/* Root Variables for Color Palette and Animations */
:root {
    --bg-dark: hsl(222, 47%, 4%);
    --bg-card: hsla(223, 47%, 9%, 0.65);
    --bg-card-hover: hsla(223, 47%, 13%, 0.8);
    --border-light: hsla(217, 30%, 60%, 0.12);
    --border-glow: hsla(186, 100%, 50%, 0.2);
    
    /* Neon Glow Accents */
    --cyan-glow: hsl(186, 100%, 50%);
    --purple-glow: hsl(265, 89%, 63%);
    --magenta-glow: hsl(317, 100%, 54%);
    
    /* Text Colors */
    --text-primary: hsl(210, 40%, 98%);
    --text-secondary: hsl(215, 20%, 75%);
    --text-muted: hsl(215, 12%, 50%);
    
    /* Shadows and Glows */
    --shadow-cyan: 0 0 15px hsla(186, 100%, 50%, 0.25);
    --shadow-purple: 0 0 15px hsla(265, 89%, 63%, 0.25);
    --box-shadow-card: 0 8px 32px 0 rgba(0, 0, 0, 0.4);
    
    --transition-smooth: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Reset and Layout */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    background-color: var(--bg-dark);
    color: var(--text-primary);
    font-family: 'Outfit', -apple-system, sans-serif;
    min-height: 100vh;
    overflow: hidden;
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}

/* Background gradient styling */
.glass-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -2;
    background: radial-gradient(circle at 20% 30%, hsla(265, 80%, 12%, 0.35) 0%, transparent 45%),
                radial-gradient(circle at 80% 70%, hsla(186, 80%, 12%, 0.3) 0%, transparent 45%),
                linear-gradient(180deg, hsl(222, 47%, 3%) 0%, hsl(222, 47%, 5%) 100%);
    background-size: cover;
}

/* App Main Container */
.app-container {
    width: 96vw;
    height: 92vh;
    max-width: 1500px;
    max-height: 900px;
    display: grid;
    grid-template-columns: 1fr 340px;
    gap: 20px;
    background-color: hsla(222, 47%, 4%, 0.55);
    border: 1px solid var(--border-light);
    border-radius: 20px;
    padding: 20px;
    box-shadow: 0 20px 70px rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(25px);
    -webkit-backdrop-filter: blur(25px);
}

/* Main Viewport Panel */
.viewport {
    display: flex;
    flex-direction: column;
    gap: 15px;
    height: 100%;
    overflow: hidden;
}

/* Header style */
.app-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-light);
    padding-bottom: 12px;
}

.header-text h1 {
    font-size: 1.5rem;
    font-weight: 800;
    letter-spacing: -0.5px;
    background: linear-gradient(135deg, #fff 40%, var(--text-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.subtitle {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-top: 2px;
}

.app-badge {
    display: flex;
    align-items: center;
    gap: 8px;
    background: hsla(186, 100%, 50%, 0.06);
    border: 1px solid hsla(186, 100%, 50%, 0.2);
    padding: 5px 12px;
    border-radius: 20px;
}

.badge-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--cyan-glow);
    box-shadow: 0 0 8px var(--cyan-glow);
    animation: pulse 2s infinite;
}

.badge-text {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--cyan-glow);
    text-transform: uppercase;
}

/* Canvas Container */
.canvas-container {
    flex-grow: 1;
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: 16px;
    position: relative;
    overflow: hidden;
    box-shadow: var(--box-shadow-card);
    cursor: grab;
}

.canvas-container:active {
    cursor: grabbing;
}

canvas {
    width: 100%;
    height: 100%;
    display: block;
}

.canvas-overlay {
    position: absolute;
    top: 15px;
    left: 15px;
    pointer-events: none;
    display: flex;
    flex-direction: column;
    gap: 6px;
    z-index: 10;
}

.overlay-tag {
    background: rgba(4, 8, 19, 0.75);
    border: 1px solid var(--border-light);
    border-radius: 6px;
    padding: 4px 10px;
    font-size: 0.7rem;
    font-weight: 600;
    letter-spacing: 0.5px;
    color: var(--text-secondary);
    text-transform: uppercase;
}

.overlay-tip {
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* Fixed Inset Pane Card */
.inset-pane {
    position: absolute;
    bottom: 15px;
    left: 15px;
    width: 140px;
    height: 165px;
    background: rgba(4, 8, 19, 0.82);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border: 1px solid var(--border-light);
    border-radius: 12px;
    padding: 8px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.45);
    z-index: 10;
    pointer-events: none;
    transition: var(--transition-smooth);
}

.inset-pane.double {
    width: 260px;
}

.inset-tag {
    font-size: 0.65rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.3px;
    color: var(--text-secondary);
}

#canvas-circle-inset {
    width: 120px;
    height: 120px;
    background: transparent;
    display: block;
}

#canvas-circle-inset.double {
    width: 240px;
    height: 120px;
}

/* Readout Grid */
.math-readout-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 15px;
}

.readout-card {
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: 12px;
    padding: 12px 16px;
    display: flex;
    flex-direction: column;
    gap: 4px;
    transition: var(--transition-smooth);
    position: relative;
    overflow: hidden;
}

.readout-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: linear-gradient(90deg, var(--purple-glow), var(--cyan-glow));
    opacity: 0.5;
}

.readout-card:hover {
    background: var(--bg-card-hover);
    border-color: var(--border-glow);
    transform: translateY(-1px);
}

.math-label {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.3px;
}

.math-value {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--cyan-glow);
    text-shadow: var(--shadow-cyan);
}

.math-formula {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.7rem;
    color: var(--text-muted);
}

/* Sidebar styling */
.sidebar {
    display: flex;
    flex-direction: column;
    gap: 20px;
    border-left: 1px solid var(--border-light);
    padding-left: 20px;
    overflow-y: auto;
}

.brand {
    display: flex;
    align-items: center;
    gap: 12px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-light);
}

.logo-icon {
    width: 28px;
    height: 28px;
    border-radius: 8px;
    background: linear-gradient(135deg, var(--cyan-glow), var(--purple-glow));
    box-shadow: var(--shadow-cyan);
}

.brand h2 {
    font-size: 1.25rem;
    font-weight: 750;
    letter-spacing: -0.5px;
    background: linear-gradient(to right, #fff, var(--text-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Mode Selector styles */
.mode-selector {
    display: flex;
    flex-direction: column;
    gap: 8px;
    padding-bottom: 15px;
    border-bottom: 1px solid var(--border-light);
}

.mode-btn {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 14px;
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: 10px;
    color: var(--text-secondary);
    font-size: 0.85rem;
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition-smooth);
}

.mode-btn:hover {
    background: var(--bg-card-hover);
    color: var(--text-primary);
    border-color: var(--purple-glow);
}

.mode-btn.active {
    background: linear-gradient(135deg, hsla(265, 89%, 63%, 0.12), hsla(186, 100%, 50%, 0.05));
    border-color: var(--purple-glow);
    color: var(--text-primary);
    box-shadow: inset 0 0 10px hsla(265, 89%, 63%, 0.08);
}

/* Control Panels */
.control-panel {
    display: flex;
    flex-direction: column;
    gap: 18px;
}

.control-panel h3 {
    font-size: 1.05rem;
    font-weight: 650;
    border-left: 3px solid var(--purple-glow);
    padding-left: 8px;
}

/* Control groups and sliders */
.control-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.control-group label {
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-secondary);
}

input[type="range"] {
    -webkit-appearance: none;
    width: 100%;
    height: 5px;
    background: hsla(215, 15%, 30%, 0.35);
    border-radius: 3px;
    outline: none;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--purple-glow);
    cursor: pointer;
    box-shadow: var(--shadow-purple);
    transition: var(--transition-smooth);
}

input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.25);
    background: var(--cyan-glow);
    box-shadow: var(--shadow-cyan);
}

.value-readout {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    color: var(--cyan-glow);
    align-self: flex-end;
}

.slider-hint {
    font-size: 0.72rem;
    line-height: 1.4;
    color: var(--text-muted);
}

/* Double sub-panel section for string-string page controls */
.sub-panel-title {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--text-primary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: -5px;
}

.sub-panel-title.left {
    border-left: 2px solid var(--cyan-glow);
    padding-left: 6px;
}

.sub-panel-title.right {
    border-left: 2px solid var(--magenta-glow);
    padding-left: 6px;
}

/* Theory box brief */
.theory-box {
    background: hsla(217, 30%, 60%, 0.03);
    border: 1px solid var(--border-light);
    border-radius: 12px;
    padding: 14px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.theory-box h4 {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--text-primary);
    text-transform: uppercase;
    letter-spacing: 0.3px;
    border-bottom: 1px solid var(--border-light);
    padding-bottom: 4px;
}

.theory-box p {
    font-size: 0.75rem;
    line-height: 1.45;
    color: var(--text-secondary);
}

/* Animations */
@keyframes pulse {
    0%, 100% {
        opacity: 1;
        box-shadow: 0 0 8px var(--cyan-glow);
    }
    50% {
        opacity: 0.4;
        box-shadow: 0 0 2px var(--cyan-glow);
    }
}