:root {
    /* Light Theme Variables */
    --bg-color: #f0f2f5;
    --card-bg: #ffffff;
    --text-primary: #1a1a1a;
    --text-secondary: #666666;
    --accent-color: #4f46e5; /* Indigo */
    --accent-hover: #4338ca;
    --danger-color: #ef4444; 
    --success-color: #10b981;
    --border-radius: 16px;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --input-bg: #f3f4f6;
    --transition-speed: 0.3s;
}

[data-theme="dark"] {
    --bg-color: #111827;
    --card-bg: #1f2937;
    --text-primary: #f9fafb;
    --text-secondary: #9ca3af;
    --input-bg: #374151;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.5);
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    transition: background-color var(--transition-speed), color var(--transition-speed);
    display: flex;
    justify-content: center;
    min-height: 100vh;
    padding: 20px;
}

.app-container {
    width: 100%;
    max-width: 500px;
    background-color: var(--card-bg);
    border-radius: var(--border-radius);
    padding: 25px;
    box-shadow: var(--shadow);
    display: flex;
    flex-direction: column;
    gap: 20px;
    height: fit-content;
    min-height: 80vh;
    transition: background-color var(--transition-speed);
}

/* Header Styles */
.header-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

h1 {
    font-weight: 600;
    font-size: 1.8rem;
    background: linear-gradient(135deg, var(--accent-color), #818cf8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.icon-btn {
    background: none;
    border: none;
    font-size: 1.2rem;
    color: var(--text-primary);
    cursor: pointer;
    padding: 8px;
    border-radius: 50%;
    transition: background-color 0.2s;
}

.icon-btn:hover {
    background-color: var(--input-bg);
}

/* Progress Bar */
.progress-section {
    margin-bottom: 20px;
}

.progress-info {
    display: flex;
    justify-content: space-between;
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 5px;
}

.progress-bar-bg {
    width: 100%;
    height: 8px;
    background-color: var(--input-bg);
    border-radius: 4px;
    overflow: hidden;
}

.progress-bar-fill {
    height: 100%;
    width: 0%;
    background-color: var(--accent-color);
    transition: width 0.5s ease-out;
    border-radius: 4px;
}

/* Inputs */
.search-box, .input-section {
    position: relative;
    display: flex;
    align-items: center;
}

.search-box i {
    position: absolute;
    left: 15px;
    color: var(--text-secondary);
}

input[type="text"] {
    width: 100%;
    padding: 12px 15px 12px 40px; /* Left padding space for icon */
    border: 2px solid transparent;
    border-radius: 12px;
    background-color: var(--input-bg);
    color: var(--text-primary);
    font-size: 1rem;
    outline: none;
    transition: border-color 0.2s;
}

.input-section input[type="text"] {
    padding-left: 15px; /* Reset padding for task input */
    border-top-right-radius: 0;
    border-bottom-right-radius: 0;
}

input[type="text"]:focus {
    border-color: var(--accent-color);
}

#add-btn {
    padding: 12px 20px;
    background-color: var(--accent-color);
    color: white;
    border: none;
    border-radius: 0 12px 12px 0;
    cursor: pointer;
    font-size: 1.1rem;
    transition: background-color 0.2s;
}

#add-btn:hover {
    background-color: var(--accent-hover);
}

/* Task List */
.task-list {
    list-style: none;
    flex-grow: 1; /* Pushes footer down */
    overflow-y: auto;
    max-height: 50vh;
}

.task-item {
    background-color: var(--bg-color); /* Slightly simplified bg for list items */
    margin-bottom: 10px;
    padding: 15px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    animation: slideIn 0.3s ease;
    transition: transform 0.2s, box-shadow 0.2s;
}

.task-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}

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

.task-content {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-grow: 1;
}

.custom-checkbox {
    width: 22px;
    height: 22px;
    border: 2px solid var(--accent-color);
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: background 0.2s;
    flex-shrink: 0;
}

.task-item.completed .custom-checkbox {
    background-color: var(--accent-color);
}

.custom-checkbox i {
    color: white;
    font-size: 12px;
    display: none;
}

.task-item.completed .custom-checkbox i {
    display: block;
}

.task-text {
    font-size: 1rem;
    transition: color 0.2s;
    word-break: break-all;
}

.task-item.completed .task-text {
    text-decoration: line-through;
    color: var(--text-secondary);
}

.task-actions {
    display: flex;
    gap: 8px;
}

.action-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 5px;
    font-size: 1rem;
    transition: color 0.2s;
}

.delete-btn:hover {
    color: var(--danger-color);
}

.edit-btn:hover {
    color: var(--accent-color);
}

/* Footer & Buttons */
footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-top: 1px solid var(--input-bg);
    padding-top: 15px;
}

.secondary-btn {
    background-color: transparent;
    border: 1px solid var(--text-secondary);
    color: var(--text-secondary);
    padding: 8px 16px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.2s;
}

.secondary-btn:hover {
    border-color: var(--accent-color);
    color: var(--accent-color);
}

.stats {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    opacity: 1;
    transition: opacity 0.2s;
}

.modal.hidden {
    opacity: 0;
    pointer-events: none;
}

.modal-content {
    background-color: var(--card-bg);
    padding: 25px;
    border-radius: var(--border-radius);
    text-align: center;
    max-width: 320px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.2);
}

.modal-content h3 {
    margin-bottom: 10px;
}

.modal-content p {
    color: var(--text-secondary);
    margin-bottom: 20px;
    font-size: 0.95rem;
}

.modal-actions {
    display: flex;
    justify-content: center;
    gap: 15px;
}

.danger-btn {
    background-color: var(--danger-color);
    color: white;
    border: none;
    padding: 8px 20px;
    border-radius: 8px;
    cursor: pointer;
}

.danger-btn:hover {
    opacity: 0.9;
}

/* Mobile Responsiveness */
@media (max-width: 480px) {
    .app-container {
        border-radius: 0;
        height: 100vh;
        max-width: 100%;
        padding: 20px;
    }
    
    body {
        padding: 0;
    }
}