:root {
    --bg: oklch(98% 0.005 250); 
    --panel-bg: oklch(95% 0.005 250); 
    --text: oklch(20% 0.005 250); 
    --subtle-text: oklch(45% 0.005 250);
    --border: oklch(80% 0.005 250); 
    --accent: oklch(60% 0.25 145); 
    --btn-bg: oklch(20% 0.005 250); 
    --btn-hover: oklch(35% 0.005 250);
    --info-box: oklch(92% 0.005 250);
}

html.dark-mode {
    --bg: oklch(15% 0.005 250); 
    --panel-bg: oklch(18% 0.005 250); 
    --text: oklch(95% 0.005 250); 
    --subtle-text: oklch(70% 0.005 250);
    --border: oklch(30% 0.005 250); 
    --accent: oklch(80% 0.3 145); 
    --btn-bg: oklch(90% 0.005 250); 
    --btn-text: oklch(15% 0.005 250);
    --btn-hover: oklch(75% 0.005 250);
    --info-box: oklch(22% 0.005 250);
}

body {
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
    background: var(--bg); 
    color: var(--text); 
    margin: 0; 
    padding: 0;
    box-sizing: border-box; 
    line-height: 1.5;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.app-header {
    display: flex; justify-content: space-between; align-items: center;
    padding: 16px 32px; border-bottom: 1px solid var(--border);
    background: var(--bg); flex-shrink: 0;
}

.app-header h2 { margin: 0; font-size: 1.5em; text-align: left; }

.app-main {
    flex: 1; display: flex; flex-direction: column; justify-content: center;
    padding: 32px 24px;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 24px;
    flex-wrap: wrap;
}

.github-btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 8px 16px; border: 1px solid var(--text);
    background: var(--btn-bg); color: var(--btn-text, var(--bg));
    text-decoration: none; font-size: 0.85em; font-weight: 600;
    text-transform: uppercase; letter-spacing: 0.05em;
    cursor: pointer; transition: background 0.2s;
}

.github-btn:hover {
    background: var(--btn-hover);
}

.theme-switch-wrapper {
    display: flex; align-items: center; justify-content: center;
    gap: 12px; font-size: 0.85em; font-weight: 600; text-transform: uppercase; letter-spacing: 0.05em; color: var(--subtle-text);
}

.theme-switch {
    position: relative; display: inline-block; width: 44px; height: 20px;
}

.theme-switch input { opacity: 0; width: 0; height: 0; }

.slider {
    position: absolute; cursor: pointer; top: 0; left: 0; right: 0; bottom: 0;
    background: var(--border); transition: 0.15s linear; border: 1px solid var(--text);
}

.slider:before {
    position: absolute; content: ""; height: 14px; width: 14px;
    left: 2px; bottom: 2px; background: var(--text); transition: 0.15s linear;
}

input:checked + .slider { background: var(--panel-bg); }
input:checked + .slider:before { transform: translateX(24px); background: var(--accent); }

.layout-grid {
    display: grid;
    grid-template-columns: 320px minmax(300px, 800px) 320px;
    justify-content: center;
    gap: 24px;
    align-items: stretch;
    max-width: 1600px;
    margin: 0 auto;
}

.sidebar-left, .main-content, .sidebar-right {
    display: flex;
    flex-direction: column;
    gap: 24px;
    min-width: 0;
}

.sidebar-left, .sidebar-right {
    position: sticky;
    top: 32px;
    height: fit-content;
}

.panel {
    border: 1px solid var(--border);
    padding: 24px;
    position: relative;
    width: 100%;
    box-sizing: border-box;
}

.result-container {
    --stage-grid-column: 24px;
    --stage-grid-row: 24px;
    display: flex; flex-direction: column;
    align-items: center;
    justify-content: center;
    flex: 1;
    min-height: 500px;
    background:
        radial-gradient(circle at center, oklch(100% 0 0 / 0.04), transparent 58%),
        linear-gradient(oklch(50% 0.005 250 / 0.08) 1px, transparent 1px),
        linear-gradient(90deg, oklch(50% 0.005 250 / 0.08) 1px, transparent 1px);
    background-position: 0 0;
    background-size: 100% 100%, var(--stage-grid-column) var(--stage-grid-row), var(--stage-grid-column) var(--stage-grid-row);
}

html.dark-mode .result-container {
    background:
        radial-gradient(circle at center, oklch(100% 0 0 / 0.06), transparent 58%),
        linear-gradient(oklch(72% 0.012 250 / 0.18) 1px, transparent 1px),
        linear-gradient(90deg, oklch(72% 0.012 250 / 0.18) 1px, transparent 1px);
    background-position: 0 0;
    background-size: 100% 100%, var(--stage-grid-column) var(--stage-grid-row), var(--stage-grid-column) var(--stage-grid-row);
}

#result-content {
    width: 100%; display: flex; flex-direction: column;
    align-items: center; justify-content: center; flex-grow: 1;
    overflow: hidden;
    min-height: 0;
    position: relative;
    z-index: 1;
    transition: width 200ms ease-out, aspect-ratio 200ms ease-out;
}

.result-placeholder-icon {
    color: var(--text);
    margin-bottom: 24px;
    opacity: 0.65;
    position: relative;
    z-index: 1;
}

.result-placeholder {
    color: var(--subtle-text);
    position: relative;
    text-align: center;
    z-index: 1;
}

.result-placeholder-title {
    font-size: 1.2em;
    font-weight: 600;
    letter-spacing: 0.05em;
    margin-bottom: 8px;
    text-transform: uppercase;
}

.result-placeholder-copy {
    font-size: 0.95em;
    opacity: 0.8;
}

#result-content.has-result {
    --result-min-width: min(100%, 420px);
    flex: 0 1 auto;
    aspect-ratio: var(--result-aspect, 1);
    width: min(100%, max(var(--result-min-width), var(--result-width, 100%)), calc(68vh * var(--result-aspect, 1)));
    max-height: min(68vh, 720px);
}

.result-container img {
    width: 100%; height: 100%; object-fit: contain; image-rendering: pixelated;
}

.result-image {
    position: absolute;
    inset: 0;
    opacity: 1;
    transition: opacity 180ms ease-out;
}

.result-image-enter,
.result-image-exit {
    opacity: 0;
}

h2 { text-transform: uppercase; letter-spacing: 0.05em; font-weight: 700; }
h5, h6 { margin-top: 0; text-transform: uppercase; letter-spacing: 0.05em; border-bottom: 1px solid var(--border); padding-bottom: 8px; }

input[type="range"] { 
    width: 100%; 
    accent-color: var(--accent);
    height: 6px;
    background: var(--border);
    outline: none;
    -webkit-appearance: none;
}
input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 16px;
    height: 16px;
    background: var(--text);
    cursor: pointer;
    border: none;
    border-radius: 0;
}

.form-group { margin-bottom: 20px; }
small { color: var(--subtle-text); font-size: 0.85em; }

.controls-container {
    opacity: 0.5; transition: opacity 0.3s; pointer-events: none;
}

.controls-container.active {
    opacity: 1; pointer-events: auto;
}

.loading-overlay {
    position: absolute; top: 0; left: 0; right: 0; bottom: 0;
    background: transparent;
    display: flex; align-items: center; justify-content: center;
    z-index: 10; opacity: 0; pointer-events: none;
}

.loading-overlay.active { opacity: 1; }

.spinner {
    width: 32px; height: 32px; border: 2px solid var(--border);
    border-top: 2px solid var(--accent);
    animation: spin 0.6s linear infinite;
}

@keyframes spin { to { transform: rotate(360deg); } }

.file-input { display: none; }
.file-input-label {
    display: block; padding: 12px 20px; background: var(--btn-bg);
    color: var(--btn-text, var(--bg)); border: 1px solid var(--text); cursor: pointer; text-align: center;
    font-weight: 600; text-transform: uppercase; letter-spacing: 0.05em; font-size: 0.85em;
}

.file-input-label:hover { background: var(--btn-hover); }
.file-input:disabled + .file-input-label {
    background: var(--panel-bg);
    color: var(--subtle-text);
    border-color: var(--border);
    cursor: not-allowed;
    opacity: 0.7;
}
.file-info {
    color: var(--subtle-text);
    display: flex;
    flex-direction: column;
    font-size: 0.9em;
    gap: 4px;
    margin-top: 10px;
    min-width: 0;
}

.file-name-line {
    overflow: hidden;
    text-overflow: clip;
    white-space: nowrap;
}

.progress-bar {
    width: 100%; height: 4px; background: var(--border);
    border-radius: 2px; overflow: hidden; margin: 10px 0;
}

.progress-fill { height: 100%; background: var(--accent); width: 0%; transition: width 0.3s; }

.color-picker-group {
    display: flex; align-items: center; gap: 10px; margin-bottom: 15px;
}

.color-picker-wrapper {
    position: relative; display: flex; align-items: center;
    gap: 10px; flex: 1;
}

.color-input {
    -webkit-appearance: none; -moz-appearance: none;
    width: 50px; height: 40px; border: 1px solid var(--text);
    cursor: pointer; background: none; padding: 0;
}

.color-input::-webkit-color-swatch-wrapper { padding: 0; }
.color-input::-moz-color-swatch { padding: 0; border: none; }
.color-input::-webkit-color-swatch { border: none; }
.color-input:focus {
    outline: none; box-shadow: 0 0 0 2px var(--accent);
}

.color-text {
    flex: 1; min-width: 80px; padding: 8px 12px;
    border: 1px solid var(--text);
    font-family: inherit; font-size: 14px;
    background: var(--bg); color: var(--text);
}
.color-text:focus {
    outline: 2px solid var(--accent);
    outline-offset: -1px;
}

.preset-colors {
    display: flex; gap: 8px; flex-wrap: wrap; margin-top: 10px;
}

.preset-color {
    width: 32px; height: 32px; cursor: pointer;
    border: 1px solid var(--border);
}

.preset-color:hover {
    border-color: var(--text); 
}

.preset-color.active {
    border-color: var(--accent) !important;
    box-shadow: inset 0 0 0 2px var(--bg), 0 0 0 2px var(--accent);
}

#toast-container {
    position: fixed; top: 20px; left: 50%; transform: translateX(-50%); z-index: 9999;
    display: flex; flex-direction: column; align-items: center; gap: 10px;
}

.toast {
    padding: 16px 20px; border: 1px solid var(--text); color: var(--btn-text, var(--bg)); font-size: 0.9em;
    opacity: 0; transform: translateY(-20px); transition: opacity 0.3s, transform 0.3s;
    min-width: 250px; font-weight: 500; font-family: inherit;
    display: flex; justify-content: space-between; align-items: center; gap: 15px;
}

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

.toast-close {
    background: none; border: none; color: inherit; font-size: 1.5em;
    cursor: pointer; padding: 0; line-height: 1; opacity: 0.7; transition: opacity 0.2s;
}

.toast-close:hover { opacity: 1; }
.toast-error { background: oklch(55% 0.2 25); color: #fff; }
.toast-success { background: oklch(60% 0.15 145); color: #000; }
.toast-warning { background: oklch(80% 0.15 80); color: #000; }
.toast-info { background: var(--text); }

.transparency-section {
    margin-top: 20px; padding-top: 20px;
    border-top: 1px solid var(--border); transition: opacity 0.3s;
}

.transparency-section.disabled { opacity: 0.5; pointer-events: none; }

.transparency-info {
    background: var(--info-box); border-left: 2px solid var(--accent);
    padding: 10px 15px; margin-bottom: 15px; border-radius: 0;
    font-size: 0.85em; border-top: 1px solid var(--border); border-right: 1px solid var(--border); border-bottom: 1px solid var(--border);
}

.download-buttons {
    display: flex; flex-direction: row; gap: 16px;
    width: 100%; flex-wrap: wrap;
}

.download-buttons button {
    flex: 1; min-width: 140px; padding: 12px 15px; border: 1px solid var(--text); background: var(--btn-bg);
    color: var(--btn-text, var(--bg)); cursor: pointer; font-weight: 600; text-transform: uppercase; letter-spacing: 0.05em;
    font-size: 0.85em; font-family: inherit;
}

.download-buttons button:hover:not(:disabled) { background: var(--btn-hover); }
.download-buttons button:disabled {
    background: var(--panel-bg);
    color: var(--subtle-text);
    border-color: var(--border);
    cursor: not-allowed; opacity: 0.7;
}

@media (max-width: 1200px) {
    .layout-grid {
        grid-template-columns: 300px 1fr;
    }
    .sidebar-right {
        grid-column: 1 / -1;
    }
    .sidebar-left,
    .sidebar-right {
        position: static;
        top: auto;
        height: auto;
    }
}

@media (max-width: 900px) {
    .layout-grid {
        grid-template-columns: 1fr;
        align-items: start;
    }
}

@media (max-width: 768px) {
    .app-header { flex-direction: column; gap: 16px; text-align: center; padding: 16px; }
    .app-header h2 { text-align: center; font-size: 1.4em; }
    .header-actions { justify-content: center; width: 100%; gap: 16px; }
    .app-main { padding: 16px; justify-content: flex-start; }
    .panel { padding: 16px; }
    .result-container { min-height: 360px; justify-content: center; }
    #result-content.has-result {
        --result-min-width: min(100%, 320px);
        width: min(100%, max(var(--result-min-width), var(--result-width, 100%)), calc(58vh * var(--result-aspect, 1)));
        max-height: 58vh;
    }
}

@media (max-width: 480px) {
    .app-header h2 { font-size: 1.2em; }
    .color-picker-group { flex-direction: column; align-items: stretch; }
    #toast-container { width: calc(100% - 32px); top: 16px; right: auto; left: 50%; transform: translateX(-50%); }
    .preset-colors { justify-content: center; }
}