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

:root {
    --bg-app: #1e1e1e;
    --bg-pane: #252526;
    --bg-header: #333333;
    --text-primary: #d4d4d4;
    --text-secondary: #808080;
    --border: #3c3c3c;
    --accent: #0e639c;
    --accent-hover: #1177bb;
    --success: #4ec9b0;
}

body {
    font-family: 'Consolas', 'Monaco', monospace;
    background: var(--bg-app);
    color: var(--text-primary);
    min-height: 100vh;
}

.app-container {
    display: flex;
    flex-direction: column;
    height: 100vh;
}

.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem 1rem;
    background: var(--bg-header);
    border-bottom: 1px solid var(--border);
    flex-wrap: wrap;
    gap: 0.5rem;
}

.header h1 {
    font-size: 1rem;
    font-weight: 500;
}

.header-controls {
    display: flex;
    gap: 0.5rem;
}

.btn-primary, .btn-secondary {
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 4px;
    font-size: 0.85rem;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-primary {
    background: var(--accent);
    color: white;
}

.btn-primary:hover:not(:disabled) {
    background: var(--accent-hover);
}

.btn-primary:disabled,
.btn-secondary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-secondary {
    background: var(--bg-pane);
    color: var(--text-primary);
    border: 1px solid var(--border);
}

.btn-secondary:hover:not(:disabled) {
    background: var(--border);
}

.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding: 1rem;
    gap: 1rem;
    overflow: auto;
}

.input-section {
    background: var(--bg-pane);
    border-radius: 6px;
    overflow: hidden;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.4rem 0.75rem;
    background: var(--bg-header);
    border-bottom: 1px solid var(--border);
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.char-count {
    font-size: 0.7rem;
}

.char-warning {
    padding: 0.5rem 0.75rem;
    background: rgba(240, 173, 78, 0.15);
    color: #f0ad4e;
    font-size: 0.75rem;
    border-radius: 4px;
    margin: 0 1rem;
}

.char-warning.hidden {
    display: none;
}

textarea {
    width: 100%;
    padding: 0.75rem;
    background: transparent;
    border: none;
    color: var(--text-primary);
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: 0.9rem;
    resize: none;
    outline: none;
    line-height: 1.6;
    min-height: 100px;
}

textarea::placeholder {
    color: var(--text-secondary);
}

.options-section {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    padding: 0.75rem;
    background: var(--bg-pane);
    border-radius: 6px;
}

.option-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.option-group label {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.option-group select {
    padding: 0.4rem 0.6rem;
    background: var(--bg-app);
    color: var(--text-primary);
    border: 1px solid var(--border);
    border-radius: 4px;
    font-size: 0.8rem;
    cursor: pointer;
}

.option-group input[type="color"] {
    width: 32px;
    height: 28px;
    border: 1px solid var(--border);
    border-radius: 4px;
    cursor: pointer;
    background: transparent;
}

.output-section {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: var(--bg-pane);
    border-radius: 6px;
}

.qr-container {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 1rem;
    background: #fff;
    border-radius: 8px;
    min-width: 220px;
    min-height: 220px;
}

.qr-placeholder {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 200px;
    height: 200px;
    color: #999;
    font-size: 0.85rem;
    text-align: center;
}

#qrCanvas {
    display: block;
}

#qrCanvas.hidden {
    display: none;
}

.download-buttons {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    justify-content: center;
}

.footer {
    padding: 0.4rem 1rem;
    background: var(--bg-header);
    border-top: 1px solid var(--border);
    font-size: 0.7rem;
    color: var(--text-secondary);
}

.toast {
    position: fixed;
    bottom: 1rem;
    right: 1rem;
    background: var(--success);
    color: var(--bg-app);
    padding: 0.5rem 1rem;
    border-radius: 4px;
    opacity: 0;
    transform: translateY(10px);
    transition: all 0.2s;
}

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