* {
    box-sizing: border-box;
}

:root {
    --bg-color: #0f172a;
    --card-bg: rgba(30, 41, 59, 0.9);
    --border-color: rgba(255, 255, 255, 0.1);
    --accent-color: #00aeffd2;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --glass-blur: 12px;
}

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    margin: 0;
    padding: 0;
    height: 100vh;
    overflow: hidden;
}

/* Full-screen canvas */
#columnCanvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: 0;
    background: radial-gradient(circle at top right, #1e293b, #0f172a);
}

/* Left sidebar controls */
.controls-sidebar {
    position: fixed;
    left: 0;
    top: 0;
    width: 380px;
    height: 100vh;
    background: var(--card-bg);
    backdrop-filter: blur(var(--glass-blur));
    border-right: 1px solid var(--border-color);
    padding: 24px;
    overflow-y: auto;
    z-index: 10;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

/* Top right info panel */
.info-panel {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 10;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

h1 {
    font-size: 1.4rem;
    font-weight: 700;
    margin: 0 0 8px 0;
    background: linear-gradient(to right, #fff, #94a3b8);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

/* Tabs */
.tabs {
    display: flex;
    gap: 4px;
    margin-top: 8px;
}

.tab-btn {
    flex: 1;
    background: rgba(15, 23, 42, 0.4);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 8px 12px;
    border-radius: 6px;
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.tab-btn:hover {
    background: rgba(15, 23, 42, 0.6);
    border-color: rgba(56, 189, 248, 0.3);
}

.tab-btn.active {
    background: var(--accent-color);
    border-color: var(--accent-color);
    color: white;
}

.tab-content {
    display: none;
    flex-direction: column;
    gap: 6px;
    margin-top: 8px;
}

.tab-content.active {
    display: flex;
}

/* Placeholder Content */
.placeholder-content {
    background: rgba(15, 23, 42, 0.3);
    border: 1px dashed var(--border-color);
    border-radius: 8px;
    padding: 20px;
    text-align: center;
}

.placeholder-text {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin: 0 0 16px 0;
}

.placeholder-list {
    text-align: left;
    color: var(--text-secondary);
    font-size: 0.85rem;
    line-height: 1.8;
    margin: 0 0 16px 0;
    padding-left: 20px;
}

.placeholder-list li {
    margin-bottom: 8px;
}

.placeholder-list strong {
    color: var(--accent-color);
}

.placeholder-hint {
    color: var(--text-secondary);
    font-size: 0.8rem;
    font-style: italic;
    margin: 0;
    opacity: 0.7;
}

label {
    font-weight: 600;
    font-size: 0.85rem;
    color: var(--accent-color);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.hint {
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin: 0;
    font-style: italic;
}

textarea,
input[type="number"],
input[type="text"] {
    background: rgba(15, 23, 42, 0.6);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    padding: 10px 12px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    line-height: 1.4;
    transition: border-color 0.2s, box-shadow 0.2s;
}

textarea {
    resize: none;
    height: 120px;
}

textarea:focus,
input[type="number"]:focus,
input[type="text"]:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.1);
}

textarea.drag-over {
    border: 2px dashed var(--accent-color);
    background: rgba(56, 189, 248, 0.05);
}

/* Display Controls */
.display-controls {
    background: var(--card-bg);
    backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 12px 16px;
}

.toggle-switch {
    display: flex;
    align-items: center;
    gap: 12px;
    cursor: pointer;
    font-size: 0.85rem;
    color: var(--text-primary);
    font-weight: 500;
}

.toggle-switch input {
    display: none;
}

.slider {
    position: relative;
    width: 36px;
    height: 20px;
    background-color: rgba(15, 23, 42, 0.6);
    border-radius: 20px;
    border: 1px solid var(--border-color);
    transition: all 0.2s;
}

.slider::before {
    content: "";
    position: absolute;
    height: 14px;
    width: 14px;
    left: 2px;
    bottom: 2px;
    background-color: var(--text-secondary);
    border-radius: 50%;
    transition: all 0.2s;
}

.toggle-switch input:checked+.slider {
    background-color: rgba(56, 189, 248, 0.2);
    border-color: var(--accent-color);
}

.toggle-switch input:checked+.slider::before {
    transform: translateX(16px);
    background-color: var(--accent-color);
}

/* Legend */
.legend {
    background: var(--card-bg);
    backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 16px;
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.legend-icon {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    display: inline-block;
}

.legend-icon.vertex {
    background: #38bdf8;
    box-shadow: 0 0 8px rgba(56, 189, 248, 0.5);
}

.legend-icon.arbitrary {
    background: #38bdf8;
    box-shadow: 0 0 8px rgba(56, 189, 248, 0.5);
    border: 1.5px solid #fff;
}

.legend-icon.rebar {
    background: #f43f5e;
    box-shadow: 0 0 8px rgba(244, 63, 94, 0.5);
}

.legend-icon.overlap {
    background: #fbbf24;
    box-shadow: 0 0 8px rgba(251, 191, 36, 0.5);
}

/* Analysis Box */
.analysis-box {
    background: var(--card-bg);
    backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 16px;
    display: flex;
    gap: 16px;
}

.stat-item {
    flex: 1;
    text-align: center;
}

.stat-item label {
    display: block;
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-bottom: 4px;
    text-transform: none;
    letter-spacing: normal;
}

.stat-item div {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--accent-color);
    font-family: 'JetBrains Mono', monospace;
}

/* Viewer Controls */
.viewer-controls {
    position: fixed;
    bottom: 24px;
    right: 24px;
    display: flex;
    flex-direction: column;
    align-items: stretch;
    gap: 12px;
    z-index: 100;
}

.primary-btn {
    background: linear-gradient(135deg, #0ea5e9, #00aeffd2);
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: 8px;
    font-weight: 600;
    font-size: 0.9rem;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
    box-shadow: 0 4px 12px rgba(56, 189, 248, 0.3);
}

.primary-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(56, 189, 248, 0.4);
}

.primary-btn:active {
    transform: translateY(0);
}

/* Popup Styles */
.draggable-popup {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: var(--card-bg);
    backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--border-color);
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
    z-index: 1000;
    min-width: 300px;
    max-width: 300px;
}

.popup-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 20px;
    border-bottom: 1px solid var(--border-color);
    cursor: move;
}

.popup-header span {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--accent-color);
}

.close-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 6px;
    transition: background 0.2s, color 0.2s;
}

.close-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
}

.popup-content {
    padding: 16px 20px;
}

.form-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
}

.form-row {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.form-row.span-3 {
    grid-column: span 3;
}

.form-row label {
    font-size: 0.8rem;
}

.form-row input {
    width: 100%;
}

.checkbox-group {
    display: flex;
    gap: 16px;
}

.check-label {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.85rem;
    color: var(--text-primary);
    cursor: pointer;
    text-transform: none;
    letter-spacing: normal;
    font-weight: normal;
}

.check-label input[type="checkbox"] {
    cursor: pointer;
}

.popup-footer {
    display: flex;
    justify-content: flex-end;
    gap: 12px;
    padding: 16px 20px;
    border-top: 1px solid var(--border-color);
}

.delete-btn {
    background: linear-gradient(135deg, #dc2626, #ef4444);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 8px;
    font-weight: 600;
    font-size: 0.9rem;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
    box-shadow: 0 4px 12px rgba(220, 38, 38, 0.3);
}

.delete-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(220, 38, 38, 0.4);
}

/* Scrollbar Styling */
.controls-sidebar::-webkit-scrollbar {
    width: 8px;
}

.controls-sidebar::-webkit-scrollbar-track {
    background: rgba(15, 23, 42, 0.3);
    border-radius: 4px;
}

.controls-sidebar::-webkit-scrollbar-thumb {
    background: rgba(56, 189, 248, 0.3);
    border-radius: 4px;
}

.controls-sidebar::-webkit-scrollbar-thumb:hover {
    background: rgba(56, 189, 248, 0.5);
}