*,
*::before,
*::after { box-sizing: border-box; }

.hero-main {
    text-align: center;
    padding: clamp(20px, 6vw, 80px) 4%; /*clamp(min, preferred, max) , 4% of the screen width*/
    max-width: 1000px;
    margin: 0 auto
}

.hero-title {
    font-size: clamp(2.2rem, 6vw, 3.25rem); /* ~35px—52px */
    margin-bottom: 20px;
    color: #ffffff;
    line-height: 1.05
}

.appName {
    color: #00bfff;
    font-weight: 700;
    font-size: inherit /* keeps same size as hero-title */
}

.hero-tagline {
    font-size: clamp(1rem, 2.2vw, 1.5rem); /* ~16px—24px */
    color: #00bfff;
    margin: 30px 0;
    font-weight: 600
}

.hero-sub {
    font-size: clamp(0.95rem, 1.8vw, 1.1875rem); /* ~15px—19px */
    line-height: 1.7;
    color: #cccccc;
    max-width: 750px;
    margin: 40px auto
}

.feature-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: clamp(16px, 3vw, 30px);
    margin: 50px 0;
    align-items: start
}

.feature-card {
    background: #1e1e1e;
    padding: clamp(18px, 2.5vw, 30px);
    border-radius: 15px;
    box-shadow: 0 6px 25px rgba(0,0,0,0.6);
    width: 100%
}

.feature-title {
    color: #00bfff;
    font-size: clamp(1.1rem, 2.2vw, 1.625rem); /* ~18px—26px */
    margin-bottom: 12px
}

.feature-desc {
    color: #ddd;
    font-size: clamp(0.875rem, 1.6vw, 0.95rem); /* ~14px—15px */
    line-height: 1.6
}

.cta-wrap {
    text-decoration: none;
    display: inline-block
}

.cta-button {
    display: inline-block;
    background: #00bfff;
    color: white;
    border: none;
    padding: clamp(10px, 2vw, 16px) clamp(18px, 4.5vw, 40px);
    font-size: clamp(1rem, 2vw, 1.25rem);
    font-weight: 700;
    border-radius: 12px;
    cursor: pointer;
    margin-top: 30px;
    box-shadow: 0 6px 20px rgba(0,191,255,0.35);
    transition: transform 0.12s ease, box-shadow 0.12s ease;
    line-height: 1
}

.cta-button:hover, .cta-button:focus {
    transform: translateY(-3px)
}

.footer-note {
    margin-top: 50px;
    color: #888;
    font-size: clamp(0.85rem, 1.2vw, 0.95rem)
}

.brand-icon {
    height: 40px;
    margin-right: 10px;
    vertical-align: middle;
    display: inline-block
}

@media screen and (max-width: 720px) {
    .hero-title {
        margin-bottom: 12px
    }
    .feature-cards {
        gap: 14px
    }
    .cta-button {
        width: 100%;
        padding: 12px 18px;
        font-size: 1.05rem
    }
    .hero-sub {
        margin: 24px auto
    }
}

@media screen and (min-width: 1200px) {
    .hero-main {
        padding-left: 6%;
        padding-right: 6%
    }
    .hero-title {font-size: clamp(2.8rem, 4vw, 3.6rem)
    }
}