:root {
    --bg: #05080d;
    --bg-soft: #080d14;
    --panel: #0b1119;
    --panel-strong: #0c121a;
    --text: #ffffff;
    --text-soft: #aab7c8;
    --text-muted: #8290a1;
    --nav-text: #c9d5e2;
    --border: #172332;
    --primary: #1687ff;
    --primary-light: #55ddff;
    --shadow: rgba(22, 135, 255, 0.4);
    --button-text: #ffffff;
}

body.light-theme {
    --bg: #eef5ff;
    --bg-soft: #f7faff;
    --panel: #ffffff;
    --panel-strong: #edf4ff;
    --text: #101821;
    --text-soft: #405266;
    --text-muted: #62738a;
    --nav-text: #2d4053;
    --border: #d7e1ee;
    --primary: #0d6cf2;
    --primary-light: #29b7ff;
    --shadow: rgba(13, 108, 242, 0.2);
    --button-text: #ffffff;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: Arial, sans-serif;
    background: radial-gradient(circle at top, rgba(22, 135, 255, 0.12), transparent 30%), var(--bg);
    color: var(--text);
    line-height: 1.8;
    min-height: 100vh;
    transition: background 0.3s ease, color 0.3s ease;
}

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


/* NAVBAR */

header {
    position: sticky;
    top: 0;
    z-index: 100;

    height: 75px;

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

    padding: 0 7%;

    background: rgba(5, 8, 13, 0.88);

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

    backdrop-filter: blur(15px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}

body.light-theme header {
    background: rgba(255, 255, 255, 0.75);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo {
    font-size: 22px;
    font-weight: 900;

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

nav {
    display: flex;
    gap: 30px;
}

nav a {
    color: var(--nav-text);
    font-size: 14px;

    transition: 0.3s;
}

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

.theme-toggle,
.youtube-button {
    border: 1px solid var(--border);
    border-radius: 10px;
    font-weight: bold;
    transition: 0.3s;
}

.theme-toggle {
    width: 42px;
    height: 42px;
    display: grid;
    place-items: center;
    background: var(--panel);
    color: var(--text);
    cursor: pointer;
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.12);
}

.youtube-button {
    padding: 9px 16px;

    background: white;
    color: black;
    box-shadow: 0 8px 18px rgba(255, 255, 255, 0.15);
}


/* HERO */

.hero {
    min-height: 700px;

    display: grid;
    grid-template-columns: 1.2fr 0.8fr;

    align-items: center;

    gap: 60px;

    padding: 80px 9%;

    background:
        radial-gradient(
            circle at 20% 50%,
            rgba(0, 140, 255, 0.2),
            transparent 35%
        );
}

.small-title {
    color: var(--primary-light);

    font-size: 12px;

    font-weight: bold;

    letter-spacing: 3px;
}

.hero h1 {
    font-size: clamp(45px, 6vw, 75px);

    line-height: 1.2;

    margin: 15px 0;
}

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

.hero-text > p:not(.small-title) {
    color: var(--text-soft);

    max-width: 600px;

    font-size: 17px;

    margin: 20px 0 30px;
}


/* BUTTONS */

.buttons {
    display: flex;

    gap: 12px;

    flex-wrap: wrap;
}

.main-button,
.second-button {
    padding: 13px 22px;

    border-radius: 12px;

    font-weight: bold;

    box-shadow: 0 10px 20px rgba(22, 135, 255, 0.14);
    transition: 0.3s;
}

.main-button {
    background: linear-gradient(
        135deg,
        #1687ff,
        #55ddff
    );

    color: white;
}

.second-button {
    border: 1px solid var(--border);

    background: var(--panel-strong);
    color: var(--text);
}

.main-button:hover,
.second-button:hover,
.youtube-button:hover,
.theme-toggle:hover {
    transform: translateY(-3px);
}


/* LOGO */

.hero-logo {
    text-align: center;

    padding: 70px 30px;

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

    border-radius: 35px;

    background: linear-gradient(
        145deg,
        rgba(20, 130, 255, 0.15),
        rgba(255,255,255,0.02)
    );
    box-shadow: 0 24px 48px rgba(0, 0, 0, 0.14);
}

.logo-circle {
    width: 150px;
    height: 150px;

    margin: auto;

    display: grid;
    place-items: center;

    border-radius: 40px;

    font-size: 90px;

    font-weight: 900;

    background: linear-gradient(
        135deg,
        #1687ff,
        #55ddff
    );

    box-shadow:
        0 0 60px rgba(22,135,255,0.4);
}

.hero-logo h2 {
    margin-top: 25px;

    letter-spacing: 8px;
}

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

    font-size: 10px;

    letter-spacing: 3px;
}


/* SECTIONS */

.section {
    padding: 100px 9%;
}

.section h2 {
    font-size: 40px;

    margin-bottom: 35px;
}


/* VIDEOS */

.videos {
    display: grid;

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

    gap: 25px;
}

.video-card {
    overflow: hidden;

    border-radius: 20px;

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

    background: var(--panel);

    box-shadow: 0 18px 36px rgba(0, 0, 0, 0.12);
    transition: 0.3s;
}

.video-card:hover {
    transform: translateY(-6px);

    border-color: #238cff;
}

.thumbnail {
    height: 220px;

    display: grid;

    place-items: center;

    position: relative;

    font-size: 25px;

    font-weight: 900;

    background: linear-gradient(
        135deg,
        #1687ff,
        #55ddff
    );
}

.thumbnail.blue {
    background: linear-gradient(
        135deg,
        #0758c9,
        #1687ff
    );
}

.thumbnail.dark {
    background: linear-gradient(
        135deg,
        #05070b,
        #172638
    );
}

.play {
    position: absolute;

    bottom: 15px;
    right: 15px;

    width: 45px;
    height: 45px;

    display: grid;
    place-items: center;

    border-radius: 50%;

    background: white;

    color: #1687ff;
}

.video-card h3 {
    padding: 15px 18px 0;
}

.video-card p {
    padding: 0 18px 20px;

    color: var(--text-muted);

    font-size: 13px;
}


/* ABOUT */

.about {
    background: var(--bg-soft);
}

.about > div {
    max-width: 850px;
}

.about p:last-child {
    color: var(--text-soft);

    font-size: 17px;
}


/* CONTACT */

.contact {
    text-align: center;
}

.social {
    display: inline-block;

    margin-top: 10px;

    padding: 13px 25px;

    border-radius: 12px;

    background: #1687ff;

    font-weight: bold;
}

.ad-bar {
    padding-top: 20px;
}

.ad-box {
    max-width: 900px;
    margin: 0 auto;
    padding: 35px 30px;
    border: 1px solid var(--border);
    border-radius: 24px;
    background: linear-gradient(135deg, rgba(22, 135, 255, 0.08), rgba(85, 221, 255, 0.04));
    text-align: center;
    box-shadow: 0 18px 36px rgba(0, 0, 0, 0.08);
}

.ad-box h2 {
    margin-bottom: 15px;
}

.ad-box > p {
    max-width: 640px;
    margin: 0 auto 25px;
    color: var(--text-soft);
}

.contact-links {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 12px;
}

.contact-links a {
    padding: 10px 18px;
    border: 1px solid var(--border);
    border-radius: 999px;
    background: var(--panel);
    color: var(--text);
    font-weight: bold;
}


/* FOOTER */

footer {
    padding: 30px 9%;

    display: flex;

    justify-content: space-between;

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

    color: var(--text-muted);

    font-size: 12px;
}

footer strong {
    color: var(--text);
}


/* MOBILE */

@media (max-width: 800px) {

    header {
        padding: 0 5%;
    }

    nav {
        display: none;
    }

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

        text-align: center;

        padding: 70px 7%;
    }

    .hero-text > p {
        margin-left: auto;
        margin-right: auto;
    }

    .buttons {
        justify-content: center;
    }

    .hero-logo {
        width: 280px;

        margin: auto;
    }

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

    .section {
        padding: 70px 7%;
    }

    footer {
        flex-direction: column;

        gap: 10px;

        text-align: center;
    }
}