:root {
    color-scheme: dark;
    font-family: "Segoe UI", Arial, sans-serif;
    font-size: 16px;
    line-height: 1.6;

    --bg: #0b1120;
    --surface: #172338;
    --text: #ffffff;
    --muted: #d1d9e6;
    --accent: #93e5ff;
    --border: #71829c;
    --focus: #ffdf70;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    min-height: 100vh;
    background: var(--bg);
    color: var(--text);
}

header {
    padding: 2.5rem clamp(1rem, 5vw, 4rem);
    border-bottom: 1px solid var(--border);
    background: var(--surface);
}

main {
    width: min(100% - 2rem, 1200px);
    margin: 2rem auto;
    display: grid;
    gap: 1.5rem;
}

section {
    padding: 1.75rem;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
}

h1, h2 {
    line-height: 1.3;
}

p {
    color: var(--muted);
    max-width: 75ch;
}

a {
    color: var(--accent);
    text-underline-offset: 0.2em;
}

a:hover {
    text-decoration-thickness: 3px;
}

:focus-visible {
    outline: 3px solid var(--focus);
    outline-offset: 4px;
}

button, input, select {
    font: inherit;
}

button {
    min-height: 44px;
    min-width: 44px;
    cursor: pointer;
}

.skip-link {
    position: absolute;
    top: 1rem;
    left: 1rem;
    z-index: 1000;
    padding: 0.75rem 1rem;
    background: #ffdf70;
    color: #0b1120;
    font-weight: 700;
    border-radius: 6px;
    transform: translateY(-200%);
}

.skip-link:focus {
    transform: translateY(0);
    outline: 3px solid #ffffff;
    outline-offset: 3px;
}

/* Arrange upload controls vertically with consistent spacing. */
#prediction-form {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 1rem;
    margin-top: 1.5rem;
}

#csv-file {
    max-width: 100%;
}

#predict-button {
    padding: 0.75rem 1.25rem;
    border: 1px solid transparent;
    border-radius: 0.5rem;
    background-color: #b8e1ff;
    color: #111827;
    font: inherit;
    font-weight: 600;
    cursor: pointer;
}

#predict-button:disabled {
    opacity: 0.65;
    cursor: wait;
}

#predict-button:focus-visible,
#csv-file:focus-visible,
#download-link:focus-visible {
    outline: 3px solid #ffdf80;
    outline-offset: 4px;
}

#upload-status {
    margin-top: 1rem;
}

#download-link:not([hidden]) {
    display: inline-block;
    margin-top: 0.75rem;
    color: #b8e1ff;
    text-decoration: underline;
    text-underline-offset: 0.2rem;
}
@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
    }
}

@media (max-width: 600px) {
    header {
        padding: 1.5rem 1rem;
    }

    section {
        padding: 1.25rem;
    }
}