:root {
    --primary-color: #007bff;
    --primary-hover: #0056b3;
    --success-color: #28a745;
    --success-hover: #1e7e34;
    --light-gray: #f0f2f5;
    --medium-gray: #dfe1e6;
    --dark-gray: #5e6c84;
    --text-color: #172b4d;
    --bg-color: #ffffff;
    --panel-width: 400px;
    --letter-panel-width: 350px; /* Added new variable for the middle panel */
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--light-gray);
    color: var(--text-color);
    margin: 0;
    padding: 0;
    height: 100vh;
    overflow: hidden;
    user-select: none;
}

.main-layout { display: flex; height: 100%; }

.controls-panel {
    width: var(--panel-width);
    flex-shrink: 0;
    background-color: var(--bg-color);
    box-shadow: 2px 0 10px rgba(0,0,0,0.05);
    display: flex;
    flex-direction: column;
    height: 100vh;
    box-sizing: border-box;
    overflow: hidden; /* Ẩn phần tràn ra ngoài */
}

.controls-panel header,
.controls-panel .download-section {
    padding-left: 25px;
    padding-right: 25px;
    flex-shrink: 0; /* Header và footer sẽ không bị co lại */
}

.controls-panel header {
    padding-top: 25px;
}

.controls-panel .download-section {
    padding-bottom: 25px;
}

.controls-content-wrapper {
    flex-grow: 1; /* Cho phép vùng này giãn ra để lấp đầy không gian */
    overflow-y: auto; /* Thêm thanh cuộn dọc khi cần */
    padding: 0 25px;
}


/* ADDED: Styles for the new middle panel for letter controls */
.letter-controls-panel {
    width: var(--letter-panel-width);
    flex-shrink: 0;
    background-color: #f8f9fa;
    padding: 25px;
    border-left: 1px solid var(--medium-gray);
    border-right: 1px solid var(--medium-gray);
    display: flex;
    flex-direction: column;
    height: 100vh;
    box-sizing: border-box;
}

.letter-controls-panel h2 {
    font-size: 1.2rem;
    margin: 0 0 15px 0;
    padding-bottom: 10px;
    border-bottom: 1px solid #eee;
    color: var(--text-color);
}

header h1 { font-size: 1.8rem; margin: 0; }
header p { font-size: 0.95rem; color: var(--dark-gray); margin: 5px 0 0; }
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 15px;
    margin-bottom: 15px;
    border-bottom: 1px solid var(--medium-gray);
}

.input-section { display: flex; gap: 10px; margin-bottom: 20px; }
input[type="text"] { width: 100%; padding: 10px 12px; font-size: 1rem; border: 1px solid #ccc; border-radius: 6px; box-sizing: border-box;}
input[type="text"]:focus { outline: none; border-color: var(--primary-color); box-shadow: 0 0 0 2px rgba(0, 123, 255, 0.25); }

button { padding: 10px 18px; font-size: 0.95rem; font-weight: 600; border: none; border-radius: 6px; cursor: pointer; transition: background-color 0.2s, transform 0.1s; }
button:active { transform: scale(0.98); }
#preview-btn { background-color: var(--primary-color); color: white; width: 100%; }
#preview-btn:hover { background-color: var(--primary-hover); }

/* MODIFIED: .controls-area no longer needs to be a flex-grow container */
.controls-area {
    overflow: hidden;
    display: flex;
    flex-direction: column;
}
.control-group h2 { font-size: 1.2rem; margin: 0 0 15px 0; padding-bottom: 10px; border-bottom: 1px solid #eee;}

/* MODIFIED: letter-controls-wrapper is now inside the new panel */
.letter-controls-wrapper {
    flex-grow: 1;
    overflow-y: auto;
    padding-right: 10px;
}
.control-group { margin-bottom: 20px; }
.control-group h3 { font-size: 1rem; color: var(--dark-gray); margin: 15px 0 10px; padding-top: 15px; border-top: 1px solid var(--medium-gray); }
.control-group:first-child h3 { border-top: none; margin-top: 0; padding-top: 0; }

.letter-title-container { display: flex; justify-content: space-between; align-items: center; }
.letter-info { display: flex; align-items: center; gap: 10px; font-size: 0.85rem; }
.change-letter-btn { font-size: 0.8rem; padding: 4px 8px; background-color: #f0f0f0; color: #333; border: 1px solid #ccc; }
.change-letter-btn:hover { background-color: #e0e0e0; }

.slider-container { display: grid; grid-template-columns: auto 1fr; align-items: center; gap: 5px 10px; margin-bottom: 5px; }
.slider-container label { grid-column: 1 / 3; font-weight: 500; font-size: 0.9rem; }
.slider-widget { grid-column: 1 / 3; display: flex; align-items: center; gap: 5px; }
.slider-widget button { font-size: 1rem; width: 25px; height: 25px; padding: 0; background-color: #e9ecef; color: #495057; border-radius: 50%; }
.slider { flex-grow: 1; margin: 0; }

.slider-widget .slider-value-input {
    width: 50px; text-align: right; font-size: 0.95rem; padding: 4px 6px; border: 1px solid #ccc; border-radius: 4px;
    font-family: monospace; font-weight: bold; color: var(--primary-color); -moz-appearance: textfield;
}
.slider-widget .slider-value-input::-webkit-outer-spin-button, .slider-widget .slider-value-input::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
.slider-widget .unit-span { font-size: 0.95rem; color: var(--dark-gray); width: 20px; text-align: left; }

.download-section { margin-top: auto; padding-top: 20px; border-top: 1px solid var(--medium-gray); flex-shrink: 0; }
#download-btn { background-color: var(--success-color); color: white; width: 100%; }
#download-btn:hover { background-color: var(--success-hover); }
#download-btn:disabled { background-color: #cccccc; cursor: not-allowed; }

.preview-panel { flex-grow: 1; padding: 30px; display: flex; justify-content: center; align-items: center; height: 100vh; box-sizing: border-box; }
.preview-area { width: 100%; height: 100%; background-color: #e9ecef; border: 3px dashed #ccc; border-radius: 8px; display: flex; justify-content: center; align-items: center; position: relative; overflow: hidden; }

#preview-canvas { max-width: 100%; max-height: 100%; object-fit: contain; cursor: grab; }
#preview-canvas:active { cursor: grabbing; }

.spinner { border: 5px solid rgba(0,0,0,0.1); border-top: 5px solid var(--primary-color); border-radius: 50%; width: 50px; height: 50px; animation: spin 1s linear infinite; position: absolute; }
@keyframes spin { 0% { transform: rotate(0deg); } 100% { transform: rotate(360deg); } }

.modal { position: fixed; z-index: 1000; left: 0; top: 0; width: 100%; height: 100%; overflow: auto; background-color: rgba(0,0,0,0.5); display: flex; justify-content: center; align-items: center; }
.modal-content { background-color: #fefefe; margin: auto; padding: 20px; border: 1px solid #888; width: 80%; max-width: 500px; border-radius: 8px; box-shadow: 0 5px 15px rgba(0,0,0,0.3); }
.modal-close-btn { color: #aaa; float: right; font-size: 28px; font-weight: bold; cursor: pointer; }
/* MODIFIED: Changed to CSS Grid for equal items */
.modal-options {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(90px, 1fr)); /* Responsive grid columns */
    gap: 15px;
    margin-top: 20px;
    max-height: 320px; /* Limit height to enable scrolling */
    overflow-y: auto; /* Enable vertical scroll on overflow */
    padding-right: 10px; /* Add space for the scrollbar */
}
.modal-option-item { display: flex; flex-direction: column; align-items: center; gap: 8px; }
.modal-thumb-container { width: 60px; height: 60px; background-color: #f0f0f0; border: 1px solid #ccc; display: flex; justify-content: center; align-items: center; font-size: 1.5rem; color: #999; }
.modal-thumb-container img { max-width: 100%; max-height: 100%; object-fit: contain; }
/* MODIFIED: Ensure button text does not wrap and shows ellipsis */
.modal-option-btn {
    background-color: var(--primary-color);
    color: white;
    width: 100%; /* Make button fill its grid cell */
    white-space: nowrap; /* Prevent text from wrapping */
    overflow: hidden; /* Hide overflowed text */
    text-overflow: ellipsis; /* Add "..." for long text */
}

#grid-controls { border-top: 1px solid var(--medium-gray); padding-top: 20px; }
.grid-visibility-toggle { display: flex; align-items: center; gap: 8px; margin-bottom: 15px; }
.grid-layer-options { display: flex; align-items: center; gap: 20px; font-size: 0.9rem; }
.grid-layer-options div { display: flex; align-items: center; gap: 5px; }

.upload-new-set-section {
    /* This class is now just a container within the flex header. */
}

/* These styles below were for the old upload form and are kept to avoid unintended changes */
.upload-new-set-section form { display: flex; flex-direction: column; gap: 10px; }
.upload-new-set-section #set-name-input { width: 100%; }
.button-like-label {
    display: inline-block; text-align: center; padding: 10px 18px; font-size: 0.95rem; font-weight: 600;
    border-radius: 6px; cursor: pointer; background-color: #6c757d; color: white; transition: background-color 0.2s;
}
.button-like-label:hover { background-color: #5a6268; }
#folder-name-display { font-size: 0.85rem; color: var(--dark-gray); font-style: italic; }
.submit-btn { background-color: var(--primary-color); color: white; }
.submit-btn:hover { background-color: var(--primary-hover); }

/* ADDED: Custom scrollbar for the modal options */
#modal-options-container::-webkit-scrollbar {
  width: 6px;
}
#modal-options-container::-webkit-scrollbar-track {
  background: rgba(0,0,0,0.05);
  border-radius: 10px;
}
#modal-options-container::-webkit-scrollbar-thumb {
  background: #ccc;
  border-radius: 10px;
}
#modal-options-container::-webkit-scrollbar-thumb:hover {
  background: #aaa;
}

/* === ADDED: STYLES FOR THEME SELECTOR === */
#theme-list-container .theme-item {
    padding: 8px 12px;
    cursor: pointer;
    border-radius: 4px;
    transition: background-color 0.2s;
}

#theme-list-container .theme-item:hover {
    background-color: var(--light-gray);
}

#theme-list-container .theme-item.selected {
    background-color: var(--primary-color);
    color: white;
    font-weight: 600;
}

.custom-scrollbar::-webkit-scrollbar {
    width: 6px;
}
.custom-scrollbar::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 10px;
}
.custom-scrollbar::-webkit-scrollbar-thumb {
    background: #d1d5db;
    border-radius: 10px;
}
.custom-scrollbar::-webkit-scrollbar-thumb:hover {
    background: #9ca3af;
}
/* === END OF ADDED STYLES === */