:root {
    --bg-main: #0b0f17;
    --card-bg: rgba(18, 24, 38, 0.95);
    --card-border: rgba(255, 255, 255, 0.1);
    --primary: #3b82f6;
    --primary-hover: #2563eb;
    --primary-glow: rgba(59, 130, 246, 0.35);
    --accent: #8b5cf6;
    --text-title: #f8fafc;
    --text-body: #94a3b8;
    --text-muted: #64748b;
    --input-bg: #161e2e;
    --input-border: #26334d;
    --radius-lg: 16px;
    --radius-md: 10px;
    --radius-sm: 6px;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

body {
    background-color: var(--bg-main);
    background-image: 
        radial-gradient(at 20% 20%, rgba(59, 130, 246, 0.15) 0px, transparent 50%),
        radial-gradient(at 80% 80%, rgba(139, 92, 246, 0.15) 0px, transparent 50%);
    color: var(--text-body);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 30px 20px;
}

.app-wrapper {
    width: 100%;
    max-width: 720px;
}

.app-header {
    text-align: center;
    margin-bottom: 28px;
}

.logo-badge {
    display: inline-block;
    padding: 6px 14px;
    background: rgba(59, 130, 246, 0.1);
    border: 1px solid rgba(59, 130, 246, 0.3);
    color: var(--primary);
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.5px;
    margin-bottom: 12px;
}

.app-header h1 {
    color: var(--text-title);
    font-size: 26px;
    font-weight: 700;
    letter-spacing: -0.5px;
    margin-bottom: 8px;
}

.subtitle {
    font-size: 14px;
    color: var(--text-body);
    line-height: 1.5;
}

.card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    padding: 30px;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5);
}

.form-group {
    margin-bottom: 22px;
}

.section-label, label {
    display: block;
    font-size: 13px;
    font-weight: 600;
    color: var(--text-title);
    margin-bottom: 8px;
}

.track-toggle {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
}

.track-btn {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    background: var(--input-bg);
    border: 1px solid var(--input-border);
    border-radius: var(--radius-md);
    color: var(--text-body);
    cursor: pointer;
    transition: all 0.25s ease;
    text-align: left;
}

.track-btn .icon { font-size: 22px; }
.track-btn .text strong { display: block; color: var(--text-title); font-size: 13px; }
.track-btn .text small { display: block; font-size: 11px; color: var(--text-muted); }

.track-btn.active {
    background: rgba(59, 130, 246, 0.15);
    border-color: var(--primary);
    box-shadow: 0 0 15px var(--primary-glow);
}

.track-btn.active .text strong { color: var(--primary); }

.upload-zone {
    border: 2px dashed var(--input-border);
    border-radius: var(--radius-md);
    background: var(--input-bg);
    padding: 24px;
    text-align: center;
    cursor: pointer;
    transition: all 0.25s ease;
    min-height: 150px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.upload-zone:hover, .upload-zone.dragover {
    border-color: var(--primary);
    background: rgba(59, 130, 246, 0.05);
}

.upload-icon-wrapper { color: var(--primary); margin-bottom: 8px; }
.upload-title { font-size: 14px; font-weight: 600; color: var(--text-title); margin-bottom: 4px; }
.upload-hint { font-size: 12px; color: var(--text-muted); }

.preview-container {
    width: 100%;
    position: relative;
    border-radius: var(--radius-sm);
    overflow: hidden;
}

.preview-container img {
    max-width: 100%;
    max-height: 220px;
    border-radius: var(--radius-sm);
    display: block;
    margin: 0 auto;
}

.preview-overlay {
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(11, 15, 23, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.2s ease;
}

.preview-container:hover .preview-overlay { opacity: 1; }

.change-img-btn {
    padding: 8px 16px;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 12px;
    font-weight: 600;
    cursor: pointer;
}

.form-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

@media (max-width: 540px) {
    .track-toggle, .form-grid { grid-template-columns: 1fr; }
}

select {
    width: 100%;
    padding: 11px 14px;
    background: var(--input-bg);
    border: 1px solid var(--input-border);
    border-radius: var(--radius-md);
    color: var(--text-title);
    font-size: 13px;
    outline: none;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%2394a3b8' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
}

select:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

.btn-generate {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: #ffffff;
    border: none;
    border-radius: var(--radius-md);
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    box-shadow: 0 4px 20px var(--primary-glow);
    margin-top: 6px;
}

.btn-generate:hover {
    box-shadow: 0 6px 24px rgba(59, 130, 246, 0.5);
}

.result-group {
    margin-top: 28px;
    padding-top: 20px;
    border-top: 1px solid var(--card-border);
}

.result-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 8px;
}

.btn-copy {
    background: rgba(255, 255, 255, 0.08);
    color: var(--text-title);
    border: 1px solid var(--card-border);
    padding: 6px 12px;
    border-radius: var(--radius-sm);
    font-size: 12px;
    font-weight: 500;
    cursor: pointer;
}

.btn-copy:hover { background: rgba(255, 255, 255, 0.15); }

textarea {
    width: 100%;
    height: 140px;
    padding: 14px;
    background: var(--input-bg);
    border: 1px solid var(--input-border);
    border-radius: var(--radius-md);
    color: #e2e8f0;
    font-size: 13px;
    line-height: 1.6;
    resize: vertical;
    outline: none;
}

.hidden { display: none !important; }

.app-footer {
    text-align: center;
    font-size: 12px;
    color: var(--text-muted);
    margin-top: 24px;
}