:root {
    --bg: #121212;
    --text: #ffffff;
    --muted: #6C757D;
    --primary: #00BFFF;
    --card: #1b1b1b;
    --ring: rgba(0, 191, 255, 0.35);
}

* {
    box-sizing: border-box
}

html,
body {
    margin: 0;
    padding: 0
}

body {
    font-family: "Open Sans", system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, "Helvetica Neue", Arial;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    align-items: center;
}

.container {
    width: min(1200px, 92%);
    margin-inline: auto
}

.site-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 0;
}

.brand {
    display: flex;
    gap: 10px;
    align-items: center;
    color: var(--text);
    text-decoration: none;
    font-weight: 600
}

.logo {
    width: 28px;
    height: 28px;
    object-fit: contain
}

.nav {
    display: flex;
    gap: 18px
}

.nav a {
    color: var(--text);
    text-decoration: none;
    opacity: .85
}

.nav a:hover {
    opacity: 1
}

.hero {
    display: grid;
    grid-template-columns: 1.1fr .9fr;
    gap: 40px;
    padding: 48px 0
}

.hero__text h1 {
    font-size: clamp(28px, 4vw, 44px);
    line-height: 1.15;
    margin: 0 0 12px
}

.lead {
    color: #e8f7ff;
    opacity: .9;
    margin: 0 0 24px
}

.cta {
    display: flex;
    flex-wrap: wrap;
    gap: 12px
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 18px;
    border-radius: 14px;
    text-decoration: none;
    font-weight: 600;
    border: 1px solid transparent;
    transition: transform .08s ease, box-shadow .2s ease, background .2s ease;
}

.btn-icon {
    font-size: 18px
}

.btn-primary {
    background: var(--primary);
    color: #031018;
    box-shadow: 0 0 0 0 var(--ring)
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 0 0 8px var(--ring)
}

.btn-outline {
    border-color: rgba(255, 255, 255, .25);
    color: var(--text);
    background: transparent
}

.btn-outline:hover {
    border-color: var(--primary);
    box-shadow: 0 0 0 8px var(--ring)
}

.note {
    font-size: 13px;
    color: var(--muted);
    margin-top: 10px
}

.hero__mock img {
    width: 100%;
    border-radius: 18px;
    background: #0e0e0e;
    border: 1px solid rgba(255, 255, 255, .06)
}

.features {
    padding: 24px 0 8px
}

.features h2,
.why h2,
.preview h2 {
    font-size: 28px
}

.grid {
    margin-top: 18px;
    display: grid;
    gap: 16px;
    grid-template-columns: repeat(4, 1fr);
}

.card {
    background: var(--card);
    border: 1px solid rgba(255, 255, 255, .05);
    padding: 18px;
    border-radius: 16px;
    min-height: 150px;
}

.card-icon {
    font-size: 22px;
    color: var(--primary);
    margin-bottom: 8px
}

.card h3 {
    margin: 4px 0 8px;
    font-size: 18px
}

.why {
    padding: 28px 0
}

.why-list {
    list-style: none;
    padding: 0;
    margin: 10px 0 0;
    color: #e1f6ff
}

.why-list li {
    display: flex;
    gap: 10px;
    align-items: flex-start;
    padding: 8px 0
}

.why-list span {
    color: var(--primary)
}

.preview {
    padding: 28px 0 48px
}

.preview-row {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin-top: 16px;
}

.preview-row img {
    width: 100%;
    border-radius: 16px;
    border: 1px solid rgba(255, 255, 255, .06);
    background: #0e0e0e
}

.site-footer {
    border-top: 1px solid rgba(255, 255, 255, .06);
    margin-top: 32px
}

.footer-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
    padding: 18px 0
}

.legal {
    display: flex;
    gap: 16px;
    flex-wrap: wrap
}

.legal a {
    color: #cfefff;
    text-decoration: none;
    opacity: .85
}

.legal a:hover {
    opacity: 1;
    text-decoration: underline
}

.copy {
    color: var(--muted)
}

.doc .doc-header {
    padding: 18px 0
}

.doc .brand {
    opacity: .9
}

.doc h1 {
    margin: 6px 0 6px;
    font-size: 30px
}

.doc-body {
    background: var(--card);
    border: 1px solid rgba(255, 255, 255, .06);
    border-radius: 16px;
    padding: 22px;
    margin: 8px auto 18px;
    /* centers horizontally */
    max-width: 1280px;
    /* keeps readable line length */
    text-align: left;
    /* keeps text left-aligned inside */
    display: block;
}

.doc-body h2 {
    margin-top: 18px;
    font-size: 20px
}

.doc-footer {
    display: flex;
    justify-content: flex-end;
    padding-bottom: 24px
}

.accordion {
    display: grid;
    gap: 10px
}

.acc-btn {
    width: 100%;
    text-align: left;
    padding: 14px 16px;
    border-radius: 12px;
    background: var(--card);
    color: var(--text);
    border: 1px solid rgba(255, 255, 255, .08);
    font-weight: 600;
    cursor: pointer;
}

.acc-btn:focus {
    outline: 2px solid var(--primary);
    outline-offset: 2px
}

.acc-panel {
    display: none;
    padding: 12px 16px;
    border-left: 2px solid var(--primary);
    background: #0f0f0f;
    border-radius: 0 12px 12px 12px;
}

.btn span {
    display: inline-block;
    vertical-align: middle;
}
.btn-icon-img {
    width: 20px;
    height: 20px;
    object-fit: contain;
    vertical-align: middle;
    margin-right: 8px;
    filter: brightness(0) invert(1);
    /* makes icons white on dark background */
}

.btn:hover .btn-icon-img {
    filter: brightness(0) saturate(100%) invert(53%) sepia(97%) saturate(1679%) hue-rotate(173deg) brightness(97%) contrast(101%);
    /* gives a blue (#00BFFF) tint on hover */
}
@media (max-width: 960px) {
    .hero {
        grid-template-columns: 1fr;
        gap: 24px
    }

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

    .preview-row {
        grid-template-columns: 1fr
    }
}

@media (max-width: 520px) {
    .nav {
        display: none
    }

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