/* ================================================
   Design Tokens - Re-using global from styles.css
   ================================================ */

.fundamentals-page {
    background: var(--bg);
    color: var(--text);
}

.fundamentals-page .navbar {
    background: var(--bg-alt);
    opacity: 0.95;
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
}

.fundamentals-page .nav-links a {
    color: var(--text-muted);
}

.fundamentals-page .nav-links a:hover,
.fundamentals-page .nav-links a.active {
    color: var(--accent);
}

.theme-switch-wrapper {
    display: flex;
    align-items: center;
    padding-left: 1rem;
}

.btn-theme {
    background: none;
    border: 1px solid var(--border);
    color: var(--text);
    font-size: 1.2rem;
    cursor: pointer;
    border-radius: 8px;
    padding: 2px 8px;
    transition: all 0.3s ease;
}

.btn-theme:hover {
    border-color: var(--neon-cyan);
    box-shadow: 0 0 10px var(--neon-cyan-glow);
}

/* Search Bar */
.search-wrapper {
    margin-top: 2.5rem;
    max-width: 600px;
}

.search-input-group {
    position: relative;
    display: flex;
    align-items: center;
    background: var(--bg-alt);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 0 1.25rem;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-sm);
}

.search-input-group:focus-within {
    border-color: var(--neon-cyan);
    box-shadow: 0 0 15px var(--neon-cyan-glow);
    transform: translateY(-2px);
}

.search-icon {
    font-size: 1.1rem;
    margin-right: 1rem;
    opacity: 0.6;
}

#activity-search {
    background: none;
    border: none;
    color: var(--text);
    padding: 1rem 0;
    width: 100%;
    font-size: 1rem;
    outline: none;
    font-family: var(--font);
}

#activity-search::placeholder {
    color: var(--text-muted);
    opacity: 0.5;
}

/* Badges (adjust margin for search) */
.badges-container {
    display: flex;
    gap: 1rem;
    margin-top: 1.5rem;
}

.badge {
    width: 45px;
    height: 45px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-alt);
    border: 1px solid var(--border);
    border-radius: 50%;
    font-size: 1.5rem;
    filter: grayscale(1) opacity(0.3);
    transition: all 0.3s ease;
    cursor: default;
}

.badge.unlocked {
    filter: none;
    opacity: 1;
    border-color: var(--neon-cyan);
    box-shadow: 0 0 10px var(--neon-cyan-glow);
    animation: badge-unlock 0.5s ease-out;
}

@keyframes badge-unlock {
    0% { transform: scale(0.5) rotate(-20deg); opacity: 0; }
    70% { transform: scale(1.2) rotate(10deg); }
    100% { transform: scale(1) rotate(0); opacity: 1; }
}

/* Activities Grid */
.module-block {
    padding: 3rem 0;
    border-top: 1px solid var(--border);
}

.block-title {
    margin-bottom: 2rem;
    font-size: 1.5rem;
}

.cyan-accent { color: var(--neon-cyan); }

.activities-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 3rem;
}
@media (max-width: 900px) {
    .activities-grid { grid-template-columns: 1fr; }
}

.activity-card {
    background: var(--card);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border);
    border-radius: 20px;
    padding: 2.5rem;
    transition: transform 0.3s ease, border-color 0.3s ease;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    box-shadow: var(--shadow-md);
}

.card-section {
    font-size: 0.85rem;
    line-height: 1.5;
    padding: 0.75rem;
    border-radius: 8px;
}

.analogy {
    background: rgba(245, 158, 11, 0.08);
    border-left: 3px solid var(--neon-amber);
    color: var(--text);
}

.instruction {
    background: rgba(6, 182, 212, 0.08);
    border-left: 3px solid var(--neon-cyan);
    color: var(--text);
}

.technical {
    background: rgba(16, 185, 129, 0.05);
    border-top: 1px solid var(--border);
    color: var(--text-muted);
}

.badge-mini {
    display: inline-block;
    font-size: 0.65rem;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.4rem;
    padding: 2px 6px;
    border-radius: 4px;
}

.analogy .badge-mini { background: var(--neon-amber); color: #000; }
.instruction .badge-mini { background: var(--neon-cyan); color: #000; }
.technical .badge-mini { background: var(--neon-green); color: #000; }

.activity-card:hover {
    transform: translateY(-5px);
    border-color: var(--neon-cyan);
}

.activity-card h3 {
    font-size: 1.1rem;
    margin-bottom: 0.75rem;
    color: var(--text);
}

.micro-learning {
    font-size: 0.95rem;
    color: var(--text-muted);
    line-height: 1.6;
    margin-bottom: 2rem;
    min-height: 4rem;
}

.activity-area {
    background: var(--bg-alt);
    border-radius: 16px;
    border: 1px dashed var(--border);
    padding: 2.5rem;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 350px;
}

.drag-container {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    width: 100%;
    margin-bottom: 1.5rem;
}

.drag-item {
    background: var(--bg);
    border: 1px solid var(--border);
    padding: 0.75rem 1rem;
    border-radius: 8px;
    cursor: grab;
    user-select: none;
    font-weight: 500;
    transition: background 0.2s, border-color 0.2s;
    text-align: center;
}

.drag-item.dragging {
    opacity: 0.5;
    border: 2px dashed var(--neon-cyan);
    transform: scale(1.05);
}

.drag-item:hover {
    border-color: var(--neon-cyan);
    background: rgba(6, 182, 212, 0.1);
}

.btn-verify {
    background: var(--neon-cyan);
    color: #000;
    border: none;
    padding: 0.6rem 1.2rem;
    border-radius: 8px;
    font-weight: 700;
    cursor: pointer;
    transition: opacity 0.2s;
    width: 100%;
}

.btn-verify:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* Recursion Activity */
.stack-controls {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    width: 100%;
    margin-bottom: 1rem;
}

.stack-visual {
    width: 80%;
    border: 2px solid var(--border);
    border-top: none;
    border-radius: 0 0 12px 12px;
    padding: 10px;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    min-height: 120px;
    transition: background 0.3s;
}

.stack-block {
    background: var(--neon-cyan);
    color: #000;
    margin-top: 4px;
    padding: 10px;
    border-radius: 6px;
    text-align: center;
    font-size: 0.85rem;
    font-weight: 700;
    position: relative;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.stack-block.winding {
    animation: block-in 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
}

.stack-block.returning {
    background: var(--neon-green);
    box-shadow: 0 0 20px var(--neon-green);
    transform: translateY(-30px);
    z-index: 10;
}

@keyframes block-in {
    from { transform: translateY(-20px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

.stack-visual.overflow {
    background: rgba(239, 68, 68, 0.3);
    border-color: var(--neon-red);
    box-shadow: 0 0 20px var(--neon-red);
}

/* Sorting Activity */
.sorting-container {
    display: flex;
    gap: 1rem;
    align-items: flex-end;
}

.sort-block {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.sort-value {
    width: 40px;
    height: 40px;
    background: var(--bg-alt);
    border: 1px solid var(--neon-cyan);
    color: var(--neon-cyan);
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    font-weight: 700;
    transition: all 0.3s;
}

.sort-block.correct .sort-value {
    background: var(--neon-green);
    color: #000;
    border-color: var(--neon-green);
    box-shadow: 0 0 10px var(--neon-green);
}

.sort-actions button {
    background: none;
    border: 1px solid var(--border);
    color: var(--text-muted);
    cursor: pointer;
    border-radius: 4px;
    padding: 2px 4px;
}

.sort-actions button:hover {
    border-color: var(--neon-cyan);
    color: var(--neon-cyan);
}

/* Nested Structures Editor */
.nested-editor {
    width: 100%;
    background: #0d1117;
    border-radius: 12px;
    padding: 2rem;
    font-family: 'Fira Code', monospace;
    font-size: 0.95rem;
    color: #e6edf3;
    position: relative;
    border: 1px solid var(--border);
    margin-bottom: 1.5rem;
}

.code-block {
    border-left: 2px solid rgba(139, 148, 158, 0.2);
    padding-left: 1.2rem;
    margin: 4px 0;
    transition: all 0.3s ease;
    border-radius: 0 4px 4px 0;
}

.code-block.level-0 { border-left-color: var(--neon-cyan); }
.code-block.level-1 { border-left-color: var(--neon-amber); background: rgba(245, 158, 11, 0.03); }

.code-block.highlight-valid {
    background: rgba(16, 185, 129, 0.1);
    border-left-color: var(--neon-green);
}

.code-block.highlight-invalid {
    background: rgba(239, 68, 68, 0.1);
    border-left-color: var(--neon-red);
}

.code-line { display: block; line-height: 1.6; }
.code-line.keyword { color: #ff7b72; }
.code-line.active-code { color: var(--neon-cyan); text-shadow: 0 0 5px var(--neon-cyan); }

.bracket-select {
    display: none; /* Removed in favor of drag-drop */
}

.drop-zone {
    display: inline-block;
    min-width: 200px;
    height: 34px;
    background: rgba(48, 54, 61, 0.4);
    border: 1px dashed #30363d;
    border-radius: 6px;
    vertical-align: middle;
    padding: 0 12px;
    font-size: 0.9rem;
    color: #8b949e;
    transition: all 0.2s;
    margin: 4px 0;
}

.drop-zone.drag-over {
    border-color: var(--neon-cyan);
    background: rgba(6, 182, 212, 0.1);
}

.drop-zone.filled {
    background: #161b22;
    border: 1px solid var(--border);
    color: #e6edf3;
    width: auto;
}

.brackets-drawer {
    display: flex;
    gap: 1rem;
    padding-top: 1.5rem;
    border-top: 1px solid rgba(139, 148, 158, 0.1);
    margin-top: 1rem;
    justify-content: center;
}

.drag-bracket {
    background: #161b22;
    border: 1px solid #30363d;
    color: #8b949e;
    padding: 6px 12px;
    border-radius: 6px;
    cursor: grab;
    font-size: 0.8rem;
    transition: all 0.2s;
}

.drag-bracket:hover {
    border-color: var(--neon-cyan);
    color: #fff;
}

.drag-bracket.dragging { opacity: 0.5; }

/* Matrix Crosshair Effect */
.matrix-container {
    display: flex;
    flex-direction: column;
    gap: 5px;
    margin-bottom: 1rem;
    position: relative;
}

.matrix-row {
    display: flex;
    gap: 5px;
}

.matrix-cell {
    width: 40px;
    height: 40px;
    background: var(--bg-alt);
    border: 1px solid var(--border);
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
}

.matrix-cell:hover {
    border-color: var(--neon-cyan);
    background: rgba(6, 182, 212, 0.2);
    z-index: 5;
}

/* Crosshair highlights */
.matrix-row:hover .matrix-cell {
    border-color: rgba(6, 182, 212, 0.3);
}

.matrix-cell.hit {
    background: var(--neon-cyan);
    box-shadow: 0 0 15px var(--neon-cyan);
    animation: hit-impact 0.4s ease-out;
}

@keyframes hit-impact {
    0% { transform: scale(1); filter: brightness(2); }
    50% { transform: scale(1.2); }
    100% { transform: scale(1); filter: brightness(1); }
}

.matrix-hint {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* String Concatenation */
.string-game {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
    width: 100%;
}

.wagon-inputs {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.wagon-inputs input {
    background: var(--bg-alt);
    border: 1px solid var(--border);
    color: var(--text);
    padding: 8px;
    border-radius: 4px;
    width: 60px;
    text-align: center;
}

.string-result {
    font-family: 'Fira Code', monospace;
    font-size: 1.2rem;
    color: var(--neon-cyan);
    padding: 10px;
    border: 1px solid var(--border);
    border-radius: 8px;
    min-width: 150px;
    text-align: center;
}

/* TDA Simulator */
.tda-simulator {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    width: 100%;
    align-items: center;
}

.tda-device {
    background: #1e293b;
    padding: 1rem;
    border-radius: 20px;
    border: 3px solid #334155;
    box-shadow: 0 10px 0 #0f172a;
    width: 160px;
}

.device-screen {
    background: #000;
    height: 80px;
    border-radius: 12px;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--neon-cyan);
    font-family: 'Fira Code', monospace;
    font-weight: bold;
    border: 2px solid #334155;
    transition: all 0.3s;
}

.device-screen.on {
    background: #064e3b;
    border-color: var(--neon-green);
    box-shadow: inset 0 0 15px rgba(16, 185, 129, 0.5);
    color: var(--neon-green);
}

.device-screen.processing {
    color: var(--neon-amber);
    animation: blink 0.5s infinite;
}

.device-controls {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
}

.ctrl-btn {
    background: #475569;
    border: none;
    color: #fff;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.2s;
    box-shadow: 0 3px 0 #1e293b;
}

.ctrl-btn:active {
    transform: translateY(2px);
    box-shadow: none;
}

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

.tda-internals {
    width: 100%;
    height: 60px;
    background: #0a0e14;
    border: 1px dashed var(--border);
    border-radius: 12px;
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    font-size: 0.7rem;
    color: var(--text-muted);
}

.gears-container {
    display: flex;
    gap: 10px;
    font-family: monospace;
    opacity: 0.2;
    transition: opacity 0.3s;
}

.gears-container.active {
    opacity: 1;
    color: var(--neon-cyan);
    animation: slide-up 0.5s infinite linear;
}

/* File Decipherer */
.file-decipherer {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
    width: 100%;
}

.pane-editor, .pane-scanner {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.pane-editor label, .pane-scanner label {
    font-size: 0.7rem;
    font-weight: 800;
    text-transform: uppercase;
    color: var(--text-muted);
}

#file-input {
    background: var(--bg);
    border: 1px solid var(--border);
    color: var(--text);
    padding: 10px;
    border-radius: 8px;
    resize: none;
    height: 80px;
    font-family: inherit;
}

.bits-display {
    background: #000;
    border: 1px solid var(--neon-green);
    padding: 15px;
    border-radius: 8px;
    min-height: 100px;
    font-family: 'Fira Code', monospace;
    color: var(--neon-green);
    font-size: 0.75rem;
    line-height: 1.4;
    word-break: break-all;
    box-shadow: inset 0 0 10px rgba(16, 185, 129, 0.1);
}

.bit-chunk {
    display: inline-block;
    padding: 2px 4px;
    background: rgba(16, 185, 129, 0.1);
    border-radius: 4px;
    margin: 2px;
}

.bits-display.scanning {
    border-color: var(--neon-cyan);
    animation: scan-line 0.5s ease-out;
}

@keyframes blink { 50% { opacity: 0.5; } }
@keyframes scan-line {
    0% { box-shadow: inset 0 100px 0 rgba(6, 182, 212, 0.05); }
    100% { box-shadow: inset 0 -100px 0 rgba(6, 182, 212, 0.05); }
}

/* Block 3: Systems */
.compilation-flow {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
}

.flow-step {
    padding: 10px;
    border: 1px solid var(--border);
    border-radius: 8px;
    width: 100%;
    text-align: center;
}

.flow-step.disabled { opacity: 0.3; }
.flow-arrow { color: var(--text-muted); font-size: 1.2rem; }

/* Scope Boxes */
.scope-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    width: 100%;
}

.scope-box {
    border: 2px dashed var(--border);
    border-radius: 12px;
    padding: 1rem;
    min-height: 100px;
}

.variable {
    background: var(--neon-amber);
    color: #000;
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 0.8rem;
    font-weight: bold;
    cursor: move;
}

/* File Viewer */
.file-viewer {
    width: 100%;
    background: var(--code-bg);
    border-radius: 8px;
    padding: 1rem;
    font-family: 'Fira Code', monospace;
}

.viewer-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 1rem;
}

.viewer-header input {
    background: var(--bg);
    border: 1px solid var(--border);
    color: var(--neon-green);
    padding: 4px;
}

.viewer-content {
    color: var(--text);
    word-break: break-all;
    min-height: 50px;
}

.matrix-text {
    color: var(--neon-green);
    text-shadow: 0 0 5px var(--neon-green);
    animation: matrix-fade 2s infinite alternate;
}


.toast {
    padding: 1rem 1.5rem;
    border-radius: 12px;
    background: var(--bg-alt);
    color: var(--text);
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    box-shadow: var(--shadow-md);
    border-left: 4px solid var(--neon-cyan);
    animation: toast-in 0.3s ease-out;
}

.toast.error { border-left-color: var(--neon-red); }
.toast.warning { border-left-color: var(--neon-amber); }
.toast.success { border-left-color: var(--neon-green); }

@keyframes toast-in {
    from { transform: translateX(100%); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

/* Responsive */
@media (max-width: 640px) {
    .activities-grid { grid-template-columns: 1fr; }
    .fundamentals-header { padding: 5rem 0 2rem; }
}