width: 700px;
    margin: 36px auto 0;
    display: flex;
    justify-content: center;
    align-items: flex-end;
    position: relative;
    height: 220px;
}

.side-image {
    width: 28%;
    max-width: 180px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.12);
    border-radius: 12px;
    position: absolute;
    bottom: 0;
    z-index: 1;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.side-image.left {
    left: 5%;
}

.side-image.right {
    right: 5%;
}

.center-image {
    width: 44%;
    max-width: 320px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.18);
    border-radius: 16px;
    position: absolute;
    left: 50%;
    transform: translateX(-50%) translateY(-18px);
    z-index: 2;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}


/* ===============================
   6. LINK
================================= */

.feature-link {
    color: #3b82f6;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 10px;
}

.feature-img {
    flex: 1;
}

.feature-img img {
    width: 100%;
    border-radius: 16px;

}

/* ===============================
   7. RESPONSIVE
================================= */
@media (max-width: 768px) {
    .hero {
        padding: 16px 0 0 0;
    }

    .hero-content {
        min-height: 220px;
        padding: 0;
    }

    .hero-bg {
        background-size: cover !important;
        background-position: center !important;
    }

    .hero-text {
        padding: 0 8px;
        top: 50%;
        left: 50%;
        transform: translate(-50%, -50%);
        position: absolute;
        width: 100vw;
        max-width: 100vw;
        z-index: 10;
    }

    .hero-text h2 {
        color: #FFD1D1;
        font-size: 20px;
        font-weight: bold;
        margin-bottom: 15px;
    }

    .hero-text h3 {
        font-size: 1.1rem;
        margin-bottom: 6px;
        color: #fff;
    }

    .hero-text p {
        font-size: 14px;
        margin-bottom: 8px;
        color: #fff;
    }

    .feature-logo {
        /* max-width: 140px; */
        margin-bottom: 10px;

    }

    .course-preview {
        height: auto;
        flex-direction: column;
        align-items: center;
    }

    .side-image,
    .center-image {
        position: static;
        width: 80%;
        max-width: none;
        transform: none;
        margin-bottom: 16px;
    }

    .center-image {
        order: 0;
    }

    .side-image.left {
        order: 1;
    }

    .side-image.right {
        order: 2;
    }
}

@media (max-width: 768px) {


    .button-style {
        font-size: 0.9rem;
        padding: 8px 16px;
    }

    /* Course preview images */
    .course-preview {
        display: flex;
        flex-direction: column;
        align-items: center;
    }

    .side-image.left,
    .side-image.right,
    .center-image {
        max-width: 90%;
        margin: 12px 0;
    }

    /* Feature rows */
    .feature-row {
        flex-direction: column !important;
        text-align: center !important;
    }

    .feature-img,
    .feature-text {
        flex: 1 1 100%;
        text-align: center !important;
    }

    .feature-img img {
        max-width: 90%;
        margin: 0 auto;
    }

    /* Logo in feature section */
    .feature-logo {
        max-width: 80%;
        height: auto;
    }

    /* Steps section (Hướng dẫn khoá học) */
    section>div {
        flex-direction: column !important;
        /* text-align: center; */
    }

    section>div img {
        max-width: 90%;
        margin: 0 auto;
    }

    section h2 {
        font-size: 1.7rem;
    }

    section h3 {
        font-size: 1.1rem;
    }

    section p,
    section li {
        font-size: 0.95rem;
    }

    /* Important information box */
    .feature-section,
    .important-box {
        padding: 16px;
    }

    ul {
        padding-left: 20px;
    }
}