:root {
    color-scheme: light;
    --color-bg: #f4f6fb;
    --color-surface: #ffffff;
    --color-surface-alt: #f0f4ff;
    --color-border: rgba(15, 23, 42, 0.08);
    --color-text: #0f172a;
    --color-text-muted: #475569;
    --color-heading: #0a0f1c;
    --color-primary: #2563eb;
    --color-primary-soft: #dbeafe;
    --color-accent: #0ea5e9;
    --radius: 18px;
    --shadow-soft: 0 25px 50px -12px rgba(15, 23, 42, 0.15);
    --shadow-card: 0 10px 30px rgba(15, 23, 42, 0.08);
    --transition: 200ms ease;
    --font-body: 'Inter', 'SF Pro Display', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

:root[data-theme='dark'] {
    color-scheme: dark;
    --color-bg: #0b1220;
    --color-surface: #101b32;
    --color-surface-alt: #0f172a;
    --color-border: rgba(255, 255, 255, 0.08);
    --color-text: #e2e8f0;
    --color-text-muted: #94a3b8;
    --color-heading: #f8fafc;
    --color-primary: #3b82f6;
    --color-primary-soft: rgba(59, 130, 246, 0.16);
    --shadow-soft: 0 25px 50px -12px rgba(15, 23, 42, 0.6);
    --shadow-card: 0 20px 45px rgba(8, 15, 30, 0.8);
}

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

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

body {
    font-family: var(--font-body);
    background: var(--color-bg);
    color: var(--color-text);
    min-height: 100vh;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

img {
    display: block;
    max-width: 100%;
}

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

button,
input,
select,
textarea {
    font: inherit;
}

button {
    cursor: pointer;
    border: none;
    transition: transform var(--transition), box-shadow var(--transition);
}

button:focus-visible,
input:focus-visible,
textarea:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

.app-shell {
    max-width: 1200px;
    margin: 0 auto;
    padding: 3rem 1.5rem 4rem;
}

.card {
    background: var(--color-surface);
    border-radius: var(--radius);
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-card);
    padding: 1.75rem;
}

.seo-warning {
    position: fixed;
    right: 24px;
    bottom: 24px;
    background: var(--color-primary);
    color: #fff;
    padding: 0.6rem 1.2rem;
    border-radius: 999px;
    font-size: 0.85rem;
    letter-spacing: 0.04em;
    box-shadow: var(--shadow-card);
    z-index: 10;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

@media (max-width: 768px) {
    .app-shell {
        padding: 2rem 1.25rem 3rem;
    }

    .card {
        padding: 1.5rem;
    }

    .seo-warning {
        left: 24px;
        right: 24px;
        border-radius: 14px;
        text-align: center;
    }
}