:root {
    --bg-primary: #0f0f13;
    --bg-secondary: #1a1a24;
    --bg-card: #22222e;
    --bg-hover: #2c2c3a;
    --accent: #6c5ce7;
    --accent-light: #a29bfe;
    --accent-glow: rgba(108, 92, 231, 0.35);
    --success: #00cec9;
    --warning: #fdcb6e;
    --danger: #ff7675;
    --text-primary: #f0f0f5;
    --text-secondary: #a0a0b8;
    --border: rgba(255, 255, 255, 0.06);
    --radius: 14px;
    --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    --font: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

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

body {
    font-family: var(--font);
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
}

.app-header {
    text-align: center;
    padding: 36px 20px 20px;
    position: relative;
}

.app-header h1 {
    font-size: 2rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent-light), var(--success));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.5px;
}

.app-header p {
    color: var(--text-secondary);
    margin-top: 6px;
    font-size: 0.95rem;
}

.app-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px 60px;
}

.upload-zone {
    border: 2px dashed rgba(108, 92, 231, 0.3);
    border-radius: var(--radius);
    padding: 56px 32px;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    background: var(--bg-secondary);
    position: relative;
    margin-bottom: 28px;
}

.upload-zone:hover,
.upload-zone.dragover {
    border-color: var(--accent);
    background: rgba(108, 92, 231, 0.06);
    box-shadow: 0 0 40px var(--accent-glow);
}

.upload-zone.has-image {
    padding: 20px;
    border-style: solid;
    border-color: var(--border);
}

.upload-icon {
    font-size: 3rem;
    margin-bottom: 12px;
    display: block;
    opacity: 0.7;
}

.upload-zone h3 {
    font-weight: 600;
    font-size: 1.1rem;
    margin-bottom: 6px;
}

.upload-zone span {
    color: var(--text-secondary);
    font-size: 0.85rem;
}

.upload-zone input[type="file"] {
    display: none;
}

.canvas-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-bottom: 28px;
}

.canvas-panel {
    background: var(--bg-secondary);
    border-radius: var(--radius);
    border: 1px solid var(--border);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.canvas-panel .panel-label {
    font-size: 0.78rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1.2px;
    color: var(--text-secondary);
    padding: 14px 18px 10px;
    border-bottom: 1px solid var(--border);
}

.canvas-panel canvas {
    width: 100%;
    height: auto;
    display: block;
    max-height: 480px;
    object-fit: contain;
    background: #111118;
}

.controls {
    display: flex;
    flex-direction: column;
    gap: 18px;
    margin-bottom: 28px;
}

.controls-group {
    background: var(--bg-secondary);
    border-radius: var(--radius);
    border: 1px solid var(--border);
    padding: 20px;
}

.controls-group h3 {
    font-size: 0.78rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1.2px;
    color: var(--text-secondary);
    margin-bottom: 14px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.controls-group h3 .badge {
    font-size: 0.65rem;
    padding: 2px 8px;
    border-radius: 20px;
    font-weight: 600;
    letter-spacing: 0.5px;
}

.badge-client {
    background: rgba(0, 206, 201, 0.15);
    color: var(--success);
}

.badge-server {
    background: rgba(108, 92, 231, 0.15);
    color: var(--accent-light);
}

.btn-row {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    border: none;
    border-radius: 10px;
    font-family: var(--font);
    font-size: 0.88rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.btn::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, transparent, rgba(255, 255, 255, 0.08));
    opacity: 0;
    transition: var(--transition);
}

.btn:hover::after {
    opacity: 1;
}

.btn:active {
    transform: scale(0.96);
}

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

.btn-filter:hover {
    background: var(--bg-hover);
    border-color: var(--success);
    box-shadow: 0 0 20px rgba(0, 206, 201, 0.15);
}

.btn-ai {
    background: linear-gradient(135deg, rgba(108, 92, 231, 0.2), rgba(162, 155, 254, 0.1));
    color: var(--accent-light);
    border: 1px solid rgba(108, 92, 231, 0.25);
}

.btn-ai:hover {
    background: linear-gradient(135deg, rgba(108, 92, 231, 0.35), rgba(162, 155, 254, 0.2));
    border-color: var(--accent);
    box-shadow: 0 0 25px var(--accent-glow);
}

.btn-reset {
    background: var(--bg-card);
    color: var(--warning);
    border: 1px solid rgba(253, 203, 110, 0.15);
}

.btn-reset:hover {
    border-color: var(--warning);
    box-shadow: 0 0 20px rgba(253, 203, 110, 0.12);
}

.btn-download {
    background: linear-gradient(135deg, rgba(0, 206, 201, 0.2), rgba(0, 206, 201, 0.08));
    color: var(--success);
    border: 1px solid rgba(0, 206, 201, 0.2);
}

.btn-download:hover {
    border-color: var(--success);
    box-shadow: 0 0 25px rgba(0, 206, 201, 0.2);
}

.btn:disabled {
    opacity: 0.35;
    cursor: not-allowed;
    pointer-events: none;
}

.action-row {
    display: flex;
    gap: 10px;
    justify-content: center;
}

.spinner-overlay {
    position: fixed;
    inset: 0;
    background: rgba(15, 15, 19, 0.7);
    backdrop-filter: blur(8px);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    flex-direction: column;
    gap: 18px;
}

.spinner-overlay.active {
    display: flex;
}

.spinner {
    width: 52px;
    height: 52px;
    border: 3px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

.spinner-overlay p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.toast {
    position: fixed;
    bottom: 30px;
    right: 30px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 14px 22px;
    font-size: 0.88rem;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.4);
    z-index: 1001;
    transform: translateY(100px);
    opacity: 0;
    transition: var(--transition);
}

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

.toast.success {
    border-left: 3px solid var(--success);
    color: var(--success);
}

.toast.error {
    border-left: 3px solid var(--danger);
    color: var(--danger);
}

.empty-state {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 200px;
    color: var(--text-secondary);
    font-size: 0.88rem;
    opacity: 0.5;
}

@media (max-width: 768px) {
    .canvas-wrapper {
        grid-template-columns: 1fr;
    }

    .btn-row {
        flex-direction: column;
    }

    .btn {
        justify-content: center;
    }

    .app-header h1 {
        font-size: 1.5rem;
    }
}