header {
    background: linear-gradient(90deg, #fff 25%, rgba(255,255,255,0.7) 50%, rgba(255,255,255,0) 100%), url('../img/xxx.jpg') no-repeat center 25%;
    background-size: cover;
    padding: 20px 40px;
    border-bottom: 3px solid #34495e;
    position: sticky;
    top: 0;
    z-index: 1000;
    overflow: hidden;
}

body.dark-mode header {
    background: linear-gradient(90deg, #1a1a1a 25%, rgba(26,26,26,0.7) 50%, rgba(26,26,26,0) 100%), url('../img/xxx.jpg') no-repeat center 25%;
    border-bottom-color: #444;
}

.header-container { display: flex; align-items: center; gap: 30px; position: relative; z-index: 1; }

.header-text {
    margin-left: 0; 
    transition: margin-left 0.3s ease;
}
.header-description { color: #425466; font-weight: 500; font-size: 0.95em; margin: 5px 0 0; }
body.dark-mode .header-description { color: #cbd5e1; }

.header-brand { font-size: 2.2em; color: #2c3e50; margin: 0; text-transform: uppercase; letter-spacing: 0.04em; }
body.dark-mode .header-brand { color: #e0e0e0; }

.header-presu-input {
    font-size: 1.8em; font-weight: bold; border: none; background: transparent;
    color: #2c3e50; width: 100%; padding: 5px 0; border-bottom: 2px solid transparent;
    transition: border-color 0.3s; margin-bottom: 10px;
}
.header-presu-input:focus { outline: none; border-bottom-color: #3498db; }
body.dark-mode .header-presu-input { color: #f8fafc; }

.budget-header { margin-bottom: 20px; }

.hero-image-container {
    flex: 0 0 80px;
    position: relative;
    cursor: pointer;
    animation: heroFloat 3s ease-in-out infinite;
}

.main-logo { width: 80px; height: 80px; object-fit: contain; border-radius: 12px; }

.hero-overlay {
    position: absolute; inset: 0; border-radius: 12px; opacity: 0;
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.5), rgba(118, 75, 162, 0.5));
    transition: opacity 0.4s ease;
}
.hero-image-container:hover .hero-overlay { opacity: 1; }

.container {
    display: grid;
    grid-template-columns: 1fr;
    align-items: start;
    gap: 18px;
    width: 100%;
    padding: 18px;
}