:root {
    --bg: #0e1116;
    --panel: #161b22;
    --panel-2: #1f2630;
    --border: #2a313c;
    --text: #e6edf3;
    --text-dim: #9aa6b2;
    --accent: #4f9eff;
    --accent-strong: #2c7be0;
    --accent-soft: rgba(79, 158, 255, 0.12);
    --success: #2ecc71;
    --danger: #ff6b6b;
    --warn: #ffb454;
    --shadow: 0 6px 28px rgba(0, 0, 0, 0.35);
    --radius: 12px;
    --radius-sm: 8px;
    --gap: 16px;
}

* {
    box-sizing: border-box;
}

/* Ensure the HTML `hidden` attribute always wins over display: flex / grid. */
[hidden] { display: none !important; }

html, body {
    margin: 0;
    padding: 0;
    background: var(--bg);
    color: var(--text);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
        "Helvetica Neue", Arial, sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    line-height: 1.55;
    min-height: 100vh;
}

a {
    color: var(--accent);
    text-decoration: none;
}

a:hover, a:focus {
    text-decoration: underline;
}

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

.container {
    max-width: 760px;
    margin: 0 auto;
    padding: 32px 20px 80px;
}

.hero {
    text-align: center;
    margin-bottom: 28px;
}

.hero h1 {
    font-size: clamp(28px, 5vw, 40px);
    margin: 0 0 6px;
    letter-spacing: -0.01em;
}

.tagline {
    color: var(--text-dim);
    margin: 0;
    font-size: 16px;
}

/* --- Lookup card --------------------------------------------------------- */

.lookup-card {
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 22px;
    box-shadow: var(--shadow);
}

#lookup-form {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

#username {
    flex: 1 1 240px;
    min-width: 0;
    padding: 12px 14px;
    font-size: 16px;
    background: var(--panel-2);
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    outline: none;
    transition: border-color 120ms ease, box-shadow 120ms ease;
}

#username:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-soft);
}

#username:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

#lookup-btn {
    padding: 12px 20px;
    font-size: 16px;
    font-weight: 600;
    color: white;
    background: var(--accent-strong);
    border: 1px solid var(--accent-strong);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: background 120ms ease, transform 80ms ease;
}

#lookup-btn:hover:not(:disabled) {
    background: var(--accent);
    border-color: var(--accent);
}

#lookup-btn:active:not(:disabled) {
    transform: translateY(1px);
}

#lookup-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.hint {
    margin: 12px 0 0;
    color: var(--text-dim);
    font-size: 13px;
}

/* --- Status / error / result --------------------------------------------- */

.status, .error, .result {
    margin-top: 18px;
    padding: 14px 16px;
    border-radius: var(--radius-sm);
    font-size: 15px;
}

.status {
    background: var(--panel-2);
    color: var(--text-dim);
    display: flex;
    align-items: center;
    gap: 10px;
}

.status::before {
    content: "";
    width: 14px;
    height: 14px;
    border: 2px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.error {
    background: rgba(255, 107, 107, 0.08);
    border: 1px solid rgba(255, 107, 107, 0.4);
    color: var(--danger);
}

.result {
    background: var(--panel-2);
    border: 1px solid var(--border);
}

.result-header {
    display: flex;
    align-items: baseline;
    gap: 10px;
    margin-bottom: 14px;
}

.result-header h3 {
    margin: 0;
    font-size: 20px;
    color: var(--text);
    word-break: break-word;
}

.result-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 14px;
    margin: 0 0 12px;
}

.result-item {
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 12px 14px;
}

.result-item dt {
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-dim);
    margin-bottom: 4px;
}

.result-item dd {
    margin: 0;
    font-size: 22px;
    font-weight: 600;
    color: var(--text);
}

.result-item.percentile-item dd {
    color: var(--accent);
}

.result-population {
    margin: 0;
    font-size: 13px;
    color: var(--text-dim);
}

/* --- Methodology --------------------------------------------------------- */

.methodology {
    margin-top: 28px;
}

#methodology-toggle {
    width: 100%;
    text-align: left;
    padding: 14px 18px;
    font-size: 15px;
    font-weight: 600;
    color: var(--text);
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 10px;
    transition: background 120ms ease;
}

#methodology-toggle:hover {
    background: var(--panel-2);
}

#methodology-toggle .chevron {
    color: var(--accent);
    transition: transform 180ms ease;
    display: inline-block;
}

#methodology-toggle[aria-expanded="true"] .chevron {
    transform: rotate(90deg);
}

.methodology-content {
    margin-top: 14px;
    padding: 22px;
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.methodology-content h3 {
    margin: 22px 0 8px;
    font-size: 18px;
    color: var(--text);
}

.methodology-content h3:first-of-type {
    margin-top: 0;
}

.methodology-content p {
    color: var(--text);
    margin: 0 0 12px;
}

.methodology-content figure {
    margin: 18px 0 8px;
    padding: 14px;
    background: var(--panel-2);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
}

.methodology-content figcaption {
    margin-top: 10px;
    font-size: 13px;
    color: var(--text-dim);
    text-align: center;
}

.disclaimer {
    background: rgba(255, 180, 84, 0.08);
    border: 1px solid rgba(255, 180, 84, 0.4);
    color: var(--warn);
    padding: 12px 14px;
    border-radius: var(--radius-sm);
    font-size: 14px;
    margin-bottom: 18px;
}

.disclaimer strong {
    color: var(--warn);
}

/* --- Footer -------------------------------------------------------------- */

.footer {
    margin-top: 40px;
    padding-top: 18px;
    border-top: 1px solid var(--border);
    font-size: 13px;
    color: var(--text-dim);
    text-align: center;
}

.footer p {
    margin: 0;
}

/* --- A11y ---------------------------------------------------------------- */

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

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

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation: none !important;
        transition: none !important;
    }
}