:root {
    --bg-1: #0f172a;
    --bg-2: #020617;
    --accent: #38bdf8;
    --accent-soft: rgba(56, 189, 248, 0.2);
    --error: #f97373;
    --text-main: #e5e7eb;
    --text-soft: #9ca3af;
    --card-bg: rgba(15, 23, 42, 0.9);
    --radius-xl: 18px;
    --shadow-strong: 0 20px 45px rgba(0, 0, 0, 0.6);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    min-height: 100vh;
    font-family: system-ui, sans-serif;
    background: radial-gradient(circle at top, #1e293b 0, #020617 50%, #000 100%);
    color: var(--text-main);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
}

.glow {
    position: fixed;
    inset: 0;
    pointer-events: none;
    background:
        radial-gradient(circle at 10% 20%, rgba(56, 189, 248, 0.18), transparent 55%),
        radial-gradient(circle at 90% 80%, rgba(59, 130, 246, 0.18), transparent 55%);
    z-index: -1;
}

.card {
    width: 100%;
    max-width: 760px;
    background: var(--card-bg);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-strong);
    border: 1px solid rgba(148, 163, 184, 0.25);
    padding: 24px;
    backdrop-filter: blur(16px);
}

.grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    margin-bottom: 18px;
}

label {
    font-size: 0.8rem;
    letter-spacing: 0.14em;
    color: var(--text-soft);
}

.label-n-k {
    margin-left: 15px;
    font-size: 0.9rem;
    letter-spacing: 0.14em;
    color: var(--text-soft);
}

input[type="number"],
input[type="text"] {
    margin-top: 10px;
    background: rgba(15, 23, 42, 0.75);
    padding: 9px 11px;
    border-radius: 10px;
    border: 1px solid rgba(148, 163, 184, 0.6);
    color: var(--text-main);
    width: 100%;
}

button {
    display: block;
    margin: 22px auto 0 auto;
    position: relative;
    border: none;
    border-radius: 999px;
    padding: 12px 22px;
    background: linear-gradient(135deg, #38bdf8, #6366f1);
    color: #ffffff;
    font-weight: 600;
    cursor: pointer;
    font-size: 1rem;
    letter-spacing: 0.05em;
    transition: transform 0.15s ease, box-shadow 0.25s ease;
    box-shadow: 0 0 12px rgba(56, 189, 248, 0.45);
    overflow: hidden;
}

ì button:hover {
    transform: translateY(-2px);
    box-shadow: 0 0 18px rgba(56, 189, 248, 0.7),
        0 0 32px rgba(99, 102, 241, 0.45);
}

button:active {
    transform: translateY(0);
    box-shadow: 0 0 10px rgba(56, 189, 248, 0.45);
}

button::after {
    content: "";
    position: absolute;
    inset: 0;
    border-radius: inherit;
    background: linear-gradient(120deg,
            rgba(255, 255, 255, 0.25) 0%,
            rgba(255, 255, 255, 0.05) 40%,
            rgba(255, 255, 255, 0) 60%);
    opacity: 0;
    transition: opacity 0.3s, transform 0.4s;
    transform: translateX(-120%);
}

button:hover::after {
    opacity: 1;
    transform: translateX(120%);
}

.switch {
    position: relative;
    width: 52px;
    height: 28px;
}

.switch input {
    display: none;
}

.slider {
    position: absolute;
    inset: 0;
    cursor: pointer;
    background: rgba(15, 23, 42, 0.9);
    border-radius: 999px;
    border: 1px solid rgba(148, 163, 184, 0.6);
}

.slider::before {
    content: "";
    position: absolute;
    height: 20px;
    width: 20px;
    left: 4px;
    top: 3px;
    background: #e5e7eb;
    border-radius: 999px;
    transition: transform .2s;
}

.switch input:checked+.slider {
    background: var(--accent);
    border-color: var(--accent);
}

.switch input:checked+.slider::before {
    transform: translateX(20px);
}

.toggle-row {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 12px;
    border-radius: 12px;
    background: radial-gradient(circle at 0 0, rgba(56, 189, 248, 0.18), transparent 60%);
    border: 1px solid rgba(148, 163, 184, 0.45);
    margin-bottom: 16px;
}

.result-card {
    border-radius: 14px;
    padding: 12px;
    background: radial-gradient(circle at top left, rgba(56, 189, 248, 0.18), transparent 65%);
    border: 1px solid rgba(148, 163, 184, 0.6);
    font-family: "JetBrains Mono", monospace;
}

.error {
    color: var(--error);
}

.label-with-info {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex: 1;
    font-size: 0.95rem;
}

.info-icon {
    margin-left: 8px;
    cursor: pointer;
    width: 20px;
    height: 20px;
    min-width: 20px;
    min-height: 20px;
    border-radius: 50%;
    background: rgba(56, 189, 248, 0.25);
    border: 1px solid var(--accent);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--accent);
    user-select: none;
    position: relative;
    transition: background 0.2s, transform 0.15s;
}

.info-icon::before {
    content: "?";
}

.info-icon:hover {
    background: rgba(56, 189, 248, 0.38);
    transform: scale(1.08);
}

.info-icon::after {
    content: attr(data-tooltip);
    position: absolute;
    right: 110%;
    top: 50%;
    transform: translateY(-50%);
    background: var(--card-bg);
    border: 1px solid rgba(148, 163, 184, 0.5);
    padding: 6px 10px;
    font-size: 0.75rem;
    width: max-content;
    max-width: 220px;
    border-radius: 8px;
    opacity: 0;
    pointer-events: none;
    transition: opacity .2s;
    color: var(--text-main);
    z-index: 20;
    white-space: normal;
    margin-right: 10px;
}

.info-icon:hover::after {
    opacity: 1;
}

@media (max-width: 560px) {

    .card {
        padding: 18px;
        border-radius: 14px;
    }

    .toggle-row {
        flex-direction: row;
        justify-content: space-between;
        padding: 10px;
    }

    .label-with-info {

        font-size: 0.85rem;
    }

    .grid {
        grid-template-columns: 1fr;
        gap: 14px;
    }

    input[type="number"],
    input[type="text"] {
        padding: 12px 14px;
        font-size: 1rem;
    }

    button {
        width: 100%;
        max-width: 260px;
        margin: 20px auto 0 auto;
        font-size: 1rem;
        padding: 14px 0;
    }

    .info-icon::after {
        left: unset;
        right: 110%;
        top: 50%;
        transform: translateY(-50%);
        text-align: left;
        max-width: 200px;
        white-space: normal;
        margin-right: 10px;
    }
}

@media (min-width: 560px) and (max-width: 820px) {

    .grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }

    button {
        margin-top: 24px;
        font-size: 1.05rem;
    }

    .info-icon::after {
        left: unset;
        right: 110%;
        top: 50%;
        transform: translateY(-50%);
        text-align: left;
        max-width: 200px;
        white-space: normal;
        margin-right: 10px;
    }
}

@media (min-width: 1200px) {
    .card {
        max-width: 820px;
    }
}