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

/* CSS Variables for theming (Premium Look) */
:root {
    --bg-color: #f0f4f8;
    --text-color: #334155;
    --panel-bg: rgba(255, 255, 255, 0.7);
    --panel-border: rgba(255, 255, 255, 0.5);
    --header-text: #1e293b;
    --input-bg: rgba(255, 255, 255, 0.9);
    --input-border: #cbd5e1;
    --input-focus: #3b82f6;
    --button-primary: linear-gradient(135deg, #6366f1, #3b82f6);
    --button-primary-hover: linear-gradient(135deg, #4f46e5, #2563eb);
    --button-danger: linear-gradient(135deg, #ef4444, #dc2626);
    --button-danger-hover: linear-gradient(135deg, #dc2626, #b91c1c);
    --button-secondary: linear-gradient(135deg, #94a3b8, #64748b);
    --button-secondary-hover: linear-gradient(135deg, #64748b, #475569);
    --status-connected: #22c55e;
    --status-disconnected: #ef4444;
    --status-connecting: #eab308;
    --footer-text: #64748b;
    --info-bar-bg: rgba(241, 245, 249, 0.8);
    --drop-zone-bg: rgba(59, 130, 246, 0.05);
    --drop-zone-border: #93c5fd;
    --file-item-bg: rgba(255, 255, 255, 0.9);
    --file-item-hover: rgba(241, 245, 249, 1);
    --shadow-sm: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --backdrop-blur: blur(12px);
}

[data-theme="dark"] {
    --bg-color: #0f172a;
    --text-color: #f1f5f9;
    --panel-bg: rgba(30, 41, 59, 0.6);
    --panel-border: rgba(255, 255, 255, 0.08);
    --header-text: #f8fafc;
    --input-bg: rgba(15, 23, 42, 0.8);
    --input-border: #334155;
    --input-focus: #60a5fa;
    --button-primary: linear-gradient(135deg, #818cf8, #3b82f6);
    --button-primary-hover: linear-gradient(135deg, #6366f1, #2563eb);
    --button-danger: linear-gradient(135deg, #f87171, #ef4444);
    --button-danger-hover: linear-gradient(135deg, #ef4444, #dc2626);
    --button-secondary: linear-gradient(135deg, #64748b, #475569);
    --button-secondary-hover: linear-gradient(135deg, #475569, #334155);
    --status-connected: #22c55e;
    --status-disconnected: #ef4444;
    --status-connecting: #eab308;
    --footer-text: #94a3b8;
    --info-bar-bg: rgba(15, 23, 42, 0.6);
    --drop-zone-bg: rgba(59, 130, 246, 0.1);
    --drop-zone-border: #3b82f6;
    --file-item-bg: rgba(30, 41, 59, 0.8);
    --file-item-hover: rgba(51, 65, 85, 1);
}

body {
    font-family: 'Outfit', sans-serif;
    background-color: var(--bg-color);
    background-image: radial-gradient(circle at top right, rgba(59, 130, 246, 0.1), transparent 40%),
                      radial-gradient(circle at bottom left, rgba(99, 102, 241, 0.1), transparent 40%);
    background-attachment: fixed;
    color: var(--text-color);
    line-height: 1.6;
    transition: background-color 0.4s ease, color 0.4s ease;
    min-height: 100vh;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Header */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 30px;
    margin-bottom: 30px;
    background: var(--panel-bg);
    backdrop-filter: var(--backdrop-blur);
    -webkit-backdrop-filter: var(--backdrop-blur);
    border: 1px solid var(--panel-border);
    border-radius: 16px;
    box-shadow: var(--shadow-md);
}

header h1 {
    color: var(--header-text);
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.5px;
    background: linear-gradient(to right, #3b82f6, #8b5cf6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.status {
    display: flex;
    align-items: center;
    gap: 15px;
}

.theme-toggle {
    display: flex;
    align-items: center;
}

#theme-btn {
    background: rgba(128, 128, 128, 0.1);
    border: none;
    font-size: 1.2rem;
    cursor: pointer;
    padding: 10px;
    border-radius: 50%;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

#theme-btn:hover {
    background: rgba(128, 128, 128, 0.2);
    transform: rotate(15deg);
}

#connection-status {
    padding: 6px 12px;
    background-color: var(--status-disconnected);
    color: white;
    border-radius: 20px;
    font-weight: 600;
    font-size: 0.85rem;
    letter-spacing: 0.5px;
    transition: background-color 0.3s ease;
}
#connection-status.connected { background-color: var(--status-connected); }
#connection-status.connecting { background-color: var(--status-connecting); }

/* Main Layout */
.main-layout {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 30px;
    flex: 1;
}

/* Editor Section */
.editor-section {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.editor-container {
    display: flex;
    flex-direction: column;
    background: var(--panel-bg);
    backdrop-filter: var(--backdrop-blur);
    border: 1px solid var(--panel-border);
    border-radius: 16px;
    box-shadow: var(--shadow-md);
    overflow: hidden;
    flex: 1;
}

#notepad {
    width: 100%;
    flex: 1;
    min-height: 500px;
    padding: 25px;
    border: none;
    font-size: 1.1rem;
    resize: none;
    font-family: 'Outfit', sans-serif;
    font-weight: 400;
    background-color: transparent;
    color: var(--text-color);
    transition: box-shadow 0.3s ease;
}

#notepad:focus {
    outline: none;
    box-shadow: inset 0 0 0 2px var(--input-focus);
}

.info-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 25px;
    background-color: var(--info-bar-bg);
    border-top: 1px solid var(--panel-border);
    font-size: 0.85rem;
    font-weight: 500;
}

/* Controls / Footer */
footer {
    background: var(--panel-bg);
    backdrop-filter: var(--backdrop-blur);
    border: 1px solid var(--panel-border);
    border-radius: 16px;
    padding: 20px;
    box-shadow: var(--shadow-sm);
    text-align: center;
}

.controls {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 12px;
}

.btn, .btn-primary, .btn-danger {
    padding: 10px 20px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.95rem;
    font-family: 'Outfit', sans-serif;
    font-weight: 600;
    color: white;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.btn { background: var(--button-secondary); }
.btn:hover { background: var(--button-secondary-hover); transform: translateY(-2px); box-shadow: 0 4px 8px rgba(0,0,0,0.15); }

.btn-primary { background: var(--button-primary); }
.btn-primary:hover { background: var(--button-primary-hover); transform: translateY(-2px); box-shadow: 0 4px 8px rgba(59, 130, 246, 0.3); }

.btn-danger { background: var(--button-danger); }
.btn-danger:hover { background: var(--button-danger-hover); transform: translateY(-2px); box-shadow: 0 4px 8px rgba(239, 68, 68, 0.3); }

footer small {
    color: var(--footer-text);
    font-size: 0.8rem;
}

/* Files Section */
.files-section {
    display: flex;
    flex-direction: column;
    gap: 20px;
    background: var(--panel-bg);
    backdrop-filter: var(--backdrop-blur);
    border: 1px solid var(--panel-border);
    border-radius: 16px;
    padding: 25px;
    box-shadow: var(--shadow-md);
    max-height: calc(100vh - 40px);
}

.files-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--panel-border);
    padding-bottom: 15px;
}

.files-header h2 {
    font-size: 1.4rem;
    font-weight: 600;
}

.drop-zone {
    border: 2px dashed var(--drop-zone-border);
    border-radius: 12px;
    background-color: var(--drop-zone-bg);
    padding: 30px 20px;
    text-align: center;
    transition: all 0.3s ease;
    cursor: pointer;
}

.drop-zone:hover, .drop-zone.dragover {
    background-color: rgba(59, 130, 246, 0.15);
    border-color: #2563eb;
    transform: scale(1.02);
}

.drop-zone-content .icon {
    font-size: 2.5rem;
    margin-bottom: 10px;
    display: block;
}

.drop-zone-content p {
    font-weight: 500;
    font-size: 1.1rem;
    margin-bottom: 5px;
}

.drop-zone-content small {
    color: var(--footer-text);
}

.files-list-container {
    flex: 1;
    overflow-y: auto;
    padding-right: 5px;
}

/* Custom Scrollbar */
.files-list-container::-webkit-scrollbar {
    width: 6px;
}
.files-list-container::-webkit-scrollbar-track {
    background: transparent;
}
.files-list-container::-webkit-scrollbar-thumb {
    background: var(--input-border);
    border-radius: 10px;
}

.files-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.files-list li {
    background: var(--file-item-bg);
    border: 1px solid var(--panel-border);
    border-radius: 10px;
    padding: 12px 15px;
    display: flex;
    align-items: center;
    gap: 15px;
    transition: all 0.2s ease;
    animation: fadeIn 0.4s ease forwards;
}

.files-list li:hover {
    background: var(--file-item-hover);
    transform: translateX(4px);
    box-shadow: var(--shadow-sm);
}

.files-list .empty-state {
    text-align: center;
    color: var(--footer-text);
    background: transparent;
    border: none;
    box-shadow: none;
    justify-content: center;
    padding: 30px;
    font-style: italic;
}

.file-icon {
    font-size: 1.8rem;
}

.file-info {
    flex: 1;
    overflow: hidden;
}

.file-info a {
    display: block;
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    margin-bottom: 4px;
    transition: color 0.2s;
}

.file-info a:hover {
    color: var(--input-focus);
}

.file-meta {
    font-size: 0.75rem;
    color: var(--footer-text);
    display: flex;
    gap: 10px;
}

.btn-delete-file {
    background: transparent;
    border: none;
    cursor: pointer;
    font-size: 1.2rem;
    padding: 5px;
    border-radius: 8px;
    opacity: 0.5;
    transition: all 0.2s ease;
}

.btn-delete-file:hover {
    opacity: 1;
    background: rgba(239, 68, 68, 0.1);
    transform: scale(1.1);
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Responsive */
@media (max-width: 992px) {
    .main-layout {
        grid-template-columns: 1fr;
    }
    .files-section {
        max-height: none;
    }
}

@media (max-width: 600px) {
    header {
        flex-direction: column;
        gap: 15px;
        padding: 15px;
    }
    .controls {
        flex-direction: column;
        align-items: stretch;
    }
}