/* ================================================
   TASKFLOW PRO — Premium To-Do App Styles
   ================================================ */

/* ============ CSS VARIABLES ============ */
:root {
    /* Colors - Light Theme */
    --bg-gradient-1: #667eea;
    --bg-gradient-2: #764ba2;
    --bg-gradient-3: #f093fb;
    --bg-gradient-4: #4facfe;
    --card-bg: rgba(255, 255, 255, 0.72);
    --card-border: rgba(255, 255, 255, 0.45);
    --card-shadow: 0 8px 32px rgba(31, 38, 135, 0.15);
    --input-bg: rgba(255, 255, 255, 0.6);
    --input-border: rgba(200, 200, 220, 0.5);
    --input-focus: #6366f1;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-tertiary: #94a3b8;
    --accent: #6366f1;
    --accent-light: #818cf8;
    --accent-glow: rgba(99, 102, 241, 0.4);
    --task-bg: rgba(255, 255, 255, 0.5);
    --task-hover: rgba(255, 255, 255, 0.75);
    --task-border: rgba(0, 0, 0, 0.06);
    --priority-high: #ef4444;
    --priority-high-bg: rgba(239, 68, 68, 0.1);
    --priority-medium: #f59e0b;
    --priority-medium-bg: rgba(245, 158, 11, 0.1);
    --priority-low: #22c55e;
    --priority-low-bg: rgba(34, 197, 94, 0.1);
    --danger: #ef4444;
    --danger-bg: rgba(239, 68, 68, 0.1);
    --filter-bg: rgba(0, 0, 0, 0.04);
    --filter-active: #6366f1;
    --scrollbar-thumb: rgba(0, 0, 0, 0.15);
    --progress-bg: rgba(0, 0, 0, 0.08);
    --overlay: rgba(255, 255, 255, 0.1);
    --transition-speed: 0.3s;
    --transition-bounce: cubic-bezier(0.34, 1.56, 0.64, 1);
    --transition-smooth: cubic-bezier(0.4, 0, 0.2, 1);
}

/* ============ DARK THEME ============ */
[data-theme="dark"] {
    --bg-gradient-1: #1a1a3e;
    --bg-gradient-2: #2d1b69;
    --bg-gradient-3: #6b21a8;
    --bg-gradient-4: #1e40af;
    --card-bg: rgba(30, 41, 59, 0.72);
    --card-border: rgba(255, 255, 255, 0.08);
    --card-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    --input-bg: rgba(255, 255, 255, 0.06);
    --input-border: rgba(255, 255, 255, 0.1);
    --input-focus: #818cf8;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-tertiary: #64748b;
    --accent: #818cf8;
    --accent-light: #a5b4fc;
    --accent-glow: rgba(129, 140, 248, 0.3);
    --task-bg: rgba(255, 255, 255, 0.04);
    --task-hover: rgba(255, 255, 255, 0.08);
    --task-border: rgba(255, 255, 255, 0.06);
    --priority-high-bg: rgba(239, 68, 68, 0.15);
    --priority-medium-bg: rgba(245, 158, 11, 0.15);
    --priority-low-bg: rgba(34, 197, 94, 0.15);
    --danger-bg: rgba(239, 68, 68, 0.15);
    --filter-bg: rgba(255, 255, 255, 0.05);
    --filter-active: #818cf8;
    --scrollbar-thumb: rgba(255, 255, 255, 0.15);
    --progress-bg: rgba(255, 255, 255, 0.08);
    --overlay: rgba(0, 0, 0, 0.2);
}

/* ============ RESET & BASE ============ */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
    transition: color var(--transition-speed) var(--transition-smooth);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 6px;
}
::-webkit-scrollbar-track {
    background: transparent;
}
::-webkit-scrollbar-thumb {
    background: var(--scrollbar-thumb);
    border-radius: 3px;
}

/* ============ ANIMATED BACKGROUND ============ */
.bg-animation {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    background: linear-gradient(135deg, var(--bg-gradient-1), var(--bg-gradient-2));
    transition: background 0.8s var(--transition-smooth);
    overflow: hidden;
}

.blob {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.5;
    will-change: transform;
}

.blob-1 {
    width: 500px;
    height: 500px;
    background: var(--bg-gradient-3);
    top: -15%;
    left: -10%;
    animation: blobFloat1 25s ease-in-out infinite;
}

.blob-2 {
    width: 400px;
    height: 400px;
    background: var(--bg-gradient-4);
    top: 50%;
    right: -10%;
    animation: blobFloat2 30s ease-in-out infinite;
}

.blob-3 {
    width: 350px;
    height: 350px;
    background: var(--bg-gradient-1);
    bottom: -10%;
    left: 30%;
    animation: blobFloat3 20s ease-in-out infinite;
}

.blob-4 {
    width: 250px;
    height: 250px;
    background: var(--bg-gradient-3);
    top: 40%;
    left: 10%;
    animation: blobFloat4 22s ease-in-out infinite;
    opacity: 0.3;
}

@keyframes blobFloat1 {
    0%, 100% { transform: translate(0, 0) scale(1) rotate(0deg); }
    25% { transform: translate(120px, 80px) scale(1.1) rotate(90deg); }
    50% { transform: translate(-60px, 160px) scale(0.9) rotate(180deg); }
    75% { transform: translate(100px, -40px) scale(1.05) rotate(270deg); }
}

@keyframes blobFloat2 {
    0%, 100% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(-100px, -80px) scale(1.15); }
    66% { transform: translate(60px, 100px) scale(0.85); }
}

@keyframes blobFloat3 {
    0%, 100% { transform: translate(0, 0) scale(1); }
    25% { transform: translate(80px, -60px) scale(1.1); }
    50% { transform: translate(-100px, -30px) scale(0.95); }
    75% { transform: translate(40px, 60px) scale(1.08); }
}

@keyframes blobFloat4 {
    0%, 100% { transform: translate(0, 0) scale(1); }
    50% { transform: translate(100px, -100px) scale(1.2); }
}

/* ============ CONFETTI CANVAS ============ */
#confetti-canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 9999;
    display: none;
}

/* ============ APP CONTAINER ============ */
.app {
    max-width: 680px;
    margin: 0 auto;
    padding: 24px 20px 100px;
    min-height: 100vh;
}

/* ============ HEADER ============ */
.header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 20px;
    padding: 0 4px;
}

.header-left {
    display: flex;
    align-items: center;
}

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

.logo-icon {
    width: 44px;
    height: 44px;
    border-radius: 14px;
    background: var(--accent);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    box-shadow: 0 4px 15px var(--accent-glow);
    transition: transform 0.3s var(--transition-bounce),
                box-shadow 0.3s var(--transition-smooth);
}

.logo-icon:hover {
    transform: rotate(-10deg) scale(1.1);
}

.logo h1 {
    font-size: 1.65rem;
    font-weight: 800;
    letter-spacing: -0.5px;
    color: var(--text-primary);
    transition: color var(--transition-speed) var(--transition-smooth);
}

.logo h1 span {
    background: linear-gradient(135deg, var(--accent), var(--accent-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 8px;
}

/* Icon Buttons */
.icon-btn {
    width: 42px;
    height: 42px;
    border: none;
    border-radius: 12px;
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-speed) var(--transition-smooth);
    border: 1px solid var(--card-border);
    position: relative;
    overflow: hidden;
}

.icon-btn::after {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--accent);
    opacity: 0;
    transition: opacity 0.3s;
    border-radius: inherit;
}

.icon-btn:hover {
    color: var(--accent);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--accent-glow);
}

.icon-btn:active {
    transform: translateY(0) scale(0.95);
}

.icon-btn .hidden {
    display: none;
}

/* ============ PROGRESS SECTION ============ */
.progress-section {
    background: var(--card-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--card-border);
    border-radius: 16px;
    padding: 16px 20px;
    margin-bottom: 16px;
    transition: all var(--transition-speed) var(--transition-smooth);
}

.progress-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
}

.progress-text {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: color var(--transition-speed);
}

.progress-percent {
    font-size: 0.875rem;
    font-weight: 700;
    color: var(--accent);
    transition: color var(--transition-speed);
}

.progress-bar {
    width: 100%;
    height: 6px;
    background: var(--progress-bg);
    border-radius: 3px;
    overflow: hidden;
    position: relative;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--accent), var(--accent-light));
    border-radius: 3px;
    width: 0%;
    transition: width 0.6s var(--transition-smooth);
    position: relative;
}

.progress-fill::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
    animation: shimmer 2s infinite;
}

@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

/* ============ MAIN CARD (GLASSMORPHISM) ============ */
.card {
    background: var(--card-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--card-border);
    border-radius: 24px;
    padding: 24px;
    box-shadow: var(--card-shadow);
    transition: all var(--transition-speed) var(--transition-smooth);
}

/* ============ SEARCH BAR ============ */
.search-wrapper {
    position: relative;
    margin-bottom: 16px;
}

.search-icon {
    position: absolute;
    left: 14px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-tertiary);
    transition: color var(--transition-speed);
    pointer-events: none;
}

.search-input {
    width: 100%;
    padding: 12px 16px 12px 42px;
    border: 1.5px solid var(--input-border);
    border-radius: 14px;
    background: var(--input-bg);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.9rem;
    font-weight: 400;
    outline: none;
    transition: all var(--transition-speed) var(--transition-smooth);
}

.search-input:focus {
    border-color: var(--input-focus);
    box-shadow: 0 0 0 4px var(--accent-glow);
    background: var(--task-hover);
}

.search-input::placeholder {
    color: var(--text-tertiary);
}

/* ============ ADD TASK SECTION ============ */
.add-section {
    margin-bottom: 20px;
}

.input-main {
    display: flex;
    gap: 10px;
    margin-bottom: 12px;
}

.task-input {
    flex: 1;
    padding: 14px 18px;
    border: 2px solid var(--input-border);
    border-radius: 16px;
    background: var(--input-bg);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.95rem;
    font-weight: 500;
    outline: none;
    transition: all var(--transition-speed) var(--transition-smooth);
}

.task-input:focus {
    border-color: var(--input-focus);
    box-shadow: 0 0 0 4px var(--accent-glow);
    background: var(--task-hover);
}

.task-input::placeholder {
    color: var(--text-tertiary);
    font-weight: 400;
}

.add-btn {
    width: 52px;
    height: 52px;
    border: none;
    border-radius: 16px;
    background: linear-gradient(135deg, var(--accent), var(--accent-light));
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-speed) var(--transition-bounce);
    box-shadow: 0 4px 15px var(--accent-glow);
    flex-shrink: 0;
}

.add-btn:hover {
    transform: translateY(-2px) scale(1.05);
    box-shadow: 0 6px 20px var(--accent-glow);
}

.add-btn:active {
    transform: translateY(0) scale(0.95);
}

/* Input Options Row */
.input-options {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap;
}

.date-picker {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 14px;
    border-radius: 10px;
    background: var(--filter-bg);
    cursor: pointer;
    transition: all var(--transition-speed);
    color: var(--text-secondary);
    font-size: 0.82rem;
    font-weight: 500;
    border: 1px solid transparent;
}

.date-picker:hover {
    background: var(--task-hover);
    border-color: var(--input-border);
}

.date-picker input[type="date"] {
    position: absolute;
    opacity: 0;
    width: 0;
    height: 0;
    pointer-events: none;
}

.date-label {
    white-space: nowrap;
}

.date-picker.has-date {
    background: rgba(99, 102, 241, 0.1);
    color: var(--accent);
    border-color: rgba(99, 102, 241, 0.2);
}

.priority-group {
    display: flex;
    gap: 4px;
    background: var(--filter-bg);
    padding: 4px;
    border-radius: 10px;
}

.priority-btn {
    padding: 6px 14px;
    border: none;
    border-radius: 8px;
    font-family: inherit;
    font-size: 0.78rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-speed) var(--transition-smooth);
    background: transparent;
    color: var(--text-tertiary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.priority-btn:hover {
    color: var(--text-primary);
}

.priority-btn.low.active {
    background: var(--priority-low-bg);
    color: var(--priority-low);
}

.priority-btn.medium.active {
    background: var(--priority-medium-bg);
    color: var(--priority-medium);
}

.priority-btn.high.active {
    background: var(--priority-high-bg);
    color: var(--priority-high);
}

/* ============ FILTERS ============ */
.filters {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 16px;
    gap: 10px;
    flex-wrap: wrap;
}

.filter-tabs {
    display: flex;
    background: var(--filter-bg);
    border-radius: 12px;
    padding: 4px;
    position: relative;
}

.filter-btn {
    padding: 8px 18px;
    border: none;
    border-radius: 10px;
    background: transparent;
    color: var(--text-secondary);
    font-family: inherit;
    font-size: 0.82rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-speed) var(--transition-smooth);
    position: relative;
    z-index: 1;
}

.filter-btn:hover {
    color: var(--text-primary);
}

.filter-btn.active {
    color: white;
}

.filter-indicator {
    position: absolute;
    top: 4px;
    left: 4px;
    height: calc(100% - 8px);
    background: var(--accent);
    border-radius: 10px;
    transition: all 0.35s var(--transition-smooth);
    z-index: 0;
    box-shadow: 0 2px 8px var(--accent-glow);
}

.clear-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 8px 14px;
    border: none;
    border-radius: 10px;
    background: var(--danger-bg);
    color: var(--danger);
    font-family: inherit;
    font-size: 0.8rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-speed) var(--transition-smooth);
    white-space: nowrap;
}

.clear-btn:hover {
    background: var(--danger);
    color: white;
    transform: translateY(-1px);
}

.clear-btn:active {
    transform: translateY(0) scale(0.97);
}

/* ============ TASK LIST ============ */
.task-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
    max-height: 55vh;
    overflow-y: auto;
    padding-right: 4px;
}

/* ============ TASK ITEM ============ */
.task-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 16px;
    background: var(--task-bg);
    border: 1px solid var(--task-border);
    border-radius: 14px;
    cursor: default;
    transition: all var(--transition-speed) var(--transition-smooth);
    animation: taskSlideIn 0.35s var(--transition-smooth) both;
    position: relative;
}

.task-item:hover {
    background: var(--task-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
}

.task-item.completed {
    opacity: 0.6;
}

.task-item.completed:hover {
    opacity: 0.8;
}

.task-item.removing {
    animation: taskSlideOut 0.3s var(--transition-smooth) forwards;
}

.task-item.dragging {
    opacity: 0.5;
    transform: scale(1.02) rotate(1deg);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
    z-index: 100;
}

.task-item.drag-over {
    border-color: var(--accent);
    box-shadow: 0 0 0 2px var(--accent-glow);
}

@keyframes taskSlideIn {
    from {
        opacity: 0;
        transform: translateX(-20px) scale(0.98);
    }
    to {
        opacity: 1;
        transform: translateX(0) scale(1);
    }
}

@keyframes taskSlideOut {
    to {
        opacity: 0;
        transform: translateX(30px) scale(0.95);
        max-height: 0;
        padding-top: 0;
        padding-bottom: 0;
        margin-bottom: 0;
        border-width: 0;
        overflow: hidden;
    }
}

/* Drag Handle */
.drag-handle {
    cursor: grab;
    color: var(--text-tertiary);
    padding: 4px 2px;
    border-radius: 4px;
    display: flex;
    align-items: center;
    opacity: 0.4;
    transition: all var(--transition-speed);
    flex-shrink: 0;
}

.drag-handle:hover {
    opacity: 1;
    color: var(--accent);
}

.drag-handle:active {
    cursor: grabbing;
}

/* Custom Checkbox */
.custom-checkbox {
    position: relative;
    width: 24px;
    height: 24px;
    flex-shrink: 0;
    cursor: pointer;
}

.custom-checkbox input[type="checkbox"] {
    position: absolute;
    opacity: 0;
    width: 100%;
    height: 100%;
    cursor: pointer;
    z-index: 2;
    margin: 0;
}

.checkmark {
    position: absolute;
    inset: 0;
    border: 2px solid var(--input-border);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.25s var(--transition-smooth);
    background: transparent;
}

.checkmark svg {
    width: 14px;
    height: 14px;
    opacity: 0;
    transform: scale(0);
    transition: all 0.2s var(--transition-bounce);
    stroke: white;
    stroke-width: 3;
}

.custom-checkbox input:checked ~ .checkmark {
    background: var(--accent);
    border-color: var(--accent);
    animation: checkPop 0.4s var(--transition-bounce);
}

.custom-checkbox input:checked ~ .checkmark svg {
    opacity: 1;
    transform: scale(1);
}

.custom-checkbox:hover .checkmark {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

@keyframes checkPop {
    0% { transform: scale(1); }
    30% { transform: scale(1.25); }
    60% { transform: scale(0.92); }
    100% { transform: scale(1); }
}

/* Task Content */
.task-content {
    flex: 1;
    min-width: 0;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.task-text {
    font-size: 0.92rem;
    font-weight: 500;
    color: var(--text-primary);
    position: relative;
    display: inline;
    word-break: break-word;
    transition: color var(--transition-speed);
}

/* Strikethrough Animation */
.task-text-inner {
    position: relative;
    display: inline;
}

.task-text-inner::after {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    width: 0;
    height: 2px;
    background: var(--text-tertiary);
    transition: width 0.4s var(--transition-smooth);
}

.task-item.completed .task-text-inner::after {
    width: 100%;
}

.task-item.completed .task-text {
    color: var(--text-tertiary);
}

/* Task Meta */
.task-meta {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}

.priority-badge {
    font-size: 0.68rem;
    font-weight: 700;
    padding: 2px 8px;
    border-radius: 6px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.priority-badge.high {
    background: var(--priority-high-bg);
    color: var(--priority-high);
}

.priority-badge.medium {
    background: var(--priority-medium-bg);
    color: var(--priority-medium);
}

.priority-badge.low {
    background: var(--priority-low-bg);
    color: var(--priority-low);
}

.due-date-badge {
    font-size: 0.72rem;
    font-weight: 500;
    color: var(--text-tertiary);
    display: flex;
    align-items: center;
    gap: 4px;
}

.due-date-badge.overdue {
    color: var(--priority-high);
    font-weight: 600;
}

.due-date-badge.today {
    color: var(--priority-medium);
    font-weight: 600;
}

/* Task Actions */
.task-actions {
    display: flex;
    gap: 4px;
    opacity: 0;
    transition: opacity var(--transition-speed);
    flex-shrink: 0;
}

.task-item:hover .task-actions {
    opacity: 1;
}

.action-btn {
    width: 32px;
    height: 32px;
    border: none;
    border-radius: 8px;
    background: transparent;
    color: var(--text-tertiary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-speed) var(--transition-smooth);
}

.action-btn:hover {
    transform: scale(1.1);
}

.action-btn.edit-btn:hover {
    background: rgba(99, 102, 241, 0.1);
    color: var(--accent);
}

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

.action-btn:active {
    transform: scale(0.9);
}

/* Inline Edit Input */
.edit-input {
    flex: 1;
    padding: 6px 10px;
    border: 2px solid var(--accent);
    border-radius: 8px;
    background: var(--input-bg);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.92rem;
    font-weight: 500;
    outline: none;
    box-shadow: 0 0 0 3px var(--accent-glow);
    min-width: 0;
}

/* ============ EMPTY STATE ============ */
.empty-state {
    display: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 40px 20px;
    text-align: center;
    animation: fadeIn 0.5s ease;
}

.empty-state.visible {
    display: flex;
}

.empty-illustration {
    color: var(--text-tertiary);
    margin-bottom: 16px;
    opacity: 0.6;
}

.empty-state h3 {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--text-secondary);
    margin-bottom: 6px;
}

.empty-state p {
    font-size: 0.88rem;
    color: var(--text-tertiary);
}

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

/* ============ FLOATING ACTION BUTTON ============ */
.fab {
    display: none;
    position: fixed;
    bottom: 28px;
    right: 28px;
    width: 60px;
    height: 60px;
    border: none;
    border-radius: 20px;
    background: linear-gradient(135deg, var(--accent), var(--accent-light));
    color: white;
    cursor: pointer;
    align-items: center;
    justify-content: center;
    box-shadow: 0 6px 20px var(--accent-glow);
    transition: all var(--transition-speed) var(--transition-bounce);
    z-index: 1000;
}

.fab:hover {
    transform: translateY(-3px) scale(1.08);
    box-shadow: 0 8px 30px var(--accent-glow);
}

.fab:active {
    transform: translateY(0) scale(0.95);
}

/* ============ FOOTER ============ */
.footer {
    text-align: center;
    padding: 24px 0;
    color: rgba(255, 255, 255, 0.5);
    font-size: 0.82rem;
    font-weight: 500;
}

[data-theme="dark"] .footer {
    color: rgba(255, 255, 255, 0.3);
}

/* ============ RESPONSIVE DESIGN ============ */
@media (max-width: 640px) {
    .app {
        padding: 16px 12px 120px;
    }

    .card {
        border-radius: 20px;
        padding: 18px 14px;
    }

    .logo h1 {
        font-size: 1.35rem;
    }

    .logo-icon {
        width: 38px;
        height: 38px;
        border-radius: 12px;
    }

    .input-main {
        flex-direction: column;
    }

    .add-btn {
        width: 100%;
        height: 46px;
        border-radius: 12px;
    }

    .input-options {
        flex-direction: column;
        align-items: stretch;
    }

    .priority-group {
        justify-content: center;
    }

    .filters {
        flex-direction: column;
        align-items: stretch;
    }

    .filter-tabs {
        justify-content: center;
    }

    .clear-btn {
        justify-content: center;
    }

    .task-actions {
        opacity: 1;
    }

    .fab {
        display: flex;
    }

    .task-list {
        max-height: 45vh;
    }

    .progress-section {
        border-radius: 14px;
    }

    .blob-1 { width: 300px; height: 300px; }
    .blob-2 { width: 250px; height: 250px; }
    .blob-3 { width: 200px; height: 200px; }
    .blob-4 { width: 150px; height: 150px; }
}

@media (max-width: 380px) {
    .filter-btn {
        padding: 7px 12px;
        font-size: 0.76rem;
    }

    .priority-btn {
        padding: 5px 10px;
        font-size: 0.72rem;
    }
}

/* ============ UTILITY ============ */
.hidden {
    display: none !important;
}

/* Focus visible for accessibility */
:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

/* Prevent text selection during drag */
.no-select {
    user-select: none;
    -webkit-user-select: none;
}