/* Pulse Tasks - Modern To-Do List App */
:root {
    --primary: #6366f1;
    --primary-hover: #4f46e5;
    --primary-light: #e0e7ff;
    --success: #10b981;
    --success-light: #d1fae5;
    --warning: #f59e0b;
    --warning-light: #fef3c7;
    --danger: #ef4444;
    --danger-light: #fee2e2;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-tertiary: #9ca3af;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 14px;
    --radius-xl: 20px;
    --transition: all 0.2s ease;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: var(--text-primary);
    line-height: 1.5;
}

.app-container {
    max-width: 600px;
    margin: 0 auto;
    min-height: 100vh;
    background: var(--bg-primary);
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-lg);
}

/* Header */
.app-header {
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 1.5rem;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo-icon {
    width: 32px;
    height: 32px;
    color: var(--primary);
}

.logo-icon svg {
    width: 100%;
    height: 100%;
}

.logo h1 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.025em;
}

.user-section {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.user-name {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
    max-width: 120px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.sign-out-btn {
    background: var(--bg-tertiary);
    border: none;
    border-radius: var(--radius-sm);
    padding: 0.5rem;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.sign-out-btn:hover {
    background: var(--border-color);
    color: var(--text-primary);
}

.sign-out-btn svg {
    width: 18px;
    height: 18px;
}

.sign-in-btn {
    background: var(--primary);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    padding: 0.625rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.sign-in-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
}

.sign-in-btn svg {
    width: 16px;
    height: 16px;
}

/* Main Content */
.main-content {
    flex: 1;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

/* Stats Section */
.stats-section {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.75rem;
}

.stat-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    transition: var(--transition);
}

.stat-card:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow-sm);
}

.stat-icon {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
}

.stat-icon.pending {
    background: var(--warning-light);
    color: var(--warning);
}

.stat-icon.completed {
    background: var(--success-light);
    color: var(--success);
}

.stat-icon svg {
    width: 20px;
    height: 20px;
}

.stat-info {
    display: flex;
    flex-direction: column;
}

.stat-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1;
}

.stat-label {
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Add Task Section */
.add-task-section {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 1rem;
}

.add-task-form {
    display: flex;
    gap: 0.75rem;
}

.task-input {
    flex: 1;
    padding: 0.75rem 1rem;
    font-size: 0.95rem;
    font-family: inherit;
    color: var(--text-primary);
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    outline: none;
    transition: var(--transition);
}

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

.task-input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.add-btn {
    background: var(--primary);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    padding: 0.75rem 1rem;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.add-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
}

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

.add-btn svg {
    width: 20px;
    height: 20px;
}

/* Filter Section */
.filter-section {
    display: flex;
    gap: 0.5rem;
    background: var(--bg-secondary);
    padding: 0.25rem;
    border-radius: var(--radius-md);
}

.filter-btn {
    flex: 1;
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    background: transparent;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
}

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

.filter-btn.active {
    background: var(--bg-primary);
    color: var(--primary);
    box-shadow: var(--shadow-sm);
}

/* Task List Section */
.task-list-section {
    flex: 1;
}

.task-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.task-item {
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 0.875rem 1rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    transition: var(--transition);
    animation: slideIn 0.2s ease;
}

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

.task-item:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow-sm);
}

.task-item.completed {
    background: var(--bg-tertiary);
    opacity: 0.75;
}

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

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

.task-checkbox:hover {
    border-color: var(--primary);
}

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

.task-checkbox svg {
    width: 14px;
    height: 14px;
    color: white;
    opacity: 0;
    transition: var(--transition);
}

.task-item.completed .task-checkbox svg {
    opacity: 1;
}

.task-content {
    flex: 1;
    min-width: 0;
}

.task-text {
    font-size: 0.95rem;
    color: var(--text-primary);
    word-break: break-word;
    transition: var(--transition);
}

.task-date {
    font-size: 0.75rem;
    color: var(--text-tertiary);
    margin-top: 0.25rem;
}

.task-actions {
    display: flex;
    gap: 0.375rem;
    opacity: 0;
    transition: var(--transition);
}

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

.task-item.completed .task-actions {
    opacity: 0.5;
}

.task-btn {
    background: transparent;
    border: none;
    border-radius: 4px;
    padding: 0.375rem;
    color: var(--text-tertiary);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.task-btn:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

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

.task-btn svg {
    width: 16px;
    height: 16px;
}

/* Empty State */
.empty-state {
    display: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 3rem 1rem;
    text-align: center;
}

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

.empty-icon {
    width: 64px;
    height: 64px;
    color: var(--text-tertiary);
    margin-bottom: 1rem;
}

.empty-icon svg {
    width: 100%;
    height: 100%;
}

.empty-message {
    font-size: 1rem;
    color: var(--text-secondary);
}

/* Footer */
.app-footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 0.75rem 1.5rem;
}

.storage-status {
    font-size: 0.75rem;
    color: var(--text-tertiary);
    text-align: center;
}

.storage-status.cloud {
    color: var(--primary);
}

/* Responsive */
@media (max-width: 480px) {
    .app-container {
        max-width: 100%;
        border-radius: 0;
    }

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

    .user-section {
        justify-content: flex-end;
    }

    .stats-section {
        gap: 0.5rem;
    }

    .stat-card {
        padding: 0.75rem;
    }

    .stat-value {
        font-size: 1.25rem;
    }

    .add-task-form {
        flex-direction: column;
    }

    .add-btn {
        width: 100%;
        padding: 0.75rem;
    }

    .filter-btn {
        padding: 0.5rem 0.75rem;
        font-size: 0.8125rem;
    }

    .task-item {
        padding: 0.75rem 0.875rem;
    }

    .task-text {
        font-size: 0.875rem;
    }
}

/* Loading State */
.loading {
    display: inline-block;
    width: 16px;
    height: 16px;
    border: 2px solid var(--border-color);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* Error State */
.error-message {
    background: var(--danger-light);
    color: var(--danger);
    padding: 0.75rem 1rem;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    text-align: center;
    margin-bottom: 1rem;
    display: none;
}

.error-message.visible {
    display: block;
}