:root {
    --black: #080b0d;
    --panel: #10161a;
    --panel-light: #182126;
    --green: #7dff9b;
    --green-dark: #173d24;
    --white: #f4f7f4;
    --muted: #8d9992;
    --line: rgba(125, 255, 155, 0.18);
    --shadow: 0 25px 70px rgba(0, 0, 0, 0.45);
}

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

html {
    scroll-behavior: smooth;
}

body {
    background: var(--black);
    color: var(--white);
    font-family: "Space Grotesk", sans-serif;
    overflow-x: hidden;
}

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

.site-header {
    width: 100%;
    padding: 1.4rem 6vw;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid var(--line);
}

.brand {
    font-family: "DM Mono", monospace;
    font-weight: 500;
    letter-spacing: 0.08em;
}

.brand span {
    color: var(--green);
}

.header-link,
.text-link {
    color: var(--muted);
    font-size: 0.85rem;
}

.header-link:hover,
.text-link:hover {
    color: var(--green);
}

.hero {
    min-height: 88vh;
    padding: 7rem 7vw;
    display: grid;
    grid-template-columns: 1fr 0.8fr;
    align-items: center;
    gap: 6rem;
    background:
        radial-gradient(circle at 80% 40%, rgba(125, 255, 155, 0.1), transparent 35%);
}

.eyebrow {
    margin-bottom: 1rem;
    color: var(--green);
    font-family: "DM Mono", monospace;
    font-size: 0.72rem;
    letter-spacing: 0.18em;
}

h1,
h2 {
    line-height: 0.9;
    letter-spacing: -0.05em;
}

h1 {
    max-width: 800px;
    font-size: clamp(4rem, 9vw, 9rem);
}

h1 span {
    display: block;
    color: var(--green);
}

.hero-text {
    max-width: 570px;
    margin: 2rem 0;
    color: var(--muted);
    font-size: 1.05rem;
    line-height: 1.7;
}

.hero-actions {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.primary-button {
    display: inline-block;
    padding: 1rem 1.4rem;
    background: var(--green);
    color: var(--black);
    font-family: "DM Mono", monospace;
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    transition: transform 0.2s, box-shadow 0.2s;
}

.primary-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 35px rgba(125, 255, 155, 0.2);
}

.calculator-art {
    padding: 1.2rem;
    background: var(--panel);
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
    transform: rotate(2deg);
}

.calc-screen {
    padding: 1.8rem;
    background: #050707;
    border: 1px solid var(--line);
    font-family: "DM Mono", monospace;
    text-align: right;
}

.calc-expression {
    display: block;
    margin-bottom: 0.7rem;
    color: var(--muted);
    font-size: 0.75rem;
}

.calc-screen strong {
    color: var(--green);
    font-size: clamp(1.3rem, 3vw, 2rem);
}

.calc-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0.5rem;
    margin-top: 0.7rem;
}

.calc-grid i {
    padding: 1rem 0.4rem;
    background: var(--panel-light);
    color: var(--green);
    font-family: "DM Mono", monospace;
    font-size: 0.75rem;
    font-style: normal;
    text-align: center;
}

.features {
    padding: 8rem 7vw;
    background: #0b1012;
}

.section-heading {
    margin-bottom: 4rem;
}

.section-heading h2,
.showcase h2,
.final-cta h2 {
    font-size: clamp(3rem, 7vw, 7rem);
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    border-top: 1px solid var(--line);
    border-left: 1px solid var(--line);
}

.feature-card {
    min-height: 250px;
    padding: 2rem;
    border-right: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
}

.feature-card span {
    color: var(--green);
    font-family: "DM Mono", monospace;
    font-size: 0.75rem;
}

.feature-card h3 {
    margin: 3rem 0 1rem;
    font-size: 1.25rem;
}

.feature-card p {
    max-width: 350px;
    color: var(--muted);
    line-height: 1.6;
}

.showcase {
    min-height: 60vh;
    padding: 7rem 7vw;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 4rem;
    background: var(--green);
    color: var(--black);
}

.showcase .eyebrow {
    color: var(--black);
}

.formula {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    font-family: "DM Mono", monospace;
    font-size: clamp(1rem, 2vw, 1.5rem);
}

.formula span {
    padding: 1rem;
    border: 1px solid var(--black);
}

.final-cta {
    min-height: 70vh;
    padding: 7rem 7vw;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
}

.final-cta h2 {
    margin-bottom: 2.5rem;
}

footer {
    padding: 2rem 7vw;
    display: flex;
    justify-content: space-between;
    gap: 1rem;
    border-top: 1px solid var(--line);
    color: var(--muted);
    font-family: "DM Mono", monospace;
    font-size: 0.72rem;
}

footer a {
    color: var(--green);
}

.reveal {
    opacity: 0;
    transform: translateY(25px);
    transition: opacity 0.7s ease, transform 0.7s ease;
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

@media (max-width: 850px) {
    .hero {
        grid-template-columns: 1fr;
        padding-top: 5rem;
        gap: 4rem;
    }

    .calculator-art {
        max-width: 550px;
        width: 100%;
        margin: auto;
    }

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

    .showcase {
        flex-direction: column;
        align-items: flex-start;
    }
}

@media (max-width: 600px) {
    .site-header {
        padding: 1.2rem 5vw;
    }

    .hero,
    .features,
    .final-cta {
        padding-left: 5vw;
        padding-right: 5vw;
    }

    h1 {
        font-size: clamp(3.5rem, 17vw, 6rem);
    }

    .hero-actions {
        flex-direction: column;
        align-items: flex-start;
    }

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

    .feature-card {
        min-height: auto;
    }

    .showcase {
        padding: 5rem 5vw;
    }

    footer {
        flex-direction: column;
        padding: 2rem 5vw;
    }
}