[data-theme="dark"] {
    --bg: #09090f;
    --surface: #121420;
    --text: #f7f8fb;
    --muted: #a7b0c0;
    --accent: #7c8cff;
    --accent-2: #30d5c8;
    --border: rgba(255, 255, 255, 0.1);
    --shadow: 0 20px 60px rgba(0, 0, 0, 0.35);
    --header-bg: rgba(9, 9, 15, 0.75);
    --glow-1: rgba(124, 140, 255, 0.35);
    --glow-2: rgba(48, 213, 200, 0.22);
    --card-top: rgba(255, 255, 255, 0.03);
    --card-bottom: rgba(255, 255, 255, 0.01);
    --badge-text: #dbeafe;
    --badge-bg: rgba(124, 140, 255, 0.2);
    --badge-border: rgba(124, 140, 255, 0.5);
    --nav-active-text: #fff;
    --btn-muted-text: #d9deeb;
    --btn-muted-bg: rgba(255, 255, 255, 0.03);
    --meta: #9aa8c3;
    --toggle-track: rgba(255, 255, 255, 0.12);
    --toggle-thumb: #f7f8fb;
    --toggle-icon: #a7b0c0;
}

[data-theme="light"] {
    --bg: #f3f5fb;
    --surface: #ffffff;
    --text: #121420;
    --muted: #5a6478;
    --accent: #5b6ee6;
    --accent-2: #1fa89c;
    --border: rgba(18, 20, 32, 0.12);
    --shadow: 0 16px 40px rgba(18, 20, 32, 0.08);
    --header-bg: rgba(255, 255, 255, 0.88);
    --glow-1: rgba(91, 110, 230, 0.18);
    --glow-2: rgba(31, 168, 156, 0.14);
    --card-top: rgba(255, 255, 255, 0.95);
    --card-bottom: rgba(243, 245, 251, 0.9);
    --badge-text: #2f3f8f;
    --badge-bg: rgba(91, 110, 230, 0.12);
    --badge-border: rgba(91, 110, 230, 0.35);
    --nav-active-text: #fff;
    --btn-muted-text: #3a4558;
    --btn-muted-bg: rgba(18, 20, 32, 0.04);
    --meta: #6b778c;
    --toggle-track: rgba(18, 20, 32, 0.12);
    --toggle-thumb: #ffffff;
    --toggle-icon: #5a6478;
}

*, *::before, *::after { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }

body {
    font-family: "Segoe UI", Roboto, Arial, sans-serif;
    background:
        radial-gradient(circle at 10% -10%, var(--glow-1), transparent 45%),
        radial-gradient(circle at 95% 10%, var(--glow-2), transparent 50%),
        var(--bg);
    color: var(--text);
    line-height: 1.65;
}

.container {
    width: min(1140px, calc(100% - 2rem));
    margin-inline: auto;
}

header {
    position: sticky;
    top: 0;
    z-index: 20;
    backdrop-filter: blur(10px);
    background: var(--header-bg);
    border-bottom: 1px solid var(--border);
}

.topbar {
    min-height: 72px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
}

.topbar-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.theme-switch {
    display: inline-flex;
    align-items: center;
    gap: .55rem;
    cursor: pointer;
    user-select: none;
    flex-shrink: 0;
}

.theme-switch input {
    position: absolute;
    opacity: 0;
    width: 0;
    height: 0;
    pointer-events: none;
}

.theme-slider {
    position: relative;
    width: 52px;
    height: 28px;
    background: var(--toggle-track);
    border: 1px solid var(--border);
    border-radius: 999px;
}

.theme-slider::before {
    content: "";
    position: absolute;
    top: 3px;
    left: 3px;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--toggle-thumb);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
    transition: transform .2s ease;
}

.theme-switch input:checked + .theme-slider::before {
    transform: translateX(24px);
}

.theme-icon {
    font-size: 1rem;
    line-height: 1;
    color: var(--toggle-icon);
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: .7rem;
    color: var(--text);
    text-decoration: none;
    font-size: 1.1rem;
    font-weight: 800;
    letter-spacing: 0.04em;
}

.brand-logo {
    display: block;
    height: 42px;
    width: auto;
    flex-shrink: 0;
}

.brand-logo--light-theme { display: none; }

[data-theme="light"] .brand-logo--dark-theme { display: none; }
[data-theme="light"] .brand-logo--light-theme { display: block; }

.brand-name {
    line-height: 1;
    white-space: nowrap;
}

nav {
    display: flex;
    flex-wrap: wrap;
    gap: .5rem;
}

nav a {
    text-decoration: none;
    color: var(--muted);
    font-weight: 600;
    padding: .5rem .9rem;
    border-radius: 999px;
}

nav a:hover,
nav a.active {
    color: var(--nav-active-text);
    background: linear-gradient(90deg, var(--accent), var(--accent-2));
}

.hero {
    padding: clamp(2rem, 6vw, 4rem) 0 1.5rem;
}

.badge {
    display: inline-block;
    font-size: .82rem;
    font-weight: 700;
    color: var(--badge-text);
    background: var(--badge-bg);
    border: 1px solid var(--badge-border);
    padding: .35rem .7rem;
    border-radius: 999px;
}

h1 {
    margin: .9rem 0 0;
    font-size: clamp(1.85rem, 4.8vw, 3.2rem);
    line-height: 1.15;
}

.hero p {
    margin-top: 1rem;
    color: var(--muted);
    max-width: 65ch;
    font-size: 1.02rem;
}

.cta-row {
    display: flex;
    gap: .8rem;
    flex-wrap: wrap;
    margin-top: 1.25rem;
}

.btn {
    display: inline-flex;
    text-decoration: none;
    font-weight: 700;
    border-radius: .85rem;
    padding: .72rem 1.05rem;
}

.btn-primary {
    color: #fff;
    background: linear-gradient(90deg, var(--accent), #9b68ff);
}

.btn-muted {
    color: var(--btn-muted-text);
    border: 1px solid var(--border);
    background: var(--btn-muted-bg);
}

footer {
    border-top: 1px solid var(--border);
    padding: 1.5rem 0 2rem;
    color: var(--muted);
    font-size: .94rem;
}

.footer-inner {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: .85rem;
}

.footer-tagline {
    margin: 0;
    max-width: 42rem;
    line-height: 1.6;
}

.footer-link {
    color: var(--accent-2);
    font-weight: 600;
    text-decoration: none;
}

.footer-link:hover {
    text-decoration: underline;
}

@media (max-width: 900px) {
    .topbar { flex-wrap: wrap; padding: .6rem 0; }
    .topbar-actions { width: 100%; justify-content: space-between; }
}