:root {
    --bg-main: #020617;
    --bg-secondary: #07101f;

    --panel: #111827;
    --panel-2: #0f172a;

    --display: #020617;

    --button: #1e293b;
    --button-alt: #152033;

    --border: #263349;

    --text: #f8fafc;
    --muted: #94a3b8;
    --subtle: #64748b;

    --accent: #38bdf8;

    --operator: #2563eb;
    --operator-dark: #1d4ed8;

    --purple: #c4b5fd;

    --warning: #fbbf24;
    --danger: #f87171;

    --success: #34d399;
}


html[data-theme="light"] {
    --bg-main: #eaf1f8;
    --bg-secondary: #f8fafc;

    --panel: #ffffff;
    --panel-2: #f1f5f9;

    --display: #f8fafc;

    --button: #e2e8f0;
    --button-alt: #dbeafe;

    --border: #cbd5e1;

    --text: #0f172a;
    --muted: #475569;
    --subtle: #64748b;

    --accent: #0284c7;

    --operator: #2563eb;
    --operator-dark: #1d4ed8;

    --purple: #7c3aed;

    --warning: #b45309;
    --danger: #dc2626;

    --success: #047857;
}


* {
    box-sizing: border-box;
}


html {
    color-scheme: dark;
}


html[data-theme="light"] {
    color-scheme: light;
}


body {
    margin: 0;

    min-height: 100vh;

    font-family:
        Inter,
        ui-sans-serif,
        system-ui,
        -apple-system,
        BlinkMacSystemFont,
        "Segoe UI",
        sans-serif;

    background:
        radial-gradient(
            circle at top,
            var(--bg-secondary),
            var(--bg-main)
        );

    color: var(--text);
}


button {
    font-family: inherit;
}


button {
    transition:
        transform 0.08s ease,
        filter 0.15s ease,
        background-color 0.15s ease,
        border-color 0.15s ease;
}


button:hover:not(:disabled) {
    filter: brightness(1.12);
}


button:active:not(:disabled) {
    transform: scale(0.97);
}


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

    outline-offset: 2px;
}


.hidden {
    display: none !important;
}


/* ============================================================
   APP
============================================================ */

.app-shell {
    width: 100%;

    display: flex;
    justify-content: center;

    padding:
        48px
        22px;
}


.calculator {
    width: 1320px;
    max-width: 100%;

    padding: 24px;

    border:
        1px solid
        var(--border);

    border-radius: 24px;

    background:
        linear-gradient(
            180deg,
            var(--panel),
            var(--panel-2)
        );

    box-shadow:
        0
        30px
        80px
        rgba(0, 0, 0, 0.3);
}


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

.calculator-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;

    gap: 16px;

    margin-bottom: 16px;
}


.title-group h1 {
    margin: 0;

    font-size: 26px;

    letter-spacing: -0.02em;
}


.title-group p {
    margin:
        7px
        0
        0;

    color: var(--muted);

    font-size: 13px;
}


.header-actions {
    display: flex;

    gap: 8px;
}


.small-header-button,
.mode-button {
    min-width: 46px;
    min-height: 38px;

    border:
        1px solid
        var(--border);

    border-radius: 9px;

    cursor: pointer;

    background: var(--button-alt);

    color: var(--accent);

    font-weight: 800;
}


.mode-button.rad {
    color: var(--purple);
}


/* ============================================================
   MAIN MODE SWITCH
============================================================ */

.calculator-mode-switch {
    display: grid;

    grid-template-columns:
        1fr
        1fr;

    gap: 8px;

    padding: 5px;

    margin-bottom: 16px;

    border:
        1px solid
        var(--border);

    border-radius: 12px;

    background: var(--display);
}


.calculator-mode-button {
    min-height: 42px;

    border: none;

    border-radius: 8px;

    cursor: pointer;

    background: transparent;

    color: var(--muted);

    font-weight: 700;
}


.calculator-mode-button.active {
    background: var(--button-alt);

    color: var(--accent);
}


/* ============================================================
   SCIENTIFIC DISPLAY
============================================================ */

.display {
    min-height: 145px;

    display: flex;
    flex-direction: column;
    justify-content: flex-end;

    padding:
        18px
        20px
        20px;

    border:
        1px solid
        var(--border);

    border-radius: 17px;

    background: var(--display);
}


.display-meta {
    display: flex;
    justify-content: space-between;
}


.display-mode {
    color: var(--accent);

    font-size: 11px;

    font-weight: 800;
}


.memory-indicator {
    color: var(--purple);

    font-size: 11px;

    font-weight: 700;
}


.expression {
    min-height: 25px;

    margin:
        5px
        0
        10px;

    text-align: right;

    color: var(--subtle);

    font-size: 14px;

    overflow-wrap: anywhere;
}


.display-value {
    text-align: right;

    font-size:
        clamp(
            32px,
            9vw,
            44px
        );

    font-weight: 700;

    overflow-x: auto;

    white-space: nowrap;

    scrollbar-width: thin;
}


.status-message {
    min-height: 22px;

    padding-top: 6px;

    color: var(--accent);

    text-align: right;

    font-size: 12px;
}


.error {
    min-height: 26px;

    display: flex;
    justify-content: flex-end;
    align-items: center;

    color: var(--danger);

    font-size: 13px;
}


/* ============================================================
   SCIENTIFIC CONTROLS
============================================================ */

.memory-grid {
    display: grid;

    grid-template-columns:
        repeat(5, 1fr);

    gap: 7px;

    margin-bottom: 10px;
}


.memory-button {
    min-height: 40px;

    border:
        1px solid
        var(--border);

    border-radius: 10px;

    cursor: pointer;

    background: var(--panel-2);

    color: var(--muted);

    font-size: 12px;

    font-weight: 800;
}


.ans-button {
    color: var(--accent);
}


.expression-controls,
.scientific-grid,
.keypad {
    display: grid;

    grid-template-columns:
        repeat(4, 1fr);

    gap: 9px;
}


.expression-controls {
    margin-bottom: 9px;
}


.scientific-grid {
    margin-bottom: 12px;
}


.button {
    min-height: 54px;

    border: none;

    border-radius: 13px;

    cursor: pointer;

    background: var(--button);

    color: var(--text);

    font-size: 17px;

    font-weight: 700;
}


.operator {
    background:
        linear-gradient(
            180deg,
            var(--operator),
            var(--operator-dark)
        );

    color: #ffffff;
}


.scientific {
    background: var(--button-alt);

    color: var(--accent);

    font-size: 14px;
}


.advanced {
    background: var(--button-alt);

    color: var(--purple);
}


.control,
.danger,
.backspace {
    background: #374151;

    color: var(--warning);
}


.expression-button {
    font-size: 19px;
}


.zero,
.backspace,
.equals {
    grid-column: span 2;
}


.equals {
    background:
        linear-gradient(
            180deg,
            #0ea5e9,
            #0284c7
        );

    color: #ffffff;
}


/* ============================================================
   SCIENTIFIC EXPRESSION
============================================================ */

.raw-expression-section {
    margin-top: 15px;
}


.expression-label-row {
    display: flex;
    justify-content: space-between;

    gap: 10px;

    margin-bottom: 7px;
}


.expression-label-row label {
    color: var(--muted);

    font-size: 12px;
}


.expression-mode-label {
    color: var(--subtle);

    font-size: 11px;
}


.expression-input {
    width: 100%;

    padding:
        12px
        14px;

    border:
        1px solid
        var(--border);

    border-radius: 10px;

    outline: none;

    background: var(--display);

    color: var(--text);

    font-family:
        "Courier New",
        monospace;

    font-size: 14px;
}


.expression-actions {
    display: flex;

    gap: 8px;

    margin-top: 8px;
}


.secondary-action,
.history-control-button {
    min-height: 35px;

    padding:
        0
        10px;

    border:
        1px solid
        var(--border);

    border-radius: 8px;

    cursor: pointer;

    background: var(--panel-2);

    color: var(--muted);
}


.secondary-action {
    flex: 1;
}


/* ============================================================
   HISTORY
============================================================ */

.history-section,
.about-section,
.bit-editor-section,
.architecture-section,
.api-section {
    margin-top: 18px;

    padding: 15px;

    border:
        1px solid
        var(--border);

    border-radius: 14px;
}


.history-header,
.bit-editor-header,
.section-heading {
    display: flex;
    justify-content: space-between;
    align-items: center;

    gap: 10px;

    margin-bottom: 12px;
}


.history-header h2,
.about-section h2,
.bit-editor-header h2,
.section-heading h2 {
    margin: 0;

    font-size: 14px;
}


.history-header span,
.bit-editor-header span,
.section-heading span {
    color: var(--subtle);

    font-size: 10px;
}


.history-actions {
    display: flex;

    gap: 7px;
}


.history-list {
    max-height: 260px;

    overflow-y: auto;

    display: flex;
    flex-direction: column;

    gap: 7px;

    scrollbar-width: thin;
}


.history-list.collapsed {
    display: none;
}


.history-empty {
    padding: 18px;

    text-align: center;

    color: var(--subtle);

    font-size: 12px;
}


.history-item {
    width: 100%;

    padding: 10px;

    border:
        1px solid
        var(--border);

    border-radius: 9px;

    cursor: pointer;

    background: var(--panel-2);

    color: var(--text);

    text-align: left;
}


.history-expression {
    display: block;

    margin-bottom: 5px;

    color: var(--muted);

    font-family:
        "Courier New",
        monospace;

    overflow-wrap: anywhere;
}


.history-result-row {
    display: flex;
    justify-content: space-between;
    align-items: center;

    gap: 10px;
}


.history-result {
    font-weight: 700;
}


.history-mode {
    color: var(--accent);

    font-size: 10px;

    white-space: nowrap;
}


/* ============================================================
   PROGRAMMER SETTINGS
============================================================ */

.programmer-settings {
    display: grid;

    grid-template-columns:
        1fr
        1fr;

    gap: 10px;

    margin-bottom: 12px;
}


.setting-group {
    padding: 11px;

    border:
        1px solid
        var(--border);

    border-radius: 11px;

    background: var(--display);
}


.setting-label {
    display: block;

    margin-bottom: 8px;

    color: var(--muted);

    font-size: 10px;

    font-weight: 700;
}


.word-size-selector {
    display: grid;

    grid-template-columns:
        repeat(4, 1fr);

    gap: 5px;
}


.signed-selector {
    display: grid;

    grid-template-columns:
        1fr
        1fr;

    gap: 5px;
}


.word-size-button,
.signed-button {
    min-height: 35px;

    border:
        1px solid
        var(--border);

    border-radius: 7px;

    cursor: pointer;

    background: var(--panel-2);

    color: var(--muted);

    font-size: 11px;

    font-weight: 800;
}


.word-size-button.active,
.signed-button.active {
    background: #172554;

    color: #7dd3fc;
}


/* ============================================================
   PROGRAMMER DISPLAY
============================================================ */

.programmer-display {
    min-height: 160px;

    padding:
        18px
        20px;

    border:
        1px solid
        var(--border);

    border-radius: 17px;

    background: var(--display);
}


.programmer-display-header {
    display: flex;
    justify-content: space-between;

    gap: 10px;

    color: var(--subtle);

    font-size: 11px;
}


#programmerBaseBadge {
    color: var(--accent);

    font-weight: 800;
}


.programmer-expression {
    min-height: 28px;

    margin-top: 14px;

    text-align: right;

    color: var(--muted);

    font-family:
        "Courier New",
        monospace;

    overflow-wrap: anywhere;
}


.programmer-main-value {
    margin-top: 8px;

    text-align: right;

    font-family:
        "Courier New",
        monospace;

    font-size: 34px;

    font-weight: 700;

    overflow-x: auto;

    white-space: nowrap;
}


.programmer-operation-state {
    margin-top: 8px;

    text-align: right;

    color: var(--subtle);

    font-size: 10px;
}


/* ============================================================
   BASE SELECTOR
============================================================ */

.base-selector {
    display: grid;

    grid-template-columns:
        repeat(4, 1fr);

    gap: 8px;

    margin-bottom: 12px;
}


.base-button {
    min-height: 42px;

    border:
        1px solid
        var(--border);

    border-radius: 10px;

    cursor: pointer;

    background: var(--panel-2);

    color: var(--muted);

    font-weight: 800;
}


.base-button.active {
    background: #172554;

    color: #7dd3fc;
}


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

.conversion-panel {
    margin-bottom: 12px;

    border:
        1px solid
        var(--border);

    border-radius: 12px;

    overflow: hidden;
}


.conversion-row {
    display: grid;

    grid-template-columns:
        50px
        minmax(0, 1fr)
        46px;

    gap: 10px;

    align-items: center;

    padding:
        8px
        10px;

    border-bottom:
        1px solid
        var(--border);
}


.conversion-row:last-child {
    border-bottom: none;
}


.conversion-row span {
    color: var(--accent);

    font-size: 11px;

    font-weight: 800;
}


.conversion-row strong {
    overflow-wrap: anywhere;

    text-align: right;

    font-family:
        "Courier New",
        monospace;

    font-size: 12px;
}


.copy-base-button {
    min-height: 26px;

    padding:
        0
        5px;

    border:
        1px solid
        var(--border);

    border-radius: 6px;

    cursor: pointer;

    background: var(--panel-2);

    color: var(--muted);

    font-size: 9px;
}


.secondary-conversion {
    background:
        rgba(56, 189, 248, 0.03);
}


/* ============================================================
   WORD INFO
============================================================ */

.word-info-panel {
    display: grid;

    grid-template-columns:
        repeat(4, 1fr);

    gap: 7px;

    margin-bottom: 12px;
}


.word-info-panel > div {
    padding:
        9px
        7px;

    border:
        1px solid
        var(--border);

    border-radius: 9px;

    background: var(--panel-2);

    text-align: center;
}


.word-info-panel span {
    display: block;

    margin-bottom: 4px;

    color: var(--subtle);

    font-size: 9px;
}


.word-info-panel strong {
    display: block;

    color: var(--text);

    font-size: 11px;
}


/* ============================================================
   BIT EDITOR
============================================================ */

.bit-grid {
    display: grid;

    grid-template-columns:
        repeat(8, minmax(0, 1fr));

    gap: 5px;
}


.bit-cell {
    min-width: 0;

    padding:
        6px
        2px;

    border:
        1px solid
        var(--border);

    border-radius: 7px;

    cursor: pointer;

    background: var(--panel-2);

    color: var(--subtle);

    text-align: center;
}


.bit-cell.active {
    background: #172554;

    color: #7dd3fc;

    border-color:
        rgba(
            56,
            189,
            248,
            0.4
        );
}


.bit-index {
    display: block;

    margin-bottom: 2px;

    font-size: 8px;

    opacity: 0.65;
}


.bit-value {
    display: block;

    font-size: 13px;

    font-weight: 800;
}


/* ============================================================
   PROGRAMMER OPERATIONS
============================================================ */

.programmer-operation-grid {
    display: grid;

    grid-template-columns:
        repeat(4, 1fr);

    gap: 8px;

    margin-bottom: 10px;
}


.programmer-operation,
.programmer-control {
    min-height: 48px;

    border: none;

    border-radius: 11px;

    cursor: pointer;

    background: var(--button-alt);

    color: var(--purple);

    font-weight: 800;
}


.rotate {
    color: var(--accent);
}


.programmer-control {
    background: #374151;

    color: var(--warning);
}


.programmer-clear {
    grid-column: span 2;
}


/* ============================================================
   HEX KEYS
============================================================ */

.hex-keypad {
    display: grid;

    grid-template-columns:
        repeat(6, 1fr);

    gap: 7px;

    margin-bottom: 9px;
}


.hex-keypad button {
    min-height: 44px;

    border: none;

    border-radius: 10px;

    cursor: pointer;

    background: var(--button-alt);

    color: var(--purple);

    font-weight: 800;
}


/* ============================================================
   PROGRAMMER KEYPAD
============================================================ */

.programmer-keypad {
    display: grid;

    grid-template-columns:
        repeat(3, 1fr);

    gap: 9px;
}


.programmer-keypad button {
    min-height: 54px;

    border: none;

    border-radius: 12px;

    cursor: pointer;

    background: var(--button);

    color: var(--text);

    font-size: 17px;

    font-weight: 700;
}


.programmer-zero {
    grid-column: span 2;
}


.programmer-equals {
    background:
        linear-gradient(
            180deg,
            #0ea5e9,
            #0284c7
        ) !important;

    color: #ffffff !important;
}


.programmer-keypad button:disabled,
.hex-keypad button:disabled {
    opacity: 0.25;

    cursor: not-allowed;
}


/* ============================================================
   ARCHITECTURE
============================================================ */

.architecture-flow {
    display: flex;
    align-items: stretch;

    gap: 6px;
}


.architecture-node {
    flex: 1;

    min-width: 0;

    padding:
        12px
        7px;

    border:
        1px solid
        var(--border);

    border-radius: 10px;

    background: var(--panel-2);

    text-align: center;
}


.architecture-node strong {
    display: block;

    margin-bottom: 5px;

    color: var(--accent);

    font-size: 11px;
}


.architecture-node span {
    display: block;

    color: var(--muted);

    font-size: 9px;

    line-height: 1.4;
}


.architecture-arrow {
    display: flex;
    align-items: center;

    color: var(--subtle);
}


/* ============================================================
   API
============================================================ */

.api-grid {
    display: grid;

    grid-template-columns:
        1fr
        1fr;

    gap: 7px;
}


.api-route {
    display: flex;
    align-items: center;

    gap: 8px;

    padding:
        9px
        10px;

    border:
        1px solid
        var(--border);

    border-radius: 9px;

    background: var(--panel-2);
}


.api-route code {
    color: var(--text);

    font-size: 11px;

    overflow-wrap: anywhere;
}


.api-method {
    min-width: 34px;

    padding:
        3px
        5px;

    border-radius: 5px;

    text-align: center;

    font-size: 8px;

    font-weight: 900;
}


.api-method.get {
    background:
        rgba(
            52,
            211,
            153,
            0.13
        );

    color: var(--success);
}


.api-method.post {
    background:
        rgba(
            56,
            189,
            248,
            0.13
        );

    color: var(--accent);
}


/* ============================================================
   ABOUT
============================================================ */

.about-section p {
    color: var(--muted);

    font-size: 12px;

    line-height: 1.65;
}


.tech-stack {
    display: flex;
    flex-wrap: wrap;

    gap: 6px;
}


.tech-stack span {
    padding:
        5px
        8px;

    border-radius: 7px;

    background: var(--panel-2);

    color: var(--accent);

    font-size: 10px;

    font-weight: 700;
}


/* ============================================================
   FOOTER
============================================================ */

.calculator-footer {
    margin-top: 20px;

    display: flex;
    justify-content: center;
    align-items: center;

    gap: 8px;

    color: var(--subtle);

    font-size: 12px;
}


.version {
    padding:
        3px
        6px;

    border-radius: 6px;

    background: var(--panel-2);
}


/* ============================================================
   WIDE DESKTOP LAYOUT
============================================================ */

@media (min-width: 1050px) {

    #scientificMode,
    #programmerMode:not(.hidden) {
        position: relative;
    }


    #programmerMode:not(.hidden) {
        padding-bottom: 32px;
    }


    #scientificMode > :not(.history-section) {
        width: calc(63% - 12px);
    }


    #scientificMode > .history-section {
        position: absolute;
        top: 0;
        right: 0;

        width: calc(37% - 12px);

        margin-top: 0;
    }


    #scientificMode > .history-section .history-list {
        max-height: 710px;
    }


    #programmerMode > .programmer-settings,
    #programmerMode > .programmer-display,
    #programmerMode > .base-selector,
    #programmerMode > .word-info-panel,
    #programmerMode > .programmer-operation-grid,
    #programmerMode > .hex-keypad,
    #programmerMode > .programmer-keypad {
        width: calc(63% - 12px);
    }


    #programmerMode > .conversion-panel,
    #programmerMode > .bit-editor-section,
    #programmerMode > .history-section {
        position: absolute;
        right: 0;

        width: calc(37% - 12px);
    }


    #programmerMode > .conversion-panel {
        top: 0;
    }


    #programmerMode > .bit-editor-section {
        top: 278px;

        margin-top: 0;
    }


    #programmerMode > .history-section {
        top: 790px;

        margin-top: 0;
    }


    #programmerMode > .history-section .history-list {
        max-height: 350px;
    }


    #programmerMode:has(#baseBIN.active) .programmer-main-value {
        font-size: 18px;

        letter-spacing: 0.02em;

        overflow-x: hidden;
    }


    #programmerMode:has(#baseOCT.active) .programmer-main-value {
        font-size: 24px;
    }


    #programmerMode:has(#baseHEX.active) .programmer-main-value {
        font-size: 27px;
    }


    .display {
        min-height: 165px;
    }


    .button,
    .programmer-keypad button {
        min-height: 58px;
    }


    .architecture-section,
    .api-section,
    .about-section {
        padding: 18px;
    }

}


@media (min-width: 1500px) {

    .app-shell {
        padding:
            56px
            32px;
    }


    .calculator {
        padding: 30px;
    }

}


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

@media (max-width: 1049px) {

    .calculator {
        width: 640px;
    }

}

@media (max-width: 640px) {

    .app-shell {
        padding: 8px;
    }


    .calculator {
        padding: 15px;

        border-radius: 18px;
    }


    .title-group h1 {
        font-size: 20px;
    }


    .programmer-settings {
        grid-template-columns:
            1fr;
    }


    .button,
    .programmer-keypad button {
        min-height: 48px;
    }


    .expression-controls,
    .scientific-grid,
    .keypad {
        gap: 7px;
    }


    .programmer-main-value {
        font-size: 28px;
    }


    .word-info-panel {
        grid-template-columns:
            1fr
            1fr;
    }


    .bit-grid {
        grid-template-columns:
            repeat(
                8,
                minmax(
                    34px,
                    1fr
                )
            );

        overflow-x: auto;

        padding-bottom: 4px;
    }


    .architecture-flow {
        flex-direction: column;
    }


    .architecture-arrow {
        justify-content: center;

        transform: rotate(90deg);
    }


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

}


@media (max-width: 420px) {

    .calculator-header {
        align-items: center;
    }


    .title-group h1 {
        font-size: 18px;
    }


    .conversion-row {
        grid-template-columns:
            42px
            minmax(0, 1fr)
            42px;
    }


    .copy-base-button {
        font-size: 8px;
    }


    .programmer-operation-grid {
        gap: 6px;
    }


    .programmer-operation,
    .programmer-control {
        min-height: 44px;

        font-size: 12px;
    }

}


.portfolio-return-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 38px;
  padding: 0 12px;
  border: 1px solid var(--border);
  border-radius: 9px;
  background: var(--button-alt);
  color: var(--accent);
  font-size: 12px;
  font-weight: 800;
  text-decoration: none;
  white-space: nowrap;
  transition: border-color .18s ease, color .18s ease, transform .18s ease;
}

.portfolio-return-link:hover,
.portfolio-return-link:focus-visible {
  border-color: var(--accent);
  color: var(--text-main);
  transform: translateY(-1px);
}

@media (max-width: 640px) {
  .portfolio-return-link {
    min-height: 34px;
    padding: 0 9px;
    font-size: 10px;
  }
}