:root {
    --bg-color: #f3f4f6;
    --grid-color: #e5e7eb;
    --text-primary: #1f2937;
    --text-secondary: #4b5563;
    
    --color-blue: #3B82F6;
    --color-yellow: #FBBF24;
    --color-green: #10B981;
    --color-red: #EF4444;
    --color-purple: #8B5CF6;
    
    --panel-bg: rgba(255, 255, 255, 0.8);
    --panel-blur: 12px;
    --panel-border: rgba(209, 213, 219, 0.5);
    
    --transition-speed: 0.2s;
}

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

body {
    font-family: 'Inter', sans-serif;
    color: var(--text-primary);
    background-color: var(--bg-color);
    overflow: hidden; /* Viewport handles scroll */
}

#viewport {
    width: 100vw;
    height: 100vh;
    overflow: auto;
}

#canvas {
    position: relative;
    width: max-content; /* Critical: Expand to fit content */
    min-width: 100vw;
    min-height: 100vh;
    background-image: radial-gradient(var(--grid-color) 1px, transparent 1px);
    background-size: 30px 30px;
    padding: 100px 400px 300px 100px; /* Big right/bottom buffers */
    display: flex;
    align-items: center;
}

#arrow-canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 1;
}

#roadmap-container {
    padding: 50px 0;
}

#roadmap {
    display: flex;
    gap: 40px;
    align-items: flex-start;
    position: relative;
    z-index: 2;
}

/* Phase Styling */
.phase {
    background: #ffffff;
    border-radius: 12px;
    padding: 20px;
    width: 280px;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    border: 3px solid transparent;
    transition: transform var(--transition-speed), box-shadow var(--transition-speed);
    cursor: grab;
    user-select: none;
}

.phase:active {
    cursor: grabbing;
}

.phase:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

.phase-header {
    font-weight: 700;
    font-size: 1.1rem;
    margin-bottom: 15px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding-bottom: 8px;
    border-bottom: 2px solid;
}

/* Color Themes */
.phase.blue { border-color: var(--color-blue); }
.phase.blue .phase-header { color: var(--color-blue); border-bottom-color: var(--color-blue); }

.phase.yellow { border-color: var(--color-yellow); }
.phase.yellow .phase-header { color: var(--color-yellow); border-bottom-color: var(--color-yellow); }

.phase.green { border-color: var(--color-green); }
.phase.green .phase-header { color: var(--color-green); border-bottom-color: var(--color-green); }

.phase.red { border-color: var(--color-red); }
.phase.red .phase-header { color: var(--color-red); border-bottom-color: var(--color-red); }

.phase.purple { border-color: var(--color-purple); }
.phase.purple .phase-header { color: var(--color-purple); border-bottom-color: var(--color-purple); }

/* Lessons & Projects */
.node-container {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.lesson {
    background: #f9fafb;
    border: 1px solid #e5e7eb;
    border-radius: 6px;
    padding: 10px;
    font-size: 0.9rem;
    color: var(--text-secondary);
    transition: background var(--transition-speed);
    cursor: help;
}

.lesson:hover {
    background: #f3f4f6;
}

.project {
    background: #ffffff;
    border: 2px solid var(--text-primary);
    border-radius: 8px;
    padding: 12px;
    font-weight: 600;
    font-size: 0.95rem;
    box-shadow: 4px 4px 0px var(--text-primary);
    margin-top: 10px;
    cursor: pointer;
    transition: transform 0.1s, box-shadow 0.1s;
}

.project:hover {
    transform: translate(-2px, -2px);
    box-shadow: 6px 6px 0px var(--text-primary);
}

.project.highlight-active {
    background: #FEF9C3; /* Highlight yellow */
    transform: scale(1.05);
}

/* Panels */
.floating-panel {
    position: fixed;
    background: var(--panel-bg);
    backdrop-filter: blur(var(--panel-blur));
    -webkit-backdrop-filter: blur(var(--panel-blur));
    border: 1px solid var(--panel-border);
    border-radius: 12px;
    padding: 15px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.05);
    z-index: 100;
}

.floating-panel label {
    display: block;
    font-size: 0.75rem;
    text-transform: uppercase;
    font-weight: 700;
    color: var(--text-secondary);
    margin-bottom: 10px;
}

#side-panel {
    position: fixed;
    top: 30px;
    right: 30px;
    width: 160px;
    background: rgba(255, 255, 255, 0.6);
    backdrop-filter: blur(var(--panel-blur));
    border: 1px solid rgba(255, 255, 255, 0.3);
    z-index: 100;
}

#side-panel:hover {
    background: var(--panel-bg);
}

.workflow-steps {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 5px;
}

.step {
    padding: 8px;
    background: #fff;
    border-radius: 6px;
    width: 100%;
    text-align: center;
    font-size: 0.85rem;
    font-weight: 600;
    border: 1px solid #e5e7eb;
}

.workflow-steps .arrow {
    color: var(--text-secondary);
    font-weight: bold;
}

#bottom-panel {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    width: fit-content;
    background: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(var(--panel-blur));
    z-index: 100;
}

.system-flow {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 20px;
}

.system-flow span:not(.connector) {
    background: #fff;
    padding: 10px 20px;
    border-radius: 8px;
    font-weight: 600;
    border: 1px solid #e5e7eb;
}

.connector {
    font-weight: bold;
    color: var(--color-green);
    font-size: 1.2rem;
}

/* Tooltip */
#tooltip {
    position: absolute;
    background: #1f2937;
    color: white;
    padding: 8px 12px;
    border-radius: 6px;
    font-size: 0.8rem;
    pointer-events: none;
    z-index: 1000;
    max-width: 200px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.hidden {
    display: none;
}

/* Arrows */
.connection-arrow {
    stroke-width: 3;
    fill: none;
    stroke: #9ca3af;
    marker-end: url(#arrowhead);
    transition: d 0.3s ease;
}

/* SVG Markers */
#arrowhead {
    fill: #9ca3af;
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}
::-webkit-scrollbar-track {
    background: #f1f1f1;
}
::-webkit-scrollbar-thumb {
    background: #cdcdcd;
    border-radius: 10px;
}
::-webkit-scrollbar-thumb:hover {
    background: #a5a5a5;
}