/* --- CSS Variables for Theming --- */
:root {
    --font-sans: 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'Courier New', Courier, monospace;

    /* Light Theme */
    --bg-color: #f4f7f9;
    --primary-text-color: #1a1a1a;
    --secondary-text-color: #555;
    --card-bg-color: #ffffff;
    --border-color: #dce4e9;
    --input-bg-color: #ffffff;
    --input-border-color: #ced4da;
    --input-readonly-bg-color: #e9ecef;
    --accent-color: #007bff;
    --accent-color-hover: #0056b3;
    --secondary-btn-bg: #6c757d;
    --secondary-btn-hover: #5a6268;
    --shadow-color: rgba(0, 0, 0, 0.08);
    --canvas-bg-color: #e9ecef;
}

body[data-theme='dark'] {
    --bg-color: #1a1a1a;
    --primary-text-color: #e1e1e1;
    --secondary-text-color: #a0a0a0;
    --card-bg-color: #2b2b2b;
    --border-color: #444;
    --input-bg-color: #333;
    --input-border-color: #555;
    --input-readonly-bg-color: #252525;
    --accent-color: #0095ff;
    --accent-color-hover: #006fbf;
    --secondary-btn-bg: #5a6268;
    --secondary-btn-hover: #484e53;
    --shadow-color: rgba(0, 0, 0, 0.2);
    --canvas-bg-color: #333;
}

/* --- General & Layout Styles --- */
body {
    font-family: var(--font-sans);
    margin: 0;
    padding: 2rem;
    background-color: var(--bg-color);
    color: var(--primary-text-color);
    transition: background-color 0.3s ease, color 0.3s ease;
    display: flex;
    justify-content: center;
}

.container {
    width: 100%;
    max-width: 1200px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-template-rows: auto 1fr;
    gap: 2rem;
}

.main-header {
    grid-column: 1 / -1;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.input-section,
.output-section {
    background-color: var(--card-bg-color);
    padding: 1.5rem;
    border-radius: 12px;
    box-shadow: 0 4px 12px var(--shadow-color);
    transition: background-color 0.3s ease;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

h1 {
    font-size: 2em;
    font-weight: 700;
    margin: 0;
}

h2 {
    font-size: 1.4em;
    margin: 0 0 1rem 0;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--accent-color);
}

/* --- Form & Input Styles --- */
.input-group {
    border: 1px solid var(--border-color);
    padding: 1rem;
    border-radius: 8px;
}

.grid-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    font-size: 0.9em;
}

input[type="text"],
input[type="number"],
select,
textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--input-border-color);
    border-radius: 6px;
    font-size: 1em;
    background-color: var(--input-bg-color);
    color: var(--primary-text-color);
    box-sizing: border-box;
    transition: all 0.3s ease;
}

input:focus, select:focus, textarea:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent-color) 25%, transparent);
}

input[readonly] {
    background-color: var(--input-readonly-bg-color);
    cursor: not-allowed;
}

input[type="checkbox"] {
    width: auto;
    margin-right: 0.5rem;
}

textarea {
    min-height: 200px;
    resize: vertical;
    font-family: var(--font-mono);
}

.note {
    font-size: 0.85em;
    color: var(--secondary-text-color);
    margin: 0.5rem 0;
}


/* --- Collapsible Section Styles --- */
.collapsible-toggle {
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    user-select: none;
    margin-bottom: 0;
    transition: margin-bottom 0.3s ease-out;
}
.collapsible-toggle .toggle-icon {
    font-size: 1.5em;
    font-weight: bold;
    transition: transform 0.3s ease-out;
}
.collapsible-toggle.active .toggle-icon {
    transform: rotate(45deg);
}
.collapsible-toggle.active + .collapsible-content {
    margin-top: 1rem;
}

.collapsible-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.35s ease-out, margin-top 0.35s ease-out;
}

/* --- Button Styles --- */
.button-group {
    display: flex;
    gap: 0.75rem;
}

button {
    background-color: var(--accent-color);
    color: white;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1em;
    font-weight: 600;
    transition: background-color 0.3s ease, transform 0.2s ease;
    flex-grow: 1;
}

button:hover {
    background-color: var(--accent-color-hover);
    transform: translateY(-2px);
}

button.secondary {
    background-color: var(--secondary-btn-bg);
}
button.secondary:hover {
    background-color: var(--secondary-btn-hover);
}

.main-actions {
    margin-top: auto;
}

/* --- Shape & Height Specific --- */
.shape-selection {
    display: flex;
    align-items: center;
    gap: 1rem;
    background-color: color-mix(in srgb, var(--bg-color) 50%, var(--card-bg-color));
    padding: 0.75rem;
    border-radius: 6px;
    margin-bottom: 1rem;
}
#heightInputGroup { display: none; }
#heightInputGroup[data-visible="true"] { display: block; }


/* --- Canvas & Output --- */
/* This style applies to both the main canvas and the corner detail canvas */
canvas {
    border: 1px solid var(--border-color);
    background-color: var(--canvas-bg-color);
    border-radius: 5px;
    width: 100%;
    height: auto;
}

.canvas-note { margin-top: 0.5rem; text-align: center; }

/* --- Dark Mode Toggle Switch --- */
.theme-switcher {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}
.theme-switcher label {
    font-size: 0.9em;
    color: var(--secondary-text-color);
    margin-bottom: 0;
}
#themeToggle {
    appearance: none;
    width: 40px;
    height: 22px;
    background-color: var(--secondary-btn-bg);
    border-radius: 11px;
    position: relative;
    cursor: pointer;
    transition: background-color 0.3s ease;
}
#themeToggle::before {
    content: '';
    position: absolute;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background-color: white;
    top: 3px;
    left: 3px;
    transition: transform 0.3s ease;
}
#themeToggle:checked {
    background-color: var(--accent-color);
}
#themeToggle:checked::before {
    transform: translateX(18px);
}

/* --- HTML report Styles --- */
#resultsOutput {
    background-color: color-mix(in srgb, var(--bg-color) 50%, var(--card-bg-color));
    padding: 1rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    min-height: 200px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}
#resultsOutput h3 {
    margin: 0;
    font-size: 1.2em;
    border-bottom: none;
}
#resultsOutput .collapsible-toggle h3 {
    padding: 0;
    border-bottom: none;
}
#resultsOutput table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1rem;
}
#resultsOutput th, #resultsOutput td {
    padding: 0.5rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
    font-size: 0.9em;
}
#resultsOutput th {
    font-weight: 600;
}
#resultsOutput tr:last-child td {
    border-bottom: none;
}
#resultsOutput .total-row td {
    font-weight: bold;
    border-top: 2px solid var(--primary-text-color);
}


/* --- Responsive Adjustments --- */
@media (max-width: 900px) {
    .container {
        grid-template-columns: 1fr;
        grid-template-rows: auto auto auto;
        gap: 1.5rem;
        padding: 1rem;
    }
    h1 { font-size: 1.5em; }
    .main-header { flex-direction: column; gap: 1rem; align-items: flex-start; }
}

@media (max-width: 480px) {
}