/* ── Reset & Base ─────────────────────────────────────────── */
:root {
    --bg:        #1a1a1a;
    --bg-card:   #242424;
    --bg-input:  #2a2a2a;
    --border:    #3a3a3a;
    --text:      #e0e0e0;
    --text-dim:  #888;
    --accent:    #38bdf8;
    --accent-dim:#1e6a9a;
    --mono:      'Cascadia Mono', 'Consolas', 'Courier New', monospace;
}

@media (prefers-color-scheme: light) {
    :root {
        --bg:        #f5f5f5;
        --bg-card:   #fff;
        --bg-input:  #fff;
        --border:    #ccc;
        --text:      #1a1a1a;
        --text-dim:  #666;
    }
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    font-size: 14px;
    color: var(--text);
    background: var(--bg);
    line-height: 1.5;
}

/* ── Loading ─────────────────────────────────────────────── */
.loading {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100vh;
    color: var(--text-dim);
    font-size: 1.2rem;
}

/* ── Layout ──────────────────────────────────────────────── */
.app-shell {
    display: flex;
    flex-direction: column;
    height: 100vh;
}

.app-header {
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    padding: 12px 24px;
    display: flex;
    align-items: center;
    gap: 16px;
    flex-shrink: 0;
}

.app-header h1 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--accent);
    white-space: nowrap;
}

.app-logo {
    width: 32px;
    height: 32px;
    border-radius: 6px;
    object-fit: cover;
}

.app-body {
    display: flex;
    flex: 1;
    min-height: 0;
}

/* ── Nav ─────────────────────────────────────────────────── */
nav.sidebar {
    width: 220px;
    background: var(--bg-card);
    border-right: 1px solid var(--border);
    padding: 12px 0;
    flex-shrink: 0;
    overflow-y: auto;
}

nav.sidebar a {
    display: block;
    padding: 8px 20px;
    color: var(--text);
    text-decoration: none;
    font-size: 0.9rem;
    border-left: 3px solid transparent;
    transition: background 0.15s, border-color 0.15s;
}

nav.sidebar a:hover {
    background: var(--bg-input);
}

nav.sidebar a.active {
    border-left-color: var(--accent);
    background: var(--bg-input);
    color: var(--accent);
    font-weight: 600;
}

/* ── Page Content ────────────────────────────────────────── */
main.page-content {
    flex: 1;
    padding: 24px;
    overflow-y: auto;
    min-width: 0;
}

.page-title {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 4px;
}

.page-subtitle {
    color: var(--text-dim);
    font-size: 0.85rem;
    margin-bottom: 20px;
}

/* ── Section Headers ─────────────────────────────────────── */
.section-header {
    color: var(--accent);
    font-weight: 600;
    font-size: 0.9rem;
    margin: 20px 0 8px;
}

.section-header:first-child {
    margin-top: 0;
}

/* ── Cards & Panels ──────────────────────────────────────── */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 16px;
    margin-bottom: 16px;
}

/* ── Controls ────────────────────────────────────────────── */
.toolbar {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
}

.toolbar label {
    font-size: 0.85rem;
    color: var(--text-dim);
}

select, input[type="text"] {
    background: var(--bg-input);
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 4px 8px;
    font-size: 0.9rem;
    font-family: inherit;
}

select:focus, input:focus, textarea:focus {
    outline: 1px solid var(--accent);
    border-color: var(--accent);
}

.fp-input {
    font-family: var(--mono);
    font-size: 0.9rem;
    color: var(--text);
    border: 2px solid var(--border);
    border-radius: 4px;
    padding: 4px 8px;
    transition: border-color 0.15s, background 0.15s, box-shadow 0.15s;
}

.fp-input:focus {
    outline: none;
    box-shadow: 0 0 0 2px currentColor;
}

textarea {
    background: var(--bg-input);
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 8px;
    font-family: var(--mono);
    font-size: 0.85rem;
    resize: vertical;
    width: 100%;
}

button, .btn {
    background: var(--accent-dim);
    color: #fff;
    border: 1px solid var(--accent);
    border-radius: 4px;
    padding: 5px 14px;
    font-size: 0.85rem;
    cursor: pointer;
    transition: background 0.15s;
}

button:hover, .btn:hover {
    background: var(--accent);
}

input[type="checkbox"] {
    accent-color: var(--accent);
}

input[type="range"] {
    accent-color: var(--accent);
    width: 180px;
}

/* ── Diagram Output ──────────────────────────────────────── */
.diagram-output {
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 12px;
    font-family: var(--mono);
    font-size: 0.82rem;
    line-height: 1.35;
    white-space: pre;
    overflow-x: auto;
    tab-size: 4;
}

/* ── Field chips ─────────────────────────────────────────── */
.field-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 12px;
}

.field-chip {
    border: 1px solid;
    border-radius: 4px;
    padding: 3px 10px;
    font-size: 0.8rem;
    cursor: pointer;
    transition: opacity 0.15s;
    user-select: none;
}

.field-chip:hover {
    opacity: 0.8;
}

.field-chip.active {
    outline: 2px solid var(--accent);
    outline-offset: 1px;
}

.field-chip .chip-name {
    font-weight: 600;
    font-size: 0.7rem;
    display: block;
}

.field-chip .chip-value {
    font-family: var(--mono);
    font-size: 0.85rem;
}

/* ── Hex display ─────────────────────────────────────────── */
.hex-display, .binary-display {
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 10px;
    display: flex;
    flex-wrap: wrap;
    gap: 2px;
    margin-bottom: 12px;
}

.hex-byte {
    font-family: var(--mono);
    font-size: 0.9rem;
    cursor: pointer;
    padding: 1px 3px;
    border-radius: 2px;
    transition: background 0.15s;
}

.hex-byte:hover {
    background: rgba(255,255,255,0.08);
}

.hex-byte.active {
    font-weight: 800;
    text-decoration: underline;
}

/* ── Binary segments ─────────────────────────────────────── */
.binary-segment {
    border-radius: 3px;
    padding: 3px 8px;
    cursor: pointer;
    text-align: center;
    user-select: none;
}

.binary-segment.active {
    outline: 2px solid var(--accent);
    outline-offset: 1px;
}

.binary-segment .seg-label {
    font-size: 0.65rem;
    opacity: 0.7;
    display: block;
}

.binary-segment .seg-bits {
    font-family: var(--mono);
    font-size: 0.85rem;
}

/* ── CPU Lab ─────────────────────────────────────────────── */
.flag-checks {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    margin: 8px 0;
}

.flag-checks label {
    display: flex;
    align-items: center;
    gap: 4px;
    cursor: pointer;
    font-size: 0.9rem;
}

.mode-slider {
    display: flex;
    align-items: center;
    gap: 8px;
    margin: 8px 0;
}

/* ── File input ──────────────────────────────────────────── */
.file-input-wrapper {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 12px;
}

.file-path {
    color: var(--text-dim);
    font-size: 0.85rem;
    font-family: var(--mono);
}

/* ── Raw bytes ───────────────────────────────────────────── */
.raw-bytes {
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 8px;
    font-family: var(--mono);
    font-size: 0.8rem;
    max-height: 200px;
    overflow-y: auto;
    word-break: break-all;
    color: var(--text-dim);
}

/* ── FP Stream Lab ──────────────────────────────────────────── */
.stream-info {
    font-family: var(--mono);
    font-size: 0.82rem;
    color: var(--text-dim);
}

.stream-desc {
    font-size: 0.82rem;
    color: var(--text-dim);
    margin-bottom: 12px;
}

.stream-controls {
    border-left: 3px solid var(--accent);
}

.offset-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    color: #fff;
    font-weight: 700;
    font-size: 0.9rem;
    font-family: var(--mono);
}

.view-name {
    font-family: var(--mono);
    color: #C678DD;
}

.btn-accent {
    background: linear-gradient(135deg, #1e6a9a, #38bdf8);
    border-color: #38bdf8;
    font-weight: 600;
}

.btn-accent:hover {
    background: linear-gradient(135deg, #38bdf8, #61AFEF);
}

.stream-roundtrip {
    border-left: 3px solid #50C878;
}

.roundtrip-steps {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}

.step {
    display: flex;
    align-items: center;
    gap: 8px;
    background: rgba(255,255,255,0.04);
    border-radius: 6px;
    padding: 6px 14px;
}

.step-num {
    width: 26px;
    height: 26px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-weight: 700;
    font-size: 0.85rem;
    flex-shrink: 0;
}

.step-text {
    font-size: 0.85rem;
}

.step-arrow {
    font-size: 1.1rem;
    color: var(--text-dim);
}

.field-dot {
    display: inline-block;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    margin-right: 6px;
    vertical-align: middle;
}

.ieee-sign {
    font-family: var(--mono);
    font-size: 1rem;
    font-weight: 700;
    text-align: center;
}

.ieee-class {
    font-size: 0.82rem;
    font-weight: 600;
    color: #7AC04A;
}

.stream-readback table,
.stream-decomposition table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.85rem;
}

.stream-readback th,
.stream-decomposition th {
    text-align: left;
    color: var(--accent);
    font-weight: 600;
    padding: 4px 10px;
    border-bottom: 1px solid var(--border);
    font-size: 0.8rem;
}

.stream-readback td,
.stream-decomposition td {
    padding: 4px 10px;
    border-bottom: 1px solid var(--border);
}

.stream-readback td.mono,
.stream-decomposition td.mono {
    font-family: var(--mono);
    font-size: 0.82rem;
}

.stream-log {
    max-height: 280px;
    overflow-y: auto;
    font-size: 0.78rem;
}

/* ── IEEE 754 Decomposition Cards ─────────────────────────────── */

.ieee-intro {
    font-size: 0.82rem;
    color: var(--muted);
    margin: 0 0 12px;
    line-height: 1.5;
}

.ieee-card-type {
    font-size: 0.75rem;
    color: var(--muted);
    padding: 1px 6px;
    border: 1px solid var(--border);
    border-radius: 4px;
}

.ieee-card-class {
    margin-left: auto;
    font-size: 0.78rem;
    font-weight: 700;
    padding: 1px 8px;
    border-radius: 4px;
}

.ieee-card-class.class-normal { background: rgba(122, 192, 74, 0.18); color: #7AC04A; }
.ieee-card-class.class-special { background: rgba(224, 108, 117, 0.18); color: #E06C75; }
.ieee-card-class.class-zero { background: rgba(136, 136, 136, 0.18); color: #999; }



.ieee-bit-bar {
    display: flex;
    gap: 2px;
    margin-bottom: 10px;
    border-radius: 4px;
    overflow: hidden;
    font-size: 0.7rem;
    font-weight: 600;
    text-align: center;
    line-height: 22px;
    height: 22px;
}

.ieee-seg {
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 0;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.ieee-seg-sign { background: #E06C75; color: #fff; border-radius: 4px 0 0 4px; }
.ieee-seg-exp  { background: #61AFEF; color: #fff; }
.ieee-seg-man  { background: #7AC04A; color: #fff; border-radius: 0 4px 4px 0; }

.ieee-fields-row {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.ieee-field {
    flex: 1 1 100px;
    min-width: 90px;
}

.ieee-field-wide {
    flex: 2 1 180px;
}

.ieee-field-label {
    font-size: 0.72rem;
    font-weight: 600;
    color: var(--muted);
    margin-bottom: 2px;
}

.ieee-bits {
    font-weight: 400;
    color: var(--accent);
    font-size: 0.68rem;
}

.ieee-field-value {
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--fg);
    padding: 4px 8px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--border);
    border-radius: 4px;
}

.ieee-field-value.mono {
    font-family: var(--mono);
    font-size: 0.82rem;
}

.ieee-sign-val {
    font-family: var(--mono);
    font-weight: 700;
    text-align: center;
}

.ieee-toggle {
    font-family: var(--mono);
    font-weight: 700;
    font-size: 0.88rem;
    background: rgba(224, 108, 117, 0.12);
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--fg);
    padding: 4px 12px;
    cursor: pointer;
    width: 100%;
    text-align: center;
    transition: background 0.15s;
}

.ieee-toggle:hover {
    background: rgba(224, 108, 117, 0.25);
}

.ieee-input {
    font-family: var(--mono);
    font-size: 0.82rem;
    font-weight: 600;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--fg);
    padding: 4px 8px;
    width: 100%;
    box-sizing: border-box;
    transition: border-color 0.15s;
}

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

.ieee-input-wide {
    min-width: 140px;
}

.field-chip-wrapper {
    display: contents;
}

.field-chip-float {
    cursor: pointer;
    position: relative;
}

.chip-expand-icon {
    font-size: 0.6rem;
    opacity: 0.6;
    margin-left: 4px;
}

.ieee-drawer {
    grid-column: 1 / -1;
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 0 0 8px 8px;
    padding: 14px 16px 12px;
    margin: -4px 0 8px 0;
    animation: drawer-open 0.2s ease-out;
}

@keyframes drawer-open {
    from { opacity: 0; max-height: 0; padding-top: 0; padding-bottom: 0; }
    to   { opacity: 1; max-height: 300px; }
}

.ieee-drawer-header {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 8px;
}

.ieee-drawer-native {
    margin-left: auto;
    font-size: 0.82rem;
    color: var(--muted);
}

.field-chip .chip-bits {
    font-family: var(--mono);
    font-size: 0.7rem;
    opacity: 0.7;
    display: block;
}

input[type="number"] {
    background: var(--bg-input);
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 4px 8px;
    font-size: 0.9rem;
}