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

body {
    background-color: #f8fafc;
    color: #1e293b;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

header {
    background: linear-gradient(135deg, #0f172a, #2563eb);
    color: #ffffff;
    text-align: center;
    padding: 40px 20px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
}

header h1 {
    font-size: 2.2rem;
    margin-bottom: 10px;
    font-weight: 700;
}

header p {
    font-size: 1rem;
    opacity: 0.9;
}

.container {
    max-width: 900px;
    margin: 30px auto;
    padding: 0 20px;
    flex: 1;
    width: 100%;
}

.card {
    background: #ffffff;
    border-radius: 12px;
    padding: 25px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.04);
    margin-bottom: 25px;
    border: 1px solid #e2e8f0;
}

.drop-zone {
    border: 2px dashed #3b82f6;
    background: #eff6ff;
    border-radius: 10px;
    padding: 45px 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    cursor: pointer;
    text-align: center;
    transition: all 0.2s ease;
}

.drop-zone:hover, .drop-zone.dragover {
    background: #dbeafe;
    border-color: #1d4ed8;
}

.drop-zone .icon {
    font-size: 50px;
    margin-bottom: 12px;
}

.label-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: #1e40af;
}

.label-sub {
    font-size: 0.85rem;
    color: #64748b;
    margin-top: 5px;
}

.controls-card h2, .result-card h2, .content-card h2 {
    font-size: 1.3rem;
    margin-bottom: 18px;
    color: #0f172a;
}

.control-group {
    margin-bottom: 18px;
}

.control-group label {
    display: block;
    font-weight: 600;
    margin-bottom: 6px;
    font-size: 0.95rem;
}

select, input[type="range"] {
    width: 100%;
    padding: 12px;
    border: 1px solid #cbd5e1;
    border-radius: 8px;
    font-size: 0.95rem;
    background: #f8fafc;
}

.primary-btn {
    background: #2563eb;
    color: white;
    border: none;
    padding: 14px;
    font-size: 1rem;
    border-radius: 8px;
    cursor: pointer;
    width: 100%;
    font-weight: bold;
    transition: background 0.2s;
}

.primary-btn:hover { background: #1d4ed8; }

.status-box {
    text-align: center;
    font-weight: bold;
    color: #2563eb;
    margin-bottom: 15px;
}

.comparison-container {
    display: flex;
    gap: 20px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.img-box {
    flex: 1;
    min-width: 250px;
    background: #f1f5f9;
    padding: 15px;
    border-radius: 8px;
    text-align: center;
}

.img-box h3 {
    font-size: 1rem;
    margin-bottom: 10px;
}

.img-box img {
    max-width: 100%;
    max-height: 250px;
    object-fit: contain;
    border-radius: 6px;
    background: #ffffff;
}

.img-meta {
    margin-top: 10px;
    font-size: 0.9rem;
}

.highlight-size { color: #16a34a; }

.savings-tag {
    display: inline-block;
    background: #dcfce7;
    color: #15803d;
    padding: 4px 12px;
    border-radius: 20px;
    font-weight: bold;
    font-size: 0.85rem;
    margin-top: 6px;
}

.download-action {
    margin-top: 20px;
}

.download-btn {
    display: block;
    width: 100%;
    text-align: center;
    background: #16a34a;
    color: white;
    border: none;
    padding: 16px;
    font-size: 1.1rem;
    border-radius: 8px;
    font-weight: bold;
    cursor: pointer;
    transition: background 0.2s, transform 0.1s;
}

.download-btn:hover { background: #15803d; }
.download-btn:active { transform: scale(0.99); }

.content-card {
    line-height: 1.6;
    color: #334155;
}

.content-card h3 { margin-top: 15px; margin-bottom: 8px; }
.content-card ul { padding-left: 20px; }
.content-card li { margin-bottom: 8px; }

footer {
    text-align: center;
    padding: 20px;
    background: #0f172a;
    color: #94a3b8;
    font-size: 0.85rem;
    margin-top: auto;
}