:root {
    --bg: #f8fafc;
    --surface: #ffffff;
    --text: #0f172a;
    --text-light: #64748b;
    --border: #e2e8f0;
    --primary: #0f172a;
    --green: #10b981;
    --red: #ef4444;
}

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

body {
    background-color: var(--bg);
    color: var(--text);
    padding: 2rem;
    min-height: 100vh;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
}

header { text-align: center; margin-bottom: 2rem; }
header h1 { font-size: 1.8rem; margin-bottom: 0.5rem; color: var(--primary); display: flex; align-items: center; justify-content: center; gap: 10px;}
header p { color: var(--text-light); font-size: 0.95rem; }

/* Sürükle Bırak Alanı */
.drop-zone {
    background: var(--surface);
    border: 2px dashed var(--border);
    border-radius: 12px;
    padding: 3rem 1rem;
    text-align: center;
    transition: all 0.2s ease;
    cursor: pointer;
    margin-bottom: 2rem;
}
.drop-zone:hover, .drop-zone.dragover {
    border-color: var(--primary);
    background: #f1f5f9;
}
.drop-zone i { color: var(--text-light); margin-bottom: 1rem; }
.drop-zone p { color: var(--text-light); margin-bottom: 1rem; }

/* Butonlar */
.btn {
    background: var(--primary);
    color: white;
    border: none;
    padding: 0.6rem 1.2rem;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}
.btn:hover { opacity: 0.9; transform: translateY(-1px); }
.btn-green { background: var(--green); }

/* Yükleniyor */
.loading {
    text-align: center;
    padding: 3rem;
    color: var(--primary);
}
.loading p { margin-top: 1rem; font-weight: 500; }

/* Sonuç Alanı ve Tablo */
#result-area { background: var(--surface); padding: 1.5rem; border-radius: 12px; box-shadow: 0 4px 6px -1px rgba(0,0,0,0.05); }
.toolbar { display: flex; justify-content: space-between; align-items: center; margin-bottom: 1rem; flex-wrap: wrap; gap: 10px; }
.status { font-weight: 600; color: var(--text-light); }
.hint { margin-top: 1rem; font-size: 0.85rem; color: var(--green); font-weight: 500; }

/* Handsontable Özelleştirmeleri (Başlıkların okunabilirliği için) */
.handsontable th { 
    background-color: #f1f5f9 !important; 
    font-weight: 700 !important; 
    color: var(--primary) !important; 
    vertical-align: middle !important;
    text-align: center !important;
    font-size: 0.75rem !important;
    line-height: 1.2 !important;
    border-bottom: 2px solid #cbd5e1 !important;
}
.handsontable td { 
    font-size: 0.85rem !important; 
}