:root {
    --bg-color: #f5f5f7;
    --panel-bg: rgba(255, 255, 255, 0.75);
    --text-main: #1d1d1f;
    --text-muted: #86868b;
    --border-color: rgba(0, 0, 0, 0.1);
    --accent: #007aff;
    --danger: #ff3b30;
    --success: #34c759;
    --input-bg: rgba(255, 255, 255, 0.9);
    --item-bg: rgba(255, 255, 255, 0.6);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    display: flex;
    justify-content: center;
    padding: 50px 20px;
    margin: 0;
}

.app-container {
    width: 100%;
    max-width: 550px;
    background: var(--panel-bg);
    border-radius: 18px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
    border: 1px solid var(--border-color);
    padding: 25px;
    overflow: hidden;
}

h1 { text-align: center; font-weight: 600; margin: 0 0 20px; font-size: 24px; }

h2 {
    font-size: 14px; text-transform: uppercase; letter-spacing: 0.5px;
    color: var(--text-muted); border-bottom: 1px solid var(--border-color);
    padding-bottom: 8px; margin-top: 30px; margin-bottom: 15px;
}

.form-group { display: flex; gap: 10px; margin-bottom: 25px; }

input[type="text"] {
    flex: 1; padding: 12px 16px; border-radius: 12px; border: 1px solid var(--border-color);
    background: var(--input-bg); color: var(--text-main); font-size: 16px; outline: none;
}

input[type="text"]:focus {
    border-color: var(--accent); box-shadow: 0 0 0 3px rgba(0, 122, 255, 0.2);
}

button.btn-primary {
    background: var(--accent); color: white; border: none; padding: 12px 20px;
    border-radius: 12px; font-size: 15px; cursor: pointer; font-weight: 500;
}
button.btn-primary:hover { opacity: 0.85; }

ul { list-style: none; padding: 0; margin: 0; }

li {
    display: flex; align-items: center; justify-content: space-between;
    gap: 10px;
    background: var(--item-bg); padding: 12px 16px; border-radius: 12px;
    margin-bottom: 10px; border: 1px solid var(--border-color);
}

li.empty { justify-content: center; color: var(--text-muted); background: transparent; border: none; }

.task-text { font-size: 16px; }
.task-text.muted { color: var(--text-muted); }
.completed .task-text { text-decoration: line-through; color: var(--text-muted); }

.actions { display: flex; gap: 5px; }
.actions form { margin: 0; }

.actions button {
    border: none; cursor: pointer; font-family: inherit;
    font-size: 13px; padding: 6px 12px; border-radius: 8px; color: white;
    font-weight: 500;
}

.btn-delete { background: var(--danger); }
.btn-restore, .btn-done { background: var(--success); }