/* CSS by claude.ai */

@import url('https://fonts.googleapis.com/css2?family=SF+Pro+Display:wght@300;400;500&family=DM+Sans:wght@300;400;500&display=swap');

/* ── Reset & base ── */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --glass-bg: rgba(255, 255, 255, 0.06);
    --glass-border: rgba(255, 255, 255, 0.18);
    --glass-highlight: rgba(255, 255, 255, 0.35);
    --glass-shadow: rgba(0, 0, 0, 0.6);
    --blur: 24px;
    --radius: 24px;
    --text: #f0f0f0;
    --text-muted: rgba(255, 255, 255, 0.45);
    --accent: #ffffff;
}

/* ── Background ── */
* {
    font-family: 'DM Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    color: var(--text);
    background-color: transparent;
}

html, body {
    height: 100vh;
    overflow: hidden;
    background-color: #0a0a0a;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 24px;
}

/* ── Heading ── */
h1 {
    font-family: 'DM Sans', sans-serif;
    font-weight: 300;
    font-size: clamp(1.6rem, 5vw, 2.8rem);
    letter-spacing: -0.04em;
    text-align: center;
    margin-bottom: 32px;
    background: linear-gradient(160deg, #ffffff 0%, rgba(255,255,255,0.5) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    filter: drop-shadow(0 0 40px rgba(255,255,255,0.15));
}

.title-result {
    margin-top: 32px;
}

/* ── Card — liquid glass ── */
.card {
    position: relative;
    width: min(380px, 90vw);
    padding: 28px 28px;
    border-radius: var(--radius);
    background: transparent;
    border: 1px solid var(--glass-border);
    box-shadow:
        0 32px 64px rgba(0,0,0,0.5),
        0 8px 24px rgba(0,0,0,0.3);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
    animation: fadeUp 0.9s cubic-bezier(0.16, 1, 0.3, 1) 0.1s both;
    overflow: hidden;
}

/* glare removed */

/* noise removed */

/* ── Input ── */
input[type="number"] {
    width: 100%;
    padding: 14px 18px;
    border-radius: 14px;
    border: 1px solid rgba(255,255,255,0.12);
    background: rgba(255,255,255,0.05);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    font-size: 1rem;
    font-weight: 300;
    color: var(--text);
    letter-spacing: 0.01em;
    outline: none;
    transition:
        border-color 0.25s ease,
        background 0.25s ease,
        box-shadow 0.25s ease;
    -moz-appearance: textfield;
    appearance: textfield;
}

input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
    -webkit-appearance: none;
}

input[type="number"]::placeholder {
    color: var(--text-muted);
    font-weight: 300;
}

input[type="number"]:focus {
    border-color: rgba(255,255,255,0.35);
    background: rgba(255,255,255,0.09);
    box-shadow:
        0 0 0 3px rgba(255,255,255,0.07),
        0 1px 0 rgba(255,255,255,0.2) inset;
}

/* ── Button ── */
button,
#submitBtn {
    width: 100%;
    padding: 14px 18px;
    border-radius: 14px;
    border: 1px solid rgba(255,255,255,0.9);
    background: rgba(255,255,255,0.92);
    color: #0a0a0a;
    font-family: 'DM Sans', sans-serif;
    font-size: 0.95rem;
    font-weight: 500;
    letter-spacing: 0.02em;
    cursor: pointer;
    transition:
        background 0.2s ease,
        transform 0.15s ease,
        box-shadow 0.2s ease,
        border-color 0.2s ease;
    box-shadow:
        0 1px 0 rgba(255,255,255,0.5) inset,
        0 4px 16px rgba(0,0,0,0.3);
    position: relative;
    z-index: 1;
}

button:hover,
#submitBtn:hover {
    background: rgba(255,255,255,1);
    box-shadow:
        0 1px 0 rgba(255,255,255,0.6) inset,
        0 8px 32px rgba(0,0,0,0.4);
    transform: translateY(-1px);
}

button:active,
#submitBtn:active {
    background: rgba(220,220,220,0.95);
    transform: translateY(0px) scale(0.99);
    box-shadow:
        0 1px 0 rgba(255,255,255,0.3) inset,
        0 2px 8px rgba(0,0,0,0.3);
}

/* ── Animations ── */
@keyframes fadeDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeUp {
    from {
        opacity: 0;
        transform: translateY(30px) scale(0.97);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

/* ── Responsive ── */
@media (max-width: 480px) {
    h1 {
        margin-bottom: 32px;
    }

    .card {
        padding: 28px 22px;
        gap: 14px;
    }

    input[type="number"],
    button,
    #submitBtn {
        padding: 13px 16px;
        font-size: 0.9rem;
    }
}

@media (prefers-reduced-motion: reduce) {
    h1, .card {
        animation: none;
    }
}

/* ── Footer ── */
footer {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 18px 24px;
    display: flex;
    justify-content: center;
    align-items: center;
    border-top: 1px solid rgba(255, 255, 255, 0.06);
    background: linear-gradient(to top, rgba(0,0,0,0.4), transparent);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

footer p {
    font-size: 0.78rem;
    font-weight: 400;
    letter-spacing: 0.04em;
    color: var(--text-muted);
    transition: color 0.2s ease;
}

footer p:hover {
    color: rgba(255, 255, 255, 0.7);
}

footer a {
    color: var(--text-muted);
    text-decoration: none;
    transition: color 0.2s ease;
}

footer a:hover {
    color: rgba(255, 255, 255, 0.7);
}