:root {
    --bg-primary: #0a0a0f;
    --bg-secondary: #12121a;
    --bg-card: #16161f;
    --bg-code: #0d0d12;
    --border: #2a2a3a;
    --text-primary: #f0f0f5;
    --text-secondary: #a0a0b8;
    --accent-green: #00ff41;
    --accent-cyan: #00cc33;
    --accent-js: #f7df1e;
    --accent-python: #3776ab;
    --accent-go: #00add8;
    --accent-rust: #dea584;
    --syntax-keyword: #ff7b9c;
    --syntax-string: #98d8a0;
    --syntax-function: #7dd3fc;
    --syntax-comment: #6a6a7a;
    --syntax-number: #fbbf24;
}

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

::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: var(--bg-secondary); }
::-webkit-scrollbar-thumb { background: #3a3a4a; border-radius: 5px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-secondary); }

body {
    font-family: 'DM Sans', system-ui, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.7;
}

.grid-bg {
    position: fixed;
    top: 0; left: 0;
    width: 100%; height: 100%;
    background-image: 
        linear-gradient(var(--border) 1px, transparent 1px),
        linear-gradient(90deg, var(--border) 1px, transparent 1px);
    background-size: 60px 60px;
    opacity: 0.08;
    pointer-events: none;
}

header {
    position: relative;
    padding: 1.5rem 2rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

h1 {
    font-size: 2rem;
    font-weight: 600;
    margin: 0;
    line-height: 1;
}

h1 span { color: var(--accent-green); }

.tagline {
    color: var(--text-secondary);
    font-size: 0.85rem;
    margin: 0.25rem 0 0 0;
}
#version-number {
    color: var(--text-muted);
    font-size: 0.7rem;
    margin-left: 0.5rem;
}

.page-layout {
    display: flex;
    min-height: calc(100vh - 120px);
}

aside {
    width: 280px;
    flex-shrink: 0;
    background: var(--bg-secondary);
    border-right: 1px solid var(--border);
    position: sticky;
    top: 0;
    height: 100vh;
    overflow-y: auto;
    padding: 1rem 0;
}


.nav-topic {
    padding: 0.75rem 1rem;
    border-left: 3px solid transparent;
    transition: all 0.15s;
}

/* Top-level topics are not clickable - just category headers */

.nav-topic-title {
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text-primary);
    margin-bottom: 0.3rem;
}

.nav-topic.active .nav-topic-title { color: var(--accent-green); }

.nav-keywords {
    display: flex;
    flex-wrap: wrap;
    gap: 0.3rem;
}

.nav-keyword {
    font-size: 0.65rem;
    color: var(--text-secondary);
    background: rgba(255,255,255,0.05);
    padding: 0.15rem 0.4rem;
    border-radius: 3px;
}

.nav-subtopic {
    padding: 0.4rem 1rem 0.4rem 1.75rem;
    cursor: pointer;
    border-left: 2px solid transparent;
    transition: all 0.15s;
    font-size: 0.8rem;
    color: var(--text-secondary);
}
.nav-subtopic:hover { 
    background: rgba(255,255,255,0.03); 
    color: var(--text-primary);
}
.nav-subtopic.active {
    background: rgba(0, 255, 65, 0.03);
    border-left-color: var(--accent-cyan);
    color: var(--accent-cyan);
}
.nav-subtopic::before {
    content: "└";
    margin-right: 0.5rem;
    opacity: 0.4;
}

main {
    flex: 1;
    max-width: 900px;
    padding: 2rem;
}

section { display: none; animation: fadeIn 0.3s ease; }
section.active { display: block; }

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    padding: 2rem;
    margin-bottom: 1.5rem;
}

h2 {
    font-size: 1.6rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

h2 .icon {
    width: 34px; height: 34px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--accent-green);
    color: var(--bg-primary);
    font-size: 0.9rem;
    font-family: 'JetBrains Mono', monospace;
}

.lesson-intro {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 1.5rem;
    line-height: 1.7;
}

.lesson-intro p {
    margin-bottom: 1rem;
}

.lesson-intro p:last-child {
    margin-bottom: 0;
}

code {
    background: rgba(0, 255, 65, 0.08);
    border: 1px solid rgba(0, 255, 65, 0.2);
    padding: 0.1rem 0.35rem;
    border-radius: 4px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85em;
    color: var(--accent-green);
}

.lang-tabs {
    display: flex;
    gap: 0;
    border-bottom: 1px solid var(--border);
    margin-top: 1rem;
}

.lang-tab {
    padding: 0.6rem 1.2rem;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-family: 'DM Sans', sans-serif;
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
    border-bottom: 2px solid transparent;
    margin-bottom: -1px;
    transition: all 0.15s;
}

.lang-tab:hover { color: var(--text-primary); }

.lang-tab.active {
    color: var(--text-primary);
    border-bottom-color: var(--accent-green);
}

.lang-tab[data-lang="javascript"].active { border-bottom-color: var(--accent-js); }
.lang-tab[data-lang="python"].active { border-bottom-color: var(--accent-python); }
.lang-tab[data-lang="go"].active { border-bottom-color: var(--accent-go); }
.lang-tab[data-lang="rust"].active { border-bottom-color: var(--accent-rust); }

.code-panel { display: none; }
.code-panel.active { display: block; }

.code-container {
    background: var(--bg-code);
    border: 1px solid var(--border);
    border-top: none;
    border-radius: 0 0 6px 6px;
    overflow: hidden;
}

.code-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem 1rem;
    border-bottom: 1px solid var(--border);
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.static-label {
    background: rgba(255, 255, 255, 0.08);
    padding: 0.2rem 0.5rem;
    border-radius: 3px;
    font-size: 0.65rem;
}

.run-btn {
    background: var(--accent-green);
    color: var(--bg-primary);
    border: none;
    padding: 0.4rem 1rem;
    border-radius: 4px;
    font-weight: 600;
    font-size: 0.75rem;
    cursor: pointer;
}

.run-btn:hover { filter: brightness(1.1); }

.code-wrapper {
    position: relative;
    height: 280px;
}

.code-gutter {
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 28px;
    background: var(--bg-secondary);
    border-right: 1px solid var(--border);
    overflow: hidden;
    z-index: 5;
    /* Match code editor font to ensure line heights align */
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    line-height: 1.6;
}

.code-gutter-inner {
    padding-top: 1rem;
}

.gutter-line {
    height: 1.6em; /* Now matches code editor line-height exactly */
    display: flex;
    align-items: center;
    justify-content: center;
}

.gutter-info-btn {
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: transparent;
    border: 1px solid var(--text-secondary);
    color: var(--text-secondary);
    font-size: 0.6rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.15s;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0.6;
}

.gutter-info-btn.unviewed {
    border: 2px solid #ffd700;
    color: #1a1a2e;
    background: linear-gradient(135deg, #ffd700 0%, #ffec8b 50%, #ffd700 100%);
    opacity: 1;
    font-weight: 700;
    box-shadow: 
        0 0 6px rgba(255, 215, 0, 0.6),
        inset 0 -2px 4px rgba(0,0,0,0.2),
        inset 0 2px 4px rgba(255,255,255,0.4);
}

.gutter-info-btn:hover {
    background: #fff;
    color: #1a1a2e;
    border-color: #fff;
    opacity: 1;
    box-shadow: 0 0 8px rgba(255, 255, 255, 0.5);
}

.code-info-tooltip {
    display: none;
    position: fixed;
    background: var(--bg-primary);
    border: 1px solid var(--accent-cyan);
    border-radius: 6px;
    padding: 0.75rem 1rem;
    width: 300px;
    max-width: 90vw;
    font-size: 0.8rem;
    color: var(--text-secondary);
    line-height: 1.5;
    z-index: 1000;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.6);
}

.code-info-tooltip.active {
    display: block;
    animation: tooltipFadeIn 0.15s ease;
}

@keyframes tooltipFadeIn {
    from { opacity: 0; transform: translateY(-5px); }
    to { opacity: 1; transform: translateY(0); }
}

.code-info-tooltip strong {
    color: var(--accent-cyan);
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

.code-info-tooltip p {
    margin: 0.4rem 0 0 0;
}

.code-info-tooltip code {
    background: rgba(0, 255, 65, 0.1);
    padding: 0.1rem 0.25rem;
    border-radius: 3px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85em;
    color: var(--accent-green);
}

.code-highlight {
    position: absolute;
    top: 0; left: 28px; right: 0; bottom: 0;
    padding: 1rem;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    line-height: 1.6;
    white-space: pre;
    overflow: auto;
    pointer-events: none;
    /* Hide scrollbars (synced via JS from textarea) */
    scrollbar-width: none; /* Firefox */
    -ms-overflow-style: none; /* IE/Edge */
}
.code-highlight::-webkit-scrollbar {
    display: none; /* Chrome/Safari/Opera */
}

.code-editor {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    line-height: 1.6;
    color: transparent;
    caret-color: var(--text-primary);
    background: transparent;
    border: none;
    padding: 1rem;
    padding-left: calc(28px + 1rem);
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    resize: none;
    outline: none;
    z-index: 1;
    white-space: pre;
    overflow: auto;
}

.code-static {
    padding: 1rem;
    padding-left: calc(28px + 1rem);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    line-height: 1.6;
    white-space: pre;
    overflow: auto;
    height: 280px;
    margin: 0;
}

.output-container { border-top: 1px solid var(--border); }

.output-header {
    padding: 0.5rem 1rem;
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    border-bottom: 1px solid var(--border);
}

.output {
    padding: 1rem;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    line-height: 1.6;
    color: var(--accent-green);
    min-height: 80px;
    white-space: pre-wrap;
}

.output-line {
    padding: 1px 4px;
    margin: 0 -4px;
    border-radius: 3px;
    transition: background 0.15s;
}

.output-line.highlighted {
    background: rgba(0, 255, 65, 0.15);
}

.expandable {
    cursor: pointer;
    background: rgba(0, 255, 65, 0.05);
    border-bottom: 1px dashed rgba(0, 255, 65, 0.3);
    padding: 0 2px;
    border-radius: 2px;
}
.expandable:hover {
    background: rgba(0, 255, 65, 0.12);
    border-bottom: 1px solid var(--accent-green);
}
.expandable .arrow { 
    display: inline-block; 
    transition: transform 0.15s; 
    margin-right: 4px;
    font-size: 0.7em;
}
.expandable.expanded .arrow { transform: rotate(90deg); }
.expandable .preview { color: var(--text-secondary); }
.expanded-content { 
    display: none; 
    margin-left: 1.5em; 
    color: var(--text-secondary);
    font-size: 0.9em;
}
.expandable.expanded + .expanded-content { display: block; }

.syntax-keyword { color: var(--syntax-keyword); }
.syntax-string { color: var(--syntax-string); }
.syntax-function { color: var(--syntax-function); }
.syntax-comment { color: var(--syntax-comment); font-style: italic; }
.syntax-number { color: var(--syntax-number); }

.info-box {
    background: linear-gradient(135deg, rgba(0, 212, 170, 0.08), transparent);
    border-left: 2px solid var(--accent-cyan);
    padding: 1rem 1.25rem;
    margin-top: 1.5rem;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.info-box strong { color: var(--accent-cyan); }

/* Notation Reference Table */
.notation-table {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 1rem;
    margin-top: 1.5rem;
}
.notation-title {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--accent-cyan);
    margin-bottom: 0.75rem;
}
.notation-grid {
    display: grid;
    grid-template-columns: 1fr auto auto;
    gap: 0.5rem 1.5rem;
    font-size: 0.85rem;
}
.notation-header {
    color: var(--text-secondary);
    font-weight: 600;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--border);
}
.notation-cell {
    color: var(--text-primary);
    padding: 0.25rem 0;
}
.notation-symbol {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.1rem;
    color: var(--accent-green);
}

.quiz {
    margin-top: 1.5rem;
    padding: 1.25rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
}
.quiz-question {
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}
.quiz-options { display: flex; flex-direction: column; gap: 0.5rem; }
.quiz-option {
    display: flex;
    align-items: center;
    padding: 0.75rem 1rem;
    background: var(--bg-code);
    border: 1px solid var(--border);
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.15s;
}
.quiz-option:hover { border-color: var(--accent-cyan); }
.quiz-option.selected { border-color: var(--accent-green); background: rgba(0,255,65,0.05); }
.quiz-option.correct { border-color: #4ade80; background: rgba(74,222,128,0.1); }
.quiz-option.incorrect { border-color: #f87171; background: rgba(248,113,113,0.1); }
.quiz-option input { display: none; }
.quiz-option .letter {
    width: 24px; height: 24px;
    display: flex; align-items: center; justify-content: center;
    background: var(--border);
    border-radius: 4px;
    margin-right: 0.75rem;
    font-size: 0.8rem;
    font-weight: 600;
}
.quiz-option.selected .letter { background: var(--accent-green); color: #000; }
.quiz-option.correct .letter { background: #4ade80; color: #000; }
.quiz-option.incorrect .letter { background: #f87171; color: #000; }
.quiz-check {
    margin-top: 1rem;
    padding: 0.6rem 1.5rem;
    background: var(--accent-green);
    color: #000;
    border: none;
    border-radius: 6px;
    font-weight: 600;
    cursor: pointer;
}
.quiz-check:disabled { opacity: 0.5; cursor: not-allowed; }
.quiz-feedback {
    margin-top: 1rem;
    padding: 0.75rem 1rem;
    border-radius: 6px;
    font-size: 0.9rem;
}
.quiz-feedback.correct { background: rgba(74,222,128,0.1); border: 1px solid #4ade80; color: #4ade80; }
.quiz-feedback.incorrect { background: rgba(248,113,113,0.1); border: 1px solid #f87171; color: #f87171; }

/* Mastery indicators */
.mastery-indicator {
    font-size: 0.7rem;
    font-weight: 600;
    padding: 0.1rem 0.4rem;
    border-radius: 4px;
    margin-left: 0.5rem;
    font-family: 'JetBrains Mono', monospace;
    white-space: nowrap;
}
.mastery-partial .mastery-indicator {
    background: rgba(251, 191, 36, 0.2);
    color: #fbbf24;
}
.mastery-almost .mastery-indicator {
    background: rgba(0, 212, 170, 0.2);
    color: var(--accent-cyan);
}
.mastery-complete .mastery-indicator {
    background: rgba(0, 255, 65, 0.2);
    color: var(--accent-green);
}
.nav-topic {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    flex-wrap: wrap;
}
.nav-topic-title {
    flex: 1;
}
.nav-subtopic {
    display: flex;
    align-items: center;
}
.nav-subtopic-text {
    flex: 1;
}

/* Progress warning / login button (top-right) */
.header-auth {
    flex-shrink: 0;
    visibility: hidden;
}
.header-auth.ready {
    visibility: visible;
}
.progress-warning {
    display: flex;
    flex-direction: column;
    font-family: inherit;
    font-size: inherit;
    align-items: flex-end;
    gap: 0.15rem;
    background: rgba(251, 191, 36, 0.1);
    border: 1px solid rgba(251, 191, 36, 0.3);
    border-radius: 6px;
    padding: 0.5rem 0.75rem;
    font-size: 0.75rem;
    color: #fbbf24;
    cursor: pointer;
    transition: all 0.2s;
    text-align: right;
}
.progress-warning:hover {
    background: rgba(251, 191, 36, 0.15);
    border-color: rgba(251, 191, 36, 0.5);
}
.progress-warning-line1 {
    white-space: nowrap;
}
.progress-warning-cta {
    color: var(--accent-green);
    font-weight: 500;
    font-size: 0.8rem;
}
#progress-summary {
    display: none;
    color: var(--accent-cyan);
}

/* Bit Flipper Widget */
.bit-flipper {
    background: var(--bg-code);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.5rem;
    margin: 1.5rem 0;
}
.bit-flipper-title {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--accent-green);
}
.bit-flipper-bits {
    display: flex;
    justify-content: center;
    gap: 0.25rem;
    margin-bottom: 1rem;
}
.bit-column {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.25rem;
}
.bit-weight {
    font-size: 0.7rem;
    color: var(--text-secondary);
    font-family: 'JetBrains Mono', monospace;
}
.bit-weight.sign-bit {
    color: #ff7b9c;
}
.bit-toggle {
    width: 2.5rem;
    height: 2.5rem;
    font-size: 1.2rem;
    font-family: 'JetBrains Mono', monospace;
    font-weight: 600;
    border: 2px solid var(--border);
    border-radius: 6px;
    background: var(--bg-secondary);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.15s;
}
.bit-toggle:hover {
    border-color: var(--accent-cyan);
}
.bit-toggle.on {
    background: var(--accent-green);
    color: #000;
    border-color: var(--accent-green);
}
.bit-column[data-bit="7"] .bit-toggle.on {
    background: #ff7b9c;
    border-color: #ff7b9c;
}
.bit-label {
    font-size: 0.65rem;
    color: var(--text-secondary);
    opacity: 0.6;
}
.bit-flipper-values {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 0.75rem;
}
.bit-value {
    display: flex;
    align-items: baseline;
    gap: 0.5rem;
}
.bit-value-label {
    font-size: 0.85rem;
    color: var(--text-secondary);
}
.bit-value-num {
    font-size: 1.5rem;
    font-weight: 600;
    font-family: 'JetBrains Mono', monospace;
    color: var(--text-primary);
}
.bit-flipper-breakdown {
    font-size: 0.8rem;
    font-family: 'JetBrains Mono', monospace;
    color: var(--text-secondary);
    text-align: center;
    margin-bottom: 1rem;
    min-height: 1.2em;
}
.bit-flipper-slider {
    margin-bottom: 1rem;
    text-align: center;
}
.bit-flipper-slider label {
    font-size: 0.85rem;
    color: var(--text-secondary);
    display: block;
    margin-bottom: 0.5rem;
}
.bit-flipper-slider input[type="range"] {
    width: 100%;
    max-width: 300px;
    accent-color: var(--accent-green);
}
#slider-value {
    color: var(--accent-cyan);
    font-family: 'JetBrains Mono', monospace;
}
.bit-flipper-ops {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}
.bit-ops-group {
    display: flex;
    align-items: center;
    gap: 0.35rem;
}
.bit-ops-label {
    font-size: 0.7rem;
    color: var(--text-secondary);
    margin-right: 0.25rem;
}
.bit-flipper-ops button {
    padding: 0.4rem 0.6rem;
    font-size: 0.85rem;
    font-family: 'JetBrains Mono', monospace;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.15s;
    min-width: 2.2rem;
}
.bit-flipper-ops button:hover {
    border-color: var(--accent-green);
    color: var(--accent-green);
}
.bit-flipper-operand {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    margin-bottom: 1rem;
    padding: 0.75rem;
    background: rgba(0, 212, 170, 0.1);
    border-radius: 6px;
}
.bit-flipper-operand span {
    font-size: 0.85rem;
    color: var(--text-secondary);
}
.bit-flipper-operand input {
    width: 4rem;
    padding: 0.35rem 0.5rem;
    font-family: 'JetBrains Mono', monospace;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-primary);
    text-align: center;
}
.bit-flipper-operand button {
    padding: 0.35rem 0.75rem;
    font-size: 0.8rem;
    background: var(--accent-cyan);
    border: none;
    border-radius: 4px;
    color: #000;
    cursor: pointer;
}
.bit-flipper-operand button:last-child {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    color: var(--text-secondary);
}
/* Achievements */
.achievements {
    margin-top: 1.5rem;
    padding: 1rem;
    background: rgba(0, 212, 170, 0.05);
    border-radius: 8px;
    border: 1px solid rgba(0, 212, 170, 0.2);
}
.achievements-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--accent-green);
    margin-bottom: 1rem;
}
.achievement-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 0.75rem;
}
.achievement {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem;
    background: var(--bg-secondary);
    border-radius: 6px;
    border: 1px solid var(--border);
    cursor: help;
    transition: all 0.2s;
}
.achievement.unlocked {
    border-color: var(--accent-green);
    background: rgba(0, 212, 170, 0.1);
}
.achievement-icon {
    font-size: 1.2rem;
    opacity: 0.5;
}
.achievement.unlocked .achievement-icon {
    opacity: 1;
}
.achievement-name {
    font-weight: 600;
    font-size: 0.85rem;
    color: var(--text-primary);
}
.achievement-desc {
    font-size: 0.75rem;
    color: var(--text-secondary);
    flex: 1;
}

/* Avalanche Effect Visualizer */
.avalanche-widget {
    background: var(--bg-code);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.5rem;
    margin: 1.5rem 0;
}
.avalanche-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--accent-cyan);
    margin-bottom: 1rem;
}
.avalanche-inputs {
    display: flex;
    gap: 1rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}
.avalanche-input-group {
    flex: 1;
    min-width: 200px;
}
.avalanche-input-group label {
    display: block;
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-bottom: 0.25rem;
}
.avalanche-input-group input {
    width: 100%;
    padding: 0.5rem 0.75rem;
    font-family: 'JetBrains Mono', monospace;
    font-size: 1rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-primary);
}
.avalanche-input-group input:focus {
    outline: none;
    border-color: var(--accent-cyan);
}
.avalanche-quick-actions {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1rem;
}
.avalanche-quick-actions button {
    padding: 0.4rem 0.8rem;
    font-size: 0.8rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.15s;
}
.avalanche-quick-actions button:hover {
    border-color: var(--accent-cyan);
    color: var(--text-primary);
}
.avalanche-results {
    margin-bottom: 1rem;
}
.avalanche-hash-row {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 0.5rem;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.75rem;
}
.hash-label {
    color: var(--text-secondary);
    width: 4rem;
}
.hash-hex {
    color: var(--text-primary);
    word-break: break-all;
}
.avalanche-comparison {
    background: var(--bg-secondary);
    border-radius: 6px;
    padding: 1rem;
    margin-top: 1rem;
}
.avalanche-bits {
    display: flex;
    flex-wrap: wrap;
    gap: 1px;
    margin-bottom: 1rem;
    justify-content: center;
}
.bit-cell {
    width: 6px;
    height: 6px;
    border-radius: 1px;
    background: var(--bg-code);
}
.bit-cell.changed {
    background: #ff6b6b;
}
.bit-cell.same {
    background: var(--accent-green);
    opacity: 0.3;
}
.avalanche-stats {
    display: flex;
    justify-content: center;
    gap: 2rem;
}
.stat-item {
    text-align: center;
}
.stat-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 600;
    font-family: 'JetBrains Mono', monospace;
    color: var(--accent-cyan);
}
.stat-label {
    font-size: 0.75rem;
    color: var(--text-secondary);
}
.avalanche-insight {
    font-size: 0.85rem;
    color: var(--text-secondary);
    text-align: center;
    font-style: italic;
    min-height: 1.2em;
}
.avalanche-insight.perfect {
    color: var(--accent-green);
}
.avalanche-insight.warning {
    color: #ffaa00;
}

/* Shift & Rotate Widget */
.shift-widget {
    background: var(--bg-code);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.5rem;
    margin: 1.5rem 0;
}
.shift-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--accent-cyan);
    margin-bottom: 1rem;
    text-align: center;
}
.shift-bits {
    display: flex;
    justify-content: center;
    gap: 4px;
    margin-bottom: 1rem;
}
.shift-bit {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.15s;
    border: 2px solid transparent;
}
.shift-bit.on {
    background: var(--accent-green);
    color: var(--bg-primary);
}
.shift-bit.off {
    background: var(--bg-secondary);
    color: var(--text-secondary);
    border-color: var(--border);
}
.shift-bit:hover {
    transform: scale(1.1);
}
.shift-bit.moving-left {
    animation: shiftPulse 0.2s ease-out;
}
.shift-bit.moving-right {
    animation: shiftPulse 0.2s ease-out;
}
@keyframes shiftPulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.15); }
    100% { transform: scale(1); }
}
.shift-value {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin-bottom: 1rem;
    font-family: 'JetBrains Mono', monospace;
}
.shift-decimal {
    font-size: 1.5rem;
    color: var(--accent-green);
}
.shift-hex {
    font-size: 1.5rem;
    color: var(--accent-cyan);
}
.shift-controls {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    align-items: center;
    margin-bottom: 1rem;
}
.shift-btn-group {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    justify-content: center;
}
.shift-btn-group button {
    padding: 0.5rem 1rem;
    font-size: 0.85rem;
    font-family: inherit;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.15s;
}
.shift-btn-group button:hover {
    border-color: var(--accent-green);
    color: var(--accent-green);
}
.shift-history {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-align: center;
    min-height: 1.5em;
    margin-bottom: 1rem;
}

/* Binary & Hex Converter Widget */
.converter-widget {
    background: var(--bg-code);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.5rem;
    margin: 1.5rem 0;
}
.converter-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--accent-cyan);
    margin-bottom: 1rem;
    text-align: center;
}
.converter-inputs {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}
.converter-field {
    text-align: center;
}
.converter-field label {
    display: block;
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-bottom: 0.25rem;
}
.converter-field input {
    width: 100px;
    padding: 0.5rem;
    font-family: 'JetBrains Mono', monospace;
    font-size: 1rem;
    text-align: center;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-primary);
}
.converter-field input:focus {
    outline: none;
    border-color: var(--accent-cyan);
}
.converter-binary-widget {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 0.5rem;
    min-width: 280px;
}
.converter-bits {
    display: flex;
    justify-content: center;
    gap: 4px;
    margin-bottom: 0.25rem;
}
.converter-bit {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: 'JetBrains Mono', monospace;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.15s;
}
.converter-bit.on {
    background: var(--accent-green);
    color: var(--bg-primary);
}
.converter-bit.off {
    background: var(--bg-secondary);
    color: var(--text-secondary);
    border: 1px solid var(--border);
}
.converter-bit:hover {
    transform: scale(1.1);
}
.converter-powers {
    display: flex;
    justify-content: center;
    gap: 4px;
    margin-bottom: 0;
}
.converter-powers span {
    width: 32px;
    text-align: center;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.6rem;
    color: var(--text-secondary);
}
.converter-breakdown {
    text-align: center;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    color: var(--accent-green);
    min-height: 1.5em;
    margin-bottom: 1rem;
}

/* Bitwise Operators Widget */
.bitwise-widget {
    background: var(--bg-code);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.5rem;
    margin: 1.5rem 0;
}
.bitwise-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--accent-cyan);
    margin-bottom: 1rem;
    text-align: center;
}
.bitwise-tables {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}
.truth-table {
    text-align: center;
}
.truth-title {
    font-family: 'JetBrains Mono', monospace;
    font-weight: 600;
    color: var(--accent-green);
    margin-bottom: 0.75rem;
}
.truth-grid-wrapper {
    display: flex;
    align-items: center;
    gap: 0.35rem;
}
.truth-axis-label {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.7rem;
    color: var(--accent-cyan);
    font-weight: 600;
}
.truth-axis-label.vertical {
    writing-mode: vertical-lr;
    transform: rotate(180deg);
}
.truth-grid-container {
    display: flex;
    flex-direction: column;
    gap: 2px;
}
.truth-col-headers {
    display: flex;
    gap: 2px;
}
.truth-col-header {
    width: 32px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    color: var(--accent-cyan);
    font-weight: 600;
    text-align: center;
}
.truth-row {
    display: flex;
    align-items: center;
    gap: 2px;
}
.truth-row-header {
    width: 20px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    color: var(--accent-cyan);
    font-weight: 600;
    text-align: center;
}
.truth-grid {
    display: flex;
    gap: 2px;
}
.truth-cell {
    width: 32px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
    padding: 0.35rem 0;
    text-align: center;
    border: 1px solid var(--border);
}
.truth-cell.highlight {
    background: rgba(0, 255, 65, 0.15);
    color: var(--accent-green);
    border-color: rgba(0, 255, 65, 0.3);
    color: var(--accent-green);
}
.truth-desc {
    font-size: 0.7rem;
    color: var(--text-secondary);
    margin-top: 0.5rem;
}
.bitwise-demo {
    background: var(--bg-secondary);
    border-radius: 6px;
    padding: 1rem;
    margin-bottom: 1rem;
}
.bitwise-demo-title {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
    text-align: center;
}
.bitwise-demo-row {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    margin-bottom: 0.5rem;
}
.bitwise-demo-row.result {
    margin-top: 0.75rem;
    padding-top: 0.75rem;
    border-top: 1px solid var(--border);
}
.bitwise-label {
    font-family: 'JetBrains Mono', monospace;
    font-weight: 600;
    color: var(--accent-cyan);
    width: 20px;
}
.bitwise-bits {
    display: flex;
    gap: 2px;
}
.bitwise-bit {
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    border-radius: 3px;
    cursor: pointer;
    transition: all 0.15s;
}
.bitwise-bit.on {
    background: var(--accent-green);
    color: var(--bg-primary);
}
.bitwise-bit.off {
    background: var(--bg-code);
    color: var(--text-secondary);
    border: 1px solid var(--border);
}
.bitwise-bit:hover {
    transform: scale(1.1);
}
#bw-bits-result .bitwise-bit {
    cursor: default;
}
.bitwise-value {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    color: var(--text-primary);
    width: 30px;
}
.bitwise-op-select {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    margin: 0.5rem 0;
}
.bw-op-btn {
    padding: 0.35rem 0.75rem;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    background: var(--bg-code);
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.15s;
}
.bw-op-btn:hover {
    border-color: var(--accent-green);
    color: var(--accent-green);
}
.bw-op-btn.active {
    background: var(--accent-green);
    color: var(--bg-primary);
    border-color: var(--accent-green);
}

/* Live Hash Widget */
.hash-widget {
    background: var(--bg-code);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.5rem;
    margin: 1.5rem 0;
}
.hash-widget-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--accent-cyan);
    margin-bottom: 1rem;
    text-align: center;
}
.hash-input-container {
    margin-bottom: 1rem;
}
.hash-input-container label {
    display: block;
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-bottom: 0.25rem;
}
.hash-input-container input {
    width: 100%;
    padding: 0.75rem;
    font-family: 'JetBrains Mono', monospace;
    font-size: 1rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-primary);
}
.hash-input-container input:focus {
    outline: none;
    border-color: var(--accent-cyan);
}
.hash-output {
    margin-bottom: 1rem;
}
.hash-output-row {
    display: flex;
    gap: 0.75rem;
    margin-bottom: 0.5rem;
    align-items: flex-start;
}
.hash-algo {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.75rem;
    color: var(--accent-cyan);
    width: 60px;
    flex-shrink: 0;
}
.hash-result {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.7rem;
    color: var(--accent-green);
    word-break: break-all;
    flex: 1;
}
.hash-info {
    text-align: center;
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

/* SHA Internals Widget */
.sha-widget {
    background: var(--bg-code);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.5rem;
    margin: 1.5rem 0;
}
.sha-widget-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--accent-cyan);
    margin-bottom: 1rem;
    text-align: center;
}
.sha-input-row {
    display: flex;
    gap: 0.75rem;
    align-items: center;
    margin-bottom: 1rem;
}
.sha-input-row label {
    font-size: 0.85rem;
    color: var(--text-secondary);
}
.sha-input-row input {
    flex: 1;
    padding: 0.5rem;
    font-family: 'JetBrains Mono', monospace;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-primary);
}
.sha-input-row button {
    padding: 0.5rem 1rem;
    font-size: 0.85rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-secondary);
    cursor: pointer;
}
.sha-input-row button:hover {
    border-color: var(--accent-cyan);
    color: var(--text-primary);
}
.sha-state {
    background: var(--bg-primary);
    border-radius: 6px;
    padding: 1rem;
    margin-bottom: 1rem;
}
.sha-round-label {
    text-align: center;
    font-size: 0.85rem;
    color: var(--accent-cyan);
    margin-bottom: 0.75rem;
    font-weight: 600;
}
.sha-registers {
    display: grid;
    grid-template-columns: repeat(8, 1fr);
    gap: 0.25rem;
    margin-bottom: 1rem;
}
.sha-reg {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 0.5rem 0.25rem;
    background: var(--bg-code);
    border-radius: 4px;
    border: 1px solid var(--border);
    transition: all 0.2s;
}
.sha-reg.changed {
    border-color: var(--accent-green);
    background: rgba(0, 255, 136, 0.1);
}
.sha-reg .reg-name {
    font-size: 0.7rem;
    color: var(--accent-cyan);
    font-weight: 600;
}
.sha-reg .reg-val {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.6rem;
    color: var(--text-primary);
    word-break: break-all;
    text-align: center;
}
.sha-operations {
    text-align: center;
    font-size: 0.75rem;
    color: var(--text-secondary);
    line-height: 1.6;
}
.sha-op-label {
    color: var(--accent-cyan);
    margin-bottom: 0.25rem;
}
.sha-controls {
    display: flex;
    justify-content: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
}
.sha-controls button {
    padding: 0.5rem 1.25rem;
    font-size: 0.85rem;
    background: var(--bg-secondary);
    border: 1px solid var(--accent-green);
    border-radius: 4px;
    color: var(--accent-green);
    cursor: pointer;
    transition: all 0.15s;
}
.sha-controls button:hover {
    background: var(--accent-green);
    color: var(--bg-primary);
}
.sha-controls button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}
.sha-final {
    text-align: center;
    padding: 1rem;
    background: rgba(0, 255, 136, 0.1);
    border: 1px solid var(--accent-green);
    border-radius: 6px;
}
.sha-final-label {
    font-size: 0.8rem;
    color: var(--accent-green);
    margin-bottom: 0.5rem;
}
.sha-final-hash {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.75rem;
    color: var(--text-primary);
    word-break: break-all;
}

/* Auth Modal */
.auth-modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
}
.auth-modal-backdrop {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
}
.auth-modal-content {
    position: relative;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 2rem;
    width: 90%;
    max-width: 400px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
}
.auth-modal-close {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
    line-height: 1;
    padding: 0;
}
.auth-modal-close:hover {
    color: var(--text-primary);
}
.auth-modal-content h2 {
    margin: 0 0 0.25rem 0;
    color: var(--accent-green);
    font-size: 1.5rem;
}
.auth-modal-subtitle {
    margin: 0 0 1.5rem 0;
    color: var(--text-secondary);
    font-size: 0.9rem;
}
.auth-modal-toggle {
    margin-top: 1.5rem;
    text-align: center;
    font-size: 0.85rem;
    color: var(--text-secondary);
}
.auth-modal-toggle button {
    background: none;
    border: none;
    color: var(--accent-cyan);
    cursor: pointer;
    text-decoration: underline;
    font-size: inherit;
}

@media (max-width: 700px) {
    header { padding: 1rem; }
    h1 { font-size: 1.5rem; }
    .page-layout { flex-direction: column; }
    aside { 
        width: 100%; 
        height: auto; 
        position: relative;
        border-right: none;
        border-bottom: 1px solid var(--border);
        max-height: 50vh;
    }
    .nav-topic { padding: 0.5rem 1rem; }
    .nav-topic-title { font-size: 0.85rem; }
    .nav-keyword { font-size: 0.6rem; }
    main { padding: 1rem; }
    .card { padding: 1.25rem; }
    .lang-tab { padding: 0.5rem 0.8rem; font-size: 0.7rem; }
    .code-editor, .code-static, .code-highlight { font-size: 0.75rem; }
    .code-wrapper { height: 200px; }
    .code-static { height: 200px; }
    .code-gutter { width: 24px; font-size: 0.75rem; }
    .code-gutter-inner { padding-top: 0.75rem; }
    .code-highlight { left: 24px; }
    .code-editor, .code-static { padding-left: calc(24px + 0.75rem); }
    .gutter-line { height: 1.6em; }
    .gutter-info-btn { width: 14px; height: 14px; font-size: 0.55rem; }
    .code-info-tooltip { width: 260px; font-size: 0.75rem; }
    
    /* Achievement/Challenge responsive fixes */
    .achievements { padding: 0.75rem; margin-top: 1rem; }
    .achievement-list { 
        grid-template-columns: 1fr;
        gap: 0.5rem;
    }
    .achievement {
        flex-wrap: wrap;
        padding: 0.5rem;
        gap: 0.5rem;
    }
    .achievement-name { font-size: 0.8rem; }
    .achievement-desc { 
        font-size: 0.7rem; 
        width: 100%;
        margin-left: 1.75rem;
    }
    
    /* Widget responsive fixes */
    .bit-flipper-widget,
    .shift-widget,
    .converter-widget,
    .bitwise-widget,
    .hash-widget,
    .avalanche-widget { 
        padding: 1rem;
        margin: 1rem 0;
    }
    .bit-flipper-bits,
    .shift-bits,
    .converter-bits { gap: 2px; }
    .bit-toggle,
    .shift-bit,
    .converter-bit { 
        width: 28px; 
        height: 28px; 
        font-size: 0.9rem;
    }
    .bitwise-bit { width: 20px; height: 20px; font-size: 0.75rem; }
    .converter-powers span { width: 28px; font-size: 0.5rem; }
    .bit-flipper-ops,
    .shift-controls { gap: 0.5rem; }
    .bit-ops-group button,
    .shift-btn-group button { 
        padding: 0.4rem 0.6rem; 
        font-size: 0.75rem;
    }
    .truth-table { transform: scale(0.9); }
    .bitwise-tables { gap: 1rem; }
}

/* Override auth component colors to match cipher-lore theme */
.auth-form-group label {
    color: var(--accent-cyan);
}
.auth-form-group input[type="email"],
.auth-form-group input[type="password"],
.auth-form-group input[type="text"] {
    background: var(--bg-primary);
    border: 1px solid var(--border);
    color: var(--text-primary);
}
.auth-form-group input::placeholder {
    color: var(--text-secondary);
}
.auth-form-group input:focus {
    border-color: var(--accent-cyan);
    background: var(--bg-primary);
}
.auth-password-toggle {
    color: var(--text-secondary);
}
.auth-password-toggle:hover {
    color: var(--accent-cyan);
}
.auth-submit-btn {
    border: 1px solid var(--border);
    color: var(--accent-green);
    background: transparent;
}
.auth-submit-btn:hover {
    border-color: var(--accent-green);
    color: var(--accent-green);
}

/* Expression Builder Widget */
.expr-widget {
    background: var(--bg-code);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.5rem;
    margin: 1.5rem 0;
}
.expr-tree {
    display: flex;
    justify-content: center;
    margin-bottom: 1.5rem;
}
.expr-node {
    display: flex;
    flex-direction: column;
    align-items: center;
}
.expr-value {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem;
    background: var(--bg-secondary);
    border: 2px solid var(--accent-green);
    border-radius: 8px;
}
.expr-value.expr-new {
    animation: expr-value-expand 0.3s ease-out;
}
@keyframes expr-value-expand {
    from {
        transform: scaleY(0);
        padding: 0;
        gap: 0;
        border-width: 0;
    }
    to {
        transform: scaleY(1);
        padding: 0.75rem;
        gap: 0.5rem;
        border-width: 2px;
    }
}
.expr-bits {
    display: flex;
    gap: 2px;
}
.expr-bit {
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
    font-weight: 600;
    border-radius: 3px;
    cursor: pointer;
    transition: all 0.15s;
}
.expr-bit.on {
    background: var(--accent-green);
    color: var(--bg-primary);
}
.expr-bit.off {
    background: var(--bg-primary);
    color: var(--text-secondary);
    border: 1px solid var(--border);
}
.expr-bit:hover {
    transform: scale(1.1);
}
.expr-value-display {
    display: flex;
    gap: 0.75rem;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.75rem;
}
.expr-decimal {
    color: var(--text-secondary);
}
.expr-hex {
    color: var(--accent-cyan);
}
.expr-node-actions {
    display: flex;
    gap: 0.5rem;
}
.expr-expand, .expr-wrap {
    padding: 0.25rem 0.5rem;
    font-size: 0.7rem;
    background: transparent;
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.15s;
}
.expr-expand:hover {
    border-color: var(--accent-cyan);
    color: var(--accent-cyan);
}
.expr-wrap:hover {
    border-color: var(--accent-purple);
    color: var(--accent-purple);
}
.expr-op {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 0.75rem;
    background: var(--bg-secondary);
    border: 2px solid var(--accent-cyan);
    border-radius: 8px;
}
.expr-op.expr-new {
    animation: expr-op-expand 0.3s ease-out;
}
@keyframes expr-op-expand {
    from {
        padding: 0;
        border-width: 0;
        margin: 0;
    }
    to {
        padding: 0.75rem;
        border-width: 2px;
    }
}
.expr-op-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.75rem;
}
.expr-op-header select {
    padding: 0.35rem 0.5rem;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--accent-cyan);
    cursor: pointer;
}
.expr-op-result-row {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem;
    margin-top: 0.5rem;
    background: var(--bg-primary);
    border-radius: 4px;
    border: 1px solid var(--accent-green);
}
.expr-op-result-label {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
    color: var(--text-secondary);
}
.expr-op-result-bits {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
    color: var(--accent-green);
    letter-spacing: 2px;
}
.expr-op-result-value {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    color: var(--text-secondary);
}
.expr-collapse {
    padding: 0.2rem 0.5rem;
    font-size: 0.75rem;
    background: transparent;
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-secondary);
    cursor: pointer;
}
.expr-collapse:hover {
    border-color: #ff6b6b;
    color: #ff6b6b;
}
.expr-operands {
    display: flex;
    flex-direction: column;
    align-items: stretch;
    gap: 0.25rem;
    padding-top: 0.5rem;
    border-top: 1px dashed var(--border);
}
.expr-operands.unary {
    align-items: center;
}
.expr-operand-row {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}
.expr-operand-label {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--accent-cyan);
    width: 1rem;
    text-align: center;
}
/* Expression Tree Widget */
.expr-tree-widget {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 1.5rem;
    background: var(--bg-secondary);
    border-radius: 8px;
    margin-bottom: 1rem;
}
.expr-tree-container {
    display: flex;
    flex-direction: column;
    align-items: center;
}
.expr-node {
    display: flex;
    flex-direction: column;
    align-items: center;
}
.expr-value-node {
    border: 2px solid var(--accent-green);
    border-radius: 4px;
    padding: 10px;
    background: var(--bg-primary);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}
.expr-op-node {
    border: 2px solid var(--accent-green);
    border-radius: 4px;
    padding: 10px;
    background: var(--bg-primary);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}
.expr-op-header {
    display: flex;
    align-items: center;
    gap: 10px;
}
.expr-op-select {
    background: var(--bg-secondary);
    border: 1px solid var(--accent-green);
    color: var(--accent-green);
    padding: 4px 8px;
    border-radius: 4px;
    font-family: 'JetBrains Mono', monospace;
    cursor: pointer;
}
.expr-op-param {
    width: 40px;
    background: var(--bg-secondary);
    border: 1px solid var(--accent-green);
    color: var(--accent-green);
    padding: 4px;
    border-radius: 4px;
    font-family: 'JetBrains Mono', monospace;
    text-align: center;
}
.expr-bits-row {
    display: flex;
    gap: 2px;
}
.expr-bit {
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: 'JetBrains Mono', monospace;
    font-size: 14px;
    font-weight: 600;
    border-radius: 3px;
    cursor: pointer;
    transition: transform 0.1s;
    border: none;
}
.expr-bit:hover {
    transform: scale(1.1);
}
.expr-bit.on {
    background: var(--accent-green);
    color: var(--bg-primary);
}
.expr-bit.off {
    background: var(--bg-secondary);
    color: var(--text-secondary);
    border: 1px solid var(--border);
}
.expr-bit.readonly {
    cursor: default;
    opacity: 0.6;
}
.expr-bit.readonly:hover {
    transform: none;
}
.expr-bit.sign-bit {
    background: #b91c1c !important;
}
.expr-bit.sign-bit.off {
    background: #7f1d1d !important;
    border-color: #991b1b;
}
.expr-powers-row {
    display: flex;
    gap: 2px;
}
.expr-power {
    width: 24px;
    text-align: center;
    font-size: 10px;
    color: var(--text-secondary);
}
.expr-value-display {
    font-size: 12px;
    color: var(--text-secondary);
}
.expr-value-display input {
    width: 50px;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    color: var(--accent-green);
    padding: 2px 4px;
    border-radius: 3px;
    font-family: 'JetBrains Mono', monospace;
    text-align: center;
}
.expr-operands {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}
.expr-btn {
    background: var(--bg-secondary);
    border: 1px solid var(--accent-green);
    color: var(--accent-green);
    padding: 4px 8px;
    border-radius: 4px;
    cursor: pointer;
    font-family: 'JetBrains Mono', monospace;
    font-size: 12px;
}
.expr-btn:hover {
    background: var(--bg-card);
    box-shadow: 0 0 10px var(--accent-green);
}
.expr-result-section {
    border-top: 1px dashed var(--border);
    padding-top: 10px;
    margin-top: 5px;
}
.expr-result-section .expr-value-display {
    margin-top: 8px;
}
.expr-controls {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    margin-top: 1rem;
}