/* Kalman Filter Flight Demo — pastel UI */

:root {
    --ink: #5a5560;
    --ink-soft: #857f8d;
    --ink-faint: #a49dab;
    --paper: #fdf8f4;
    --paper-2: #fffcfa;
    --page: #f3ecef;
    --line: #ece2e6;
    --violet: #a78bda;
    --violet-soft: #b9a7e6;
    --coral: #ff9e9e;
    --coral-deep: #ef7f88;
    --butter: #ffe08a;
    --mint: #bfe6c3;
    --sky: #c9d6ff;
    --peach: #ffd9c4;
    --rose: #f7b8c4;
    --shadow: 0 10px 26px rgba(122, 104, 128, .13);
    --shadow-sm: 0 4px 12px rgba(122, 104, 128, .10);
    --r-lg: 18px;
    --r-md: 14px;
    --r-sm: 10px;
}

* {
    box-sizing: border-box;
}

[hidden] {
    display: none !important;
}

html,
body {
    height: 100%;
}

body {
    margin: 0;
    color: var(--ink);
    background:
        radial-gradient(1200px 700px at 12% -10%, #ffe9dc 0%, rgba(255, 233, 220, 0) 60%),
        radial-gradient(1000px 600px at 95% 105%, #e3e0ff 0%, rgba(227, 224, 255, 0) 62%),
        var(--page);
    font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    font-size: 15px;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    overflow: hidden;
}

h1,
h2,
h3 {
    margin: 0;
    font-weight: 650;
    letter-spacing: -.01em;
}

/* ---------- layout ---------- */

.app {
    display: flex;
    gap: 16px;
    height: 100vh;
    height: 100dvh;
    padding: 16px;
    align-items: stretch;
}

.stage {
    flex: 1 1 auto;
    min-width: 0;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.topbar {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 16px;
    flex-wrap: wrap;
    padding: 0 4px;
}

.titles h1 {
    font-size: 19px;
}

.titles p {
    margin: 2px 0 0;
    font-size: 13px;
    color: var(--ink-soft);
    max-width: 68ch;
}

.backlink {
    color: #8d7bb8;
    text-decoration: none;
    font-size: 13px;
    font-weight: 550;
    padding: 6px 12px;
    border-radius: 999px;
    background: rgba(255, 255, 255, .68);
    box-shadow: var(--shadow-sm);
    white-space: nowrap;
    transition: transform .15s ease, background .15s ease;
}

.backlink:hover {
    background: #fff;
    transform: translateX(-2px);
}

.backlink:focus-visible,
.btn:focus-visible,
input:focus-visible {
    outline: 3px solid rgba(167, 139, 218, .55);
    outline-offset: 2px;
}

/* ---------- world ---------- */

.world-card {
    position: relative;
    flex: 1 1 auto;
    min-height: 240px;
    border-radius: var(--r-lg);
    overflow: hidden;
    box-shadow: var(--shadow);
    background: var(--sky);
}

#world {
    display: block;
    width: 100%;
    height: 100%;
}

.hud {
    position: absolute;
    top: 12px;
    left: 12px;
    right: 12px;
    display: flex;
    flex-wrap: wrap;
    gap: 7px;
    pointer-events: none;
}

.chip {
    display: inline-flex;
    align-items: baseline;
    gap: 6px;
    padding: 5px 11px;
    border-radius: 999px;
    background: rgba(255, 253, 251, .93);
    box-shadow: 0 2px 8px rgba(110, 95, 120, .18);
    font-size: 12px;
    font-variant-numeric: tabular-nums;
    color: var(--ink);
    backdrop-filter: blur(6px);
}

.chip b {
    font-weight: 600;
    font-size: 10.5px;
    letter-spacing: .06em;
    text-transform: uppercase;
    color: #9089a0;
}

.chip-sig b,
.chip-err b {
    text-transform: none;
    letter-spacing: 0;
    font-size: 11px;
}

.chip-err {
    background: rgba(255, 236, 236, .9);
}

.chip-sig {
    background: rgba(238, 232, 253, .9);
}

.chip-gps {
    background: rgba(255, 246, 219, .92);
}

.chip-gps.out {
    background: rgba(255, 223, 230, .95);
    color: #a8556a;
}

.chip-gps.out b {
    color: #c98a99;
}

.legend {
    position: absolute;
    right: 12px;
    bottom: 12px;
    display: flex;
    gap: 12px;
    padding: 6px 12px;
    border-radius: 999px;
    background: rgba(255, 253, 251, .8);
    box-shadow: 0 2px 8px rgba(110, 95, 120, .14);
    font-size: 11.5px;
    color: var(--ink-soft);
    backdrop-filter: blur(6px);
}

.legend span {
    display: inline-flex;
    align-items: center;
    gap: 5px;
}

.sw {
    width: 12px;
    height: 4px;
    border-radius: 3px;
    display: inline-block;
}

.sw-truth {
    background: var(--coral);
}

.sw-est {
    background: var(--violet);
}

.sw-gps {
    background: var(--butter);
    height: 8px;
    width: 8px;
    border-radius: 50%;
}

.sw-cov {
    background: var(--violet-soft);
    height: 9px;
    width: 14px;
    border-radius: 50%;
    opacity: .55;
}

.paused-veil {
    position: absolute;
    inset: 0;
    display: grid;
    place-items: center;
    background: rgba(253, 248, 244, .2);
    backdrop-filter: blur(1px);
}

.paused-veil span {
    padding: 9px 22px;
    border-radius: 999px;
    background: rgba(255, 253, 251, .93);
    box-shadow: var(--shadow);
    font-size: 13px;
    letter-spacing: .16em;
    text-transform: uppercase;
    color: var(--ink-soft);
}

/* ---------- chart ---------- */

.chart-card {
    flex: 0 0 auto;
    background: var(--paper);
    border-radius: var(--r-lg);
    box-shadow: var(--shadow);
    padding: 10px 14px 12px;
}

.chart-head {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 12px;
    flex-wrap: wrap;
    margin-bottom: 4px;
}

.chart-head h2 {
    font-size: 13px;
    color: var(--ink);
}

.chart-note {
    font-size: 11.5px;
    color: var(--ink-faint);
}

#chart {
    display: block;
    width: 100%;
    height: 132px;
}

/* ---------- panel ---------- */

.panel {
    flex: 0 0 312px;
    max-width: 312px;
    background: var(--paper);
    border-radius: var(--r-lg);
    box-shadow: var(--shadow);
    overflow: hidden;
    transition: box-shadow .3s ease;
}

.panel-inner {
    height: 100%;
    overflow-y: auto;
    padding: 14px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    scrollbar-width: thin;
    scrollbar-color: #ded3da transparent;
}

.panel-inner::-webkit-scrollbar {
    width: 9px;
}

.panel-inner::-webkit-scrollbar-thumb {
    background: #e3d8de;
    border-radius: 9px;
    border: 2px solid var(--paper);
}

body.outage .panel {
    box-shadow: 0 0 0 2px rgba(247, 184, 196, .85), var(--shadow);
}

.buttons {
    display: flex;
    gap: 8px;
}

.btn {
    flex: 1 1 0;
    font: inherit;
    font-size: 13.5px;
    font-weight: 600;
    color: var(--ink);
    padding: 10px 12px;
    border: none;
    border-radius: var(--r-md);
    background: #fff;
    box-shadow: var(--shadow-sm);
    cursor: pointer;
    transition: transform .12s ease, box-shadow .12s ease, background .15s ease;
}

.btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 6px 16px rgba(122, 104, 128, .16);
}

.btn:active {
    transform: translateY(0);
}

.btn-primary {
    background: linear-gradient(160deg, #cbb8f0, #a78bda);
    color: #fff;
}

.btn.attention {
    background: linear-gradient(160deg, #ffd0b8, #ffb59a);
    color: #7a4a37;
}

.restart-hint {
    margin: -4px 0 0;
    font-size: 12px;
    color: #9b6a55;
    background: #fff0e6;
    border-radius: var(--r-sm);
    padding: 7px 10px;
}

.card {
    background: var(--paper-2);
    border: 1px solid var(--line);
    border-radius: var(--r-md);
    padding: 12px 12px 4px;
}

.card h3 {
    font-size: 12px;
    letter-spacing: .07em;
    text-transform: uppercase;
    color: var(--ink-soft);
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 10px;
}

.tag {
    font-size: 9.5px;
    letter-spacing: .04em;
    text-transform: uppercase;
    font-weight: 600;
    padding: 2px 7px;
    border-radius: 999px;
}

.tag-restart {
    background: #ffeadd;
    color: #a5705a;
}

.tag-live {
    background: #e2f4e5;
    color: #558a63;
}

.ctl {
    margin-bottom: 12px;
}

.ctl label {
    display: flex;
    align-items: baseline;
    gap: 6px;
    font-size: 12.5px;
    color: var(--ink);
    margin-bottom: 3px;
}

.ctl label i {
    font-style: italic;
    color: var(--ink-soft);
}

.val {
    margin-left: auto;
    font-size: 11.5px;
    font-variant-numeric: tabular-nums;
    color: #7d6f92;
    background: #f2edfa;
    border-radius: 999px;
    padding: 1px 8px;
    white-space: nowrap;
}

.hint {
    margin: 0 0 12px;
    font-size: 11.5px;
    line-height: 1.45;
    color: var(--ink-faint);
}

/* range sliders */

input[type=range] {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 20px;
    background: transparent;
    margin: 0;
    cursor: pointer;
}

input[type=range]::-webkit-slider-runnable-track {
    height: 7px;
    border-radius: 999px;
    background: linear-gradient(90deg, #ffd9c4, #d9cdf3);
}

input[type=range]::-moz-range-track {
    height: 7px;
    border-radius: 999px;
    background: linear-gradient(90deg, #ffd9c4, #d9cdf3);
}

input[type=range]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 17px;
    height: 17px;
    margin-top: -5px;
    border-radius: 50%;
    background: #fff;
    border: 3px solid var(--violet);
    box-shadow: 0 2px 5px rgba(122, 104, 128, .28);
    transition: transform .12s ease;
}

input[type=range]::-moz-range-thumb {
    width: 17px;
    height: 17px;
    border-radius: 50%;
    background: #fff;
    border: 3px solid var(--violet);
    box-shadow: 0 2px 5px rgba(122, 104, 128, .28);
}

input[type=range]:hover::-webkit-slider-thumb {
    transform: scale(1.12);
}

/* switch */

.switch-row {
    margin-bottom: 8px;
}

.switch {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
}

.switch input {
    position: absolute;
    opacity: 0;
    width: 0;
    height: 0;
}

.switch .track {
    flex: 0 0 auto;
    width: 46px;
    height: 26px;
    border-radius: 999px;
    background: #f0c9d3;
    box-shadow: inset 0 1px 3px rgba(120, 90, 100, .18);
    position: relative;
    transition: background .2s ease;
}

.switch .knob {
    position: absolute;
    top: 3px;
    left: 3px;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: #fff;
    box-shadow: 0 2px 5px rgba(122, 104, 128, .3);
    transition: transform .2s cubic-bezier(.3, 1.4, .5, 1);
}

.switch input:checked+.track {
    background: linear-gradient(120deg, #bfe6c3, #9fd8ae);
}

.switch input:checked+.track .knob {
    transform: translateX(20px);
}

.switch input:focus-visible+.track {
    outline: 3px solid rgba(167, 139, 218, .55);
    outline-offset: 2px;
}

.switch-label {
    font-size: 13px;
}

.switch-label em {
    font-style: normal;
    font-weight: 600;
    color: #5f8f6e;
}

body.outage .switch-label em {
    color: #bf6b7f;
}

/* checkboxes */

.checks {
    display: grid;
    gap: 8px;
    margin-bottom: 14px;
}

.check {
    display: flex;
    align-items: center;
    gap: 9px;
    font-size: 12.5px;
    cursor: pointer;
}

.check input {
    position: absolute;
    opacity: 0;
    width: 0;
    height: 0;
}

.check .box {
    flex: 0 0 auto;
    width: 18px;
    height: 18px;
    border-radius: 6px;
    background: #fff;
    border: 2px solid #e0d6e6;
    position: relative;
    transition: background .15s ease, border-color .15s ease;
}

.check input:checked+.box {
    background: var(--violet);
    border-color: var(--violet);
}

.check input:checked+.box::after {
    content: "";
    position: absolute;
    left: 4.5px;
    top: 1px;
    width: 4px;
    height: 9px;
    border: solid #fff;
    border-width: 0 2px 2px 0;
    transform: rotate(42deg);
}

.check input:focus-visible+.box {
    outline: 3px solid rgba(167, 139, 218, .55);
    outline-offset: 2px;
}

/* footer */

.panel-foot {
    border-top: 1px dashed var(--line);
    padding-top: 10px;
    color: var(--ink-soft);
    font-size: 11.8px;
    line-height: 1.55;
}

.panel-foot p {
    margin: 0 0 8px;
}

.panel-foot .sizes {
    color: var(--ink-faint);
    font-variant-numeric: tabular-nums;
}

.panel-foot .keys {
    margin-bottom: 0;
    color: var(--ink-faint);
}

kbd {
    font: inherit;
    font-size: 10.5px;
    background: #fff;
    border: 1px solid var(--line);
    border-bottom-width: 2px;
    border-radius: 5px;
    padding: 0 5px;
    color: var(--ink-soft);
}

.fatal {
    position: fixed;
    inset: auto 16px 16px 16px;
    background: #fff0f2;
    color: #9c5468;
    padding: 12px 16px;
    border-radius: var(--r-md);
    box-shadow: var(--shadow);
    font-size: 13px;
    z-index: 20;
}

/* ---------- responsive ---------- */

@media (max-width: 900px) {
    body {
        overflow: auto;
    }

    .app {
        flex-direction: column;
        height: auto;
        min-height: 100dvh;
        padding: 12px;
    }

    .stage {
        flex: 0 0 auto;
    }

    .world-card {
        flex: 0 0 auto;
        height: 52vh;
        min-height: 320px;
    }

    .panel {
        flex: 0 0 auto;
        max-width: none;
        width: 100%;
    }

    .panel-inner {
        height: auto;
        overflow: visible;
    }

    .hud {
        gap: 6px;
    }

    .legend {
        display: none;
    }
}

@media (max-width: 560px) {
    .chip {
        font-size: 11px;
        padding: 4px 9px;
    }
}

@media (prefers-reduced-motion: reduce) {

    .btn,
    .backlink,
    .switch .knob,
    input[type=range]::-webkit-slider-thumb {
        transition: none;
    }
}