body {
    margin: 0;
    font-family: Arial, sans-serif;
    background: linear-gradient(135deg, #0f172a, #1e293b);
    color: #e2e8f0;
}

/* =========================
   LAYOUT
========================= */

.container {
    max-width: 900px;
    margin: auto;
    padding: 20px;
    text-align: center;
}

h1 {
    font-size: 36px;
}

.sub {
    color: #94a3b8;
}

/* =========================
   CARD
========================= */

.card {
    background: rgba(255,255,255,0.05);
    backdrop-filter: blur(10px);
    border-radius: 16px;
    padding: 30px;
    text-align: left;
}

/* =========================
   INPUTS
========================= */

.input-group {
    margin-bottom: 20px;
}

input[type=range] {
    width: 100%;
}

/* =========================
   BUTTONS
========================= */

.btn,
.btn-secondary {
    width: 100%;
    padding: 14px;
    margin-top: 10px;
    border-radius: 10px;
    border: none;
    font-size: 16px;
    cursor: pointer;
}

.btn {
    background: #3b82f6;
    color: white;
}

.btn-secondary {
    background: #475569;
    color: white;
}

/* =========================
   RESULTS
========================= */

.result-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
    margin-top: 20px;
}

#result {
    background: rgba(255,255,255,0.05);
    padding: 20px;
    border-radius: 12px;
}

.result-item {
    display: flex;
    justify-content: space-between;
    margin-bottom: 10px;
}

.result-item strong {
    color: #60a5fa;
}

/* =========================
   SEO SECTION
========================= */

.seo-content {
    max-width: 800px;
    margin: 60px auto;
    text-align: left;
}

a {
    color: #60a5fa;
}

/* =========================
   LOADER (FIXED)
========================= */

#loader {
    position: fixed;
    inset: 0;
    background: #0f172a;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    z-index: 99999;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 5px solid #1e293b;
    border-top: 5px solid #3b82f6;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}