:root {
    color-scheme: light;
    --brand-green: #0f766e;
    --brand-green-dark: #0a4f4a;
    --brand-blue: #0b5fa5;
    --brand-blue-dark: #084879;
    --ink: #102a2b;
    --muted: #53666a;
    --surface: #ffffff;
    --canvas: #f3f7f6;
    --border: #c9d8d6;
    --danger: #9f1d2d;
    --success-surface: #e7f6ef;
    --danger-surface: #fff0f2;
    --focus: #ffbf47;
    --radius-sm: 0.5rem;
    --radius: 0.9rem;
    --radius-lg: 1.4rem;
    --shadow: 0 1rem 2.5rem rgb(16 42 43 / 0.09);
    --space-1: 0.35rem;
    --space-2: 0.65rem;
    --space-3: 1rem;
    --space-4: 1.5rem;
    --space-5: 2.25rem;
    --space-6: 3.5rem;
    font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html { background: var(--canvas); color: var(--ink); }
body { margin: 0; min-height: 100vh; display: flex; flex-direction: column; line-height: 1.55; }
a { color: var(--brand-blue-dark); text-underline-offset: 0.2em; }
a:hover { color: var(--brand-green-dark); }
button, input, select, textarea { font: inherit; }
button, .button { min-height: 2.75rem; }
:focus-visible { outline: 0.2rem solid var(--focus); outline-offset: 0.2rem; }

.skip-link { position: fixed; inset: 0 auto auto 0; z-index: 100; padding: var(--space-2) var(--space-3); background: var(--ink); color: white; transform: translateY(-120%); }
.skip-link:focus { transform: translateY(0); }
.site-header { display: flex; align-items: center; justify-content: space-between; gap: var(--space-3); padding: var(--space-3) clamp(1rem, 4vw, 4rem); background: var(--surface); border-bottom: 1px solid var(--border); }
.brand { display: inline-flex; align-items: center; gap: var(--space-2); color: var(--ink); font-size: 1.15rem; font-weight: 800; text-decoration: none; }
.brand-mark { display: grid; width: 2.4rem; aspect-ratio: 1; place-items: center; border-radius: 0.75rem 0.75rem 0.2rem 0.2rem; background: linear-gradient(145deg, var(--brand-green), var(--brand-blue)); color: white; }
.nav-list { display: flex; align-items: center; flex-wrap: wrap; justify-content: flex-end; gap: var(--space-3); margin: 0; padding: 0; list-style: none; }
.nav-list a, .link-button { font-weight: 700; }
.inline-form { display: inline; margin: 0; }
.link-button { border: 0; padding: 0; min-height: auto; background: transparent; color: var(--brand-blue-dark); text-decoration: underline; text-underline-offset: 0.2em; cursor: pointer; }
.site-main { width: min(74rem, 100%); margin-inline: auto; flex: 1; padding: clamp(1.25rem, 4vw, 4rem); }
.site-footer { padding: var(--space-4); color: var(--muted); text-align: center; }

.hero { max-width: 55rem; margin: clamp(1rem, 8vh, 6rem) auto var(--space-6); text-align: center; }
.hero h1, .auth-card h1 { margin: 0 0 var(--space-3); font-size: clamp(2.1rem, 8vw, 4.4rem); line-height: 1.04; letter-spacing: -0.04em; }
.lead { font-size: clamp(1.05rem, 2.5vw, 1.35rem); color: var(--muted); }
.eyebrow { margin: 0 0 var(--space-2); color: var(--brand-green-dark); font-size: 0.8rem; font-weight: 800; letter-spacing: 0.12em; text-transform: uppercase; }
.board-finder { max-width: 42rem; margin: var(--space-5) auto 0; text-align: left; }
.board-finder > label { display: block; margin-bottom: var(--space-2); font-weight: 750; }
.input-action { display: grid; gap: var(--space-2); }
.feature-grid { display: grid; gap: var(--space-3); }
.feature-grid article { padding: var(--space-4); border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); }
.feature-grid h3 { margin-top: 0; }

input, select, textarea { width: 100%; min-height: 2.75rem; padding: 0.7rem 0.8rem; color: var(--ink); background: white; border: 1px solid #8da7a4; border-radius: var(--radius-sm); }
textarea { min-height: 7rem; resize: vertical; }
.button { display: inline-flex; align-items: center; justify-content: center; padding: 0.7rem 1.1rem; border: 0; border-radius: var(--radius-sm); background: var(--brand-green); color: white; font-weight: 800; text-decoration: none; cursor: pointer; }
.button:hover { background: var(--brand-green-dark); color: white; }
.button-secondary { background: var(--brand-blue); }
.button-secondary:hover { background: var(--brand-blue-dark); }
.button-small { min-height: 2.35rem; padding: 0.45rem 0.75rem; }

.auth-shell { display: grid; place-items: start center; }
.auth-card { width: min(34rem, 100%); padding: clamp(1.25rem, 4vw, 2.5rem); border: 1px solid var(--border); border-radius: var(--radius-lg); background: var(--surface); box-shadow: var(--shadow); }
.auth-card h1 { font-size: clamp(2rem, 8vw, 3.1rem); }
.stack-form { display: grid; gap: var(--space-2); margin-block: var(--space-4); }
.stack-form label:not(.check-row) { margin-top: var(--space-1); font-weight: 750; }
.check-row { display: flex; align-items: center; gap: var(--space-2); min-height: 2.75rem; }
.check-row input { width: 1.25rem; min-height: 1.25rem; accent-color: var(--brand-green); }
.field-help, .optional { color: var(--muted); font-size: 0.9rem; font-weight: 400; }
.auth-alternative { border-top: 1px solid var(--border); padding-top: var(--space-3); }
.auth-alternative summary { min-height: 2.75rem; cursor: pointer; color: var(--brand-blue-dark); font-weight: 750; }
.auth-links { text-align: center; }
.status { padding: var(--space-3); border-left: 0.3rem solid var(--brand-green); border-radius: var(--radius-sm); background: var(--success-surface); }
.status-error { border-left-color: var(--danger); background: var(--danger-surface); color: #6f1421; }
.visually-hidden { position: absolute !important; width: 1px !important; height: 1px !important; padding: 0 !important; margin: -1px !important; overflow: hidden !important; clip: rect(0, 0, 0, 0) !important; white-space: nowrap !important; border: 0 !important; }

@media (min-width: 42rem) {
    .input-action { grid-template-columns: minmax(0, 1fr) auto; }
    .feature-grid { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 36rem) {
    .site-header { align-items: flex-start; }
    .nav-list { gap: var(--space-2); font-size: 0.9rem; }
    .brand > span:last-child { display: none; }
}

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { scroll-behavior: auto !important; animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
}

@media (prefers-color-scheme: dark) {
    :root { color-scheme: dark; --ink: #effaf8; --muted: #b5c9c6; --surface: #0d2c38; --canvas: #071b24; --border: #31515c; --brand-blue-dark: #80c4ff; --brand-green-dark: #76dccd; --success-surface: #123d38; --danger-surface: #421b24; }
    input, select, textarea { color: var(--ink); background: #102f39; border-color: #66828a; }
}