:root {
    --bg: #f4f8fb;
    --text: #14213d;
    --muted: #52607a;
    --card: #ffffff;
    --accent: #0ea5e9;
    --accent-strong: #0369a1;
    --ring: rgba(14, 165, 233, 0.28);
    --shadow: 0 16px 36px rgba(15, 23, 42, 0.12);
}

body[data-theme="night"] {
    --bg: #0b1020;
    --text: #e5ecff;
    --muted: #a5b4d4;
    --card: #141a2e;
    --accent: #38bdf8;
    --accent-strong: #7dd3fc;
    --ring: rgba(125, 211, 252, 0.35);
    --shadow: 0 20px 44px rgba(2, 6, 23, 0.45);
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
    font-family: "SUIT", sans-serif;
    color: var(--text);
    background:
        radial-gradient(circle at 12% 12%, #d9f2ff 0%, transparent 36%),
        radial-gradient(circle at 88% 8%, #ffe6cc 0%, transparent 30%),
        linear-gradient(145deg, #eef4fb 0%, var(--bg) 70%);
}

body[data-theme="night"] {
    background:
        radial-gradient(circle at 12% 12%, rgba(56, 189, 248, 0.22) 0%, transparent 36%),
        radial-gradient(circle at 88% 8%, rgba(59, 130, 246, 0.22) 0%, transparent 30%),
        linear-gradient(145deg, #070b15 0%, var(--bg) 72%);
}

.container {
    width: min(1080px, 92vw);
    margin: 3.4rem auto 3rem;
}

.hero {
    text-align: center;
    margin-bottom: 1.8rem;
}

.eyebrow {
    margin: 0;
    color: var(--accent-strong);
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

h1 {
    margin: 0.3rem 0 0.45rem;
    font-family: "Black Han Sans", sans-serif;
    font-size: clamp(2rem, 5.8vw, 3.2rem);
    letter-spacing: 0.01em;
}

.sub-title {
    margin: 0 0 1.2rem;
    color: var(--muted);
    font-size: 1rem;
}

.theme-switch {
    display: inline-flex;
    gap: 0.45rem;
    margin-bottom: 0.9rem;
    padding: 0.35rem;
    border-radius: 999px;
    background: rgba(148, 163, 184, 0.16);
}

.theme-btn {
    border: none;
    border-radius: 999px;
    padding: 0.45rem 0.9rem;
    font-size: 0.82rem;
    font-weight: 800;
    letter-spacing: 0.06em;
    color: var(--muted);
    background: transparent;
    cursor: pointer;
}

.theme-btn.is-active {
    color: #ffffff;
    background: linear-gradient(135deg, var(--accent), #22d3ee);
}

.generated-at {
    margin: 0 0 1rem;
    color: var(--muted);
    font-size: 0.95rem;
    font-weight: 500;
}

#generate-btn {
    border: none;
    border-radius: 999px;
    background: linear-gradient(135deg, var(--accent), #22d3ee);
    color: #ffffff;
    font-size: 1rem;
    font-weight: 700;
    padding: 0.78rem 1.4rem;
    cursor: pointer;
    box-shadow: 0 14px 28px rgba(14, 165, 233, 0.26);
    transition: transform 140ms ease, box-shadow 140ms ease;
}

#generate-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 20px 30px rgba(14, 165, 233, 0.3);
}

#generate-btn:focus-visible {
    outline: 3px solid var(--ring);
    outline-offset: 3px;
}

.set-grid {
    display: grid;
    gap: 0.9rem;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.lotto-set {
    background: var(--card);
    border-radius: 18px;
    padding: 0.9rem 1rem 1rem;
    box-shadow: var(--shadow);
    border: 1px solid rgba(226, 232, 240, 0.75);
    animation: rise 280ms ease both;
}

.set-title {
    margin: 0 0 0.7rem;
    font-size: 1.02rem;
    font-weight: 800;
    color: var(--accent-strong);
}

.numbers-row {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.lotto-number {
    width: 2.55rem;
    aspect-ratio: 1;
    border-radius: 50%;
    background: linear-gradient(145deg, #ecfeff 0%, #bae6fd 100%);
    border: 1px solid #7dd3fc;
    display: grid;
    place-items: center;
    font-size: 0.95rem;
    font-weight: 800;
    color: #0c4a6e;
}

body[data-theme="night"] .lotto-number {
    background: linear-gradient(145deg, rgba(56, 189, 248, 0.22) 0%, rgba(99, 102, 241, 0.28) 100%);
    border-color: rgba(125, 211, 252, 0.44);
    color: #dbeafe;
}

@keyframes rise {
    from {
        opacity: 0;
        transform: translateY(8px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@media (max-width: 640px) {
    .container {
        margin-top: 2rem;
    }

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

    .lotto-number {
        width: 2.35rem;
        font-size: 0.9rem;
    }
}