:root {
    --bg-color: #121212;
    --card-bg: #1e1e1e;
    --text-main: #e0e0e0;
    --text-muted: #888888;
    --accent: #00e676; /* Neon Green */
    --accent-hover: #00c853;
    --zip-btn: #2979ff; /* Corporate Blue */
    --border-color: #333;
}

body {
    font-family: 'Inter', 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    margin: 0;
    padding: 20px;
    display: flex;
    justify-content: center;
    -webkit-font-smoothing: antialiased;
}

.container { width: 100%; max-width: 650px; text-align: center; }

/* Header */
.header-top {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 15px;
    position: relative;
    margin-bottom: 5px;
}

.refresh-btn {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-muted);
    padding: 6px 12px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.75rem;
    position: absolute;
    right: 0;
    top: 5px;
    transition: 0.3s;
}
.refresh-btn:hover { border-color: var(--text-main); color: var(--text-main); }

h1 { margin: 0; font-size: 2rem; letter-spacing: -1px; }
.highlight { color: var(--accent); }
p { color: var(--text-muted); margin-top: 5px; font-size: 0.95rem; }

/* Controls Area */
.controls {
    margin: 25px 0;
    background: var(--card-bg);
    padding: 20px;
    border-radius: 12px;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 20px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.3);
}

.control-group { flex: 1; text-align: left; }
.control-group label { display: block; font-size: 0.85rem; color: var(--text-muted); margin-bottom: 8px; }

/* Range Slider */
input[type="range"] { width: 100%; cursor: pointer; accent-color: var(--accent); }

/* Dropdown Select Styling */
.control-select {
    width: 100%;
    background-color: var(--bg-color);
    color: var(--text-main);
    border: 1px solid var(--border-color);
    padding: 8px 12px;
    border-radius: 6px;
    font-size: 0.9rem;
    outline: none;
    cursor: pointer;
}
.control-select:focus { border-color: var(--accent); }

/* Drop Zone */
.drop-zone {
    border: 2px dashed var(--border-color);
    border-radius: 12px;
    padding: 50px 20px;
    cursor: pointer;
    transition: all 0.3s ease;
    background-color: rgba(255,255,255,0.02);
}
.drop-zone:hover, .drop-zone.dragover {
    border-color: var(--accent);
    background-color: rgba(0, 230, 118, 0.05);
}
.icon-upload { font-size: 2rem; margin-bottom: 10px; }
.browse-btn { color: var(--accent); font-weight: 600; text-decoration: underline; }

/* Action Buttons */
.action-area { margin: 25px 0; }
.hidden { display: none; }

.btn-zip {
    background-color: var(--zip-btn);
    color: white;
    border: none;
    padding: 14px 30px;
    font-size: 1rem;
    border-radius: 8px;
    cursor: pointer;
    width: 100%;
    font-weight: 600;
    box-shadow: 0 4px 12px rgba(41, 121, 255, 0.3);
    transition: 0.2s;
}
.btn-zip:hover { filter: brightness(1.1); transform: translateY(-1px); }
.btn-zip:disabled { background-color: var(--border-color); cursor: not-allowed; box-shadow: none; }

/* Result Cards */
.result-card {
    background: var(--card-bg);
    margin-top: 15px;
    padding: 15px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    gap: 15px;
    text-align: left;
    border: 1px solid var(--border-color);
    animation: fadeIn 0.4s ease-out;
}
.result-card img { width: 55px; height: 55px; object-fit: cover; border-radius: 6px; }

.file-info { flex-grow: 1; }
.file-name { font-weight: 600; display: block; font-size: 0.95rem; color: var(--text-main); }
.file-details { font-size: 0.8rem; color: var(--text-muted); display: block; margin-top: 3px; }
.savings { color: var(--accent); font-weight: bold; }

.download-btn {
    background-color: rgba(255,255,255,0.1);
    color: var(--text-main);
    text-decoration: none;
    padding: 8px 16px;
    border-radius: 6px;
    font-size: 0.85rem;
    font-weight: 600;
    transition: 0.2s;
}
.download-btn:hover { background-color: var(--accent); color: #000; }

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}