:root {
    --font-family: 'Inter', sans-serif;
    /* Colors - Dark Premium Theme */
    --bg-color: #0f172a;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent-color: #38bdf8;
    --accent-hover: #0ea5e9;
    --danger-color: #ef4444;
    --success-color: #22c55e;
    --glass-bg: rgba(30, 41, 59, 0.7);
    --glass-border: rgba(255, 255, 255, 0.1);
    --glass-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
    --radius-lg: 16px;
    --radius-md: 12px;
    --radius-sm: 8px;
    --radius-xs: 4px;
    --transition-fast: 0.2s ease;
    --transition-medium: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-primary);
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
}

/* Dynamic Background */
.background-gradient {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at 50% 0%, #1e293b 0%, #0f172a 100%);
    z-index: -1;
}

.background-gradient::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at 50% 50%, rgba(56, 189, 248, 0.1) 0%, transparent 50%);
    animation: pulse 10s infinite alternate;
}

@keyframes pulse {
    0% {
        transform: scale(1);
        opacity: 0.5;
    }

    100% {
        transform: scale(1.2);
        opacity: 0.8;
    }
}

/* App Container */
.app-container {
    width: 100%;
    max-width: 480px;
    height: 100%;
    margin: 0 auto;
    padding: 24px;
    display: flex;
    flex-direction: column;
}

/* Header */
.app-header {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
    margin-bottom: 12px;
    padding: 0 4px;
}

.title-container {
    grid-column: 2;
    text-align: center;
}

.header-right {
    grid-column: 3;
    display: flex;
    justify-content: flex-end;
    gap: 8px;
}

.app-header h1 {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    background: linear-gradient(135deg, #fff 0%, #94a3b8 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 4px;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.icon-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 8px;
    border-radius: 50%;
    transition: var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    position: relative;
    align-items: center;
    margin-bottom: 12px;
}

/* Input Area */
.input-area {
    margin-bottom: 20px;
}

.input-wrapper {
    display: flex;
    gap: 12px;
    padding: 0px;
    align-items: center;
}

input[type="text"] {
    flex: 1;
    background: rgba(15, 23, 42, 0.6);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-md);
    padding: 0 16px;
    height: 48px;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 1rem;
    outline: none;
    transition: var(--transition-fast);
}

input[type="text"]:focus {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 2px rgba(56, 189, 248, 0.2);
}

input[type="text"]::placeholder {
    color: var(--text-secondary);
    opacity: 0.7;
    transform: translateY(-1px);
}

#add-btn {
    background: var(--accent-color);
    border: none;
    border-radius: var(--radius-xs);
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: #fff;
    transition: var(--transition-fast);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

#add-btn:hover {
    background: var(--accent-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.15);
}

#add-btn:active {
    transform: translateY(1px);
}

/* List Area */
.list-area {
    flex: 1;
    overflow-y: auto;
    min-height: 0;
    padding-right: 4px;
    scrollbar-width: thin;
    scrollbar-color: rgba(148, 163, 184, 0.2) transparent;
    display: flex;
    flex-direction: column;
}

.list-area::-webkit-scrollbar {
    width: 6px;
}

.list-area::-webkit-scrollbar-track {
    background: transparent;
}

.list-area::-webkit-scrollbar-thumb {
    background: rgba(148, 163, 184, 0.2);
    border-radius: 10px;
}

.shopping-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.list-item {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-md);
    padding: 12px 16px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    transition: var(--transition-medium);
    animation: fadeIn 0.3s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateX(-10px);
    }

    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.checkbox {
    width: 24px;
    height: 24px;
    border: 2px solid var(--glass-border);
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition-fast);
    flex-shrink: 0;
}

.checkbox:hover {
    border-color: var(--success-color);
    background: rgba(34, 197, 94, 0.1);
}

.list-item.completed .checkbox {
    border-color: var(--success-color);
    background: var(--success-color);
}

.checkbox::after {
    content: '✓';
    color: white;
    font-size: 12px;
    font-weight: bold;
    display: none;
}

.list-item.completed .checkbox::after {
    display: block;
}

/* New accessible checkbox input + custom label */
.checkbox-input {
    /* Visually hide native input but keep it accessible */
    position: absolute !important;
    width: 1px !important;
    height: 1px !important;
    padding: 0 !important;
    margin: -1px !important;
    overflow: hidden !important;
    clip: rect(0 0 0 0) !important;
    white-space: nowrap !important;
    border: 0 !important;
}

.checkbox-custom {
    width: 24px;
    height: 24px;
    border: 2px solid var(--glass-border);
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition-fast);
    flex-shrink: 0;
    background: transparent;
    box-sizing: border-box;
}

.checkbox-input:focus+.checkbox-custom {
    box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.12);
    border-color: var(--accent-color);
    outline: none;
}

.checkbox-custom::after {
    content: '✓';
    color: white;
    font-size: 13px;
    font-weight: 700;
    display: none;
    line-height: 1;
    margin: 0;
    padding: 0;
    transform: translateY(-1px);
}

.checkbox-input:checked+.checkbox-custom {
    background: var(--success-color);
    border-color: var(--success-color);
}

.checkbox-input:checked+.checkbox-custom::after {
    display: block;
}

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

.text-content {
    display: flex;
    flex-direction: column;
    justify-content: center;
    min-width: 0;
}

.item-author {
    font-size: 0.6rem;
    color: var(--text-secondary);
    margin-bottom: 2px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.item-text {
    font-size: 1rem;
    transition: var(--transition-fast);
    white-space: normal;
    overflow-wrap: anywhere;
    word-break: break-word;
}

.list-item.completed .item-text {
    text-decoration: line-through;
    opacity: 0.6;
}

.item-actions {
    display: flex;
    align-items: center;
    gap: 12px;
}

.qty-controls {
    display: flex;
    align-items: center;
    gap: 8px;
    background: transparent;
    padding: 0;
    border: none;
}

.qty-display {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-right: 8px;
    min-width: 20px;
    text-align: center;
}

.qty-btn {
    background: var(--accent-color);
    border: none;
    color: #fff;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    border-radius: var(--radius-xs);
    transition: var(--transition-fast);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    font-size: 1.2rem;
}

.qty-btn:hover {
    background: var(--accent-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.15);
}

/* Prevent long unbroken words from overflowing buttons */
.qty-btn,
.sort-btn,
.delete-btn,
#delete-completed-btn,
#add-btn {
    white-space: normal;
    overflow-wrap: anywhere;
    word-break: break-word;
}

.delete-btn {
    background: transparent;
    border: none;
    cursor: pointer;
    color: var(--text-secondary);
    transition: var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 4px;
    border-radius: 50%;
    width: 32px;
    height: 32px;
}

.delete-btn:hover {
    color: var(--danger-color);
    background: rgba(239, 68, 68, 0.1);
}

/* List Controls */
.list-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 12px;
    gap: 12px;
}

.sort-controls {
    display: flex;
    gap: 8px;
}

.sort-btn {
    background: var(--accent-color);
    border: none;
    border-radius: var(--radius-xs);
    padding: 8px 12px;
    color: #fff;
    cursor: pointer;
    font-size: 0.9rem;
    transition: var(--transition-fast);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.sort-btn:hover {
    background: var(--accent-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.15);
}

.sort-btn:active {
    transform: translateY(1px);
}

/* Delete Completed Button */
#delete-completed-btn {
    background: var(--danger-color);
    border: none;
    border-radius: var(--radius-xs);
    padding: 8px 12px;
    color: #fff;
    cursor: pointer;
    transition: var(--transition-fast);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    margin-left: auto;
}

#delete-completed-btn:hover {
    background: #b91c1c;
    transform: translateY(-1px);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.15);
}

#delete-completed-btn:active {
    transform: translateY(1px);
}

/* Utility hidden class */
.hidden {
    display: none !important;
}

/* Toast styles */
.app-toast {
    position: fixed;
    left: 50%;
    bottom: 24px;
    transform: translateX(-50%) translateY(12px);
    background: rgba(24, 27, 34, 0.95);
    color: var(--text-primary);
    padding: 10px 16px;
    border-radius: 8px;
    box-shadow: 0 6px 24px rgba(2, 6, 23, 0.6);
    opacity: 0;
    transition: opacity 240ms ease, transform 240ms ease;
    z-index: 10000;
    pointer-events: none;
}

.app-toast.visible {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
    pointer-events: auto;
}

.app-toast.success {
    background: rgba(34, 197, 94, 0.95);
    color: #fff;
}

.app-toast.error {
    background: rgba(239, 68, 68, 0.95);
    color: #fff;
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 16px 0;
    color: var(--text-secondary);
    font-style: italic;
    width: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 50px;
}

.empty-state.hidden {
    display: none;
}