:root {
    --bg: #071426;
    --bg2: #0B1D3A;
    --panel: rgba(16, 34, 72, .82);
    --panel2: rgba(8, 21, 47, .72);
    --line: rgba(148, 163, 184, .18);
    --text: #F8FAFC;
    --muted: #94A3B8;
    --soft: #CBD5E1;
    --blue: #2563EB;
    --blue2: #60A5FA;
    --green: #22C55E;
    --yellow: #F59E0B;
    --red: #EF4444;
    --radius: 18px;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    color: var(--text);
    font-family: Arial, Helvetica, sans-serif;
    background:
        radial-gradient(circle at 20% 10%, rgba(37, 99, 235, .18), transparent 24%),
        radial-gradient(circle at 90% 20%, rgba(96, 165, 250, .12), transparent 25%),
        linear-gradient(135deg, var(--bg), var(--bg2) 65%, #0F2A55);
    min-height: 100vh;
}

a {
    color: inherit;
}

.app-shell {
    min-height: 100vh;
    display: flex;
}

.sidebar {
    width: 292px;
    position: fixed;
    inset: 0 auto 0 0;
    background: rgba(5, 14, 30, .88);
    backdrop-filter: blur(16px);
    border-right: 1px solid var(--line);
    padding: 24px 18px;
}

.brand {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    padding: 4px 6px 24px;
    border-bottom: 1px solid var(--line);
}

.brand-mark {
    width: 46px;
    height: 46px;
    border-radius: 14px;
    background: linear-gradient(135deg, var(--blue), var(--blue2));
    display: grid;
    place-items: center;
    font-size: 25px;
    font-weight: 900;
    box-shadow: 0 12px 30px rgba(37, 99, 235, .25);
}

.brand-title {
    font-size: 22px;
    font-weight: 900;
    letter-spacing: -.3px;
}

.brand-subtitle {
    margin-top: 3px;
    color: var(--muted);
    font-size: 13px;
}

.nav {
    margin-top: 22px;
    display: grid;
    gap: 6px;
}

.nav a {
    display: flex;
    align-items: center;
    gap: 11px;
    padding: 12px 13px;
    border-radius: 13px;
    color: var(--soft);
    text-decoration: none;
    transition: .16s ease;
}

.nav a:hover,
.nav a.active {
    background: rgba(37, 99, 235, .24);
    color: #fff;
}

.nav a.disabled {
    opacity: .52;
    cursor: not-allowed;
}

.nav em {
    margin-left: auto;
    color: var(--muted);
    font-size: 11px;
    font-style: normal;
}

.nav-section {
    color: #64748B;
    font-size: 11px;
    font-weight: 800;
    letter-spacing: .08em;
    text-transform: uppercase;
    margin: 18px 8px 6px;
}

.sidebar-footer {
    position: absolute;
    bottom: 22px;
    left: 18px;
    right: 18px;
    text-align: center;
    color: #64748B;
    font-size: 12px;
}

.sidebar-footer a {
    text-decoration: none;
}

.main {
    margin-left: 292px;
    width: calc(100% - 292px);
    padding: 38px;
}

.page-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 24px;
    margin-bottom: 24px;
}

.eyebrow {
    color: var(--blue2);
    font-size: 13px;
    font-weight: 900;
    text-transform: uppercase;
    letter-spacing: .08em;
    margin-bottom: 8px;
}

.page-header h1 {
    margin: 0;
    font-size: 42px;
    letter-spacing: -.8px;
}

.page-header p {
    margin: 10px 0 0;
    color: var(--muted);
    font-size: 17px;
    max-width: 840px;
    line-height: 1.55;
}

.open-vault,
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    background: linear-gradient(135deg, var(--blue), #1D4ED8);
    color: #fff;
    padding: 13px 18px;
    border-radius: 13px;
    font-weight: 800;
    box-shadow: 0 14px 30px rgba(37, 99, 235, .22);
    border: 0;
}

.hero {
    position: relative;
    overflow: hidden;
    padding: 38px;
    border-radius: 28px;
    background:
        radial-gradient(circle at right top, rgba(96, 165, 250, .28), transparent 30%),
        linear-gradient(135deg, rgba(16, 34, 72, .96), rgba(8, 21, 47, .82));
    border: 1px solid rgba(96, 165, 250, .24);
    box-shadow: 0 24px 70px rgba(0, 0, 0, .22);
}

.hero h2 {
    margin: 0;
    font-size: 38px;
    letter-spacing: -.8px;
}

.hero p {
    max-width: 850px;
    color: var(--soft);
    line-height: 1.75;
    font-size: 17px;
}

.search-wrap {
    margin-top: 24px;
}

.search-wrap input {
    width: 100%;
    max-width: 720px;
    padding: 17px 18px;
    border-radius: 15px;
    background: rgba(5, 14, 30, .65);
    border: 1px solid rgba(148, 163, 184, .25);
    color: #fff;
    font-size: 16px;
    outline: none;
}

.grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
    margin-top: 22px;
}

.card,
.article {
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 24px;
    box-shadow: 0 18px 50px rgba(0, 0, 0, .18);
}

.card h3,
.article h2,
.article h3 {
    margin-top: 0;
}

.card p,
.article p,
.article li {
    color: var(--soft);
    line-height: 1.68;
}

.guide-card {
    text-decoration: none;
    display: block;
    transition: transform .16s ease, border-color .16s ease;
}

.guide-card:hover {
    transform: translateY(-3px);
    border-color: rgba(96, 165, 250, .45);
}

.guide-icon {
    font-size: 32px;
    margin-bottom: 12px;
}

.guide-meta {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 14px;
    margin-bottom: 22px;
}

.guide-meta div {
    background: var(--panel2);
    border: 1px solid var(--line);
    border-radius: 16px;
    padding: 15px;
}

.guide-meta span {
    display: block;
    color: var(--muted);
    font-size: 12px;
    margin-bottom: 6px;
}

.guide-meta strong {
    font-size: 15px;
}

.article {
    max-width: 1080px;
}

.article h2 {
    margin-top: 38px;
    padding-top: 28px;
    border-top: 1px solid var(--line);
}

.article h2:first-child {
    margin-top: 0;
    padding-top: 0;
    border-top: 0;
}

.callout {
    margin: 18px 0;
    padding: 17px 18px;
    border-radius: 16px;
    border: 1px solid var(--line);
    background: rgba(8, 21, 47, .62);
}

.callout strong {
    display: block;
    margin-bottom: 7px;
}

.callout.info {
    border-color: rgba(96, 165, 250, .42);
    background: rgba(37, 99, 235, .14);
}

.callout.tip {
    border-color: rgba(34, 197, 94, .42);
    background: rgba(34, 197, 94, .10);
}

.callout.warn {
    border-color: rgba(245, 158, 11, .48);
    background: rgba(245, 158, 11, .12);
}

.callout.danger {
    border-color: rgba(239, 68, 68, .48);
    background: rgba(239, 68, 68, .12);
}

.steps {
    counter-reset: step;
    display: grid;
    gap: 14px;
    margin: 18px 0;
}

.step {
    background: rgba(5, 14, 30, .38);
    border: 1px solid var(--line);
    border-radius: 16px;
    padding: 18px;
    color: var(--soft);
    line-height: 1.65;
}

.step::before {
    counter-increment: step;
    content: counter(step);
    display: inline-grid;
    place-items: center;
    width: 30px;
    height: 30px;
    margin-right: 10px;
    border-radius: 50%;
    background: var(--blue);
    color: #fff;
    font-weight: 900;
}

.screenshot {
    margin: 18px 0 26px;
    border-radius: 20px;
    border: 1px solid rgba(148, 163, 184, .20);
    background: rgba(5, 14, 30, .42);
    padding: 14px;
}

.screenshot img {
    width: 100%;
    display: block;
    border-radius: 14px;
}

.screenshot-placeholder {
    min-height: 240px;
    border: 1px dashed rgba(148, 163, 184, .38);
    border-radius: 14px;
    display: grid;
    place-items: center;
    color: var(--muted);
    text-align: center;
    padding: 24px;
}

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

.faq {
    display: grid;
    gap: 12px;
}

.faq-item {
    background: rgba(5, 14, 30, .35);
    border: 1px solid var(--line);
    border-radius: 14px;
    padding: 17px;
}

.faq-item h3 {
    margin: 0 0 8px;
}

.video-box {
    display: flex;
    gap: 16px;
    align-items: center;
    background: linear-gradient(135deg, rgba(37, 99, 235, .18), rgba(96, 165, 250, .09));
    border: 1px solid rgba(96, 165, 250, .28);
    border-radius: 18px;
    padding: 20px;
    margin: 18px 0;
}

.video-icon {
    width: 56px;
    height: 56px;
    border-radius: 16px;
    display: grid;
    place-items: center;
    background: rgba(37, 99, 235, .32);
    font-size: 25px;
}

.badge {
    display: inline-block;
    padding: 5px 10px;
    border-radius: 999px;
    background: rgba(37, 99, 235, .22);
    color: #BFDBFE;
    font-size: 13px;
    font-weight: 800;
}

@media (max-width: 980px) {
    .app-shell {
        display: block;
    }

    .sidebar {
        position: relative;
        width: 100%;
        min-height: auto;
    }

    .sidebar-footer {
        position: static;
        margin-top: 25px;
    }

    .main {
        margin-left: 0;
        width: 100%;
        padding: 24px;
    }

    .page-header,
    .grid,
    .guide-meta {
        display: block;
    }

    .open-vault {
        margin-top: 18px;
    }

    .grid > *,
    .guide-meta > * {
        margin-bottom: 14px;
    }

    .page-header h1 {
        font-size: 32px;
    }
}