/* =====================================================
   RESET & BASE
   ===================================================== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-main);
    color: var(--text-primary);
    line-height: 1.5;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* =====================================================
   ANIMATED BACKGROUND
   ===================================================== */
.animated-background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: -1;
    overflow: hidden;
    background-color: var(--bg-main);
    pointer-events: none;
}

.glow-orb {
    position: absolute;
    border-radius: 45% 55% 70% 30% / 50% 30% 70% 50%;
    filter: blur(90px);
    opacity: 0.35;
    animation: float 25s infinite linear;
}

[data-theme="dark"] .glow-orb { opacity: 0.5; }
[data-theme="light"] .glow-orb { opacity: 0.15; }

.orb-1 {
    width: 500px; height: 500px;
    background: var(--accent-orange);
    top: -150px; left: -150px;
    animation-duration: 25s;
}
.orb-2 {
    width: 600px; height: 600px;
    background: var(--accent-purple);
    bottom: -200px; right: -150px;
    animation-duration: 22s;
    animation-delay: -5s;
}
.orb-3 {
    width: 400px; height: 400px;
    background: #00d2ff;
    top: 30%; left: 50%;
    animation-duration: 28s;
    animation-delay: -10s;
}

@keyframes float {
    0%   { transform: translate(0, 0) scale(1) rotate(0deg); }
    33%  { transform: translate(60px, 60px) scale(1.1) rotate(120deg); }
    66%  { transform: translate(-40px, -20px) scale(0.9) rotate(240deg); }
    100% { transform: translate(0, 0) scale(1) rotate(360deg); }
}

/* =====================================================
   NAVIGATION
   ===================================================== */
.glass-nav {
    position: fixed;
    top: 0; left: 0;
    width: 100%;
    z-index: 1000;
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--glass-border);
    padding: 0.6rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    font-size: 1.25rem;
    font-weight: 700;
    text-decoration: none;
    color: transparent;
    background: var(--gradient-orange);
    background-size: 200% auto;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    cursor: pointer;
    letter-spacing: -0.02em;
    animation: shine 3s linear infinite;
}

@keyframes shine {
    to {
        background-position: 200% center;
    }
}

.nav-brand-container {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.beta-badge {
    font-size: 0.6rem;
    font-weight: 700;
    padding: 0.2rem 0.5rem;
    background: var(--accent-orange);
    color: white;
    border-radius: 999px;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.nav-links {
    display: flex;
    gap: 2rem;
    list-style: none;
    align-items: center;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: color var(--transition-fast);
    cursor: pointer;
}

.nav-links a:hover { color: var(--text-primary); }

.theme-toggle {
    background: transparent;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    padding: 0.5rem;
    transition: background var(--transition-fast);
}

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

[data-theme="dark"] .sun-icon  { display: block; }
[data-theme="dark"] .moon-icon { display: none; }
[data-theme="light"] .sun-icon { display: none; }
[data-theme="light"] .moon-icon { display: block; }

/* =====================================================
   LAYOUT
   ===================================================== */
.app-container {
    margin-top: 53px; /* nav height */
    height: calc(100vh - 53px - 45px); /* nav + footer */
    position: relative;
    overflow: hidden;
}

.view-section {
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 100%;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    display: flex;
    flex-direction: column;
}

.view-section.active {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    position: relative;
}

/* =====================================================
   HOME VIEW
   ===================================================== */
.home-container {
    padding: 3rem 2rem;
    max-width: 1000px;
    margin: auto;
    width: 100%;
}

.hero-section {
    text-align: center;
    margin-bottom: 3rem;
}

.hero-section h1 {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    letter-spacing: -0.04em;
    color: var(--text-primary);
}

.hero-section p {
    color: var(--text-secondary);
    font-size: 1.125rem;
    max-width: 600px;
    margin: 0 auto;
}

.category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

/* Category Cards — uses CSS variable, works in both light & dark */
.category-card {
    background: var(--card-glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 2rem;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    transition: transform var(--transition-fast), border-color var(--transition-fast), background var(--transition-fast), box-shadow var(--transition-fast);
}

.category-card:hover {
    background: var(--card-glass-bg-hover);
    border-color: var(--accent-orange);
    transform: translateY(-2px);
}

.category-card.coming-soon {
    cursor: default;
    opacity: 0.65;
}

.category-card.coming-soon:hover {
    transform: none;
    border-color: var(--glass-border);
    background: var(--card-glass-bg);
    cursor: not-allowed;
}

.card-accent {
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 3px;
    background: var(--gradient-orange);
    opacity: 0;
    transition: opacity var(--transition-fast);
}

.category-card:not(.coming-soon):hover .card-accent { opacity: 1; }

.card-badge {
    position: absolute;
    top: 1rem;
    right: 1rem;
    font-size: 0.7rem;
    font-weight: 600;
    padding: 0.2rem 0.6rem;
    border-radius: 9999px;
    border: 1px solid rgba(255,255,255,0.15);
    background: rgba(255,255,255,0.07);
    color: var(--text-secondary);
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.category-card h3 {
    font-size: 1.2rem;
    margin-bottom: 0.6rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.01em;
}

.category-card p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.6;
}

/* =====================================================
   VISUALIZER VIEW LAYOUT
   ===================================================== */
.visualizer-layout {
    display: flex;
    height: 100%;
}

/* SIDEBAR */
.sidebar {
    width: 300px;
    flex-shrink: 0;
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-right: 1px solid var(--glass-border);
    display: flex;
    flex-direction: column;
    padding: 1.25rem;
    gap: 1.25rem;
    overflow-y: auto;
}

.sidebar-header {
    border-bottom: 1px solid var(--glass-border);
    padding-bottom: 0.75rem;
}

.sidebar-header h2 {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

/* MAIN VISUALIZATION AREA */
.visualization-area {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding: 1.5rem;
    position: relative;
    overflow: hidden;
    background-color: transparent;
}

/* =====================================================
   PROBLEM DESCRIPTION (SIDEBAR)
   ===================================================== */
.problem-description h2 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.02em;
    margin-bottom: 0.5rem;
    line-height: 1.3;
}

.problem-description p {
    color: var(--text-secondary);
    font-size: 0.875rem;
    line-height: 1.65;
}

.difficulty-badge {
    display: inline-block;
    font-size: 0.7rem;
    font-weight: 600;
    padding: 0.2rem 0.65rem;
    border-radius: 9999px;
    margin-bottom: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.difficulty-badge.easy   { background: rgba(34, 197, 94, 0.15); color: #22c55e; border: 1px solid rgba(34,197,94,0.3); }
.difficulty-badge.medium { background: rgba(255, 172, 27, 0.15); color: #ffac1b; border: 1px solid rgba(255,172,27,0.3); }
.difficulty-badge.hard   { background: rgba(239, 68, 68, 0.15);  color: #ef4444; border: 1px solid rgba(239,68,68,0.3); }

/* =====================================================
   INFO PANEL (SIDEBAR BOTTOM)
   ===================================================== */
.info-panel {
    margin-top: auto;
    padding: 0.75rem;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--glass-border);
    border-radius: 8px;
    font-size: 0.8rem;
    color: var(--text-secondary);
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.info-panel strong { color: var(--text-primary); font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.05em; }

/* =====================================================
   FORM CONTROLS
   ===================================================== */
.control-group {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.control-group label {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Inputs — fixed: uses --input-bg so dark mode has visible bg, and real border */
.modern-input {
    width: 100%;
    padding: 0.65rem 0.875rem;
    border: 1px solid var(--glass-border);
    border-radius: 8px;
    background: var(--input-bg);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.9rem;
    outline: none;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.modern-input:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(255, 100, 0, 0.15);
}

.modern-input::placeholder { color: var(--text-secondary); opacity: 0.6; }

/* =====================================================
   BUTTONS
   ===================================================== */
.btn {
    padding: 0.65rem 1.25rem;
    border-radius: 8px;
    font-family: inherit;
    font-weight: 500;
    font-size: 0.9rem;
    cursor: pointer;
    border: 1px solid transparent;
    transition: transform 0.1s ease, box-shadow var(--transition-fast), opacity 0.2s;
    display: inline-flex;
    justify-content: center;
    align-items: center;
    gap: 0.4rem;
    white-space: nowrap;
}

.btn:active  { transform: scale(0.97); }
.btn:disabled { opacity: 0.4; cursor: not-allowed; transform: none; }

/* Primary — orange gradient */
.btn-primary {
    background: var(--gradient-orange);
    color: #ffffff;
}
.btn-primary:hover:not(:disabled) {
    box-shadow: 0 0 18px rgba(255, 100, 0, 0.35);
}

/* Icon/secondary — dark glass style */
.btn-icon {
    background: var(--input-bg);
    border: 1px solid var(--glass-border);
    color: var(--text-primary);
}
.btn-icon:hover:not(:disabled) {
    border-color: rgba(255, 255, 255, 0.2);
    background: var(--card-hover-bg);
}

/* Reset button */
.btn-ghost {
    background: transparent;
    border: 1px solid var(--glass-border);
    color: var(--text-secondary);
    font-size: 0.8rem;
    padding: 0.4rem 0.85rem;
}
.btn-ghost:hover:not(:disabled) { color: var(--text-primary); border-color: rgba(255,255,255,0.2); }

/* =====================================================
   CANVAS AREA
   ===================================================== */
.canvas-container {
    flex: 1;
    position: relative;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-bottom: 1rem;
    min-height: 0;
}

.canvas {
    flex: 1;
    border: 1px solid var(--glass-border);
    border-radius: 14px;
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 2rem;
    overflow: hidden;
}

/* Progress Bar */
.progress-bar-track {
    height: 3px;
    background: var(--glass-border);
    border-radius: 9999px;
    overflow: hidden;
    flex-shrink: 0;
}

.progress-bar-fill {
    height: 100%;
    width: 0%;
    background: var(--gradient-orange);
    border-radius: 9999px;
    transition: width 0.1s linear;
}

/* =====================================================
   BOTTOM CONTROLS BAR
   ===================================================== */
.bottom-controls {
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: 14px;
    padding: 1rem 1.25rem;
    flex-shrink: 0;
}

.controls-row {
    display: flex;
    align-items: flex-end;
    gap: 1.25rem;
    flex-wrap: wrap;
}

.approach-group { flex: 0 0 180px; }
.input-group    { flex: 1; min-width: 180px; }
.target-group   { flex: 0 0 90px; }
.speed-group    { flex: 0 0 130px; }
.actions-group  { flex: 0 0 auto; }

.playback-controls {
    flex: 0 0 auto;
    display: flex;
    gap: 0.5rem;
}

/* Speed Slider */
.speed-control {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.speed-slider {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 4px;
    border-radius: 9999px;
    background: var(--glass-border);
    outline: none;
    cursor: pointer;
    margin-top: 0.4rem;
}

.speed-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--accent-orange);
    cursor: pointer;
    border: 2px solid rgba(255,255,255,0.2);
    transition: transform var(--transition-fast);
}

.speed-slider::-webkit-slider-thumb:hover { transform: scale(1.2); }

.speed-label {
    display: flex;
    justify-content: space-between;
    font-size: 0.7rem;
    color: var(--text-secondary);
    margin-top: 2px;
}

/* =====================================================
   CUSTOM SELECT DROPDOWNS
   ===================================================== */
.custom-select-wrapper {
    position: relative;
    width: 100%;
}

.custom-select-trigger {
    width: 100%;
    padding: 0.65rem 0.875rem;
    border: 1px solid var(--glass-border);
    border-radius: 8px;
    background: var(--input-bg); /* FIXED: was --bg-main (pure black) */
    color: var(--text-primary);
    font-size: 0.9rem;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 0.5rem;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
    user-select: none;
}

.custom-select-trigger svg { flex-shrink: 0; transition: transform var(--transition-fast); }

.custom-select-trigger:hover { border-color: var(--primary-color); }

.custom-select-wrapper.open .custom-select-trigger {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(255, 100, 0, 0.15);
}

.custom-select-wrapper.open .custom-select-trigger svg { transform: rotate(180deg); }

.custom-select-options {
    position: absolute;
    top: calc(100% + 6px);
    left: 0; right: 0;
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: 8px;
    box-shadow: var(--shadow-md);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: opacity var(--transition-fast), transform var(--transition-fast), visibility var(--transition-fast);
    z-index: 200;
    max-height: 250px;
    overflow-y: auto;
}

.custom-select-wrapper.open .custom-select-options {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.custom-select-option {
    padding: 0.65rem 0.875rem;
    font-size: 0.9rem;
    color: var(--text-primary);
    cursor: pointer;
    transition: background var(--transition-fast);
}

.custom-select-option:first-child { border-radius: 8px 8px 0 0; }
.custom-select-option:last-child  { border-radius: 0 0 8px 8px; }

.custom-select-option:hover { background: var(--card-hover-bg); }
.custom-select-option.selected {
    color: var(--accent-orange);
    font-weight: 600;
}

/* =====================================================
   ARRAY VISUALIZATION ELEMENTS
   ===================================================== */
.array-container {
    display: flex;
    gap: 1rem;
    align-items: flex-end;
    padding-bottom: 50px;
    position: relative;
}

.array-element {
    width: 60px;
    height: 60px;
    background: var(--element-bg);
    border: 1.5px solid var(--element-border);
    color: var(--element-text);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.25rem;
    font-weight: 700;
    border-radius: 12px;
    position: relative;
    transition: border-color var(--transition-medium), color var(--transition-medium);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

/* FIXED: Use class toggling, not GSAP backgroundColor on gradient elements */
.array-element.active {
    border-color: var(--accent-orange) !important;
    color: var(--accent-orange) !important;
    background: rgba(255, 100, 0, 0.1) !important;
}

.array-element.found {
    border-color: var(--accent-green) !important;
    color: var(--accent-green) !important;
    background: rgba(34, 197, 94, 0.1) !important;
}

.array-element .index-label {
    position: absolute;
    bottom: -28px;
    font-size: 0.7rem;
    color: var(--text-secondary);
    font-weight: 500;
    white-space: nowrap;
}

.pointer {
    position: absolute;
    font-size: 0.875rem;
    font-weight: 700;
    bottom: -50px;
    letter-spacing: -0.02em;
}

.pointer.i { color: var(--accent-orange); }
.pointer.j { color: var(--accent-purple); }

/* =====================================================
   DATA STRUCTURE VISUALIZERS
   ===================================================== */
.variables-container {
    position: absolute;
    top: 1.25rem;
    right: 1.25rem;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    align-items: flex-end;
    z-index: 10;
}

.map-visualizer {
    background: var(--input-bg);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    padding: 0.875rem;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    min-width: 170px;
    opacity: 0;
}

.map-visualizer h4 {
    margin-bottom: 0.625rem;
    font-size: 0.7rem;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--glass-border);
    padding-bottom: 0.5rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.map-entry {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    padding: 0.35rem 0.5rem;
    border-radius: 6px;
    opacity: 0;
    transform: translateY(8px);
}

.map-key { color: var(--accent-orange); font-weight: bold; }
.map-val { color: var(--accent-purple); font-weight: bold; }

/* =====================================================
   MESSAGE / STEP BAR
   ===================================================== */
.message-bar {
    position: absolute;
    bottom: 1.25rem;
    left: 50%;
    transform: translateX(-50%);
    background: var(--text-primary);
    color: var(--bg-main);
    padding: 0.5rem 1.25rem;
    border-radius: 9999px;
    font-weight: 600;
    font-size: 0.85rem;
    opacity: 0;
    z-index: 50;
    white-space: nowrap;
    max-width: 90%;
    text-align: center;
    pointer-events: none;
    letter-spacing: 0.01em;
}

/* =====================================================
   TOAST NOTIFICATIONS
   ===================================================== */
#toast-container {
    position: fixed;
    bottom: 4rem;
    right: 1.5rem;
    z-index: 9999;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    align-items: flex-end;
}

.toast {
    padding: 0.75rem 1.25rem;
    border-radius: 10px;
    font-size: 0.875rem;
    font-weight: 500;
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    opacity: 0;
    transform: translateY(10px) scale(0.95);
    transition: opacity 0.2s, transform 0.2s;
    pointer-events: none;
    max-width: 300px;
}

.toast.show {
    opacity: 1;
    transform: translateY(0) scale(1);
}

.toast-info {
    background: var(--glass-bg);
    color: var(--text-primary);
}

.toast-coming-soon {
    background: rgba(107, 27, 255, 0.15);
    border-color: rgba(107, 27, 255, 0.35);
    color: var(--text-primary);
}

/* =====================================================
   STEP COUNTER
   ===================================================== */
.step-counter {
    font-size: 0.75rem;
    color: var(--text-secondary);
    font-variant-numeric: tabular-nums;
}

/* =====================================================
   STEP LOG PANEL
   ===================================================== */
.step-log {
    background: var(--input-bg);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    overflow: hidden;
    flex-shrink: 0;
    height: 140px;
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    display: flex;
    flex-direction: column;
    margin-bottom: 0.75rem;
}

.step-log-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.45rem 0.875rem;
    border-bottom: 1px solid var(--glass-border);
    background: rgba(255, 255, 255, 0.02);
    flex-shrink: 0;
}

.step-log-title {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-secondary);
}

.step-log-title svg {
    color: var(--accent-orange);
    flex-shrink: 0;
}

.step-log-clear {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 0.7rem;
    color: var(--text-secondary);
    padding: 0.1rem 0.4rem;
    border-radius: 4px;
    transition: color var(--transition-fast), background var(--transition-fast);
    font-family: inherit;
}

.step-log-clear:hover {
    color: var(--text-primary);
    background: var(--glass-border);
}

.step-log-entries {
    overflow-y: auto;
    flex: 1;
    padding: 0.375rem 0;
    scroll-behavior: smooth;
}

/* Scrollbar styling */
.step-log-entries::-webkit-scrollbar {
    width: 3px;
}
.step-log-entries::-webkit-scrollbar-track {
    background: transparent;
}
.step-log-entries::-webkit-scrollbar-thumb {
    background: var(--glass-border);
    border-radius: 9999px;
}

.step-log-entry {
    display: flex;
    align-items: baseline;
    gap: 0.625rem;
    padding: 0.22rem 0.875rem;
    font-size: 0.8rem;
    line-height: 1.4;
    animation: log-entry-in 0.2s ease forwards;
    opacity: 0;
}

@keyframes log-entry-in {
    from { opacity: 0; transform: translateX(-6px); }
    to   { opacity: 1; transform: translateX(0); }
}

.step-log-entry:hover {
    background: rgba(255, 255, 255, 0.02);
}

.log-step-num {
    font-family: 'Courier New', monospace;
    font-size: 0.68rem;
    color: var(--accent-orange);
    font-weight: 700;
    flex-shrink: 0;
    min-width: 2rem;
    opacity: 0.7;
}

.log-step-msg {
    color: var(--text-secondary);
    flex: 1;
}

/* Last entry (current step) gets highlighted */
.step-log-entry.current .log-step-msg {
    color: var(--text-primary);
}
.step-log-entry.current .log-step-num {
    opacity: 1;
}

/* Type-specific entry colors */
.step-log-entry.type-success .log-step-msg { color: var(--accent-green); }
.step-log-entry.type-success .log-step-num { color: var(--accent-green); }
.step-log-entry.type-fail    .log-step-msg { color: #ef4444; }

/* =====================================================
   FOOTER
   ===================================================== */
.footer {
    border-top: 1px solid var(--glass-border);
    padding: 0.75rem 2rem;
    text-align: center;
    background: var(--glass-bg);
    color: var(--text-secondary);
    font-size: 0.8rem;
}

/* =====================================================
   RESPONSIVE
   ===================================================== */
@media (max-width: 900px) {
    .visualizer-layout { flex-direction: column; }
    .sidebar {
        width: 100%;
        border-right: none;
        border-bottom: 1px solid var(--glass-border);
        max-height: 40vh;
    }
    .hero-section h1 { font-size: 2.5rem; }
    .controls-row { gap: 0.75rem; }
    .approach-group, .speed-group { flex: 0 0 100%; }
    .input-group { flex: 1 1 120px; }
    .target-group { flex: 0 0 80px; }
}

@media (max-width: 600px) {
    .glass-nav { padding: 0.6rem 1rem; }
    .nav-brand { font-size: 1.05rem; }
    .nav-brand-container { gap: 0.4rem; }
    .beta-badge { font-size: 0.5rem; padding: 0.15rem 0.4rem; }
    .nav-links { gap: 0.75rem; }
    .nav-links a { font-size: 0.85rem; }
    .visualization-area { padding: 0.75rem; }
    .bottom-controls { padding: 0.75rem; }
}

/* =====================================================
   LIVE VARIABLES PANEL  (top-left of canvas)
   ===================================================== */
.var-panel {
    position: absolute;
    top: 1.25rem;
    left: 1.25rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    z-index: 10;
    pointer-events: none;
}

.var-panel-title {
    font-size: 0.65rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-secondary);
    margin-bottom: 0.1rem;
}

.var-chips-row {
    display: flex;
    flex-wrap: wrap;
    gap: 0.4rem;
}

/* Individual variable chip */
.var-chip {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    padding: 0.3rem 0.65rem;
    border-radius: 8px;
    font-family: 'Courier New', monospace;
    font-size: 0.85rem;
    border: 1px solid;
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    opacity: 0;
    transform: translateY(-6px);
    transition: opacity 0.25s ease, transform 0.25s ease;
}

.var-chip.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Type color variants */
.var-chip.counter {
    background: rgba(255, 100, 0, 0.1);
    border-color: rgba(255, 100, 0, 0.35);
    color: var(--accent-orange);
}
.var-chip.computed {
    background: rgba(107, 27, 255, 0.1);
    border-color: rgba(107, 27, 255, 0.35);
    color: #a78bfa;
}
.var-chip.constant {
    background: rgba(255, 255, 255, 0.05);
    border-color: var(--glass-border);
    color: var(--text-secondary);
}

.var-chip-name {
    font-weight: 500;
    opacity: 0.7;
    font-size: 0.78rem;
}

.var-chip-eq {
    opacity: 0.4;
    font-size: 0.78rem;
}

.var-chip-value {
    font-weight: 700;
}

/* Flash animation when value updates */
@keyframes var-flash {
    0%   { background: rgba(255,100,0,0.35); }
    100% { background: transparent; }
}

.var-chip.flash {
    animation: var-flash 0.4s ease-out forwards;
}

/* =====================================================
   PSEUDOCODE PANEL (sidebar)
   ===================================================== */
.pseudocode-panel {
    border: 1px solid var(--glass-border);
    border-radius: 10px;
    overflow: hidden;
    flex-shrink: 0;
}

.pseudocode-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem 0.75rem;
    background: rgba(255,255,255,0.03);
    border-bottom: 1px solid var(--glass-border);
    cursor: pointer;
    user-select: none;
}

.pseudocode-header span {
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-secondary);
}

.pseudocode-toggle-icon {
    color: var(--text-secondary);
    font-size: 0.75rem;
    transition: transform var(--transition-fast);
}

.pseudocode-panel.collapsed .pseudocode-toggle-icon {
    transform: rotate(-90deg);
}

.pseudocode-body {
    padding: 0.5rem 0;
    overflow: hidden;
    transition: max-height 0.25s ease;
    max-height: 300px;
}

.pseudocode-panel.collapsed .pseudocode-body {
    max-height: 0;
}

.code-line {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.2rem 0.75rem;
    font-family: 'Courier New', monospace;
    font-size: 0.78rem;
    color: var(--text-secondary);
    border-radius: 4px;
    margin: 0 0.25rem;
    transition: background 0.15s, color 0.15s;
    cursor: default;
}

.code-line-num {
    font-size: 0.65rem;
    color: var(--text-secondary);
    opacity: 0.4;
    min-width: 1rem;
    text-align: right;
    user-select: none;
}

.code-line.active-line {
    background: rgba(255, 100, 0, 0.12);
    color: var(--text-primary);
    border-left: 2px solid var(--accent-orange);
    padding-left: calc(0.75rem - 2px);
}

.code-line.active-line .code-line-num {
    color: var(--accent-orange);
    opacity: 1;
}

/* Indentation helpers */
.code-line.indent-1 { padding-left: 1.5rem; }
.code-line.indent-2 { padding-left: 2.5rem; }
.code-line.active-line.indent-1 { padding-left: calc(1.5rem - 2px); }
.code-line.active-line.indent-2 { padding-left: calc(2.5rem - 2px); }

/* keyword syntax colors */
.kw  { color: #c084fc; } /* purple — for, if, return */
.fn  { color: #60a5fa; } /* blue — function names */
.num { color: #fb923c; } /* orange — numbers */
.str { color: #4ade80; } /* green — strings */
.cm  { color: #6b7280; font-style: italic; } /* grey — comments */

/* =====================================================
   CANVAS EMPTY STATE
   ===================================================== */
.canvas-empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    color: var(--text-secondary);
    text-align: center;
    pointer-events: none;
    user-select: none;
    opacity: 0.5;
}

.canvas-empty-state svg {
    opacity: 0.4;
}

.canvas-empty-state p {
    font-size: 0.9rem;
    max-width: 200px;
    line-height: 1.5;
}

.canvas-empty-state .kbd {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    margin-top: 0.25rem;
    font-size: 0.75rem;
}

.kbd-key {
    background: var(--glass-border);
    border: 1px solid rgba(255,255,255,0.15);
    border-radius: 4px;
    padding: 0.1rem 0.4rem;
    font-family: monospace;
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* =====================================================
   APPROACH INFO STRIP
   ===================================================== */
.approach-info {
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-top: 0.2rem;
    line-height: 1.4;
    display: none;
}

.approach-info.visible { display: block; }

/* =====================================================
   FAIL STATE
   ===================================================== */
@keyframes fail-pulse {
    0%, 100% { border-color: var(--element-border); }
    50%       { border-color: #ef4444; background: rgba(239,68,68,0.1); }
}

.array-element.fail {
    animation: fail-pulse 0.5s ease 2;
    border-color: #ef4444 !important;
    color: #ef4444 !important;
}