@import url("https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;500;600&display=swap");

:root {
    color-scheme: dark;
    --bg: #181a1d; --text: #e6e6e6; --muted: #9299a1; --surface: #22252a;
    --border: #363a40; --surface-hover: #282c31; --border-hover: #50565e;
    --accent-border: #52787c; --surface-deep: #191c1f; --border-strong: #41464d;
    --accent: #a8c9cc; --subtle: #69717a; --warning-border-soft: #62583c;
    --warning: #d6b56a; --footer: #626970; --link: #9da5ad; --bright: #ffffff;
    --border-soft: #34383e; --label: #9ca3aa; --label-strong: #b7bdc4;
    --input-bg: #17191c; --input-text: #f2f2f2; --input-border: #40454c; --focus: #6f9fa3;
    --divider: #373b41; --quiet: #777f87; --bar-track: #30343a; --danger-fill: #74474a;
    --warning-fill: #74643e; --normal-fill: #3f5c5f; --marker: #f1f1f1;
    --scale-text: #8d959d; --scale-quiet: #686f77; --status-border: #4b5158;
    --warning-text: #d6b76a; --warning-border: #806c3e; --danger-text: #e07878;
    --danger-border: #914848; --border-alt: #343a40; --note: #8f979f;
    --result-accent: #b8cfd1; --value-text: #c7cbcf; --secondary: #6f767d;
    --button-bg: #1d2024; --button-border: #4a5057; --overlay-bg: rgba(10,12,14,.92);
    --overlay-card: #171a1d; --overlay-border: #3a4046; --close-bg: rgba(20,23,26,.85);
    --help-border: #9a7440; --help-bg: rgba(154,116,64,.08); --help-accent: #d6a45f;
}

:root[data-theme="light"] {
    color-scheme: light;
    --bg: #eef1f2; --text: #20282c; --muted: #5f6b71; --surface: #ffffff;
    --border: #cbd3d6; --surface-hover: #f5f7f7; --border-hover: #98a7ac;
    --accent-border: #5e8c91; --surface-deep: #e8eeee; --border-strong: #b6c2c6;
    --accent: #245f66; --subtle: #68777d; --warning-border-soft: #b49b60;
    --warning: #795b16; --footer: #667278; --link: #4e6067; --bright: #172126;
    --border-soft: #d1d8da; --label: #56666c; --label-strong: #46575d;
    --input-bg: #ffffff; --input-text: #182126; --input-border: #aebbc0; --focus: #39777d;
    --divider: #d3dadc; --quiet: #64747a; --bar-track: #dfe5e7; --danger-fill: #a95c61;
    --warning-fill: #a88b42; --normal-fill: #4e7b7f; --marker: #182126;
    --scale-text: #5c6a70; --scale-quiet: #718087; --status-border: #aab7bb;
    --warning-text: #765713; --warning-border: #a98535; --danger-text: #a13d43;
    --danger-border: #b65b60; --border-alt: #c8d1d4; --note: #596a70;
    --result-accent: #285f65; --value-text: #26343a; --secondary: #69797f;
    --button-bg: #f4f7f7; --button-border: #aebbc0; --overlay-bg: rgba(28,35,38,.72);
    --overlay-card: #ffffff; --overlay-border: #b9c4c8; --close-bg: rgba(238,242,243,.94);
    --help-border: #9b752c; --help-bg: rgba(155,117,44,.09); --help-accent: #73520f;
}


/* ==================================================
   LazyLoop
================================================== */

* {
    box-sizing: border-box;
}

html {
    -webkit-tap-highlight-color: transparent;
}

body {
    margin: 0;
    font-family:
        "JetBrains Mono",
        "Cascadia Mono",
        Consolas,
        monospace;
    background: var(--bg);
    color: var(--text);
}

a {
    color: inherit;
}


/* ==================================================
   MAIN LAYOUT
================================================== */

.container {
    width: 100%;
    max-width: 900px;
    margin: 0 auto;
    padding: 50px 22px;
}


/* ==================================================
   HEADER
================================================== */

.main-header {
    margin-bottom: 35px;
}

.main-header h1 {
    margin: 0;
    font-size: 34px;
    font-weight: 600;
    letter-spacing: -1px;
}

.main-header p {
    margin: 7px 0 0;
    color: var(--muted);
    font-size: 15px;
}


/* ==================================================
   LANDING PAGE
================================================== */

.tool-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}

.tool-card {
    min-height: 150px;
    display: grid;
    grid-template-columns:
        72px
        1fr
        auto;
    align-items: center;
    gap: 18px;
    padding: 24px;
    text-decoration: none;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 10px;
    transition:
        background 120ms ease,
        border-color 120ms ease,
        transform 80ms ease;
}

.tool-card:hover {
    background: var(--surface-hover);
    border-color: var(--border-hover);
}

.tool-card:active {
    transform: scale(0.985);
}

.primary-tool {
    grid-column: 1 / -1;
    min-height: 180px;
    border-color: var(--accent-border);
}

.tool-symbol {
    width: 68px;
    height: 68px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--surface-deep);
    border: 1px solid var(--border-strong);
    border-radius: 8px;
    color: var(--accent);
    font-size: 20px;
    font-weight: 600;
}

.primary-tool .tool-symbol {
    width: 76px;
    height: 76px;
    font-size: 22px;
}

.tool-info h2 {
    margin: 0;
    font-size: 21px;
    font-weight: 600;
}

.tool-info p {
    margin: 7px 0 0;
    color: var(--muted);
    font-size: 13px;
}

.tool-arrow {
    color: var(--subtle);
    font-size: 35px;
    font-weight: 300;
}


/* --------------------------------------------------
   TOOL IN PROGRESS
-------------------------------------------------- */

.tool-card.in-progress {
    border-color: var(--warning-border-soft);
}

.tool-card.in-progress .tool-symbol,
.tool-card.in-progress .tool-arrow {
    color: var(--warning);
}

.tool-title-row {
    display: flex;
    align-items: center;
    gap: 12px;
}

.progress-status {
    color: var(--warning);
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.04em;
    white-space: nowrap;
}

footer {
    margin-top: 40px;
    text-align: center;
    color: var(--footer);
    font-size: 12px;
}


/* ==================================================
   CALCULATOR
================================================== */

.back-link {
    display: inline-block;
    margin-bottom: 25px;
    color: var(--link);
    text-decoration: none;
    font-size: 14px;
}

.back-link:hover {
    color: var(--bright);
}

.calculator-card {
    padding: 30px;
    background: var(--surface);
    border: 1px solid var(--border-soft);
    border-radius: 10px;
}

.calculator-card h2 {
    margin-top: 0;
    margin-bottom: 14px;
    color: var(--label);
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 1px;
}


/* ==================================================
   ENGINEERING RANGE
================================================== */

.engineering-grid {
    display: grid;
    grid-template-columns:
        1fr
        1fr
        1fr;
    gap: 16px;
    margin-bottom: 28px;
}

label {
    display: flex;
    flex-direction: column;
    gap: 7px;
    color: var(--label-strong);
    font-size: 13px;
}

input {
    width: 100%;
    padding: 12px;
    font-family: inherit;
    background: var(--input-bg);
    color: var(--input-text);
    border: 1px solid var(--input-border);
    border-radius: 5px;
    font-size: 18px;
}

input:focus {
    outline: none;
    border-color: var(--focus);
}

input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
    margin: 0;
    -webkit-appearance: none;
}

input[type="number"] {
    -moz-appearance: textfield;
    appearance: textfield;
}


/* ==================================================
   CONVERSION
================================================== */

.divider {
    height: 1px;
    margin: 6px 0 30px;
    background: var(--divider);
}

.conversion {
    display: grid;
    grid-template-columns:
        1fr
        auto
        1fr;
    align-items: end;
    gap: 24px;
}

.value-input {
    display: flex;
    align-items: center;
    gap: 10px;
    width: 100%;
}

.value-input input {
    flex: 1 1 auto;
    width: 0;
    min-width: 0;
    font-size: 27px;
    font-weight: 500;
}

.value-input span {
    flex: 0 0 auto;
    min-width: 0;
    color: var(--label);
    font-size: 15px;
    white-space: nowrap;
}

.conversion-arrow {
    padding-bottom: 9px;
    color: var(--focus);
    font-size: 30px;
}

.percent {
    margin-top: 25px;
    text-align: center;
    color: var(--label);
    font-size: 16px;
}

.percent span {
    color: var(--text);
    font-size: 24px;
}


/* ==================================================
   SIGNAL DISPLAY
================================================== */

.signal-section {
    margin-top: 30px;
    padding-top: 26px;
    border-top: 1px solid var(--divider);
}

.signal-bar-wrap {
    position: relative;
    max-width: 680px;
    margin: 0 auto;
}

.signal-region-names {
    position: relative;
    height: 22px;
    margin-bottom: 6px;
    color: var(--quiet);
    font-size: 9px;
    font-weight: 600;
    letter-spacing: 0.5px;
}

.signal-region-names span {
    position: absolute;
}

.region-low {
    left: 0;
}

.region-normal {
    left: 50%;
    transform: translateX(-50%);
}

.region-high {
    right: 0;
}

.signal-bar {
    position: relative;
    height: 14px;
    display: flex;
    overflow: visible;
    background: var(--bar-track);
    border-radius: 7px;
}

.zone {
    height: 100%;
}

.failure-low {
    width: 1.12%;
    background: var(--danger-fill);
    border-radius: 7px 0 0 7px;
}

.warning-low {
    width: 2.25%;
    background: var(--warning-fill);
}

.measurement {
    width: 89.89%;
    background: var(--normal-fill);
}

.warning-high {
    width: 5.62%;
    background: var(--warning-fill);
}

.failure-high {
    width: 1.12%;
    background: var(--danger-fill);
    border-radius: 0 7px 7px 0;
}

.signal-marker {
    position: absolute;
    top: 50%;
    width: 4px;
    height: 28px;
    background: var(--marker);
    border-radius: 2px;
    transform:
        translate(-50%, -50%);
    box-shadow:
        0 0 0 2px var(--bg);
}

.nominal-scale {
    position: relative;
    height: 22px;
    margin-top: 8px;
    color: var(--scale-text);
    font-size: 11px;
}

.nominal-scale span {
    position: absolute;
    transform: translateX(-50%);
}

.scale-low {
    left: 3.37%;
}

.scale-middle {
    left: 48.31%;
}

.scale-high {
    left: 93.26%;
}

.signal-unit {
    margin-top: 0;
    text-align: center;
    color: var(--scale-quiet);
    font-size: 10px;
}


/* ==================================================
   STATUS
================================================== */

.signal-status {
    width: fit-content;
    margin: 20px auto 0;
    padding: 8px 15px;
    border-radius: 5px;
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.8px;
}

.signal-status.in-range {
    color: var(--label);
    border: 1px solid var(--status-border);
}

.signal-status.warning {
    color: var(--warning-text);
    border: 1px solid var(--warning-border);
}

.signal-status.failure {
    color: var(--danger-text);
    border: 1px solid var(--danger-border);
}


/* ==================================================
   Pt100
================================================== */

.standard-info {
    margin-bottom: 28px;
    padding: 14px 16px;
    background: var(--surface-deep);
    border: 1px solid var(--border-alt);
    border-radius: 6px;
    color: var(--note);
    font-size: 12px;
    line-height: 1.7;
}

.standard-info strong {
    color: var(--result-accent);
    font-weight: 500;
}

.pt100-reference {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    margin-top: 28px;
}

.reference-item {
    padding: 14px;
    text-align: center;
    background: var(--surface-deep);
    border: 1px solid var(--border-soft);
    border-radius: 6px;
}

.reference-temperature {
    display: block;
    margin-bottom: 5px;
    color: var(--quiet);
    font-size: 11px;
}

.reference-resistance {
    color: var(--value-text);
    font-size: 14px;
}

.range-note {
    margin: 22px 0 0;
    text-align: center;
    color: var(--secondary);
    font-size: 11px;
}

.pressure-warning {
    display: none;
}

.calculated-field {
    display: flex;
    flex-direction: column;
    gap: 7px;
}

.calculated-field > label {
    color: var(--label-strong);
    font-size: 13px;
}

.calculated-value {
    min-height: 54px;
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px;
    background: var(--button-bg);
    border: 1px solid var(--border-soft);
    border-radius: 5px;
}

.calculated-value span:first-child {
    color: var(--value-text);
    font-size: 27px;
    font-weight: 500;
}

.calculated-value span:last-child {
    color: var(--label);
    font-size: 15px;
}


/* --------------------------------------------------
   Help overlay
-------------------------------------------------- */

.help-button {
    margin-left: 6px;
    width: 24px;
    height: 24px;
    padding: 0;
    border: 1px solid var(--button-border);
    border-radius: 50%;
    background: var(--button-bg);
    color: var(--value-text);
    font: inherit;
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
}

.help-overlay {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 1000;
    padding: 20px;
    background: var(--overlay-bg);
    overflow-y: auto;
}

.help-overlay.open {
    display: flex;
    justify-content: center;
    align-items: flex-start;
}

.help-overlay-content {
    position: relative;
    width: 100%;
    max-width: 700px;
    margin: auto;
    background: var(--overlay-card);
    border: 1px solid var(--overlay-border);
    border-radius: 8px;
}

.help-overlay-content img {
    display: block;
    width: 100%;
    height: auto;
    border-radius: 8px;
}

.help-close {
    position: absolute;
    top: 10px;
    right: 10px;
    z-index: 1;
    width: 44px;
    height: 44px;
    border: none;
    border-radius: 50%;
    background: var(--close-bg);
    color: var(--value-text);
    font: inherit;
    font-size: 28px;
    cursor: pointer;
}


/* --------------------------------------------------
   Range warning
-------------------------------------------------- */

.range-warning {
    margin-top: 18px;
    padding: 12px 14px;
    border: 1px solid var(--help-border);
    border-radius: 6px;
    background: var(--help-bg);
    color: var(--help-accent);
    font-size: 14px;
    line-height: 1.5;
}


/* ==================================================
   MOBILE
================================================== */

@media (max-width: 650px) {

    .container {
        padding: 28px 16px;
    }

    .main-header {
        margin-bottom: 25px;
    }

    .main-header h1 {
        font-size: 26px;
    }

    .main-header p {
        font-size: 13px;
    }

    .tool-grid {
        grid-template-columns: minmax(0, 1fr);
        gap: 12px;
    }

    .primary-tool {
        grid-column: auto;
        min-height: 150px;
    }

    .tool-card {
        min-height: 120px;
        grid-template-columns:
            64px
            minmax(0, 1fr)
            auto;
        padding: 18px;
        gap: 15px;
    }

    .tool-symbol,
    .primary-tool .tool-symbol {
        width: 62px;
        height: 62px;
        font-size: 18px;
    }

    .tool-info {
        min-width: 0;
    }

    .tool-info h2 {
        font-size: 19px;
        overflow-wrap: anywhere;
    }

    .tool-info p {
        font-size: 12px;
        overflow-wrap: anywhere;
    }

    .tool-title-row {
        flex-wrap: wrap;
        gap: 8px;
    }

    .progress-status {
        font-size: 10px;
    }

    .calculator-card {
        padding: 20px;
    }

    .engineering-grid {
        grid-template-columns:
            1fr
            1fr;
    }

    .level-calculator-page .engineering-grid {
        grid-template-columns: minmax(0, 1fr);
    }

    .engineering-grid > label {
        display: grid;
        grid-template-rows: 2.6em auto;
        align-content: start;
    }

    .engineering-grid label:last-child {
        grid-column: 1 / -1;
    }

    .conversion {
        grid-template-columns: 1fr;
        gap: 12px;
    }

    .conversion-arrow {
        padding: 0;
        text-align: center;
        transform: rotate(90deg);
    }

    .value-input input {
        min-height: 56px;
        padding: 10px 8px;
        font-size: 22px;
    }

    .engineering-grid input {
        min-height: 50px;
    }

    .signal-region-names {
        font-size: 8px;
    }

    .pt100-reference {
        grid-template-columns: 1fr;
    }
}

/* Shared theme control, inserted by theme.js */
.theme-toggle {
    position: fixed; top: 16px; right: 16px; z-index: 1000;
    min-width: 44px; height: 38px; padding: 0 12px;
    font: 600 12px/1 "JetBrains Mono", "Cascadia Mono", Consolas, monospace;
    background: var(--button-bg); color: var(--accent);
    border: 1px solid var(--button-border); border-radius: 6px; cursor: pointer;
}
.theme-toggle:hover { background: var(--surface-hover); border-color: var(--border-hover); }
.theme-toggle:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }
@media (max-width: 650px) { .theme-toggle { top: 10px; right: 10px; height: 36px; padding: 0 10px; } }

/* Signed numeric inputs */
.sign-toggle {
    flex: 0 0 44px;
    width: 44px;
    height: 54px;
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: inherit;
    font-size: 20px;
    font-weight: 600;
    line-height: 1;
    background: var(--button-bg);
    color: var(--accent);
    border: 1px solid var(--button-border);
    border-radius: 5px;
    cursor: pointer;
}

.sign-toggle:hover {
    background: var(--surface-hover);
    border-color: var(--border-hover);
}

.sign-toggle:focus-visible {
    outline: 2px solid var(--focus);
    outline-offset: 2px;
}

.sign-toggle:active {
    transform: scale(0.96);
}

@media (max-width: 650px) {
    .sign-toggle {
        height: 56px;
    }
}