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

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: Arial, Helvetica, sans-serif;
    background: #05070b;
    color: #ffffff;
    min-height: 100vh;
}


/* ================================
   NAVIGATION
================================ */

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

    background: rgba(5, 7, 11, 0.95);

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

    position: sticky;
    top: 0;
    z-index: 100;
}

.logo {
    text-decoration: none;
    color: white;
    font-size: 22px;
    font-weight: 700;
}

.nav-links {
    display: flex;
    gap: 30px;
}

.nav-links a {
    color: #b7bec9;
    text-decoration: none;
    font-size: 15px;
    transition: 0.3s;
}

.nav-links a:hover,
.nav-links .active {
    color: #ffffff;
}


/* ================================
   MAIN CONTAINER
================================ */

.main-container {
    width: 90%;
    max-width: 1150px;
    margin: auto;
}


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

.hero {
    text-align: center;
    padding: 90px 20px 60px;
}

.badge {
    display: inline-block;

    padding: 8px 16px;

    border: 1px solid #303844;
    border-radius: 30px;

    color: #9da7b5;

    font-size: 12px;
    font-weight: 600;

    letter-spacing: 1.5px;

    margin-bottom: 25px;
}

.hero h1 {
    font-size: clamp(40px, 6vw, 70px);
    line-height: 1.05;

    margin-bottom: 20px;
}

.hero p {
    max-width: 650px;
    margin: auto;

    color: #9ca5b2;

    font-size: 17px;
    line-height: 1.7;
}


/* ================================
   SUBJECT SECTION
================================ */

.subject-section {
    padding: 30px 0 80px;
}

.subject-section h2 {
    text-align: center;
    font-size: 34px;
    margin-bottom: 12px;
}

.section-description {
    text-align: center;
    color: #89929f;
    margin-bottom: 45px;
}


/* ================================
   SUBJECT CARDS
================================ */

.subjects {
    display: grid;

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

    gap: 25px;
}

.subject-card {
    display: block;

    text-decoration: none;
    color: white;

    padding: 32px;

    background: #0b0f15;

    border: 1px solid #1b222c;

    border-radius: 18px;

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

.subject-card:hover {
    transform: translateY(-8px);

    border-color: #586575;

    background: #10151d;
}


/* ================================
   SUBJECT ICON
================================ */

.subject-icon {
    width: 65px;
    height: 65px;

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

    border-radius: 15px;

    margin-bottom: 25px;

    font-size: 27px;
    font-weight: bold;

    background: #151b24;

    border: 1px solid #29313c;
}

.math-icon {
    color: #ffffff;
}

.science-icon {
    color: #ffffff;
}

.computer-icon {
    color: #ffffff;
}


/* ================================
   SUBJECT CONTENT
================================ */

.subject-content h3 {
    font-size: 24px;

    margin-bottom: 12px;
}

.subject-content p {
    color: #919ba8;

    line-height: 1.7;

    font-size: 14px;

    min-height: 70px;
}

.start {
    display: inline-block;

    margin-top: 20px;

    font-size: 14px;
    font-weight: 600;

    color: #ffffff;
}


/* ================================
   INFORMATION BOX
================================ */

.info-box {
    padding: 35px;

    margin-bottom: 80px;

    border-radius: 18px;

    background: #0b0f15;

    border: 1px solid #1b222c;
}

.info-box h3 {
    font-size: 21px;
    margin-bottom: 12px;
}

.info-box p {
    color: #929ba8;
    line-height: 1.7;
    max-width: 750px;
}


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

.features {
    display: flex;

    gap: 60px;

    margin-top: 30px;

    padding-top: 25px;

    border-top: 1px solid #1c232d;
}

.features div {
    display: flex;
    flex-direction: column;

    gap: 6px;
}

.features strong {
    font-size: 22px;
}

.features span {
    color: #818b98;
    font-size: 13px;
}


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

footer {
    padding: 30px 20px;

    text-align: center;

    border-top: 1px solid #151b23;

    color: #68727f;

    font-size: 13px;

    line-height: 2;
}


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

@media (max-width: 850px) {

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

    .subject-card {
        padding: 28px;
    }

    .hero {
        padding-top: 65px;
    }

}


@media (max-width: 600px) {

    .navbar {
        padding: 17px 5%;
    }

    .logo {
        font-size: 18px;
    }

    .nav-links {
        gap: 13px;
    }

    .nav-links a {
        font-size: 12px;
    }

    .hero h1 {
        font-size: 42px;
    }

    .hero p {
        font-size: 15px;
    }

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

    .features {
        gap: 25px;
    }

}