:root {
    color-scheme: light;
    --desk: #dfe4e9;
    --cap: #fbfcfd;
    --cap-edge: #b4bdc8;
    --ink: #17202b;
    --ink-soft: #4d5a6a;
    --cobalt: #2747d8;
    --cobalt-edge: #152a8f;
    --on-cobalt: #ffffff;
    --amber: #f1b02f;
    --amber-edge: #a87410;
    --on-amber: #17202b;
    --error: #a8231b;
    --ok: #1c7a45;
    --field: #fbfcfd;
    --field-edge: #b4bdc8;
    --field-foot: #f0f3f6;
    --line: #d5dbe2;
    --hover: #e3e8ee;
    --ring: rgba(39, 71, 216, 0.22);
    --sans: "Avenir Next", "Segoe UI", "Helvetica Neue", system-ui, sans-serif;
    --mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
        color-scheme: dark;
        --desk: #14181e;
        --cap: #2a323d;
        --cap-edge: #0b0e12;
        --ink: #e9eef4;
        --ink-soft: #9ba8b8;
        --cobalt: #4a69f2;
        --cobalt-edge: #2238a8;
        --error: #ff8f85;
        --ok: #5fd08f;
        --field: #1d232b;
        --field-edge: #38424f;
        --field-foot: #181d24;
        --line: #2c3541;
        --hover: #2a323d;
        --ring: rgba(74, 105, 242, 0.35);
    }
}

:root[data-theme="dark"] {
    color-scheme: dark;
    --desk: #14181e;
    --cap: #2a323d;
    --cap-edge: #0b0e12;
    --ink: #e9eef4;
    --ink-soft: #9ba8b8;
    --cobalt: #4a69f2;
    --cobalt-edge: #2238a8;
    --error: #ff8f85;
    --ok: #5fd08f;
    --field: #1d232b;
    --field-edge: #38424f;
    --field-foot: #181d24;
    --line: #2c3541;
    --hover: #2a323d;
    --ring: rgba(74, 105, 242, 0.35);
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }

body {
    margin: 0;
    background: var(--desk);
    color: var(--ink);
    font: 400 1rem/1.5 var(--sans);
    -webkit-tap-highlight-color: transparent;
    overflow-wrap: anywhere;
}

button { touch-action: manipulation; }

[hidden] { display: none !important; }

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip-path: inset(50%);
}

.bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding: 1rem clamp(1rem, 4vw, 3rem);
    padding-top: max(1rem, env(safe-area-inset-top));
    padding-left: max(clamp(1rem, 4vw, 3rem), env(safe-area-inset-left));
    padding-right: max(clamp(1rem, 4vw, 3rem), env(safe-area-inset-right));
}

.brand { flex: none; font-weight: 700; font-size: 1.125rem; letter-spacing: 0.01em; white-space: nowrap; }
.bar-actions { display: flex; align-items: center; gap: 0.625rem; min-width: 0; color: var(--ink-soft); }
.bar-actions .key { flex: none; white-space: nowrap; }
#who-name { min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

main {
    max-width: 60rem;
    margin: 0 auto;
    padding: 1rem clamp(1rem, 4vw, 3rem) 4rem;
    padding-left: max(clamp(1rem, 4vw, 3rem), env(safe-area-inset-left));
    padding-right: max(clamp(1rem, 4vw, 3rem), env(safe-area-inset-right));
    padding-bottom: max(4rem, env(safe-area-inset-bottom));
}

/* The keyboard */
.board {
    display: grid;
    gap: clamp(3px, 0.8vw, 8px);
    max-width: 44rem;
    margin-bottom: 2.5rem;
}

.board-row {
    display: grid;
    grid-template-columns: repeat(20, 1fr);
    gap: clamp(3px, 0.8vw, 8px);
}

.board-row:nth-child(2) { padding-left: 2.5%; }
.board-row:nth-child(3) { padding-left: 7.5%; }

.cap {
    grid-column: span 2;
    aspect-ratio: 1;
    display: grid;
    place-items: center;
    background: var(--cap);
    border: 1px solid var(--cap-edge);
    border-bottom-width: clamp(3px, 0.7vw, 6px);
    border-radius: clamp(4px, 1vw, 9px);
    font-weight: 600;
    font-size: clamp(0.75rem, 2.4vw, 1.25rem);
    transition: transform 90ms ease-out, background-color 90ms ease-out;
}

.cap.space { grid-column: 6 / span 10; aspect-ratio: auto; height: clamp(1.5rem, 5vw, 2.75rem); }

.cap.down {
    background: var(--cobalt);
    border-color: var(--cobalt-edge);
    color: var(--on-cobalt);
    transform: translateY(2px);
}

.cap.space.down { background: var(--amber); border-color: var(--amber-edge); color: var(--on-amber); }

h1 {
    margin: 0 0 1.5rem;
    font-size: clamp(1.5rem, 4vw, 2.25rem);
    line-height: 1.15;
    font-weight: 700;
    letter-spacing: -0.01em;
}

label { display: block; font-weight: 600; }

:focus-visible { outline: 3px solid var(--cobalt); outline-offset: 2px; }

/* Buttons are keycaps too. */
.key {
    padding: 0.5rem 1.25rem;
    background: var(--cap);
    border: 1px solid var(--cap-edge);
    border-bottom-width: 4px;
    border-radius: 7px;
    color: var(--ink);
    font: 600 1rem/1.4 var(--sans);
    cursor: pointer;
}

.key:active:not(:disabled) { transform: translateY(2px); border-bottom-width: 2px; margin-bottom: 2px; }
.key:disabled { opacity: 0.5; cursor: default; }
.key-main { background: var(--cobalt); border-color: var(--cobalt-edge); color: var(--on-cobalt); }
.key-quiet { padding: 0.375rem 0.875rem; font-size: 0.9375rem; }

/* Log in */
.auth form { max-width: 22rem; }
.auth label { margin-bottom: 0.375rem; }

.auth input {
    width: 100%;
    margin-bottom: 1rem;
    padding: 0.625rem 0.75rem;
    background: var(--field);
    border: 1px solid var(--field-edge);
    border-radius: 8px;
    color: var(--ink);
    font: inherit;
}

.auth input:focus { outline: none; border-color: var(--cobalt); box-shadow: 0 0 0 3px var(--ring); }
.auth .key-main { width: 100%; margin-top: 0.5rem; }

.error { margin: 0 0 1rem; color: var(--error); font-weight: 600; }
.status { margin: 1rem 0 0; min-height: 1.5rem; color: var(--ink-soft); }

/* Encrypt and decrypt */
.keybar { display: flex; flex-wrap: wrap; align-items: center; gap: 0.75rem 1rem; min-height: 2.75rem; margin-bottom: 1rem; }

/* The two choices are keycaps; the chosen one stays pressed. */
.seg { display: inline-flex; gap: 0.375rem; }
.seg-opt { position: relative; display: block; font-weight: 600; cursor: pointer; }
.seg-opt input { position: absolute; inset: 0; margin: 0; opacity: 0; cursor: pointer; }

.seg-opt span {
    display: flex;
    align-items: center;
    padding: 0.4375rem 0.875rem;
    background: var(--cap);
    border: 1px solid var(--cap-edge);
    border-bottom-width: 4px;
    border-radius: 7px;
    font-size: 0.9375rem;
    line-height: 1.4;
    white-space: nowrap;
}

.seg-opt input:checked + span {
    margin-top: 2px;
    background: var(--cobalt);
    border-color: var(--cobalt-edge);
    border-bottom-width: 2px;
    color: var(--on-cobalt);
}

.seg-opt input:focus-visible + span { outline: 3px solid var(--cobalt); outline-offset: 2px; }

.keyfield {
    flex: 1 1 16rem;
    display: flex;
    align-items: center;
    min-width: 0;
    padding-right: 0.25rem;
    background: var(--field);
    border: 1px solid var(--field-edge);
    border-radius: 10px;
    transition: border-color 120ms ease-out, box-shadow 120ms ease-out;
}

.keyfield:focus-within { border-color: var(--cobalt); box-shadow: 0 0 0 3px var(--ring); }
.keyfield.invalid { border-color: var(--error); }

.keyfield input {
    flex: 1;
    min-width: 0;
    padding: 0.5625rem 0.75rem;
    background: transparent;
    border: 0;
    outline: none;
    color: var(--ink);
    font: inherit;
}

.keyfield input::placeholder { color: var(--ink-soft); opacity: 0.75; }
.keynote { margin: -0.375rem 0 1rem; color: var(--ink-soft); font-size: 0.875rem; }

.panes { display: grid; grid-template-columns: 1fr 1fr; gap: 1.5rem; }

.field {
    display: flex;
    flex-direction: column;
    min-width: 0;
    background: var(--field);
    border: 1px solid var(--field-edge);
    border-radius: 12px;
    overflow: hidden;
    transition: border-color 120ms ease-out, box-shadow 120ms ease-out;
}

.field:focus-within { border-color: var(--cobalt); box-shadow: 0 0 0 3px var(--ring); }
.field.filled { animation: filled 700ms ease-out; }

@keyframes filled {
    0% { border-color: var(--cobalt); box-shadow: 0 0 0 6px var(--ring); }
    100% { box-shadow: 0 0 0 0 transparent; }
}

.field-head {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 1rem;
    padding: 0.75rem 1rem 0.25rem;
}

.count { color: var(--ink-soft); font-size: 0.8125rem; font-variant-numeric: tabular-nums; }
.count.near { color: var(--error); font-weight: 600; }

.field textarea {
    display: block;
    width: 100%;
    height: 12rem;
    min-height: 6rem;
    padding: 0.25rem 1rem 0.75rem;
    background: transparent;
    border: 0;
    outline: none;
    resize: vertical;
    color: var(--ink);
    font: inherit;
    line-height: 1.55;
}

.field textarea::placeholder { color: var(--ink-soft); opacity: 0.75; }
.field textarea.mono { font-family: var(--mono); font-size: 0.9375rem; word-break: break-all; }

.field-foot {
    display: flex;
    align-items: center;
    gap: 0.25rem;
    min-height: 3.5rem;
    padding: 0.5rem 0.625rem 0.5rem 0.75rem;
    background: var(--field-foot);
    border-top: 1px solid var(--line);
}

.spacer { flex: 1; }

.tool-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.375rem;
    padding: 0.4375rem 0.625rem;
    background: none;
    border: 0;
    border-radius: 7px;
    color: var(--ink-soft);
    font: 600 0.875rem/1.2 var(--sans);
    cursor: pointer;
}

@media (hover: hover) {
    .tool-btn:hover:not(:disabled) { background: var(--hover); color: var(--ink); }
    .copy.done:hover:not(:disabled) { color: var(--ok); }
}
.tool-btn:active:not(:disabled) { background: var(--hover); color: var(--ink); }
.tool-btn:disabled { opacity: 0.4; cursor: default; }

.icon {
    width: 1rem;
    height: 1rem;
    fill: none;
    stroke: currentColor;
    stroke-width: 1.5;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.copy .icon-done { display: none; }
.copy.done { color: var(--ok); }
.copy.done:active:not(:disabled) { color: var(--ok); }
.copy.done .icon-copy { display: none; }
.copy.done .icon-done { display: block; }

.tool .error { margin: 1.25rem 0 0; }

/* Phones */
@media (max-width: 40rem) {
    .bar { padding-bottom: 0.5rem; }
    .bar-actions { gap: 0.5rem; }
    .board { margin-bottom: 1.5rem; }
    .panes { grid-template-columns: 1fr; gap: 1rem; }
    .field textarea { height: 8.5rem; }
    .auth form { max-width: none; }
    main { padding-top: 0.5rem; }
}

/* Touch screens: 16px text stops iOS zooming into fields, and controls get finger-sized targets. */
@media (pointer: coarse) {
    .auth input, .field textarea, .field textarea.mono { font-size: 1rem; }
    .auth input { padding: 0.75rem; }
    .key { min-height: 2.75rem; }
    .tool-btn { min-height: 2.75rem; padding: 0.5rem 0.75rem; }
    .field-foot { padding: 0.5rem; }
    .seg-opt span { min-height: 2.75rem; }
    .keyfield input { padding-block: 0.6875rem; }
}

@media (prefers-reduced-motion: reduce) {
    .cap, .field, .keyfield { transition: none; }
    .field.filled { animation: none; }
}